CN114571695A

CN114571695A - Forming equipment and method for producing plane plastic net by one-step method

Info

Publication number: CN114571695A
Application number: CN202210366826.4A
Authority: CN
Inventors: 侯立新; 孙响; 张晓波
Original assignee: Jining Dingyuan Machinery Co ltd; Hebei Hengsu Plastic Netting Co ltd
Current assignee: Jining Dingyuan Machinery Co ltd; Hebei Hengsu Plastic Netting Co ltd
Priority date: 2022-04-08
Filing date: 2022-04-08
Publication date: 2022-06-03

Abstract

The invention discloses a forming device and a method for producing a plane plastic net by a one-step method, which solve the technical problems of reducing the production cost of the plastic net and causing material waste. The process is greatly simplified, the production efficiency is improved, meanwhile, the plane plastic net product is a completely continuous product, and the subsequent cutting can be carried out randomly according to the requirement, so that the problem that the crease can not be removed in the production of the disclosed technical method is solved; in addition, the product formed by the one-step method has no mutual overlapping points and no stress concentration phenomenon generated by punching, so that the formed mesh has high tensile strength and enhanced tearing resistance.

Description

Forming equipment and method for producing plane plastic net by one-step method

Technical Field

The invention belongs to the technical field of plastic net production, and particularly relates to a forming device and a forming method for producing a plane plastic net, in particular to a device and a forming method for realizing plastic net forming in one step.

Background

In the field of mesh production technology for plastic extrusion processing, the processing methods which have been disclosed so far are: 1) the method comprises the steps of utilizing two circular dies, namely an inner die and an outer die, wherein grooves are formed in the inner die and the outer die, forming a rhombic plastic net cylinder through the rotation of the inner die and the outer die in different directions, then carrying out cooling setting through a setting cylinder, cutting the cooled and set net cylinder by a blade, and then unfolding the net cylinder to form a net sheet, wherein the published patent technologies comprise US4057449 and CN 205167609U. 2) The method comprises the steps of utilizing two circular inner dies, two circular outer dies and a circular cutter, wherein the inner dies are provided with grooves, extruding and molding a viscous-fluid cylindrical object in a gap between the inner dies and the outer dies, then utilizing the cutter to do reciprocating motion to cut out a cylindrical net barrel with rectangular meshes, utilizing the cutter to cut open after shaping is carried out through the circular shaping barrel, and then unfolding the net barrel to form a mesh sheet, wherein the published patent technologies comprise US4656075, CN205929395U and CN 206830576U. 3) The sheet-like material is formed and extruded into a viscous state by a plate head, then pressed into a flat sheet by a three-roll calender, cooled and set, and then punched out into a flat sheet with a mesh structure by a punch and a die, and the patent technology is disclosed in GB 1116181A.

The above-disclosed technical methods, although capable of forming a web, have the following drawbacks:

1. the inner die and the outer die are formed into a cylinder firstly through the rhombic net sheets which are formed by rotating in different directions, and then are pulled and cut, the method has the advantages that creases which cannot be removed are formed on the surface of the net material, the local mechanical structure of the net sheets is damaged, in addition, the net sheets are formed by stranded wires which form meshes, the tensile strength is low through up-down lap joint forming, and the large radial and axial tensile force cannot be borne. In this method, in the case of a high molecular polymer material having a low viscosity, for example, a material such as PET or PA, the molten plastic material sags at a position from the die outlet to the shaping cylinder, and the molten cylinder is deformed by the weight of the material, thereby damaging the mesh structure. The mesh produced by the method has the advantages that the strands forming the meshes are formed by up-down lap joint, the surface of the mesh is uneven, and the application occasions are limited.

2. The production method of the rectangular mesh by utilizing the circular reciprocating motion of the die and the cutter is also a method of forming a cylinder firstly and then drawing and cutting, and the method also has the advantages that the surface of the mesh is provided with the fold which can not be removed, and the local mechanical structure of the mesh is damaged. In this method, in the case of a high molecular polymer material having a low viscosity, for example, a material such as PET or PA, the molten plastic material sags at a position from the die outlet to the shaping cylinder, and the molten cylinder is deformed by the weight of the material, thereby damaging the mesh structure.

3. The method of forming the plate by using the plate head three-roller calender and then punching the plate into the mesh can form the mesh with smooth upper and lower surfaces, but the production equipment is complicated, the equipment cost is high, the process steps are very various, the mesh cannot be formed by one-time punching or extruding during punch forming, the thinning area needs to be further heated and melted to form the mesh, and the production cost is high. In addition, as the punching die is used for punching, the raw materials in the punched hole are leftovers, so that the raw materials are wasted greatly, and the energy waste is serious.

Disclosure of Invention

The invention designs a forming device and a method for producing a plane plastic net in order to simplify the production process of the plastic net, solve the technical problems of reducing the production cost of the plastic net and causing material waste, can realize the forming process of the plastic net through one step of working procedure, and simultaneously can ensure that the upper surface and the lower surface of the plastic net after one-step forming are both planes, thereby simplifying the process.

The technical scheme of the invention is that the forming equipment for producing the plane plastic net by the one-step method comprises a feeding mechanism, a forming mechanism and a discharging traction mechanism, and the key is as follows: the forming mechanism comprises a machine head provided with a material receiving port, a dispersing cavity and a long-strip slit lip, and a forming die arranged at the slit lip, wherein the forming die comprises a lip die fixed at the slit lip and a cutting die close to the slit lip, the cutting die has a degree of freedom of reciprocating up and down by virtue of a driving mechanism, the lip die is a long strip with a smooth surface, and the cutting die is a toothed cutter with a first groove and a first protrusion; or the lip die is a strip shape with a second groove and a second bulge on the surface, and the cutting die is a cutter with a smooth cutting edge.

The feeding mechanism comprises an extruder, and an outlet of the extruder is hermetically connected with a material receiving port of the machine head.

The discharging traction mechanism is a group of traction rollers arranged below the slit lip, and a cooling water jacket is arranged in each traction roller.

And the rotating directions of two adjacent traction rollers in the traction roller group are opposite.

The forming device also comprises a conveying mechanism of the final product.

The key of the forming method of the plane plastic net of the forming device is as follows: the forming method controls the raw material in a molten state at the slit lip to flow out or not flow out according to the structure of the forming die by the aid of the forming die formed by the protrusions and the grooves through intermittent up-and-down movement of the cutting die, and realizes the one-step forming process of the planar plastic net.

The intrinsic viscosity of the raw material in a molten state is set to be 0.5-0.9 dL/g.

The temperature of the raw materials in the molten state is controlled at 170-210 ℃.

The forming method also comprises a cooling and solidifying process, wherein the formed plastic net is subjected to traction, cooling and solidification through a group of traction rollers with heat exchange cooling to form a continuous solidification and conveying process.

The core technical scheme of the invention is that the flow direction change of the raw material in a molten state at the slit lip is realized by the intermittent motion of the cutting die in the forming die, and the forming process of the mesh is realized by utilizing the tooth-shaped structure in the die, namely the principle that the convex part can block the flowing direction of the raw material and the groove can allow the raw material to flow out.

The beneficial effect of the invention is that,

1. the forming equipment structure and the forming control method solve the problem that the polymer raw material with lower viscosity cannot be directly produced by an extrusion method.

2. The raw materials in a molten state can be molded into a flat latticed plastic product in one step, the process is greatly simplified, the production efficiency is improved, meanwhile, the planar plastic net product is a completely continuous product, and the planar plastic net product can be cut randomly according to the requirement subsequently, so that the problem that creases cannot be removed in the production of the disclosed technical method is solved; in addition, the product formed by the one-step method has no mutual overlapping points and no stress concentration phenomenon generated by punching, so that the formed mesh has high tensile strength and enhanced tearing resistance.

3. In addition, the equipment and the method can realize zero waste of raw materials, do not produce leftovers of punching in production, save raw materials, save energy and reduce production cost.

4. The upper surface and the lower surface of the plastic net sheet produced by the invention are both planes, the problem that the mesh ribs produced by the disclosed technical method are mutually lapped and uneven is solved, and convenience is provided for the subsequent process of laminating non-woven fabrics or films.

5. The design of adding the cooling water jacket in the traction roller can be used for carrying out traction conveying on a formed product on one hand, and can be used for realizing a cooling and solidifying process in the traction process on the other hand, so that the process procedures are greatly reduced, and the occupied area of more equipment is reduced.

Drawings

FIG. 1 is a schematic view of the structure of the molding apparatus of the present invention.

Fig. 2 is a schematic view of the structure of a flat plastic web produced by the forming apparatus of the present invention.

Fig. 3 is a schematic view of a first embodiment of the cutting die of the present invention.

Fig. 4 is a schematic cross-sectional view of fig. 3.

FIG. 5 is a schematic view of a first embodiment of the lip die of the present invention.

Fig. 6 is a schematic cross-sectional view of fig. 5.

Fig. 7 is a schematic view of two embodiments of the cutting die of the present invention.

Fig. 8 is a schematic cross-sectional view of fig. 7.

FIG. 9 is a schematic view of a second embodiment of the lip die of the present invention.

Fig. 10 is a schematic cross-sectional view of fig. 9.

In the attached drawing, 1 is an extruder, 2 is a machine head, 2-1 is a material receiving port, 2-2 is a dispersing cavity, 2-3 is a slit lip, 3-1 is a lip die, 3-2 is a cutting die, 4 is a driving mechanism, 5-1 is a first groove, 5-2 is a first protrusion, 6-1 is a second groove, 6-2 is a second protrusion, 7 is a conveying mechanism, 8 is a planar plastic net, and 9 is a cooling water jacket.

Detailed Description

Referring to fig. 1, a molding apparatus for producing a flat plastic web in one step, an extruder 1 supplies a head 2 with a molten raw material, the molten raw material is dispersed in a dispersion chamber 2-2 in the head 2 into a flat sheet shape, a slit lip 2-3 of the head 2 is provided with a flat slit, and the molten raw material flows out from the flat slit. A forming die with a groove and a protrusion structure is arranged outside the flat slit, the forming die comprises a lip die 3-1 fixed at the position of a slit lip 2-3 and a cutting die 3-2 capable of realizing up-and-down reciprocating motion, and the cutting die 3-2 can perform controllable up-and-down reciprocating motion by means of a driving mechanism 4. The drive mechanism 4 may be a pneumatic cylinder or a servo motor. When the cutting die 3-2 is positioned at the lower end of the reciprocating motion, the cutting die 3-2 and the lip die 3-1 are tightly attached, only one row of holes are reserved, and a part of molten raw materials can flow out to form longitudinal ribs of the planar plastic net 8; when the cutting die 3-2 is positioned at the upper end of the reciprocating motion, the cutting die 3-2 is separated from the lip die 3-1, the molten raw materials are not blocked by a structure formed between the two dies, and all the raw materials can pass through the slit lip 2-3 to form the transverse ribs of the planar plastic net 8. In this way, a planar plastic net 8 with a mesh structure is formed at the outlet of the die lip of the plate head, as shown in fig. 2. The up-and-down movement stroke of the cutting die 3-2 can be adjusted according to the thickness requirement of the production plane plastic net 8. The maximum value is set for the gap height of the slit lip 2-3, and the thickness of the planar plastic net 8 is controlled by the upper end position of the cutting die 3-2, for example, 2mm, 3mm, 5 mm. Of course, a group of machine heads 2 with different heights inside the slit lips 2-3 can be designed, and the machine heads can be replaced according to the requirements, so that other adverse effects caused by contact of the cutting die 3-2 with materials can be avoided.

Referring to fig. 3-10, the forming die may be implemented in two ways.

Referring to fig. 3-6, one is that the fixed lip die 3-1 is a strip with a smooth surface, and the cutting die 3-2 is designed as a toothed cutter with a first groove 5-1 and a first protrusion 5-2, i.e. the cutting die 3-2 is designed as a toothed structure. When the cutting die 3-2 moves to the lower end to be tightly contacted with the lip die 3-1, the first bulge 5-2 can block the path of the raw material, so that the raw material can only flow out from the position of the first groove 5-1 to form a longitudinal rib. The width of the first groove 5-1 is the width of the longitudinal ribs, the depth of the first groove 5-1 is the thickness of the longitudinal ribs, and a group of cutting dies with different parameters can be manufactured according to requirements so as to meet users with different requirements.

Referring to fig. 7-10, the fixed lip die is a strip with a second groove 6-1 and a second protrusion 6-2 on the surface, and the cutting die 3-2 is designed as a smooth-edge cutting tool, i.e. the lip die 3-1 is designed as a tooth-like structure. When the cutting die 3-2 moves to the position that the lower end is tightly contacted with the lip die 3-1, the second bulge 6-2 can block the going path of the raw material, so that the raw material can only flow out from the position of the second groove 6-1 to form a longitudinal rib. The width of the second groove 6-1 is the width of the longitudinal ribs, the depth of the second groove 6-1 is the thickness of the longitudinal ribs, and a group of lip dies with different parameters can be manufactured according to requirements so as to meet users with different requirements. However, the transverse ribs and the longitudinal ribs of the planar plastic net 8 processed in this way are not in the same plane, and a staggered and crossed grid shape is formed.

In the specific forming method, the extrusion speed of the extruder 1, the intrinsic viscosity of the molten raw material, the descending residence time of the cutting die 3-2 and the ascending residence time of the cutting die 3-2 need to be comprehensively set, and the product parameters needed by a user can be reasonably adjusted. The method can be realized by setting and controlling the whole equipment through PLC.

The design that the cooling water jacket 9 is arranged in the traction roller 5 can support the planar plastic net 8 attached to the traction roller 5 out through rotary motion on one hand, and can directly realize cooling solidification in the process of traction and support out on the other hand, so that the planar plastic net sheet with the net-shaped structure is continuously formed. Normal temperature water in the cooling water jacket 9 enters from one end and exits from the other end, and the heat of the plane plastic net 8 is taken away by a pipeline passing through the middle. Since the temperature of the flat plastic web 8 is also at least above 150 ℃ immediately after the shaping, the purpose of the cooling is primarily to avoid the flat plastic web 8 from sticking to the drawing roller 5. Of course, the outer surface of the pulling roll 5 may also be provided with some anti-blocking coating. After the first-stage cooling, the temperature of the plane plastic net 8 can be reduced to be below 100 ℃, and after the two-stage or three-stage cooling, the plane plastic net can be cooled to 30 ℃, and then the plane plastic net can be naturally cooled to the room temperature through the subsequent conveying mechanism 7 to be cut and packed.

Adopt opposite rotation's direction between adjacent in the traction roller 5 group, can reduce the more even atress and the cooling of the plane plastic net 8 of production, upper surface and lower surface all can receive cooling and traction, only cool off simultaneously and pull, can guarantee the homogeneity of plane plastic net 8 atress. Otherwise, under the condition of higher temperature, the net sheet is likely to be broken or deformed, so that the yield is greatly reduced.

Claims

1. The utility model provides a former of one-step method production plane plastic net, includes feeding mechanism, forming mechanism and ejection of compact drive mechanism, its characterized in that: the forming mechanism comprises a machine head (2) provided with a material receiving opening (2-1), a dispersing cavity (2-2), a long-strip-shaped slit lip (2-3) and a forming die arranged at the slit lip (2-3), wherein the forming die comprises a lip die (3-1) fixed at the slit lip (2-3) and a cutting die (3-2) close to the slit lip (2-3), the cutting die (3-2) has up-and-down reciprocating freedom degree by virtue of a driving mechanism (4), the lip die (3-1) is a long strip with a smooth surface, and the cutting die (3-2) is a toothed cutter with a first groove (5-1) and a first protrusion (5-2); or the lip die (3-1) is a strip shape with a second groove (6-1) and a second bulge (6-2) on the surface, and the cutting die (3-2) is a cutter with a smooth cutting edge.

2. The forming apparatus for producing planar plastic web in one step according to claim 1, wherein: the feeding mechanism comprises an extruder (1), and an outlet of the extruder (1) is hermetically connected with a material receiving port (2-1) of the machine head (2).

3. The forming apparatus for producing planar plastic web in one step according to claim 1, wherein: the discharging traction mechanism is a group of traction rollers (5) arranged below the slit lips (2-3), and a cooling water jacket (9) is arranged inside the traction rollers (5).

4. A forming apparatus for producing a planar plastic web in a one-step process, as claimed in claim 3, wherein: and the rotating directions of two adjacent traction rollers (5) in the traction roller (5) group are opposite.

5. The forming apparatus for producing planar plastic web in one step according to claim 1, wherein: the forming device also comprises a conveying mechanism (7) of the final product.

6. A method of forming a planar plastic web from the forming apparatus of claim 1, wherein: the molding method controls the raw material in a molten state at the slit lip (2-3) to flow out or not flow out according to the structure of the molding die by the intermittent up-and-down movement of the cutting die and the molding die formed by the protrusion and the groove, thereby realizing the one-step molding process of the planar plastic net.

7. A method of forming a planar plastic web, as claimed in claim 6, wherein: the intrinsic viscosity of the raw material in a molten state is set to be 0.5-0.9 dL/g.

8. A method of forming a planar plastic web, as claimed in claim 6, wherein: the temperature of the raw materials in the molten state is controlled at 170-210 ℃.

9. A method of forming a planar plastic web, as claimed in claim 6, wherein: the forming method also comprises a cooling and solidifying process, wherein the formed plastic net is subjected to traction, cooling and solidification through a group of traction rollers (5) with heat exchange cooling to form a continuous solidification and conveying process.