CN113844059A

CN113844059A - Method for producing a fibre-reinforced plastic pipe section module and pipe section module

Info

Publication number: CN113844059A
Application number: CN202111196103.6A
Authority: CN
Inventors: 罗庆君; 张建庭
Original assignee: Hebei Hengrui Composite Material Co ltd
Current assignee: Hebei Hengrui Composite Material Co ltd
Priority date: 2021-10-14
Filing date: 2021-10-14
Publication date: 2021-12-28
Anticipated expiration: 2041-10-14
Also published as: CN113844059B

Abstract

The present disclosure provides a method of manufacturing a fibre reinforced plastic pipe section module, the pipe section module comprising at least a first surface and a second surface, and a first end region and a second end region arranged at both axial ends of the pipe section module, the manufacturing method using a vacuum infusion forming method, characterized in that a mould arrangement is provided: a master mold providing a first surface configuration; a first auxiliary mold and a second auxiliary mold providing a configuration of a second surface of the second end region; wherein the main mould provides a corrugated configuration disposed substantially parallel between the front end region and the rear end region of the pipe section module, and wherein the forming surface of the first subsidiary mould is provided with at least one ridge formation and the forming surface of the second subsidiary mould is provided with at least one groove formation, the vacuum forming bag being arranged such that the main mould, the first subsidiary mould, the second subsidiary mould, together with the vacuum forming bag, form a vacuum infusion cavity in common communication. The present disclosure also provides a segment module.

Description

Method for producing a fibre-reinforced plastic pipe section module and pipe section module

Technical Field

The present disclosure relates to the field of pipe laying and pipe joining using fiber reinforced plastic articles, and more particularly to forming such articles using vacuum infusion methods.

Background

There are many applications for pipes. Taking a domestic culvert channel as an example, a reinforced concrete structure is generally adopted, but the reinforced concrete structure has the technical problems of long production period, high transportation cost, long construction period, short service life, more potential safety hazards and the like.

The pipeline prepared from the composite material has the remarkable advantage of corrosion resistance. Winding processes to make glass reinforced plastic pipe is a well known pipe application.

The applicant of the same application develops a technology for applying the SMC composite material to ducts and ducts, and provides mechanical properties with competitive advantages, high strength and low deformability besides remarkable corrosion resistance. See patent document 1, patent document 2 below for details.

Patent document 1

The patent application filed by the same applicant as the present application, application No. CN202020468924.5, publication No. CN212505912U, 2021, 2/9/10, entitled "duct member, duct assembly, duct member, duct assembly, and duct". This patent application discloses a culvert member integrally formed from SMC composite material via a molding process. The application also teaches a culvert assembly, culvert member, culvert assembly, and culvert.

Patent document 2

Patent applications filed by the same applicant as the present application, publication (bulletin) nos.: CN112984232A, application No.: CN202110438627.5, application date: 2021-04-22, entitled "pipe assembly and pipe fitting method", which discloses a pipe assembly comprising: a first pipe section comprising at least one small-diameter end, a second pipe section comprising at least one large-diameter end, and a spacer device, wherein at least the second pipe section is composed of a plurality of pipe section modules, which are provided with lateral connection means on both sides, which are arranged longitudinally or axially along the pipe section, wherein, during assembly, the plurality of pipe section modules of the second pipe section are caused to wrap the small-diameter end of the first pipe section at the large-diameter end.

The SMC composite material mould pressing process is applied to prepare the pipe fittings, and the satisfactory application effect is achieved. However, the molding process has its own limitations, i.e., the cost of the disposable mold is high, and the process is particularly prominent in the production of large-sized products.

The inventors have instead developed a vacuum infusion process, also known as a vacuum infusion process. The vacuum infusion process comprises a dual-mode vacuum infusion process and a vacuum bag pressing process. The patent documents cited below relate to vacuum bagging processes.

Patent document 3

Publication No. CN106881881B entitled "method for processing weatherable glass fiber reinforced plastic products by vacuum infusion", application No. CN201710198055.1, applicant, Chongqing Hai Qing New Material Co., Ltd. The invention provides a method for processing a weather-resistant glass fiber reinforced plastic product by vacuum infusion, which comprises the following steps: preparing a mould, spraying a gel coat layer, laying at least 3 layers of glass fibers, laying a porous isolating membrane, laying a flow guide pipe, laying a flow guide net, laying a vacuum bag, vacuumizing, introducing resin and demoulding; the laying sequence of the flow guide pipe and the flow guide net in the traditional vacuum leading-in processing method is changed, and the inner surface of the prepared glass fiber reinforced plastic product has no pipe pressing marks.

The above documents are incorporated herein by reference in their entirety.

Disclosure of Invention

[ problem to be solved ]

One of the objectives of the present disclosure is to provide a solution that is particularly suitable for improving the production, connection, sealing, and laying of large-caliber pipelines. In particular, the product of the present disclosure is a unit module for manufacturing a built-up type pipeline by using a vacuum infusion method instead, and the unit module can also be applied to a built-up type tank body.

However, the vacuum infusion process is usually well suited to use a mold in combination with a vacuum bag, the molding surface being provided by the molding surface of the mold, the other surface being covered by the vacuum bag, and being substantially conformal to the thickness of the fiber lay-up, and not readily formed into a well-defined, distinct, individual configuration.

However, the object product required by the present disclosure requires a special assembly mechanism, for example, 2-3 modules are assembled circumferentially to form a pipe section, a rubber strip groove is required to be arranged on the outer circumferential surface of the first end portion, and when the outer circumferential surface is wrapped by another pipe section, a special socket structure is realized to realize the connection and sealing between the two pipe sections. In addition, it is also desirable to provide further reinforcement formations on the outer peripheral surface of the second end portion and to improve the flexibility and adaptability of the assembly and application of the product. However, the vacuum introduction process must be modified to accommodate the requirements of the product.

[ solution ]

To solve the above technical problems and achieve the object of the present disclosure, the present disclosure provides solutions of the following aspects.

In one aspect of the present disclosure, there is provided a method of manufacturing a pipe segment module of fibre reinforced plastic, the pipe segment module comprising at least a first surface and a second surface, and a first end region and a second end region arranged at both axial ends of the pipe segment module, two or more pipe segment modules being arranged in the same axial direction and being circumferentially connected to obtain a circumferentially closed pipe segment, the manufacturing method using a vacuum infusion forming method, characterized in that a mould arrangement is provided: a master mold providing the first surface configuration; a first secondary mold providing a configuration of a second surface of the first end region; a second secondary mold providing a configuration of a second surface of the second end region; wherein the main mould provides a corrugated configuration of substantially parallel disposition between the front end region and the rear end region of the pipe section module, the corrugated configuration being formed by an alternating arrangement of elongate recesses and elongate protrusions in the axial direction, and the forming surface of the first sub-mould is provided with at least one ridge formation for forming a strip groove on an outer surface of a first end region of the pipe section module, the strip groove extending substantially in the circumferential direction, and the forming surface of the second sub-mould is provided with at least one groove formation extending substantially in the circumferential direction for forming a reinforcement rib on an outer surface of a second end region of the pipe section module, the main mould and the first and second sub-moulds being removably secured to each other, and a vacuum forming bag is arranged such that the main mould, the first sub-mould, the second sub-mould, the vacuum forming bag are arranged such that the main mould, the first sub-mould, the second sub-mould, the vacuum forming bag, and the tube module are removably secured to each other, The second auxiliary mold and the vacuum forming bag form a vacuum perfusion cavity which is communicated and shared.

Further, it is preferable that a configuration in which a front end portion inner flange configuration is provided also on the first sub die, and a configuration in which a rear end portion outer flange configuration is provided also on the second sub die.

Preferably, the bead at the second end can also be provided as an outer flange. The inner and outer flanges provide a particularly cost effective reinforcement in the present product, since the marginal outer ends of the tube sections are also the most vulnerable areas and need to be particularly reinforced. The design and arrangement of the mould of the process are easy to realize the structural design requirement. Furthermore, the design of the inner flange of the first end part and the outer flange of the second end part skillfully avoids the interference on the assembly pipe section of the mould and the socket connection of the special pipe section of the technical scheme, and is simple and optimized in process design.

Further, according to the process improvement of the present disclosure, a plurality of functional layers and fiber layers are laid on the master mold, and the fiber layers are arranged as follows: laying a layer of chopped glass fiber mat on the whole forming surface of the main die from the forming surface close to the main die; next to the chopped glass fiber mat, laying at least two layers of fiber woven cloth on the whole forming surface of the main die, wherein the fiber woven cloth of the same layer forms a joint in a butt joint mode, the joint of the fiber woven cloth of the same layer is approximately orthogonal to the joint of the fiber woven cloth of the adjacent layer, and the joints of the fiber woven cloth of the layer at intervals are approximately parallel and are arranged in a staggered mode; and arranging fibers on the forming surfaces of the first auxiliary die and the second auxiliary die respectively as follows: and (3) arranging at least one layer of fiber woven cloth close to the forming surface of the auxiliary die, and then arranging continuous glass fiber bundles extending along the circumferential direction to fill the grooves in the forming surface of the auxiliary die.

Further, at least two layers of fiber woven fabrics laid on the whole forming surface of the main mold are arranged to be a layer of hoop thick fabric laid in a hoop direction, an adjacent layer is arranged to be a layer of axial thin fabric laid in an axial direction, the weight of the hoop thick fabric is larger than that of the axial thin fabric, and the fiber woven fabrics laid in the hoop direction and the fiber woven fabrics laid in the axial direction are alternately carried out.

In a further aspect, it is preferred that 6 to 14 layers of the fiber woven cloth are laid on the entire forming surface of the master mold. More preferably, in the present product, 8 layers of the fiber woven fabric are laid over the entire molding surface of the master mold.

The above solution, at first, fully considering and optimizing the laying of the fiber layer using the main mold as the base, the key point is that the hoop laying and the axial laying are alternately performed, and the grammes of the fiber woven cloth laid in the hoop direction is larger than that of the fiber woven cloth laid in the axial direction, so the laying operation obviously focuses on the hoop strength of the module, that is, the hoop strength of the product body assembled into the pipe section and the tank body is considered, further, the hoop laying and the axial laying are alternately performed, the joint area of each layer can be approximately orthogonal, the insufficient strength of the joint is effectively dispersed, further, the spaced layers are both axially laid or both annularly laid, for example, the laying of the non-whole cloth can be put at different positions, thereby, the joints of the interlayer are further staggered. Thus, the laying of the multi-layered fiber cloth, even if the butt-joint type seam is adopted, maximally defines the dispersed seam and the staggered seam, and the orientation of the seam is crossed, thereby improving the fiber reinforcement effect.

In addition, the auxiliary die is provided with a local outer surface configuration and a substrate for independently laying the fiber layer, in the scheme of the disclosure, a thin fiber woven fabric is independently laid at the auxiliary die, then a surrounding fiber bundle is laid, the fiber bundle is easier to orient and extrude into a groove arranged on the forming surface of the auxiliary die, a continuous fiber bundle arranged along the circumferential direction is formed, and the fiber bundle is wrapped by the fiber fabric, so that the protruding reinforcing effect can be given to two end regions of the pipe section module after the product is formed, and the laying mode can be economical and maximize the compressive strength of ribs filled by the continuous fiber bundle in the circumferential direction of the pipeline.

The continuous glass fiber mentioned above means a longer glass fiber. The drawing process forms continuous glass fibers that are typically produced by winding in a drawing machine for tens of minutes. The technical term "chopped glass fiber" is used in contrast to continuous glass fiber, i.e. continuous glass fiber is cut into short fibers, for example, of several centimeters in length. The continuous fibers may be woven into a fiber cloth. In the above, the woven fiber cloth is laid on the forming surface of the auxiliary die, and then the continuous fiber bundle is laid in the groove configuration of the auxiliary die, so that the woven fiber cloth provides a wrapping effect for the continuous fiber bundle after the product is formed. The continuous fiber bundle is more easily positioned to fill the trench. In the fiber laying of the auxiliary mold, a continuous fiber bundle is used in combination with a fiber woven fabric.

In the operation of the present disclosure, the flow guide net is provided at a position where each auxiliary mold is close to the molding surface of the auxiliary mold, and at a position where the main mold is not opposite to the auxiliary mold, the flow guide net is provided at a position away from the molding surface of the main mold, so that each flow guide net covers each fiber layer in the entire mold cavity from above. Therefore, in the technical scheme, in the forming process, the resin nozzle (the glue injection port) applies resin to the flow guide net, and the resin permeates and is impregnated from the upper part to the lower part of the fiber layer.

Preferably, the plurality of resin injection ports are aligned with the surface recessed channels on one side of the master mold, respectively, and the plurality of vacuum nozzles are aligned with the surface recessed channels on the opposite side of the master mold, respectively, so that the recessed channels for forming the corrugated structure on the master mold provide a flow guide path for the resin during vacuum infusion, which helps to rapidly disperse and impregnate the fiber layer with the resin. Whereby the additional arrangement of the resin-distributing pipe in the vacuum chamber can be omitted.

In still another aspect, the primary mold and the secondary mold have different temperature settings, and the secondary mold surface temperature is controlled to be lower than the primary mold temperature.

In a further aspect of the invention, there is provided a pipe section module prepared by the above method.

With respect to circumferential and longitudinal or axial descriptions, the target product of the present disclosure is a pipe segment module for assembly into a pipe segment and a pipeline or duct, whether a mold or a product, for ease of description, is described by the circumferential and axial and/or central axes of the pipe segment, etc. Since the target product is produced by means of a mould, the main mould of which provides the basic profile of the product, said axial and circumferential directions also coincide with the pipe section mould and the assembled pipe section.

[ advantageous effects of the present disclosure ]

First, the present disclosure provides a vacuum infusion process for producing a pipe segment module which can assemble a pipe segment having a large-diameter end, and which is carried out at a construction site, a plurality of pipe segment modules are assembled at the site to form a pipe segment providing a large-diameter end, the end portion of the pipe segment constituting the large-diameter end surrounds the small-diameter end of a first pipe segment by a site assembly operation, and then the plurality of pipe segment modules providing the large-diameter end are tightly coupled to each other at adjacent edges in a longitudinal direction of a pipeline or a pipe segment, whereby the coupling with the first pipe segment in an axial direction of the pipeline is completed while a second pipe segment is assembled.

The structure and method for connecting a plurality of components to form a large-diameter end and a small-diameter end, which surround the small-diameter end, are different from the conventional screw connection or socket connection between pipe sections, and even the fastening operation does not need to be operated at the joint or contact of the large-diameter end and the small-diameter end, but can be operated only on the body of the pipe section, which brings unexpected operational convenience. The connection operation is repeated, and the pipeline connection and the laying can be conveniently realized.

By adopting the improved vacuum infusion process, the production of the product can be realized, and further, the improved vacuum infusion process is particularly suitable for flexible design of the product and research and development and supply of products with special sizes due to the fact that investment of modules and investment of equipment can be effectively reduced, so that the culvert pipe or the assembled tank prepared from the fiber reinforced plastics has stronger market adaptability and is more flexible.

The technical scheme of the present disclosure relates to the two-sided molding of the product, but does not adopt the double-mold vacuum infusion process of the prior art, but adopts the vacuum bag pressing process improved by the inventor. The double-mold vacuum filling process only adopts a mold to form a closed vacuum cavity, and is difficult to operate for large-size products required by the scheme, and the manual mold stripping and the equipment mold stripping are not ideal enough, so the cost is improved. In addition, it is difficult for the process to achieve the high glass fiber content and strength of the target product of the present disclosure.

The technical scheme disclosed by the invention effectively provides a unique and innovative application mode of the vacuum bag pressing process, provides local double-sided forming of the product, designs unique fiber combination laying, positioning and product orientation reinforcement aiming at the target product, and further improves and optimizes the mechanical property of the product under the condition of controlling the cost. And the characteristics of the new process are fully combined and utilized, the configuration of the product is further enriched, and the applicability and the adaptability of the module product are expanded.

The technical scheme provided by the disclosure is particularly suitable for providing large-caliber pipeline products, the modules provided by the disclosure are suitable for being assembled to form composite material pipelines, and the mechanical properties of the products are suitable for buried devices, particularly engineering products such as buried culverts or culverts.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

FIG. 1 is a schematic perspective view of an assembled pipe section and 2 pipe sections ready to be interconnected of a pipe section module of the present disclosure;

FIG. 2 is a schematic view of the receiving and sealing structure of FIG. 1 after assembly of the 2 pipe sections;

FIG. 3 is a schematic perspective view of two pipe segment modules of the present disclosure connected front to back, with the inner surface of the sheet material in a curve;

FIG. 4 shows the outer surfaces of two sheets of material joined back and forth in the arc shown in FIG. 3;

FIG. 5 is a cross-sectional view of a pipe segment module taken normal to the axial direction;

FIG. 6A is a schematic view of a sealing configuration between pipe sections;

FIG. 6B is a schematic view of another embodiment of an inter-segment seal configuration;

FIG. 7 is a schematic diagram of a primary and secondary mold layout according to an embodiment of the disclosure;

FIG. 8 is a partial schematic cross-sectional view of the first secondary mold and article shown in FIG. 7;

FIG. 9 is a partial schematic cross-sectional view of the second secondary mold and article shown in FIG. 7;

FIG. 10 is a schematic view of the mold arrangement and the layup of layers of material;

FIG. 11 schematically illustrates the manner in which a fiber-woven cloth is laid on a master mold;

FIG. 12 is a first embodiment of the arrangement of the vacuum nozzle and the glue injection port on the master mold;

FIG. 13 is a schematic view of the assembly between the primary and secondary molds;

FIG. 14 is a second embodiment of the arrangement of the vacuum nozzle and the glue injection port on the master mold; and

fig. 15 is a schematic view of an example receiving structure and sealing structure.

Detailed Description

The present disclosure will be described in further detail with reference to the drawings and embodiments. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the present disclosure. It should be further noted that, for the convenience of description, only the portions relevant to the present disclosure are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict. Technical solutions of the present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Unless otherwise indicated, the illustrated exemplary embodiments/examples are to be understood as providing exemplary features of various details of some ways in which the technical concepts of the present disclosure may be practiced. Accordingly, unless otherwise indicated, features of the various embodiments may be additionally combined, separated, interchanged, and/or rearranged without departing from the technical concept of the present disclosure.

The use of cross-hatching and/or shading in the drawings is generally used to clarify the boundaries between adjacent components. As such, unless otherwise noted, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for a particular material, material property, size, proportion, commonality between the illustrated components and/or any other characteristic, attribute, property, etc., of a component. Further, in the drawings, the size and relative sizes of components may be exaggerated for clarity and/or descriptive purposes. While example embodiments may be practiced differently, the specific process sequence may be performed in a different order than that described. For example, two processes described consecutively may be performed substantially simultaneously or in reverse order to that described. In addition, like reference numerals denote like parts.

When an element is referred to as being "on" or "on," "connected to" or "coupled to" another element, it can be directly on, connected or coupled to the other element or intervening elements may be present. However, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there are no intervening elements present. For purposes of this disclosure, the term "connected" may refer to physically, electrically, etc., and may or may not have intermediate components.

For descriptive purposes, the present disclosure may use spatially relative terms such as "below … …," below … …, "" below … …, "" below, "" above … …, "" above, "" … …, "" higher, "and" side (e.g., as in "side wall") to describe one component's relationship to another (other) component as illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below … …" can encompass both an orientation of "above" and "below". Further, the devices may be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, when the terms "comprises" and/or "comprising" and variations thereof are used in this specification, the presence of stated features, integers, steps, operations, elements, components and/or groups thereof are stated but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof. It is also noted that, as used herein, the terms "substantially," "about," and other similar terms are used as approximate terms and not as degree terms, and as such, are used to interpret inherent deviations in measured values, calculated values, and/or provided values that would be recognized by one of ordinary skill in the art.

In the description herein, reference to the description of the terms "one embodiment/mode," "some embodiments/modes," "example," "specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/mode or example is included in at least one embodiment/mode or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to be the same embodiment/mode or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/aspects or examples and features of the various embodiments/aspects or examples described in this specification can be combined and combined by one skilled in the art without conflicting therewith.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Application example of a pipe segment Module

The present disclosure is directed to developing new processes, developing new molds, and putting into production new specifically designed products that meet the requirements of configuration and mechanics, one of the important applications of which is to make a segment module. For ease of understanding, an application example of the pipe segment module is described below by way of example.

As previously explained, the present disclosure is directed to further developments by the inventors previously invested in significant effort to prepare pipes from composite materials, extending the applicability of the product with new processes. In particular, in the present embodiments, the present disclosure employs a new process and improved configuration for making the tube segment modules that can be applied to assembled culverts and culverts.

With respect to the pipe section modules of the present disclosure, similar configurations to those produced by the previously developed SMC molding process may be produced, however, to accommodate the new process and address the lack of reinforcement of the new process, it is preferable to provide further targeted configuration improvements. However, the steps and effects of the disclosed pipe section module assembly are similar to those of previous SMC pipe section modules, which is one of the intended purposes and technical effects of the present disclosure.

Referring to fig. 1-6, fig. 1 shows a pipe segment module 90 (article or product embodiment of the present disclosure) that is assembled circumferentially to form a first pipe segment 10 and a second pipe segment 20 that are axially joined to form a pipe assembly 1.

Fig. 1 illustrates a perspective view of 2 pipe sections (first pipe section 10, second pipe section 20) to be connected to each other, wherein the second pipe section 20 is on the left and the first pipe section 10 is on the right. Note that it is assembled into the pipe assembly 1 not directly inserted, as will be described later. Fig. 2 shows a pipe section socket construction, a strip groove 70 in the form of a groove and a sealing material, i.e. a spacer 30, which is a sealing strip, a sealing ring or the like.

Fig. 3 and 4 are perspective views of two pipe segment modules 90 removed from a 2-pipe segment joined back and forth, showing the inner and outer surfaces of two corrugated arc plates. Fig. 5 is a cross-sectional view of the pipe segment module 90 taken normal to the axial direction.

An already assembled first pipe section 10 provided with a small-diameter end 60, and a second, yet unassembled pipe section 20, which will be assembled from 3 pipe section modules 90 to provide a large-diameter end 50 after assembly, while at the same time a small-diameter end 60 will be provided at its other end, this second pipe section 20 will serve as the "first pipe section 10" in the next installation unit for providing the "small-diameter end 60" on the right, in the next pipe section joining operation, or, in the next pipe section assembly joining mechanism, whereby a periodic operation or arrangement is provided in the laying of the entire pipeline.

The pipe sections are connected with each other to form a pipeline or a pipeline. The pipe assembly 1 is formed by connecting at least two pipe sections. For convenience of illustration, the present disclosure is distinguished by the fact that the pipe segments provide the connection mechanism, such as the small diameter end 60, the large diameter end 50, or the flange end, during the assembly process, and thus, the pipe segments may be pipe segment units that do not provide the connection mechanism, or the first pipe segment 10 that provides the small diameter end 60, or the second pipe segment 20 that provides the large diameter end 50, as well as pipe segments that are provided with other types of connection mechanisms.

The pipe sections in this example are a first pipe section 10 (with a small diameter end) and a second pipe section 20 (with a large diameter end), respectively, and the first pipe section 10 and the second pipe section 20 in this example are of virtually identical construction, except that different coupling mating mechanisms are provided in each pipe section connection, and therefore are given different designations to facilitate explanation and understanding of the disclosed embodiments. Thus, in this example, both sections are assembled from at least two section modules 90, and in FIG. 1, three section modules 90 are shown assembled.

A pipeline assembling step:

1) a first pipe section 10 is provided, the first pipe section 10 being either an assembled pipe section or an integrated pipe section, and only the small diameter end 60 needs to be provided as a first mounting means.

2) A second pipe segment 20 is provided, the second pipe segment 20 providing a large diameter end 50 and being made up of a plurality of pipe segment modules 90, the pipe segment modules 90 being provided with lateral connection means 80 on both sides, the lateral connection means 80 being arranged in the longitudinal or axial direction of the pipe segment.

During assembly, the plurality of pipe segment modules 90 of the second pipe segment 20 are wrapped at their large diameter ends 50 about the small diameter ends 60 of the first pipe segment 10, and adjacent lateral connection means, such as lateral flanges, of each pipe segment module 90 of the second pipe segment 20 are secured to each other in the circumferential direction. Lateral flanges are provided along the edges of each pipe segment module 90, with mounting holes between adjacent flanges being aligned and secured by screw or rivet connections. Because the spacer 30 is disposed between the outer surface of the small-diameter end 60 and the inner surface of the large-diameter end 50, and the spacer 30 has a predetermined thickness or height, the gap between the large-diameter end 50 and the small-diameter end 60 is partially filled after the assembly is completed, so that the large-diameter end 50 and the small-diameter end 60 are compressed and tightly fitted. Referring to fig. 6A and 6B, the combination of the strip groove 70 and the sealing strip (spacer 30) in this example provides a securing effect for the spacer 30, and by virtue of the resilient deformability of the sealing strip provides a further sealing effect between the pipe section joints in addition to a press fit effect for assembly.

3) Upon completion of the above assembly, the second pipe segment 20 provides the small diameter end 60, whereby the second pipe segment 20 can be used as the first pipe segment 10 in the next assembly unit, the corresponding positioning of the pipe segment modules 90 of the additional second pipe segment 20 is continued, the spacer means 30 is arranged to provide the operation of surrounding the small diameter end 60 with the large diameter end 50, and the third pipe segment, not shown, is used as the next second pipe segment 20 to secure its adjacent lateral connection means 80 to each other.

Thereby, the small diameter end 60 of the second pipe section 20, which is tightly fixed in the axial direction, can be circumferentially surrounded by the other multi-mold of the second pipe section 20, further forming a connecting mechanism in which the large diameter end 50 surrounds the small diameter end 60. And repeating the installation in sequence to assemble and lay the pipeline.

Therefore, in the laying process of the pipeline, the pipeline sections can be assembled and connected.

In addition, although the application example only presents the first pipe section 10, the second pipe section 20 is used for the assembly example. In practice, it is also possible to introduce, for example, other types of pipe sections in the assembly implementation, for example, both ends being small-diameter ends, so that both ends are each constructed in a socket connection with a large-diameter end, etc. Alternatively, the other end is directly provided with a blocking structure or the like. Therefore, the description will also directly describe the pipe section instead of the first pipe section 10 and the second pipe section 20.

Two-pipe segment module and preparation examples

1 brief description of the disclosure the vacuum infusion process (vacuum bag forming process)

The fiber part in the fiber reinforced plastic can be carbon fiber, aramid fiber, glass fiber, or the like. The resin may be an unsaturated resin, an epoxy resin, a urethane resin, or the like. The articles of the present disclosure are applied to large buried culvert pipes or vessels, and glass fiber reinforced plastic is a lower cost option from a cost control standpoint. Glass fiber reinforced plastics, i.e., composites of glass fibers and resin. Various glass fiber materials, such as chopped glass fibers, glass fiber cloth, glass fiber bundles made of continuous fibers, and various resins, are commercially available.

According to the technical scheme, the pipe section module is prepared by adopting a vacuum introduction process (vacuum bag forming process). The forming process method is characterized in that intermediate materials to be formed, namely, all fiber layers, auxiliary materials and the like are arranged and sealed between a mold and a vacuum bag, and the intermediate products are pressurized through vacuumizing, so that the products are more compact and have better mechanical properties. The vacuum bag forming process is suitable for hand pasting, spraying and prepreg forming processes and can be used together with an oven, an autoclave and the like.

The pipe section module made in this embodiment is suitable for further assembly of large diameter spliced pipelines/tanks. The conventional vacuum bag forming process uses a single forming surface for the mold cavity, and in this embodiment, a double-sided mold cavity is used, that is, one surface of the product is provided with a forming surface (first surface) by the main mold, and the opposite surface (second surface) of the product is provided with an auxiliary mold, the auxiliary mold is provided with a forming surface for a part in the second surface, and the rest is provided with a vacuum bag limiting shape.

The major diameter assembles the advantage of pipeline/jar body vacuum bag pressure molding:

(1) compared with the winding forming pipeline: the diameter of the assembled and formed pipeline is not limited by the process, the diameter of the wound and formed pipeline is limited by the transportation size, the maximum diameter is generally 3.2 meters, and the transportation cost is high due to the integral transportation.

(2) Compared with the die assembly pipeline, the investment cost of the die equipment is lower, the investment cost of the die of the vacuum bag die process is only equal to 1/20 of the cost of the die process, and the size is not influenced by the table surface and the opening height of the press like the die process.

(3) The disadvantages are slow forming speed and consumption of auxiliary materials such as disposable vacuum bag films and the like in the forming process.

2. Construction variations and examples of pipe segment modules of the present disclosure

In contrast to the molding process, the pressure applied during the production process by the vacuum bagging process is primarily from the vacuum within the mold cavity. The vacuum action may help the resin or other flowable material to impregnate the fibrous layers, but the cavity pressure is much lower than during the molding process, which is a detrimental factor in the strength of the product.

In order to make up for the disadvantages, the preparation of the product is subjected to unique process design, including mold setting, vacuum mold cavity setting, fiber layer laying and product structure adjustment. For example, to the product configuration, i.e., the configuration of the pipe segment module 90 as shown in fig. 1-6.

As shown in fig. 6A and 6B, two different embodiments are shown, in which both the spacer means (joint strip, sealing ring, etc.) 30 and the groove (joint strip groove) 70 are shown, i.e. after assembling the pipe section modules 90 into circumferentially closed pipe sections, the outer surface of one end of the pipe section is provided with the joint strip groove 70, and the spacer means 30 in the form of a joint strip is placed in the joint strip groove 70, so that one end of the other pipe section surrounds and fixes the end to form a receiving connection between the two pipe sections, and the joint strip groove 70 and the spacer means 30 in the form of a joint strip mechanism provide the sealing function.

Thus, the present disclosure requires at least one secondary mold to provide a configuration corresponding to the surface of an end region of the pipe segment mold 90 for forming the strip trough 70.

Fig. 6B shows a second embodiment in which reinforcing structures are provided to both ends of the segment module 90, for example, as shown in fig. 8 and 9, a small-diameter-end inner flange 200, a large-diameter-end first reinforcing rib (outer flange) 240, and a large-diameter-end second reinforcing rib 250 are added to both end regions, respectively. Fig. 8 and 9 also show these configurations provided by the first and second secondary dies.

As shown in fig. 9, the second end region has two additional ribs on the outer surface, i.e., a first large diameter end rib 240, the first large diameter end rib 240 also serving as an outer flange at one end of the pipe section, and a second large diameter end rib 250. According to the consideration of different sizes of products, only one reinforcing rib or more reinforcing ribs can be arranged. When a plurality of pipe sections are assembled into a pipeline or highway culvert, since such external flanges and reinforcing ribs are provided on the outer surface of the large diameter end 50 of the pipe sections, they do not interfere with the socket connection between the pipe sections.

Utilizing the features of the vacuum infusion process employed in the present disclosure, a circumferentially disposed continuous fiber bundle is added in the area of both ends of the product or pipe segment module 90, such as at the spacing between corresponding ribs, flanges, and grooves, by the unique design of the laid fibers. The fiber bundles are adapted to be received and secured in a bead-like configuration on the outer surface of the product, and are particularly advantageous for providing reinforcement. In addition, in two end regions, the fiber fabric layer is additionally arranged, so that a wrapping effect is provided for the fiber bundles, and the strength of the two end regions is further improved. Other variations, including the laying of the fibrous layers of the article as a whole, provide unique arrangements of fibrous layer combinations, as described hereinafter.

Pipe section modules 90 prepared using the unique process of the present disclosure are used to assemble pipe sections and pipe section assemblies of the above application examples, with the parameters of the exemplary products shown in table 1.

The disclosed pipe section modules, also known as single piece corrugated sheets, are curved corrugated sheets that are assembled into circumferentially enclosed pipe sections or tanks. The outer flange and inner flange mechanisms described above are further utilized as the tank body, and parts such as the plugging plates can be added to both ends of the pipe section.

Table 1 exemplary parameters of the application of the presently disclosed pipe segment modules (also known as single piece corrugated board) to the assembly of pipe products

SN: ring stiffness in KN/m²Other size units: mm is

Referring to fig. 15 and table 2 below, the socket and spigot and rubber strip sizing arrangement for the pipe sections and pipe section assemblies of the above embodiments is illustrated. The female configuration refers to the fit between the small diameter end 60 and the large diameter end 50 of the pipe section. The first pipe segment 10 is assembled to provide the small diameter end 60, and the pipe segment modules 90 of the second pipe segment 20, for example, the large diameter end counterparts of the three pipe segment modules 90, are first wrapped around the small diameter end 60 while the adjoining side couplings are tightened against each other to achieve a socket-and-spigot connection in the axial direction between the pipe segments. With this unique assembly step and design, the small diameter end 60 is received within the large diameter end 50, and in fact the large diameter end 50 is received in surrounding relation to the small diameter end 60.

For ease of description, the concept of small and large diameter ends of assembled pipe sections is also borrowed for each pipe section module 90, i.e., the unitary article provided by the present disclosure, i.e., the end regions of the article (first end region 290 and second end region 300) are used to form the small and large diameter ends 60 and 50, respectively, of the assembled pipe section.

To facilitate understanding of the present disclosure, further dimensional examples of the socket and the rubber seal are provided, as illustrated in fig. 15 and the description provided in table 2. These designs include the consideration that for the convenience of laying the vacuum bag, the flow guide net, the release cloth, the fiber layer, etc. in the internal groove of the auxiliary mold, it is preferable to set the groove width not less than 30mm, taking DN4000 tube as an example, wherein the groove width is 40mm, the rubber hardness grade is preferably 70, the compression ratio of the rubber is calculated by 30%, and the diameter of the rubber ring is preferably about 2 times the groove depth, for example 46 mm.

TABLE 2

Socket position size design (unit mm) is illustrated by using DN4000 pipe as an example

Description of the drawings: nominal diameter, here the net average of the inside diameter, taken into account the corrugation height, minus the wall thickness. The D1 size is not referred to in this table.

3. Mold set-up examples

In this embodiment, a main mold, i.e., the main mold 280, and two auxiliary molds, i.e., the first auxiliary mold 260 and the second auxiliary mold 270, are used. Referring to fig. 7, the arrangement of the first secondary mold 260, the second secondary mold 270, and the primary mold 280 is schematically illustrated. The master mold 280 is used to provide an integral configuration of the entire interior wall of the pipe segment module 90, which in this embodiment provides a smooth configuration of the interior surfaces of the first end region 290 and the second end region 300 of the pipe segment module 90, and a corrugated sheet-like interior wall configuration therebetween. Although described in terms of corrugated sheet form in this embodiment, the pipe segment module 90 is not flat, but rather has an axial direction and a curvature about the axial direction, in fact because it has a curvature.

In the present disclosure, the secondary mold is used to provide a localized configuration of the second surface of the article. Two secondary molds are provided in this embodiment to provide the configuration of the outer surface of the product in the front and back end regions of the article.

As shown in fig. 8, the first auxiliary mold 260 provides a configuration of the groove 70 corresponding to the outer surface of the pipe segment mold 90, where the groove 70 in this embodiment provides a continuous groove 70, also referred to as a bead groove, for placing a bead or bead of sealant, or other sealant material, when the pipe segment mold 90 is assembled to form a closed pipe segment. In addition, the first auxiliary mold 260 is further configured to arrange the inner flange 200 at the foremost end of the product, and the inner flange 200 constitutes a ring-shaped inner flange after the product is assembled. This inner flange 200 may provide additional reinforcement and may also serve as a connection means for blind pipe plugging or as a connection mechanism for connecting other components, such as elbows and the like. In addition, the first sub-die 260 also provides a small diameter end transition 220 of the pipe segment module 90 that is configured to smoothly connect with the intermediate corrugated plate configuration of the pipe segment module 90.

A second auxiliary mold 270 providing a rib configuration, as shown in fig. 9, in this embodiment, a first rib (outer flange) 240 with a large diameter end is provided, the first rib is located at the rearmost end of the product, and protrudes from the outer surface, and can be provided as an outer flange, and similarly, the outer flange, such as the inner flange 200 described above, can also be used as a connecting device for blind pipe plugging, or as a connecting mechanism for connecting other parts, such as a elbow or the like. Further, a second reinforcing rib 250 with a large-diameter end can be arranged, so that the product is further reinforced.

The second auxiliary die 270, which is configured to smoothly connect with the intermediate corrugated plate configuration of the pipe segment module 90, provides the large diameter end transition 230 of the pipe segment module 90.

The large-diameter end transition part 230 and the small-diameter end transition part 220 are formed based on the design of two auxiliary dies, so that the parts connected with the corrugations of the corrugated plate arranged in the middle section area of the pipe section module 90 are of arc-shaped structures, the consistency with the corrugated structure of the upper surface of the corrugated plate is ensured, and the inner surface and the outer surface are in streamline transition, so that the vacuum diversion bag can be smoothly laid, and the accumulation of rich resin is reduced. 4. Lay layer setting and vacuum bag arrangement between mould

In the manufacturing process, the mold is provided with a release agent 310, a flow guide net 320, a release cloth 330, a reinforcing fiber layer 340 and the like in an interlayer, and finally the mold cavity is wrapped and closed by a vacuum bag 350. Referring to FIG. 10, the above-described lay-up arrangement is schematically illustrated.

4.1 the lay-up on master mold 280 is set up as follows:

4.1.1 applying mold release agent 310 to the upper surface of master mold 280 (i.e., the molding surface of master mold 280 here), to the entire molding surface of master mold 280;

4.1.2 lay up the reinforcing fiber layer 340 on the master mold 280 to the entire molding surface, where the laying up of the reinforcing fiber layer 340 is as follows:

4.1.2.1 laying of layers of reinforcing fibers on master mold 280:

(1) the forming surface nearest the master mold 280 is first laid with a layer of chopped glass mat;

(2) then, a fiber woven cloth is laid, as schematically illustrated with reference to fig. 11. In this embodiment, a plurality of layers of fiber-woven cloth are laid on the master mold 280, and a minimum of 4 layers, preferably 8 to 12 layers, are laid. Two kinds of fiber woven cloth are selected for alternately laying on the upper layer and the lower layer: one layer is a thick cloth which is laid in a circumferential direction, is called as 'circumferential thick cloth' again, and is laid on a main die 280 in a circumferential direction by using fiber woven cloth with the width of 3 meters, the warp direction of 720 grams per square meter and the weft direction of 84 grams per square meter, wherein the circumferential direction refers to a direction which is consistent with the assembly of a product into a closed ring and is also a direction which is approximately orthogonal to the axial direction penetrating through the front end and the rear end; the adjacent layers are laid axially, and a thin cloth, referred to herein as an "axial thin cloth", is laid axially along the axis of the master mold 280 (where the axis of the master mold 280 coincides with the axis of the product) using a woven fiber cloth having a width of 3 m, a warp direction of 180 g/m, and a weft direction of 20 g/m. The circumferential thick cloth and the axial thin cloth are alternately laid in an upper and lower adjacent layer mode. The circumferential thick cloth and the axial thin cloth mean that the fabric density and the fabric gram weight of the former are larger than those of the latter. The fiber woven cloth is laid along the warp direction of the fabric. The direction parallel to the selvedges is the warp direction, and the other side is the weft direction. The laying scheme is designed, the selected production process characteristics are considered, the circumferential mechanical property of the product is preferentially ensured, and the product which accords with the practical performance is obtained in the most economic mode.

The warp direction of the fiber woven fabric is the unwinding direction of the fiber woven fabric, so the warp direction or the length direction is typically not limited in the product laying, on the other hand, the width of the fiber woven fabric (or simply referred to as "fabric") is limited, and in this embodiment, the fabric with the width of 3 meters is selected, so for large-size products, the seam splicing is required in the laying of the fiber woven fabric due to the width limitation.

As shown in fig. 11, taking a corrugated plate with a diameter of 4 meters (in this embodiment, the pipe segment module 90 with a radian is taken as an example, three pieces are assembled into a pipe segment with a diameter of 4 meters), a first layer of fiber woven fabric is laid on a master mold 280, and laid in a circumferential direction, as indicated by a circumferential or hoop arrow, a fiber woven fabric with a width of 3 meters is laid from the left side to the right side, since the warp direction of the fabric is consistent with the circumferential direction, there is typically no seam in the circumferential direction, but there is a seam between different fabric webs at the front and the back, and the width of the front fabric is 3 meters and then the width of the back fabric is 1.5 meters, and a circumferential seam is formed between the two fabrics. In other words, when laying the first layer, fig. 11 shows a cloth laid in a hoop direction, and a cloth having a width of 3 m from front to back is butted against a cloth having a width of 1.5 m in the axial direction to form a seam.

Next, still referring to fig. 11, axial arrows indicate laying a second layer of fiber-woven cloth, each cloth laid from front to back, while adjacently arranging fiber-woven cloth of 3 m-1.5 m width from left to right in sequence.

Regarding the seam processing of the fiber woven cloth on the same layer, in order to ensure the uniform thickness of the product, no matter the fiber woven cloth is axially laid or annularly laid, the two fiber woven cloths form a seam in a butt joint mode, namely, the edges of the two fiber woven cloths are closely abutted, but the two fiber woven cloths are not overlapped with each other.

The absence of overlapping seams introduces mechanical disadvantages. To eliminate this disadvantageous effect, the offset arrangement of the seams of the individual layers is further optimized. Continuing with the above-mentioned three-piece assembled 4 meter diameter pipe section example, how to consider operational feasibility and maximize staggered joint placement is described: 1) the first layer of circumferential thick cloth is laid, and 3 meters of width and 1.5 meters of width are adjacently laid from front to back; 2) the second layer of 'axial thin cloth' is laid, and 4 pieces of cloth with the width of 3 meters, the width of 3 meters and the width of 1.5 meters are laid adjacently from left to right; the third layer of circumferential thick cloth is laid, and two pieces of cloth with the width of 1.5 meters to 3 meters are laid adjacently from front to back; the fourth layer of 'axial thin cloth' is laid, the first layer from left to right is 1.5 meters wide-3 meters wide, and 4 pieces of cloth are laid adjacently. It is also noted that the size of the cloth used in the axial direction is greater than the axial length laid, due to the corrugated configuration of the main mould. For example, in a module having a length of 3 m, the size of the cloth used from front to back is larger due to the corrugated structure, and typically, the width of the cloth actually used is about 4.5 m, which varies according to the wave pitch of the wave height.

In this embodiment, it is preferable to lay 12 layers in total, and the fifth to twelfth layers are processed in accordance with the laying manner of the first to fourth layers. The advantage of laying like this, utilize upper and lower adjacent layer hoop lay alternate with axial lay, and, the laying order change between different layers of hoop lay, make the joint product between upper and lower adjacent layer orthogonal each other; the seams between the two layers are staggered. Therefore, the strength of the product is ensured, and the wall thickness of the product is ensured to be consistent.

4.1.3 the release cloth 330 is laid on the main mold 280 to the edges of the two sub-molds (260, 270) and must not be laid under the two sub-molds.

4.1.4 the flow directing net 320 is then laid over the main mould 280 to the edges of the two secondary moulds (260, 270) and must not be laid under the two secondary moulds (260, 270).

4.2 lay-up arrangement of subsidiary moulds (not specifically illustrated, in the present embodiment, two subsidiary moulds, namely, the first subsidiary mould 260 and the second subsidiary mould 270)

4.2.1 applying a mold Release agent 310 inside the auxiliary mold (lower surface/mold surface)

4.2.2 paving a flow guide net 320 in the auxiliary die to the position of the flow guide net 320 of the main die 280, and overlapping the flow guide net with the width of about 10 cm;

4.2.3 laying a piece of release fabric 330 in the auxiliary mold and a piece of release fabric 330 in the main mold 280, overlapping the pieces of release fabric 330 for a width of about 10cm

4.2.4 laying of the fiberglass layer 340 on the auxiliary mold: 2 layers of warp-wise 720 g/square meter and weft-wise 84 g/square meter fiber woven cloth are laid in the attached mould along the circumferential direction and tightly attached to the mould layer, and then continuous glass fiber bundles are laid in the mould groove, wherein the continuous glass fiber bundles refer to fiber bundles which are not woven into cloth until the mould groove is filled. The glass fiber bundle is completely wrapped by the molded glass fiber cloth layer. The glass fiber bundles can enter the long strip-shaped grooves of the mold more easily, the long strip-shaped grooves correspondingly form reinforcing ribs, or partition walls between the rubber strip grooves, or inner flanges, outer flanges and other structures, the laying mode of the fiber bundles can economically improve the compressive strength of the ribs in the annular direction of the pipeline to the maximum extent, and the fiber bundles can flow into the narrow grooves more easily than the fiber woven cloth to be in place. Therefore, the fiber distribution state of the glass fiber bundles completely wrapped by the formed glass fiber cloth layer is specially designed, and the mechanical property of the product is optimized.

4.3 after the main mold and the auxiliary mold are locked through the positioning bolts, adhesive tapes are adhered to the upper surfaces of the periphery of the auxiliary mold, so that the sealing of the adhesive tapes and the vacuum bag is ensured, and the resin glue solution is prevented from entering the upper surface of the auxiliary mold. And laying a vacuum bag on the upper surface of the main and auxiliary molds, wherein the width of the vacuum bag is about 20cm greater than the width of the periphery of the main mold, so that the adhesive tape and the vacuum bag are well sealed.

5. Arrangement of vacuumizing and glue injection holes

A spiral vacuum-pumping pipe may be laid on one side of the mold, a plurality of vacuum-pumping nozzles 390 are connected to the spiral vacuum-pumping pipe, and a resin runner groove is laid on the other side, a plurality of glue injection ports 380 are provided on the resin runner groove, and the resin paste flows from one side of the mold to the other side of the mold by means of a groove-forming runner and vacuum pressure (see fig. 13). Thus, the resin draft tube laid in the vacuum chamber can be omitted. Vacuum equipment, resins, and the like are commercially available.

The resin injection port 380 for supplying resin is disposed on the upper surface of the flow guide net, and the groove position on the main mold is positioned by the resin injection port 380 on the main mold, whereby the resin flow passage is formed by the groove.

Upper and lower molds are used at both ends of the product, that is, the main mold 280 is a lower mold, the two auxiliary molds are upper molds, and the vacuum bag entirely surrounds the auxiliary molds. And, sealing and fixing the vacuum bag periphery at the outer edge of the master mold. Therefore, the forming surface of the main die, the forming surface of the auxiliary die and the vacuum bag form a communicated vacuum die cavity substantially together.

The upper parts of both ends of the main mold 280 face the two auxiliary molds, respectively, resulting in a reduction in the flow rate of the resin at the position, and therefore, the positions corresponding to the auxiliary molds at both ends of the main mold 280 are provided with the separate glue injection port 380 and the vacuum nozzle 390 for increasing the local pressure and accelerating the local flow of the resin.

In order to prevent the glue injection port 380 and the vacuum pumping nozzle 390 from being blocked, the glue injection port 380 and the vacuum pumping nozzle 390 extend to the flow guide net below the auxiliary die, so that effective gas guiding and effective resin flowing are guaranteed. Bolts for fastening the auxiliary mold are provided on the outer side of the glue injection port 380 (fig. 13), and also on the outer side of the vacuum air nozzle 390 (not shown in the drawings, which is disposed on the other side in the same manner as the above-described glue injection port 380), preventing the bolts from being adhered with resin paste.

6 clamping and fixing of two-end auxiliary die

Auxiliary mold mounting grooves 410 are provided at positions of the main mold 280 as shown in fig. 13, corresponding auxiliary molds are placed in the auxiliary mold mounting grooves 410 at both ends of the main mold 280 and fixed by fixing bolts 400 of the main mold and the auxiliary molds, and the fixing bolts 400 of the main mold and the auxiliary molds are provided outside the glue injection port 380 and the vacuum suction nozzle 390 in order to prevent the resin paste from adhering the bolts and to prevent the bolts from blocking the glue injection passage and the vacuum suction passage.

Examples of temperature, resin viscosity and temperature of the Primary and Secondary molds

As shown in table 3 below, examples of the master mold, the slave mold, the combined control and setting of resin viscosity and temperature are given for the convenience of understanding the present invention.

TABLE 3 mold temperature and resin viscosity and temperature settings examples

8 Process control of vacuum infusion operations

8.1 connecting vacuum spiral pipelines of the vacuum gauge, starting to vacuumize, continuing to pump for 8-12 minutes after the vacuum degree on the pressure gauge reaches 0.1MPa, then closing a valve of the vacuum pump, keeping the whole system in a pressure maintaining state, and if the vacuum pressure on the pressure gauge is reduced to be less than-0.002 MPa within 5 minutes, determining that the vacuum degree of the system is qualified; generally, a movable vacuum pumping device is adopted, 2 vacuum pumps are arranged, two pumps are started during perfusion, and one pump is closed after the perfusion is finished.

8.2 after the vacuum is qualified, optionally laying a second layer of vacuum bag for the sake of safety, vacuumizing, and performing vacuum test in the previous step to meet the requirement.

8.3 checking the surface temperature of the mould, whether the main mould 280 is controlled between 30 and 35 ℃, whether the auxiliary mould is controlled between 28 and 30 ℃, and if the requirement is not met, adjusting a mould heating system to ensure that the surface temperature of the mould meets the requirement.

8.4 close all doors and windows to make the air in the workshop stable, there is not convection current, otherwise can cause the surface temperature of the product inhomogeneous and cause dangerous phenomena such as the resin flow velocity inhomogeneous.

8.5 inspecting the surface temperature of the product, if the difference between the surface temperature of the product and the surface temperature of the mould is less than 3 ℃, the next step can be carried out, otherwise, a covering is required to be added on the surface of the product so as to ensure that the temperature is more uniform on the thickness of the whole product.

8.6 measuring the temperature of the mixed resin, wherein the temperature is between 27 and 30 ℃, and correspondingly, the viscosity is between 150 and 250cps, and then the flow characteristic of the resin can be judged to be qualified. If the temperature is too high, equipment such as an air conditioner and the like is required to be adopted for cooling; if the temperature is too low, it is necessary to heat the resin component materials to raise the temperature of the resin after mixing and to accelerate the flow.

8.7 to remove a large amount of air bubbles from the resin, the resin was placed in a closed steel container, evacuated for 5 minutes, and then poured into the product under a vacuum pressure of 0. lMPa.

8.8 the glue injection openings 380 at the two ends of the auxiliary mould are opened at first, and then the middle 4 glue injection openings 380 are opened.

8.9 resin infusion was performed. Because the flow directing webs are disposed on the fiber layers at both the secondary mold and at the primary mold 280, the resin saturates the glass fibers from top to bottom.

8.10 in the whole pouring process, the vacuum pressure is kept constant and is 0.1MPa, the temperature of the mould and the ambient temperature are kept constant, and the temperature of the resin can be increased by 2-3 ℃, which is an allowable condition.

The filling amount of the 8.11 resin is about 0.30-0.32 times of the total weight of the glass fiber cloth layer.

8.12 end of perfusion, close the perfusion valve. Curing is continued for 4-5 hours, and demolding is carried out.

Second embodiment of arranging glue injection nozzle and vacuum device

The arrangement of the glue injection ports 380 and the vacuum air extraction nozzles 390 is designed to correspond to the specific configuration of the target product of the present disclosure. The primary die 280, as well as the secondary dies (first secondary die 260 and second secondary die 270) are provided with circumferentially extending grooves or recesses, i.e. corresponding to the corrugated formations on the primary die, and ribs or grooves of the strip on the secondary die, which formations provide circumferentially extending recess and projection formations on the die. With this configuration, another way of injecting glue is proposed, as shown in fig. 14, arranging a vacuum injection cavity, disposing a plurality of injection holes 380 through the vacuum bag at the highest positions of the peaks directly above the laid main mold 280, and disposing evacuation air nozzles 390 around the main mold 280, wherein the evacuation air nozzles 390 shown in fig. 14 are disposed opposite to the grooves at the groove portions of the corrugation structure of the main mold, in the figure, at both sides parallel to the extending direction of the grooves, along the edges, in order to enhance the vacuum effect of the auxiliary mold near the edges of the vacuum cavity, and the sealing and evacuation effects for the first auxiliary mold 260 and the second auxiliary mold 270. In addition, a glue injection port 380 is respectively arranged at the highest point of the two auxiliary molds through the first auxiliary mold 260 and the second auxiliary mold 270.

The arrangement is also another method which utilizes the corresponding mould configuration of the product, optimizes the flow channel arrangement of the resin in the production process and improves the resin flowing and the impregnation effect on the fiber layer.

Other variant embodiments

The present disclosure has selected as a typical application the tube segment modules, i.e., a single piece of manufacture for assembling tube segments, which may be further assembled into a stent, which may be of the same configuration or of different configurations, so long as they are capable of being assembled to one another into a stent. In addition, the single piece article of the present disclosure is also suitable for assembly into large size can bodies. For example, assembled individual pipe sections with an inner flange at the front end and an outer flange at the rear end, each of which can be engaged with a different closure member. Furthermore, the pipe segment modules themselves may have different configuration changes, for example, depending on the application, both ends may be provided with a portion constituting an inner flange, or both ends may be provided with a portion constituting an outer flange. Additionally, the second sub-mold may not be used if the second end region of the pipe section does not require an outer surface configuration.

According to the application scenario and the size of the product, the thickness of the product can be adjusted, so that the temperature of the mold and the like in the process, the viscosity of the resin, the arrangement of the vacuum tubes and the arrangement of the glue injection ports 380, and the like can be properly adjusted.

In the above solution of the present disclosure, firstly, the laying of the fiber layer using the main mold as the base is fully considered and optimized, the key point is that the hoop laying and the axial laying are performed alternately, and the grammes of the fiber woven cloth for hoop laying is greater than that of the fiber woven cloth for axial laying, so the laying operation obviously focuses on the hoop strength of the module, that is, the hoop strength of the product body assembled into the pipe section and the tank body is considered, further, the hoop laying and the axial laying are performed alternately, the joint area of each layer can be approximately orthogonal, the insufficient strength of the joint is effectively dispersed, further, although the spaced layers are axially laid or circumferentially laid, the laying of the non-whole cloth can be assisted by, for example, placing the laying of the non-whole cloth at different positions, thereby further staggering the joints of the interlayer. Thus, the laying of the multi-layered fiber cloth, even if the butt-joint type seam is adopted, maximally defines the dispersed seam and the staggered seam, and the orientation of the seam is crossed, thereby improving the fiber reinforcement effect.

The present disclosure includes at least the following concepts:

concept 1. a method of manufacturing a fibre reinforced plastic pipe section module, said pipe section module comprising at least a first surface and a second surface, and a first end region and a second end region arranged at both axial ends of said pipe section module, with two or more pipe section modules arranged in the same axial direction and joined in circumferential direction for obtaining a circumferentially closed pipe section,

the manufacturing method adopts a vacuum infusion forming method and is characterized in that,

the die device is arranged as follows:

a master mold providing the first surface configuration;

a first secondary mold providing a configuration of a second surface of the first end region;

a second secondary mold providing a configuration of a second surface of the second end region;

wherein the primary mold provides a corrugated configuration disposed generally parallel between the first end region and the first end region of the pipe segment module, the corrugated configuration being comprised of elongated recesses and elongated protrusions alternating in the axial direction, and,

the forming surface of the first auxiliary mould is provided with at least one ridge formation for forming a strip groove on the outer surface of the first end region of the pipe section module, the strip groove extending substantially in the circumferential direction, and

said second subsidiary mould forming surface being provided with at least one groove formation extending substantially in said circumferential direction for forming a bead on the outer surface of the second end region of the pipe section module,

removably fixing the primary mold and the first and second secondary molds to each other, and,

and arranging the vacuum forming bag, so that the main die, the first auxiliary die, the second auxiliary die and the vacuum forming bag form a vacuum perfusion cavity which is communicated and shared.

Concept 2. the method according to concept 1, characterized in that a configuration for providing an inner flange configuration at the end of the first end region is also provided on the first secondary mould.

Concept 3. the method according to concept 1, characterized in that a configuration is also provided on the second secondary mould providing an outer flange configuration at the end of the second end region.

Concept 4. the method according to concept 1, comprising the step of laying a plurality of functional layers and a fibre layer on the master mould, the fibre layer being arranged to: firstly, a layer of chopped glass fiber mat is laid on the whole forming surface of the main die from the forming surface close to the main die to the forming surface far away from the main die; next to the chopped glass fiber mat, laying at least two layers of fiber woven fabrics on the whole forming surface of the main die, wherein the fiber woven fabrics of the same layer form a joint in a butt joint mode, the joint of the fiber woven fabrics of the same layer is approximately orthogonal to the joint of the fiber woven fabrics of the adjacent layer, and the joints of the fiber woven fabrics of the layers which are separated from each other are approximately parallel and are arranged in a staggered mode; and

arranging fiber layers on the forming surfaces of the first auxiliary die and the second auxiliary die respectively as follows: and arranging at least one layer of fiber woven cloth close to the forming surface of the auxiliary die, and then arranging continuous glass fiber bundles extending along the circumferential direction to fill the grooves on the forming surfaces of the first auxiliary die and the second auxiliary die.

Concept 5. the method according to concept 4, characterized in that at least two layers of fiber woven cloth laid over the entire forming surface of the master mold are arranged with one layer of hoop thick cloth laid circumferentially and one layer of axial thin cloth laid axially next to each other, the hoop thick cloth having a higher grammage than the axial thin cloth.

Concept 6. the method according to concept 4, characterized in that 6-14 layers of fibre cloth are laid over the entire forming surface of the main mould.

Concept 7. according to the method of concept 1, a flow guide net is arranged on the forming surface of each secondary mould close to the secondary mould, and a flow guide net is arranged on the main mould far away from the forming surface, so that each flow guide net covers the fiber layer in the vacuum perfusion cavity from the upper side.

Concept 8. the method according to concept 1, wherein the temperature settings of the primary mold and the secondary mold are differentiated, and the secondary mold surface temperature is controlled to be lower than the primary mold temperature.

Concept 9. the method according to concept 7, comprising arranging a plurality of glue injection ports at a top of the vacuum infusion chamber, wherein the plurality of glue injection ports are respectively arranged at wave crests of the corrugated structure and in top openings of the first and second auxiliary molds.

Concept 10. a pipe section module, characterized in that it is manufactured by a method according to concepts 1 to 9.

It will be understood by those skilled in the art that the foregoing embodiments are merely for clarity of illustration of the disclosure and are not intended to limit the scope of the disclosure. Other variations or modifications may occur to those skilled in the art, based on the foregoing disclosure, and are still within the scope of the present disclosure.

Claims

1. A method of manufacturing a fibre reinforced plastic pipe section module, said pipe section module comprising at least a first surface and a second surface, and a first end region and a second end region arranged at both axial ends of the pipe section module, using two or more pipe section modules arranged in the same axial direction and joined in circumferential direction for obtaining a circumferentially closed pipe section,

the die device is arranged as follows:

a master mold providing the first surface configuration;

2. A method according to claim 1, characterised in that a configuration for providing an inner flange configuration at the end of the first end region is also provided on the first secondary mould.

3. A method according to claim 1, characterised in that a configuration is also provided on the second secondary mould providing an outer flange configuration at the end of the second end region.

4. A method according to claim 1, comprising the step of laying on said master mould a plurality of functional layers and a fibrous layer arranged: firstly, a layer of chopped glass fiber mat is laid on the whole forming surface of the main die from the forming surface close to the main die to the forming surface far away from the main die; next to the chopped glass fiber mat, laying at least two layers of fiber woven fabrics on the whole forming surface of the main die, wherein the fiber woven fabrics of the same layer form a joint in a butt joint mode, the joint of the fiber woven fabrics of the same layer is approximately orthogonal to the joint of the fiber woven fabrics of the adjacent layer, and the joints of the fiber woven fabrics of the layers which are separated from each other are approximately parallel and are arranged in a staggered mode; and

5. A method according to claim 4, characterized in that at least two layers of fibre-woven cloth are laid on the whole forming surface of the main mould, arranged with one layer of circumferentially thick cloth laid circumferentially and one layer of axially thin cloth laid axially next to each other, the circumferentially thick cloth having a higher grammage than the axially thin cloth.

6. A method according to claim 4, characterised by laying 6-14 layers of fibre-woven cloth over the entire forming surface of the main mould.

7. A method according to claim 1, wherein a flow-guiding net is arranged on the forming surface of each secondary mould close to the secondary mould, and a flow-guiding net is arranged on the main mould far from the forming surface, so that each flow-guiding net covers the fiber layer in the vacuum infusion cavity from the upper side.

8. The method of claim 1, wherein the primary mold and the secondary mold have different temperature settings, and the secondary mold surface temperature is controlled to be lower than the primary mold temperature.

9. The method of claim 7, comprising arranging a plurality of glue injection ports at a top of the vacuum infusion chamber, wherein the plurality of glue injection ports are respectively arranged at wave crests of the wave formations and within top openings of the first and second secondary molds.

10. A pipe section module, wherein the pipe section module is made by the method of claims 1 to 9.