MXPA00003156A - Coextruded mechanical fastener constructions - Google Patents

Abstract

A web (10) of material has a plurality of stems (12) extending from at least one side of the web. The web includes a first layer (14) of material having a first side and a second side and a second layer (16) of material. The second layer of material has a first side which faces the first side of the first layer and a second side from which the plurality of stems extend. The first and second layers of material are joined together while they are both molten, before either layer has cooled. The first and second layers of material can be formed of thermoplastic material or melt processable polymeric material. A method of making a web of material includes selecting a first material for a first layer of material and selecting a second material for a second layer of material. The first and second layers of material are melt formed. Then, the first and second layers of material are joined while the layers are in the molten state to form a multiple layer sheet. Next, a plurality of stems are formed on at least the second layer of material. Melt forming can include simultaneously melt forming the first and second layers of material such as by coextrusion.

Description

COEXTRUID MECHANICAL FIXING CONSTRUCTIONS TECHNICAL FIELD This invention relates to network constructions with rods. More particularly, the invention relates to network constructions with rods formed from at least two polymeric materials.

BACKGROUND OF THE INVENTION Hook and loop fasteners, such as those currently sold under the Scotchmate trademark "by 3M, are a common mechanical fastener." A common hook shape is a mushroom-shaped hook that can also be used as a mechanical fastener Hermaphrodite by coupling other hooks instead of curls These hook structures, formed on nets to create a fastener, are of a common type of network with rods A rod means a protrusion from a surface, such as a network, regardless of its shape, length or length-to-width ratio, geometry or other characteristics US Pat Nos. 4,056,593 and 4,959,265 describe an initial method of extruding polymeric networks with vertical rods, known as rods with rods, the REF network: 33144 with rods It is formed of a single material In the hook structure of US Pat. No. 5,077,870, a single component thermoplastic resin is extruded of a tool which has an array of cavities which, when separated, form an array of rods. The rods are then calendered to produce a wider head at the top of the rod. The shape, dimensions and angularity of the ridges of the head and the number of rods per area determine the ease of capture and the tenacity of curl retention on the hook. The hook material and the rod determine the flexibility of the hook, the rigidity of the rod and the friction of the hook to the curl. Some resins used in the hook structure are high modulus thermoplastics which provide adequate strength to hold the hook structure but do not provide adequate flexural strength to prevent the hooks from fracturing or breaking during release of the loop. In addition, the hook does not provide low friction for the movement of the curl from the top to the bottom side of the hook. The U.S. patent 5,393,475 describes a method for making a network with rods, with rods on both sides using two different materials. This patent describes the extrusion of two different materials to form portions of two bases and form hooks by allowing the material to fill cavities on two rollers between which the material passes.

After this, the base portions are pressed between the two rolls for laminating or gluing together. In one embodiment, a third layer with a mechanical affinity for the first two layers is used. This process necessarily cools the two streams before rolling. The hooks can also be manufactured using an extrusion profile, forming a protruding protrusion on the net. The projection then slides sideways and then bends or stretches to form a plurality of rods. The heads can be formed on the rods either before or after cutting. There is a need for nets with rods, such as mechanical fasteners, that have a wider variety of properties to meet more varied applications.

BRIEF DESCRIPTION OF THE INVENTION The present invention is a network of material having a plurality of rods extending from at least one side of the network. The network includes a first layer of material having a first side and a second side, and a second layer of material. The second layer of material has a first side which is oriented towards the first side of the first layer, and a second side from which the plurality of rods extend. The first and second layers of material are joined together while both are melted, before any layer has cooled. The first and second layers of material can be formed of thermoplastic material or melt-processable polymeric material. The first layer of material differs from the second layer of material and, in one embodiment, the material forming the first layer projects into and forms at least part of the rods formed on the second layer. In another embodiment, one of the layers is discontinuous and includes a plurality of portions of the respective material without connecting with the other portions of the same respective material. The portions have shapes that are selected from the group of bars, prisms, spheres, parallelepipeds, angular and regular shapes and irregular curved shapes. In other alternative embodiments, both surfaces of the network may have rods, and one or more of these rods may have lids. In addition, at least one surface of the network may be receptive to a dye for durable image formation for use in printed material and graphic applications or may have frictional or release characteristics. In addition, additional layers of material can be formed and can be joined with the first and second layers while they are all melted, before any layer has cooled.

The invention is also a method for manufacturing a network of material having a plurality of rods. The method includes selecting a first material for a first layer of material and selecting a second material for a second layer of material. The first and second layers of material are formed by fusion. Then, the first and second layers of material are joined while the layers are in the molten state to form a multi-layered sheet. Then, a plurality of rods are formed on at least the second layer of material. The rods can be formed by pressing the multi-layered sheets against at least one temperature-controlled surface containing an array of holes to form an array of rods. The layers can be formed at the tips of the rods by pressing the rods against a heated surface to form the lids on the tips of the rods. Alternatively, the rods may be formed by extruding multiple layers of a melt processable or thermoplastic material through a shaped die to form a multilayer sheet having a plurality of raised protrusions on at least one surface. A plurality of steep edges are passed perpendicularly through the projections, and the multi-layer sheet is stretched to separate each projection into a plurality of rods. The rods may be formed with a hook shape or subsequently pressed against a heated surface to form a hook or rod with a lid. The melt forming step can include the simultaneous melting of the first and second layers of material. The joining step may include joining the first and second layers before any layer has cooled. The melt formation can be carried out by co-extrusion of the first and second layers of material.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of a network with rods in which the rods are formed from a layer of continuous bottom material, and a portion of the rods and the surface of the network between the rods are covered by the upper layer of rods. material . Figure 2 is a cross-sectional view of a network with rods wherein the upper part of the rods, a portion of the rods and the network surface between the rods are covered by a discontinuous upper layer of material, and most of of the rods are formed from a continuous lower layer of material.

Figure 3 is a cross-sectional view of a network with rods wherein the network has rods and a network surface between the rods covered by a continuous top layer of material, and the rods have a core predominantly of a layer of inferior material . Figure 4 is a cross-sectional view of a network with rods in which the network has rods and a network surface between the rods covered by a continuous top layer of material, and the rods have a core minimally of a layer of inferior material . Figure 5 is a cross-sectional view of a network with rods, wherein the network has rods and a network surface between the rods formed by a continuous top layer of material. Figure 6 is a cross-sectional view of a network with rods wherein the rods are formed of many substantially multiple continuous layers of material. Figure 7 is a cross-sectional view of a network with rods wherein the rod is formed entirely from a continuous outer layer of material and the base regions contain discontinuous regions of elastic material. Figure 8 is a cross-sectional view of a network having rod surfaces on both sides where the rod on one side is composed of a different material compared to the rod on the other side.

DETAILED DESCRIPTION The mechanical fastener hook structures are of a type of network with rods. These mechanical fasteners have some type of hook formed on a rod which, in turn, is formed on a network. In some applications, the hook structures and base supports are made of multiple components. In the present invention, these multiple components are formed together, for example by melt forming (such as extrusion) to improve the operating properties of the mechanical fastener. These performance improvements depend on the selection of materials and include: hook strength: hook and rod flexibility, durability, wear resistance, curl retention, curl coupling, softness, appearance, shear and cut resistance. The selected materials and configurations are suited to the properties of the mechanical fastener for individual applications. Another type of network with rods has rod structures without a lid. The surface of the rod can be coincident with itself when the surface of the rods is self-adhesive. Some properties that affect the performance improvement include the thickness of the layers of material, - Ji the construction of the rod (if the rods are formed of one or more materials and the relative placement of the materials if the rods are composed of more than one material), the geometry of the layer (continuous, discontinuous or multilayer), the density of the rods, the geometry of the rods (if the rods are essentially straight or inclined or have shaped hooks), and the characteristics of the second surface of the construction. The multi-layer fasteners include at least two thermoplastic (or melt-processable polymer) layers that are formed, and are joined while the layers are in a molten state and are cooled, with at least one surface having an array of rods . Each of the materials may have some different properties. For example, one can be ductile while the other can be rigid. Some examples of material types are polyolefins such as polypropylene or polyethylene; other thermoplastics such as polystyrene, polycarbonate, polymethyl methacrylate, ethylene and vinyl acetate copolymers, ethylene-vinyl acetate modified acrylate polymers and copolymers of ethylene and acrylic acid; elastomers such as natural or synthetic rubber, styrene block copolymers containing isoprene, butadiene or ethylene (butylene) blocks, metallocene catalyzed polyolefins, polyurethanes or polydiorganosiloxanes; pressure sensitive adhesives such as acrylic, natural or synthetic rubber, adherent styrene block copolymers, adherent polyorganosiloxane urea copolymer and amorphous poly (1-alkene); heat-melting adhesives such as ethylene-vinyl acetate; ductile thermoplastics such as nylon or polyvinyl chloride; non-adhesive adhesives; or combinations. Multiple layers such as more than three and typically up to one hundred layers may also result in new compositions of network constructions with rod surfaces having properties that may be different from the individual materials used. The materials can also be used to provide the desired features on either or both sides of the network. Some examples of this include adhesive surfaces, surfaces that can provide an abrasive or high friction surface, release surfaces that can provide a low friction surface and active surfaces that provide a receptive surface for materials such as adhesives, coatings or dyes for produce a durable image. The dyes can cover a wide range of materials such as inks in water or inks in organic solvents, or inks that are made up of 100% active material. These inks can be cured by methods such as exposure to UV light or electrostatic graphic image formation. The coatings can - ?? - include any amount of materials either as 100% solid material, or dissolved or dispersed in any combination of water and organic solvents. An example would be a coating that allows the material to be printed by an inkjet printer. The thickness of the relative layer influences the part that the particular material can play. A thin layer of adhesive that forms the outer layer of a rod and a rigid polymer that forms the thick core of a rod results in an array of rods that is stiffer, compared to one that has a thick layer of adhesive on a core rigid thin. By controlling the thickness, the viscosity and the processing conditions, numerous constructions of the base and the stem can be made. These constructions together with the selection of the material, determine the operation of the final mechanical fastener hook. Figure 1 shows a first construction of a sheet or net 10 having rods 12. This construction uses two layers of coextruded material, an upper layer 14 and a lower layer 16. In this construction also, a lower layer material is used. The lower layer 16 forms the base of the sheet and the core and the upper portion of the rods 12. The upper layer 14 forms a surface layer on the base of the sheet and around the lower portion of the rods. As shown in Figure 1, as well as in many of the other embodiments, only one material is used to form the upper and lower layers 14, 16. In alternative embodiments, a plurality of materials and a plurality of sublayers can be formed from the respective upper and lower layers 14, 16. Figure 2 shows a construction with more material in the upper layer 14 than in the construction of figure 1. The lower layer 16 again forms the base of the sheet 10 and the core of the rods 12. Here, the upper layer 14 forms a crown on a rod manufactured from the lower layer 16. The upper layer 14 also forms a surface layer on the base of the sheet, which includes a coating of material that surrounds the base of the rod. In Figure 3, the lower layer 16 forms the base of the sheet 10 and a column of core material for the rods 12. The upper layer 14 forms the surface layers on the base and on the rods. In Figure 4, the lower layer 16 again forms the base of the sheet 10 and a small portion of the rods 12. The upper layer 14 forms the surface layer on the base and forms most of the material of the rod. The lower layer can form any portion of the rods to the point where the upper layer forms the base sheet and the rods, and the lower layer is a smooth continuous sheet that is not part of the rods. Figure 5 shows a similar modality to that of Figure 4. In Figure 5, the lower layer 16 forms the base of the sheet 10 and the upper layer 14 forms the surface layer of the base and forms the entire material of the rod. . Figure 6 shows a construction of sheet with rods that uses many layers 18 of material. These various layers can be as few as two layers or slots of different layers. The layers can be of two or more different materials that can optionally be repeated in different layers. The base of the sheet and the rods are formed of many layers of material. This construction can result in a final product with only one material (the uppermost layer) building the surface layer of the base and forming the outer surface of the rods. Alternatively, as shown, the rods may have many layers exposed along the length of the rod from the bottom of the rod to the top. The layers of the sheets with rods before the formation of the rods, can be formed simultaneously or in series, insofar as they are joined while both are melted, before both layers have cooled. Therefore, the layers are not laminated together and cooled simultaneously. After the rods are formed on one side of the network, no additional material is added to the other side of the network to complete the network. Optionally, another material can be applied as adhesives and impressions to the network, depending on the proposed use and application for the network. The coextrusion can occur by passing different melt streams from different extruders in a multiple die or in a multi-layer feed block and a film die. In the power block technique, at least two different materials of different extruders are fed into different slots (usually 2 or up to more than 200) in a feed block. The individual streams fuse in the feed block and enter a die as a stratified stack that flows out in layered sheets as the material leaves the die. The laminated sheet leaving the die is passed between a nip formed by two rollers. At least one of which has a surface worked to create the rods. Alternatively the rods can be formed by passing the network through a die lip with a pattern to form a net having ridges below the net, cutting the ridges and stretching the net to separate the rods. A multiple die combines the different melt streams of different extruders in the die lip. The layers are then handled as in the above to form rods. This method is usually limited to 2-3 stratified films due to the increasing complexity as the number of layers increases. The series forming can be carried out, for example by sequential extrusion, by extruding one layer first and then extruding another layer. This can be carried out with one or more dies. Alternatively, the layers can be formed into molds or by other known methods. Simultaneous training can be carried out, for example, by coextrusion. You can use a single multiple die or a block of. feeding which is divided into multiple cavities to create multiple layers which can be used. Alternatively, the layers can be formed into molds or by other known methods. The density of the rods depends on the application for the product. The most useful are the densities that vary from 12-465 scions / cm2 (81-3000 scions / inch2). Many different rod geometries can be used. The rods can be straight, inclined or with head. Stem heads can be shaped like mushrooms, golf tees or nail heads. They can have an extruded profile. Straight rods may be self-incriminating, may have an outer layer of pressure sensitive adhesive (PSA), or may be subsequently coated with a PSA. The network with rods can also have a uniform surface with a layer coextruded on the smooth side of the net (the side opposite the rods) that combines the function of mechanical fastening of the surface with rods, with another function. As shown in Figure 7, the rod network 10 can be formed of a discontinuous layer 20, which can include a plurality of portions of material not connected to other portions of the same material and a continuous layer 22. The portions may have any shape including, for example, bars, prisms, spheres, parallelepipeds, angular and irregular shapes and irregular curved shapes. In one embodiment, the discontinuous portions may be formed of an elastic material. They may be continuous elastic regions included in continuous outer layers to provide local stretchable regions. In this embodiment, the melt viscosity of the continuous non-elastic material is preferably greater than that of the discontinuous elastic material to improve the stretching of the downstream network of the elastic domains. In one embodiment, as shown in Figure 8, a plurality of rods 12, with or without heads, can be formed on both sides of the network 10. These networks can be used, for example, for roller covers to pull around of a wrap or for other areas where controlled friction is desired.

In addition, various additives may be used such as physical or chemical blowing agents (for foaming or expanding a section or all of one or more layers) or fillers (to alter the material firmness and flow properties). One use of the estimating agents is to form a lid on the foam by placing the foaming agent in the material at the tip of the rod. It is also possible to use microspheres, flame retardants, internal release agents, dyes, thermally conductive particles and electrically conductive particles. The hooks can be made by finishing off the rods to form mushroom heads as described in U.S. Pat. No. 5,077,870. In addition, the hooks can be manufactured using profile extrusion, forming a prolonged projection on the network. The projection is then cut laterally and then stretched to form a plurality of rods. The heads can be formed on the rods either before or after cutting. This is described in U.S. Pat. No. 4,894,060. The rod networks of this invention can be used in virtually any application as well as in any other network with rods.

EXAMPLES This invention is further illustrated by the following examples which are not designed to limit the scope of the invention. In the examples, all parts, ratios and percentages are by weight unless otherwise indicated. The following test methods are used to characterize the compositions of networks with rods in the following examples: Adhesion test to 180 ° detachment Network samples with 1.25 cm wide and 15 cm long rods are tested for addition to the 180 ° peel to stainless steel and / or a biaxially oriented smooth die cut of polypropylene films. Samples adhere to the test surfaces by rolling the tapes with a 2.1 kg (4.5 lb.) roller using 4 passes. After allowing control under controlled conditions of temperature and humidity (approximately 22 ° C, 50% relative humidity) for approximately 1 hour, the belts are tested using a Model 3M90 slip / detach tester available from Instrumentors, Inc., in a 180 ° geometry at a peel rate of 30.5 cm / min (12 inches / min), unless otherwise indicated. The results are presented in N / dm.

Tear resistance test One end of the sample, approximately 75 cm long and exactly 63 mm wide, is placed in a vertical plane with the largest dimension extending horizontally with the ends of the sample held between a pair of fixed jaws horizontally spaced 2.5 mm apart. a pair of movable jaws that hold the other end of the sample. A 20 mm groove is made in the lower edge of the sample between the two pairs of jaws. A pendulum is then allowed to fall freely, which transports a circumferentially graded scale, tearing the pre-cut sample along the continuation of the slot. A gauge mounted on the scale indicates the resistance of the sample to the tear, in grams. This test is commonly referred to as the Elmendorf tear strength test and the values are presented in grams / fold.

Performance load test (ASTM D-882-81) A 25.4 mm (1.0 inch) wide and approximately 150 ml strip is mounted on a tear strain machine, an Instrumenta tension test system, with the upper and lower jaws 25.4 mm apart. The jaws are then separated at a speed of 254 mm / min (10 inches / min) until the point of performance is reached. The descending network direction of the films is tested after the films are equilibrated at 70-72 ° C and 50% relative humidity for approximately 2 weeks. The load to yield is reported in pounds / inch in width.

Impact resistance test The impact resistance is tested. Two types of tests are carried out: (a) full sheet and (b) a rectangular area of 2.5 cm (1 inch). In the full sheet test, several sheets are cut, each with a measurement of 10.2 cm x 15.2 cm (4 inches x 6 inches) from a larger sheet that has been conditioned for 24 hours at approximately 23 ° C in 50% relative humidity, and then placed in a sample holder. The sample holder is then placed in a TMI Dynamic Ball Tester model 13-13 that has a pointer placed on "p.". A pendulum, with a predetermined weight, is released and impacts the sample. The position of the pointer is recorded in units of cm / kg. In the 2.5 cm (1 inch) groove test, several sheets are cut, each with a measurement of 2.5 cm x 15.2 cm (1 inch x 6 inches) from a larger sheet that has been conditioned for 24 hours at approximately 23 ° C and 50% relative humidity. The ends are maintained to form a curl and part of the curl is placed in a Sentinel Heat Sealer model number 12AS from Packaging Industries, Inc., which has been set at 0.62 MPa (90 psi) for 0.2 sec with the heat off. The resulting strip is placed, with a groove across its width of 2.5 cm approximately halfway down the length of the strip, in the middle part of the support and held in place with an adhesive tape of 12.3 mm wide. The sample holder is then placed in a TMI Dynamic Ball Tester model 13-13, the sample is tested and the impact is recorded against the slot. The results are presented as described above with the full width test.

Testing of pressure by tape Ink adhesion is evaluated using the tape pressure adhesion test (ASTM # 3359). The Tape Pressure Laying Test consists of grooving an ink layer with a corner of a single-edged razor without damaging the underlying print surface, making lines approximately 1 cm apart in a pattern of crossed rhombuses. A piece of Scotch tape "610 (3M) of approximately 10 cm long is applied to the area with crossed diamonds using a PAl applicator (3M) attaching approximately 8 cm of the tape to the ink, which leaves a free end to be fastened The tape is held by one hand of the examiner while the other hand holds the graph stationary.The tape is pulled back approximately 180 ° as quickly as possible by the examiner.A result is excellent when not ink is removed by the tape, a good result is when they are removed a little (5% or less), a poor result is when significant portions of the ink are removed (5% -25%), and is considered a failed test when almost all the ink has been removed.

Examples 1-5 The films with surface of rods in examples 1-5 all have a layer of PSA on the surface side of rods and have self-incising fasteners. In Example 1, component A, (top layer 14), HL-2542-X (a rubber-based PSA in the form of granules available from HB Fuller) is fed into a single screw extruder having a diameter of approximately 25 mm. (1.0 inch) and L / D of 24/1, a screw speed of 15.7 rpm and an elevation profile of up to approximately 182 ° C. Component A is passed through the extruder and continuously discharged at a pressure of at least 0.69 MPa (100 psi) through a heated neck tube and into a hole in an adjustable three-way feed block. Coats (Cloeren ™ Model 86-120-398, available from Cloeren Co. and adjusted for two coats) which is mounted on a 25.4 cm (10 inch) wide film die (Ultraflex die "* 40, model 88 11741, available Extrusion Dies, Inc.) Component B (lower layer 16), Shell SRD 7-560 (an ethylene / polypropylene impact copolymer now available from Union Carbide), it is fed into the second single screw extruder which has a diameter of approximately 32 mm (1.25 inches), an L / D of 24/1, a screw speed of 30 rpm and a temperature profile that increases stably up to about 204 ° C. Component B is continuously discharged at a pressure of at least about 0.69 MPa (100 psi) through a heated neck tube and into a second hole in the three layer feed block. The feed block and the die are adjusted to approximately 193 ° C. The separation of dies from 05 to 0.8 mm (20 to 30 thousandths of an inch). The two-layer cast construction, an upper layer, component A, and a base layer, component B are discharged from the die, dropped as a feed into a nip formed by two rollers having a narrowing pressure of 0.62 Kpa ( 90 psi). The first roller has a machined surface that is presented at 59 ° C and contains cavities with diameters of approximately 280 micrometers (11 mils), depths exceeding approximately 2.5 mm (100 mils) and spaced approximately 813 microns ( 32 thousandths of an inch) resulting in an array of rods having a shoot density of approximately 140 stems / cm2 (900 rods / inch2). The second roller has a surface coated with chromium that is also heated to 59 ° C. The upper side of the two-layer cast construction faces the machined surface and the base side faces the chrome surface. The resulting stamped film is removed from the machined surface at a rate of approximately 1.5 m / min (5 ft.m.) to form a film with a surface with rods, with projections of bar-like rods extending from the surface of the film with a diameter of approximately 300 micrometers and a height of 587 micrometers. These rod structures, reminiscent of that of Figure 3, are completely covered with the adhesive layer and have a core of component B. In Examples 2-5, the film with rod surface is manufactured in a manner similar to the of Example 1, except that a machined surface having a different hole density, a different extruder for component A and different process conditions are those that are used. The machined surface has a cavity density that results in films with surfaces with rods that have approximately 390 stems / cm2 (2500 rods / inch2). Component A is fed into a single screw extruder having a diameter of about 32 mm (1.25 inches) an L / D of 30/1. The screw speeds for the extruders that move component A and component B are in a ratio of 12.0 / 30.0, 7.0 / 9.3, 7.0 / 9.3 and 10.0 / 9.25 for examples 2-5, respectively, and the maximum temperatures of The extruders that feed components A and B are 185 ° C / 204 ° C, 205 ° C / 221 ° C, 205 ° C / 221 ° C and 185 ° C / 204 ° C for examples 2-5 respectively. Network speeds are 1.2 m / min (7 ft. Ft.), 2.1 mm / min (7 ft. Ft.), 3.0 m / min (10 ft. Ft.) And 2.1 m / min (7 ft. Ft.) For examples 2- 5 respectively. The narrowing of the rollers for each example has a pressure of 0.62 MPa (90 psi) and the surfaces of each roller are heated to 65 ° C, 60 ° C, 60 ° C and 48 ° C for examples 2-5 respectively. The films with rod surfaces of Examples 1-5 are tested for adhesion and release at 180 ° (using the test described above). The results are set forth in Table 1, together with the extruder screw speed ratios for component A and component B and the density of rods for each example Table 1 The coextruded films with surface with rods are self-incriminating and do not require a topped tip and a counterpart of curls to be held together mechanically. Adhesion is altered by the thickness of component A, as determined by the relative screw speeds used for component A and component B, the film network speed, the array density of rods. At a low settling density, the PSA (component A) at the tips of the rods and the base between the rods are the primary mating surfaces because the distance between the rods is much greater than the diameter of the rods . At a high rod arrangement density, the sides of the rods and the valleys between the rods are the primary coupling surfaces because PSA covers several sides of the rods and the base between the rods. When the density of arrangement of rods is sufficient to result in a high frequency of lateral coupling of the rods, the thicknesses of the adhesive layer have a more significant effect.

Examples 6-12 and comparative example 1 The films with rod surfaces in Examples 6-12 are made up of various combinations of at least two different polymers including thermoplastics, thermoplastic elastomers and elastomers. Component A acts as a coating layer and Component B acts as a core layer. In each example, 0.5 to 1.0% by weight of a blue pigment is added and added to one component, and 0.5 to 1.0% by weight of a red pigment is added to the other component to allow visual determination of the configuration of the pigments. rods and the heads and subsequent bodies of the shaped rods. The film with a rod surface of Example 6 is manufactured in a manner similar to that of Example 1, except that different materials and process conditions are used. Component A is PP7644 (a polypropylene polymer, which has a melt flow of 23 g / 10 sec, available from Amoco) and component B is PP5A95 (a polypropylene polymer, with a melt flow of 9.5 g / 10 sec). Component A is passed at 102 rpm through a single screw extruder 32 mm (1.25 inches), 24/1 of (L / D) which is heated to about 246 ° C. The component B is passed at 60 rpm through a single screw extruder (19 mm (0.75 inches), 38/1 L / D) which is heated to approximately 216 ° C. The feed block is heated to approximately 246 ° C. The film with surface with rods moves at a speed of 1.5 m / min (5 feet). The surface of the roller having the machined surface is heated to about 50 ° C and the roller having the surface coated with chromium is heated to about 50 ° C. Upon visual examination, the rods on the surface resemble the rods shown in figure 3. The rods combine a softer feel of the softer thermoplastic component A, with the rigid core support of the harder thermoplastic B component. In Example 7, the rod-surface film is manufactured in a manner similar to that of Example 6, except that component A is PP5A95 is passed through a 45 rpm channel of a single screw extruder of 19 mm (0.75 inches) Killion "8 with an L / D of 32/1 that is heated to approximately 216 ° C. Component B is ENGAGE" "EG8200 (an ethylene / poly-α-olefin copolymer available from Dow Plastics Co. ) and is passed through a 75 rpm channel with a single Killion 32 mm (1.25 inch) screw extruder with a 24/1 L / D that is heated to approximately 232 ° C. The film with surface with rods moves at a speed of 2.4 m / min (8 feet). The roller with the machined surface and the roller with the chromium coated surface are heated to approximately 70 ° C. Upon visual examination, the rods on the surface resemble the rods shown in figure 1. The tips of the rods have a greater friction of the elastic component B combined with a more rigid support of the formation of the cylinder of component A thermoplastic more rigid. In example 8, a film with a surface with rods is manufactured in a manner similar to that of Example 7, except that component A is Engage ™ EG8200 and passed through a 50 rpm channel of the extruder and component B is PP5A95 and it is passed through a 70 rpm extruder. The film with surface with rods moves at a speed of 2.1 m / min (7 feet). The roller with the machined surface and the roller with the chromium coated surface are cooled to approximately 7 ° C before visual examination, the rods of the surface remind the rod shown in figure 1. The tips of the rods have a friction smaller of the more rigid thermoplastic component A combined with the more flexible support of the cylinder formation of the elastomeric component B. In Example 9, the rod-surface film is manufactured in a manner similar to that of Example 7, except that component A is "Trick" 11 EG8200 and passed through 60 rpm of the extruder and component B is Styron "666D (a polystyrene available from Dow Chemical Co.) and passed at 60 rpm through the extruder. The film with surface with rods moves at a speed of 2.1 m / min (7 feet). The roller with the machined surface and the roller with the chromium coated surface are heated to approximately 7 ° C. Upon visual examination, the rods on the surface resemble the rods shown in Figure 3. The rods combine a smooth feel of the elastomeric component A with the rigid core support of a hard thermoplastic B component. In Example 10, the surface film with rods is manufactured in a manner similar to that of Example 7, except that component A is passed at 60 rpm through the extruder, and component B is a pre-mixed mixture of 20 weight percent of Styron "1 * 666D and 80 weight percent of PP5A95, and passed at 50 rpm through the extruder The film with surface with rods travels at a speed of 3.0 m / min (10 feet p.m. The roller with the machined surface and the roller with the surface coated with chromium is heated to approximately 50 ° C. Upon visual examination, the rods on the surface resemble the rod shown in Fig. 3. The rods combine the softer feel of the less rigid thermoplastic component A, with the reinforcement supplied by a core having elongated discontinuous regions of a stiffer thermoplastic in the continuous region of the same material as the coating. a film with a surface with rods in a manner similar to that of Example 7, except that component A is No. 1057 (a polypropylene homopolymer, with a melt flow rate of 11 g / 10 sec, available from Union Carbide) , and is passed at 15 rpm through a single screw 38 mm (1.5 inch) Davis Standard Model DS15S extruder having an L / D of 24: 1 and a temperature profile that increases from about 190 ° C up to 232 ° C. Component B is a pre-blended blend of Carbide "1 * 5A97 (a polypropylene homopolymer, with a melt flow rate of 5 g / 10 sec, available from Union Carbide) and Vector" 1 * 4111 (a styrene block copolymer) e, isoprene available from Dexco Polymers). The mixture is produced in a weight ratio of 40:60 and is passed at 15 rpm through a 64 mm (2.5 inch) single screw extruder Davis Standard model 25IN25 having a L / D of 24: 1 and a temperature profile that increases from approximately 204 ° C to 232 ° C. The Cloeren "* 3-ply feed block is a model J.O. 90-802, and the punch is a Cloeren" Epoch Extrusion J.O. 90-82 of 63.5 mm (25 inches). The relative feed rates of component A and component B result in a film having an ABA construction, wherein the weight ratio of ABA is 10:80:10. The film with surface of rods moves at a speed of 12.2 m / min (40 feet pm). The roller with the machined surface and the roller with the chromium coated surface are heated to approximately 38 ° C. Before a visual examination, the rods on the surface are reminiscent of the rod shown in figure 3. The thermoplastic elastomer component B provides an elastic rod core that increases the flexibility of the rods, and a core of component A made of the rods which makes them properly rigid. In addition, the long excess of component B provides a more elastic base film than that permitted by the film with rod surface which is significantly more elastic than one made only of component A. In comparative example 1, a film with surfaces with rods only from a single layer of SRD 7-560 having a thickness and density of arrangement of rods similar to those of example 11.

In example 12, the rod-surface film is manufactured in a manner similar to that of example 11, except that component A is Attane "4802 (a low density polyethylene available from Dow Chemical Co.) and passed to 48 rpm through an extruder, and component B is SRD 7-560 and passed through the extruder at 122 rpm Component A is routed to the outside of two layers of the feed block, and component B is directed to the middle layer The relative feed rates of component A and component B result in a film having an ABA construction, where the weight ratio of ABA is 10:80:10. at a speed of 18.3 m / min (60 ft. ft.) The roller with the machined surface and the roller with the chromium-coated surface are heated to approximately 71 ° C. Upon visual examination, the rods on the surface remind the rod shown in figure 3. The low molecular weight of the thermoplastic component B provides a less rigid core core which causes the rods to have a softer feel. The cover of component A returns to suitably rigid rods. In addition, the excess of the length of the component B provides a more flexible base film than is allowed for the film with surface with rods which is significantly less rigid than that of the comparative example 1.

As seen in examples 6-12, the properties of the heads, the rods and the base surface can vary over a wide range depending on both the type of the polymer components used as a coating or a core material as well as the configuration of the polymers in the bodies, the heads of the finished rods and the base film. In addition, multiple-layer rods are observed that fill the machined surface more completely than homogeneous rods (example 12 versus comparative example 1).

Example 13 A surface film is manufactured with three-layer rods with a discontinuous middle layer. The film is manufactured in a manner similar to that used in example 12, except that different materials and process conditions are used. Component A is SDR 7-560 and is passed at 50.1 and 41.3 rpm through two 64 mm (2.5 inch) single screw extruders, each with 24: 1 L / D and a temperature profile that is increases from approximately 218 ° C to 274 ° C, and inside the outside of two layers of a 3-layer adjustable aperture feed block Cloeren "Model Component B, Kraton" G1657 (a linear block copolymer of styrene-butylene, available from Shell Chemical Co. ), is fed at 45 rpm through single screw extruders of 38 mm (1.5 inches) having an L / D of 24: 1 and a temperature profile that increases from approximately 160 ° C to 204 ° C and inside of the middle layer of the power block. A steel insert is bolted to the bottom span, and the top span moves to contact the insert and restrict the flow of component B into 6 mm wide (1/4 inch) slots that are machined on the insert at intervals of 83 mm (3-1 / 4 inches). Component B exits the channels of the insert and is encapsulated by the upper and lower layers of component A just before entering the contact area of the Cloeren punch of 45.7 mm (18 inches) .The roller with the machined surface and the roller with the chromium-coated surface are maintained at approximately 26 ° C and 6 ° C, respectively The film of the surface with rods is moved at a speed of 15.2 m / min (50 ft.m.) and has a height of rods of approximately 760 micrometers (30 mils), a rod density of approximately 140 rods / cm2 (900 rods / inch2) and a total weight of approximately 170 g / m2. The surface film of rods is then passed over a heated roller at approximately 137 ° C to cause the tips of the rods to soften and form heads or caps in mushroom shapes. When the film is pulled in the transverse direction, the film shows elastic stretch properties in the region where discontinuous component B is embedded.

Examples 14, 15 and Comparative Example 2 The films of surfaces with rods of examples 14 and 15 are composed of two different polymers, component A and component B, arranged in alternating layers, that is, ABA ... BA, as shown in figure 6. In the example 14, the rod-surface film is manufactured in a manner similar to that of Example 6, except that different materials and different processing conditions are used which include a multi-layer arrangement resulting in a polymer network having 29 layers. Component A is Carbide "1 * 7-587 (a polypropylene copolymer, available from Union Carbide), and passed at 122 rpm through a Davis Standard single screw extruder model 25IN25 of 64 mm (2.5 inches) which has L / D of 24: 1 and a temperature profile that increases from about 204 ° C to 232 ° C. Component B is Exact "4041 (a polyolefin of ethylene-butene copolymer, available from Exxon) and passed at 48 rpm through a single screw extruder Davis Standard model DS 1 5 S 38 mm (1.5 inches) having an L / D of 24: 1 and a temperature profile that increases from approximately 190 ° C to 232 ° C. The two cast materials are then supplied in predetermined slot positions in a 70 mm (97.5 inch) model number 71 extruder die available from Johnson Plástic Machinery. The feed block contains an insert that has a linear array of adjacent grooves, each with an X dimension (width) of 12.5 mm for all layers (ie, interior and exterior) of component A. other slots have an X dimension of 9.4 mm. The transfer tubes connected each to the extruder with the first and second manifolds of distribution which supply the materials to the predetermined slot positions in the insert. There are 29 slots 15 for component A and 14 for component B. The product exiting the insert has a generally rectangular cross section and has alternating layers of component A and component B. After leaving the insert, the product is comparatively uniformly compressed along its Y axis (height) while it is comparatively uniformly expanding along its X axis (width) . The now wide and relatively thin film is passed through adjustable lips of the die to obtain a flat film. Feed rates are adjusted to provide a film having a weight ratio of component A to component B of 80:20. The film moves at a speed of 16.5 m / min (54 feet). The roller having the machined surface and the roller having the chromium coated surface are heated to approximately 71 ° C and 93 ° C, respectively. The film of the surface with rods of example 15 is manufactured in a manner similar to that of example 14, except that 121 grooves are used, resulting in a film having 61 alternating layers of component A and 60 alternating layers of component B , and the speed of the film is 12.2 m / min (40 ft.). In Comparative Example 2, a film with a surface with rods is made from only a single layer of Carbide ™ 7-587 having a thickness and density of arrangement of rods similar to that of Example 14. Each film with surface with Rods are tested to determine their tear strength, performance load and impact resistance. The results are shown in the following table. Table 2 As seen in Table 2, the tear strength and impact resistance of films with multi-layer rod surfaces exceeds those of the comparative example. Under the cross section by SEM, it is surprisingly observed that the multiple layers remain intact in the rods.

Example 16 and Comparative Example 3 Example 16 demonstrates the applicability of the present invention to prepare a sheet with surface with rods that readily accepts printing or other signs. A polypropylene two-component rod-shaped film (Shell "SRD 7-560") and Bynell copolymer "3101 (an ethylene-vinyl acetate-acrylate copolymer copolymer, available from EI DuPont de Nemours, ILMINGTON, is manufactured. Delaware) Polypropylene is extruded at approximately 55 rpm from a single screw 3.8 mm extruder (Johnson Company) having an L / D of 30: 1 and a temperature profile that increases from approximately 150 ° C to 205 ° C. Separately, the copolymer is extruded at about 20 rpm from a single screw extruder Killion (Killion Company, Ann Arbor, Michigan) having an L / D of 30: 1 and a temperature profile that is increases from about 150 ° C to about 205 ° C. The two extrudates are combined into a 203 mm wide split multiple film die (Extrusion Dies, Incorporated, Chippewa Falls, Wisconsin) .The two-component film that is extruded will be ge to the narrowing between the upper and middle rollers of a three-roll stack having provision for cooling and rotating at 2.68 m / min (8.8 feet / min). The upper and lower rollers are made of chromium coated steel, and the middle roller is covered with rubber, the rubber has a uniform arrangement of 0.508 mm (0.020 inch) diameter by 2.03 mm (0.080 inch) deep holes in its surface. The arrangement of holes is placed in alternating rows equally spaced parallel to the axis of rotation of the roller. The spacing between the holes in each row is 2.79 mm (0.110 inches) and the rows are 1.40 mm (0.055 inches) apart. Upon exiting the constriction between the upper and middle rollers, the film is allowed to remain in contact with the middle roller for 180 ° of travel (until it enters and exits the narrowing between the middle and lower rollers) and is then transferred to the lower roller . After being transported in contact with the surface of the lower roller by approximately 180 ° of displacement, the surface bicomponent film with resulting rods is directed to a coiler. The resulting film has one side with polypropylene rods and a smooth side consisting of a 25 to 50 mm thick layer of Bynel copolymer. In Comparative Example 3, a film with a rod surface made of shell polypropylene SRD7-560 having the rod dimensions and rod arrangement density similar to comparative example 2 (except that the film speed is 12.2 m / min (40 ft. pm)) is subsequently processed to finish off the rods. The film with surface with rods is then coated with a layer of Bynel "1 * 3101 that has a thickness of 25 micrometers using a single screw extruder Prodex Model 13524 of 44 mm (1.35 inches) that has an L / D of 14: 1 and a temperature profile that increases to approximately 227 ° C and a single layer die having a width of approximately 305 mm (12 inches) .The network moves at a speed of 9.1 m / min (20 feet / minute). The extrusion coating occurs in the heated nip where a roll with chrome is heated to 121 ° C and a rubber support roll that makes contact with the surface of the rods is heated to 10 ° C to maximize the bond interfacial without distorting the structures of the auctioned rods.

Example 16 and Comparative Example 3 are subsequently corona treated and coated with SSKP-4000 black flexo ink (available from Werneke Inks, Plymouth, Minnesota) using a Pamarco Hand Proofer (available from Pamarco Inc., Roselle, New Jersey) . The ink is allowed to dry at ambient conditions for ten minutes. A good print quality is obtained for each sample and the placement test is performed by pressing a tape in each one. For example 16, good ink adhesion is demonstrated and there is no delamination of component B from component A. For comparative example 3, good ink adhesion is demonstrated, but some delamination is observed between component B and component A.

Example 17 A surface material with rods similar to that of Example 16 is coextruded in a different manner. A single cloeren layer of the roughly 70 cm wide die is fed with a material from a 3-layer Cloeren feed block that fits for only two layers. Component A is combined with Union Carbide SRD 7-587 96% and 4% Spectrum Reed pigment concentrate (11000409224), which is passed at 15.9 rpm through a 64 mm Davis Standard single screw extruder that has an L / D ratio of 24: 1 and a temperature profile that increases from 215 ° C to 260 ° C. Component B is a combination of 96% Bynel 3101 and 4% Reed Spectrum pigment concentrate, which is passed at 27 rpm through the Davis Standard 38 mm single screw extruder which has a L / D ratio of 24.1, and a temperature profile that increases from approximately 150 ° C to 205 ° C. Feed rates are adjusted such that the thickness of the film of component A is about 130 to 150 micrometers, plus the height of the pins, and component B is about 25 to 50 micrometers thick. The film of the surface with rods moves at a speed of 16.8 m / min. The rollers with the various machined surfaces are heated to approximately 52 ° C and the chromium coated rollers are heated to approximately 15 ° C. In both cases, the average narrowing pressures are 159 kPa (23 psi). A finished network with a width of 50 cm is obtained, after trimming the edges. The product is manufactured with bolt densities of 50 bolts / cm2 and 140 bolts / cm2. The network with rods is then passed at 12 m / min through two heated constrictions where the heated roller oriented towards the surface of rods is heated to approximately 140 ° C and the cold chrome roller is oriented to layer B and it is cooled to approximately 7 ° C. Mushroom-shaped caps are formed on the rods while the layer of component B remains unchanged. Layer B is treated with corona-type air to improve the ink receptivity of layer B. A first sample with a bolt density of 140 bolts / cm2 is printed by the Scotchprint electrostatic process "1 * .Printed transfer paper 8603 heat laminate in the smooth B-layer using an Orea III laminator with an upper roll temperature of 92 ° C and a lower roll temperature of 56 ° C, with a pressure of 345 kPa (50 psi) and rolled at a speed 0.76 m / min, a complete transfer of the image is obtained, the visual examination shows that a defect-free transfer with good color density is obtained, a second sample having bolt densities of 50 bolts / cm2 and 140 is printed. bolts / cm2 with Scotchcal 9705 black screen printing ink using a 390T screen and cured with focused UV lamps, with medium pressure mercury vapor at 168 mJ / cm2 (American Ultraviolet Co., Murray Hill, NJ). i Membranes are tested to determine ink adhesion using the tape pressure positioning test. Excellent ink adhesion is obtained for both batches. These samples are screen-printed with SCOTCHCAL 3972 solvent-based screen printing ink using a 225 mesh and dried at 66 ° C for 30 minutes. Excellent quality and printing is obtained and both samples pass the ribbon pressure test with excellent results. In both cases, delamination between the layers of 'Bynel 3101 and SRD 7-587 is not observed during the tape laying test.

Example 18 Lot 9701-3 is prepared as in example 17 having an ink jet receiver coating (3M 8502URC) heat-laminated on the smooth side of material 9701-3, on a 3M 9540 laminator at 82 ° C, 0.3 meters / min and 441 kPa (64 psi). The subsequent construction is then fed through a Novajet III ink jet printer (Encad Inc. 6059 Cornerstone Ct. W., San Diego, California), with American inkjet ink (American Inkjet, 13 Alexander Rd, Billeria , Massachusetts.). The analysis with the belt pressure test indicates good anchoring of the ink without the ink being removed from the surface of the network.

Comparative Example 4 A rod surface of the same comparative example 3 is treated with a crown type in the same manner. An ink jet receiver coating is laminated to the smooth surface of the coating and printed in the same manner as in Example 18. The analysis with the tape pressure positioning test results in the complete removal of the ink and the coating of ink jet receiver of the surface of the network.

Example 19 The films with rod surfaces of the example 19 are composed of two different polymers, component A and component B, placed in a two-layer configuration shown in figure 8, wherein each side of the film has an array of rods protruding from the surface. The film with surface with rods of the example 19 demonstrates the effectiveness of the present invention for making an industrial roll coating material having projections on both major surfaces, each of a different composition. Such articles provide an improved friction surface with an integral joint system. A molten bicomponent polymer film having two main surfaces is prepared by extruding material through a multi-component two-component film die divided by two single-screw extruders, both operating at 204 ° C. The first major surface of the two-component film is component A, polypropylene SRD 7-560 Shell, now available from Union Carbide Corporation, Danbury, CT. The second main surface is component B, Rexflex "1 * FP-D1720 flexibilized propylene, commercially available from Rexene Corporation, Dallas, Texas." The extruded bicomponent film is introduced into the constriction between the upper roller and the middle of a vertical stacking. three rollers with aluminum coated, temperature controlled rotating simultaneously 12.70 cm (5 inches) in diameter cylindrical The middle and top rollers have aluminum covers with cylindrical cavities 0.66 mm (0.026 inches) deep by 0.46 mm (0.018 inches) in diameter and 1.32 mm (0.052 inches) in depth by 0.46 mm (0.018 inches) in diameter, respectively placed in rows parallel to the rotational axis around the circumference of each roller, the cavities and the rows are separated 1.41 mm (0.0556 inches). Alternating rows of 0.71 mm (0.0278 inch) cavities are diverted to produce an alternating arrangement. The continuous bicomponent fused film is deposited within the constriction between the upper and middle rollers, the roller is rotated by approximately 180 ° to the constriction between the middle and lower rollers wherein the now partially cooled bicomponent film is contacted and transferred to the surface of the third roller, which is a steel roller coated with chrome, and the third roller rotates another 180 ° when the molded bicomponent article is removed from the surface of the second roller by a controlled winder. The rods formed on the first main surface are easily deformable to a mushroom-shaped lid upon contact with a hot surface to provide a suitable mechanical clamping surface to coincide with a surface having a fibrous curl surface or thereabove. The projections formed in this manner on the second main surface were strong and flexible, providing controlled friction when coupled to a transverse web or sheet when used as the contact surface of an industrial roller.

Example 20 The film with surface with rods of example 20 is composed of two different polymers, component A and component B, placed in a triple layer of ABA configuration having rods as shown in figure 1, wherein the middle layer composed of component B it is elastic and is capable of releasing tension that might otherwise be present in subsequent processing operations. This film is manufactured using extrusion.

Component A, SRD 7-560, is fed into a single screw extruder having a diameter of 64 mm, a L / D ratio of 24: 1, a speed of 122 rpm and a rising temperature profile of 185 ° C to 232 ° C. Component B, Exact "1 * ULDPE, a linear low density polyethylene available from Exxon, is fed into a single screw extruder having a diameter of 3.8 mm, an L / D ratio of 24: 1, a speed of 41 rpm and a rising temperature profile from 185 ° C to 232 ° C. The component A is then passed into the top and bottom of a 46 mm (18 in) wide three layer punch and passed through the component B within the middle part to form a three layer cast film The three layer cast film is fed into a constriction formed by two rolls having a machined surface side and a smooth surface side and pressed with a force of up to 0.41 MPa (60 psi). The machined surface contains cavities with a diameter of approximately 430 micrometers (17 mils), depths exceeding approximately 1.52 mm (60 mils) and separations resulting in a arrangement of rods having a shoot density of approximately 50 stems / cm2 (324 rods / inch2). The two surfaces have a temperature that is maintained at approximately 90 ° C. The resulting stamped film is removed from the machined surface at a speed of approximately 16.5 m / min (55 ft.m.) to form a film with a surface with rods reminiscent of that of Fig. 4. The film has a base thickness of approximately 127 micrometers (5 mils) with bar-like rod projections extending from the surface of the film having a diameter of approximately 430 micrometers and a stem height of approximately 760 micrometers (30 thousandths of an inch). The 127 micron base film consists of three layers, two outer layers of component A having a thickness of approximately 51 micrometers (2 mils) and a middle layer of component B having a thickness of approximately 25 micrometers (1 mil) of an inch). The film with surface with rods is then run at 7.6 m / min (25 ft. Ft.) With the surface with rods in the upper part through a heated stack of two narrows of three rollers to form the lids at the end of the rods. rods that have diameters of 760 micrometers (30 mils) and heights of approximately 510 micrometers (20 mils). The two outer rollers are heated to approximately 149 ° C, the middle roller to approximately 16 ° C and the separations of both narrowings are between 380-635 micrometers (15-25 mils).

The surface film with three-layer rods, with capped rods, is used as the support in a coated abrasive article, which is produced in a manner similar to the teachings of U.S. Pat. 5,551,961. The abrasive mineral used is a heat-treated aluminum oxide grade 180, and both the production and sizing coatings are a combination of phenolic binders and urea formaldehyde. As a result of the middle layer of the low molecular weight stretchable thermoplastic, much of the stress inherently induced in the abrasive film of the homopolymer having a mechanical clamping surface by the elaborate coating and curing process is reduced, and the resulting abrasive film It has better properties, such as curly. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (16)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A network of material having two sides and a plurality of rods extending from at least one side of the network, characterized in that it comprises: a first layer of material having a first side and a second side, a second layer of material having a first side which is oriented towards the first side of the first layer, and a second side from which the plurality of rods extends where the first and second layers of material are joined together while both are melted before that each of the layers has cooled, wherein the first layer of material differs from the second layer of material, and the material forming the first layer protrudes into and forms at least part of the rods formed in the second layer .

2. The network according to claim 1, characterized in that the first and second layers of material are each formed of at least one layer having at least one melt-processable polyester material.

3. The network according to claim 1 or 2, characterized in that one of the layers is discontinuous and comprises a plurality of portions of the respective material not connected to our portions of the same respective material, wherein the portions have shapes that are selected from the group of bars, prisms, spheres, parallelepipeds, angular and regular shapes and irregular curved shapes.

4. The network according to any of claims 1 to 3, characterized in that both sides of the network have rods.

5. The network according to any of claims 1 to 4, characterized in that one or more of the rods have lids.

6. The network according to any of claims 1 to 5, characterized in that at least one side of the network is receptive to dye for the formation of a durable graphic image or durable printed material.

7. The network according to claim 6, characterized in that the first layer is one of (1) a receptive layer for image transfer, screen printing, lithographic printing and ink jet printing, and (2) a receptive primer for adhesives. and pressure sensitive coatings.

8. The network according to any of claims 1 to 7, characterized in that the rods are uncovered and have an outer surface that is self-adhesive.

9. The network according to any of claims 1 to 8, characterized in that the first and second layers of material are formed simultaneously and the net additionally comprises additional covers of material formed simultaneously and joined with the first and second layers while they are all melted, before that any layer has cooled.

10. A method for manufacturing a network of material having a plurality of rods extending from at least one side of the network, wherein the method is characterized in that it comprises the steps of: selecting at least a first material from a first layer of material, selecting at least one first material for a first layer of material, selecting at least one second material for a second layer of material, melt-forming, from the first material, the first layer having a first surface and a second surface, melt-forming, from the second material, the second layer having a first surface and a second surface, joining the first surfaces of the first and second layers of material while the layers are in the molten state to form a multiple layer sheet, and forming a plurality of rods on at least the second surface of the second layer of material, wherein this stage forming comprises comprising the plurality of rods of at least one of the first material and the second material, and the method further comprises the step of selecting relative amounts of the first and second materials so that the first material which forms the first layer protrudes inside or through and form part of the rods formed on the second surface of the second layer.

11. The method according to claim 10, characterized in that the melt forming step comprises at least one of: (1) melt forming each of the first and second layers from at least one molten processable polymeric material, and (2) coextruding the first and second layers of material.

12. The method according to claim 10 or 11, characterized in that the step of forming the rod comprises pressing a multi-layer sheet against at least one controlled temperature surface containing an array of holes to form an array of rods.

13. The method according to claim 12, characterized in that it further comprises the step of pressing the rods against a heated surface to form the caps on the tips of the rods.

14. The method according to any of claims 10 to 13, characterized in that the step of forming rods comprises: passing a multiple layer sheet through a shaped die to form a plurality of raised protrusions on at least one surface of the multi-layered sheet, passing a plurality of edges pronounced perpendicularly through the projections, and - stretching the multi-layered sheet to separate each projection into a plurality of rods.

15. The method according to any of claims 10 to 14 characterized in that it further comprises the melt formation of additional layers of material; and joining the additional layers of material to the first and second layers of material while the layers are in the molten state to form a multilayer sheet.

16. The method according to any of claims 10 to 15, characterized in that the step of melt forming comprises simultaneously melt forming the first and second layers of material and the joining step comprises joining the first and second layers before any layer has cooled CONSTRUCTIONS SUBJECT SUMMARY OF THE INVENTION A network (10) of material has a plurality of rods (12) extending from at least one side of the network. The network includes a first layer (14) of material having a first side and a second side, and a second layer (16) of material. The second layer of material has a first side which is oriented towards the first side of the first layer and the second side from which the plurality of rods extend. The first and second layers of material are joined together while both are melted, before any layer has cooled. The first and second layers of material can be formed of thermoplastic material or melt processable polymeric material. A method for making a web of material includes selecting a first material for a first layer of material, and selecting a second material for a second layer of material. The first and second layers of material are formed fused. Then, the first and second layers of material are joined while the layers are in the molten state to form a multiple layer sheet. Subsequently, a plurality of rods are formed on at least the second layer of material. The melt formation can include melt-forming the first and second layers of material simultaneously, for example by coextrusion.