Method for manufacturing a surface zipper and surface zipper

Abstract

Manufacturing process for a surface zipper with: an injection molding step in which injection molding is carried out to form a molded part (1x) in which a column group (3x) which is a set of a plurality of columns (31x) and a base plate (2) with a surface from which the column group (3x) protrudes are integrated in a single body; a step of receiving the molded part (1x) in a space formed between a lower template (51) and an upper template (52) of a template (5), wherein a tip area of ​​the column group (3x) projects upwards from the upper template (52); a cutting step in which the tip area of ​​the column group (3x) is cut off by sliding an edge of a cutting device (C) over an upper surface of the upper template (52) to form a cut product (1y) in which a group of small columns (3y) that is shorter than the column group (3x) and the base plate (2) are integrated into a single body; a step of removing the cut product (1y) from the template (5); a melting step in which a tip region of the group of small columns (3y) is melted to form column body regions (31a), which are unmelted regions, and engagement regions (31b), which are molten regions and are thicker than the column body regions (31a) of the small columns (31y) forming the groups of small columns (3y); and a cooling step in which the engagement areas (31b) are cooled to determine shapes of a plurality of engagement elements (31) including the column body areas (31a) and the engagement areas (31b), thereby forming a surface zipper (1) in which an engagement element group (3) which is a set of the plurality of engagement elements (31) and the base plate (2) are integrated in a single body.

Description

Technical field

[0001] The present invention relates to a method for manufacturing a flat zipper which is formed in one piece by injection molding, and to a flat zipper. State of the art

[0002] As an example of a surface zipper, there is a surface zipper in which a base plate and a variety of engagement elements, which protrude from a surface of the base plate, are molded as a single piece. There are different types of engagement elements, and one example is an engagement element called a mushroom, where the engagement element has a shape similar to a mushroom.

[0003] As an example of a prior art method for manufacturing a surface zipper including mushroom-shaped locking elements, there is a method that uses a base mold for forming a base plate, a head mold for forming mushroom caps, and a destructively removable stem mold for forming columnar mushroom stems (Patent Document 1). In this manufacturing method, after injection molding using the molds is carried out, the destructively removable stems are melted with, for example, water to move the base mold and the head mold in a direction in which they are separated from each other, thus allowing the mold to be opened. Patent Documents 2 and 3 also disclose a method for manufacturing a surface zipper with mushroom-shaped locking elements. Patent document 1: JP H07 - 509 668 A Patent document 2: US 5,077,870 A Patent document 3: US 5,785,784 A

[0004] However, the manufacturing process described above for the destructively removable handle mold essentially requires a material different from a resin, which is a molding material. Furthermore, it is necessary to consider how the destructively removable handles, melted with water, will be disposed of after molding. Summary

[0005] Therefore, an objective of the present invention is to provide a manufacturing process for a flat zipper and a flat zipper in which a material other than a mold material has to be used as little as possible.

[0006] A manufacturing process for a surface zipper according to one aspect of the embodiments of the present invention is according to claim 1 and comprises (1) an injection molding step, (2) a cutting step, (3) a melting step and (4) a cooling step. (1) The injection molding step is a step in which injection molding is carried out to form a molded part in which a column group, which is a set of multiple columns, and a base plate with a surface from which the column group protrudes are integrated into a single body. (2) The cutting step is a step in which a tip area of ​​the column group is cut off in order to form a cut product in which a group of small columns, which is shorter than the column group, and the base plate are integrated into a single body. (3) The melting step is a step in which a tip region of the group of small columns is melted in order to form column body regions which are unmelted regions and engagement regions which are molten regions and which are thicker than the column body regions of the small columns forming the group of small columns. (4) The cooling step is a step in which the engagement areas are cooled to determine shapes of a plurality of engagement elements including the column areas and the engagement areas, thereby forming a surface zipper in which an engagement element group, which is a set of a plurality of engagement elements, and the base plate are integrated in a single body.

[0007] In the melting step, it is irrelevant whether a heating device, acting as a heat source for melting the tip region of the group of small columns, comes into contact with the group of small columns. If the heating device does come into contact with the group of small columns, molten resin can adhere to the heating device and may lead to defective products. Therefore, it is preferred that the melting step be carried out as follows.

[0008] This means that the melting step involves positioning a heating device relative to the tip area of ​​the group of small columns in a non-contact state.

[0009] It is preferred that the engagement area of ​​each engagement element of the surface zipper manufactured according to this embodiment is as follows.

[0010] This means that each of the intervention areas comprises an intervention surface that projects from a tip of the respective column body area in its circumferential direction over the entire circumference.

[0011] An angle of intersection between the engagement surface and a side surface of the column body area is not of particular importance, but is preferably as follows.

[0012] This means that the angle of intersection between the contact surface and a side surface of the respective column body area is greater than or equal to 90° and less than 150°.

[0013] A surface zipper according to another aspect of the embodiments of the present invention is according to claim 5 and comprises a base plate and an engagement element group that are integrally molded by injection molding. The engagement element group comprises a plurality of engagement elements that project in their thickness direction from a plurality of positions on a surface of the base plate. Each of the engagement elements has a layered structure consisting of resin layers extending from the interior of the base plate and comprises a column body region projecting in its thickness direction from a surface of the base plate and a spherical segment-shaped engagement region with an engagement surface that projects from an outer circumference of a tip of the column body region over its entire circumference.In the column body area, the resin layers are formed parallel along a longitudinal direction of the column body area, and in the engagement area, the resin layers extend radially from the tip of the column body area, and the resin layers are layered in a circumferential direction in a cross-section.

[0014] In the manufacturing process for a surface zipper according to the embodiments of the present invention, a material other than a resin is essentially not required for the mold material. Since the cut-off tip area of ​​the column assembly can be collected and reused, it is possible to easily dispose of unwanted material generated in the manufacturing process.

[0015] By arranging the heating element in such a way that it does not come into contact with the group of small columns during the melting step, it is possible to reduce the occurrence of defective products.

[0016] The surface zipper according to another aspect of the embodiments of the present invention has a structure in which each engagement element is formed by laminating resin layers extending from the interior of the base plate and is manufactured by the manufacturing process for a surface zipper according to the aspect of the embodiments of the present invention. Brief description of the drawings

[0017] The accompanying drawings show: Fig. 1A and Fig. Figure 1B shows a top view and a front view, respectively, illustrating an example of a surface zipper manufactured according to the present invention; Fig. Figure 2 is a cross-sectional view showing an injection molding step; Fig. 3A, Fig. 3B and Fig. 3C are cross-sectional views showing a detailed sequence of a cutting step; Fig. 4A, Fig. 4B and Fig. 4C are diagrams showing a cutting step, a melting step, and a cooling step; Fig. 5A and Fig. 5B are photographs showing conditions observed with a polarizing microscope, where Fig. 5A represents a cross-section of a molded part and Fig. 5B shows a cross-section of an example of a surface zipper; Fig. 6 is a photograph depicting a surface zipper according to a comparative example; Fig. Figure 7 is a photograph depicting a surface zipper manufactured according to an example of a manufacturing process according to the present invention; and Fig. 8A and Fig. 8B are diagrams that illustrate other examples of the injection molding step. Detailed description

[0018] An example of a flat zipper 1 manufactured according to the present invention is a mushroom-head flat zipper, as described in Fig. 1A and Fig. Figure 1B is shown. An example of the mushroom-head surface zipper 1 according to the present invention comprises a base plate 2 and an engagement element group 3 which projects from a surface in a thickness direction of the base plate 2.

[0019] The surface zipper 1 according to the present invention is used, for example, as a male-part surface zipper. In a more specific example, if two interlocking surface zippers consist of a male-part and a female-part surface zipper, the male-part surface zipper can consist of the surface zipper 1 according to the present invention, and the female-part surface zipper can consist of a surface zipper in which a plurality of loops project from a woven or knitted base fabric as engagement elements.If two interlocking surface zippers consist of male-part surface zippers, both male-part surface zippers can consist of the surface zipper 1 according to the present invention, or only one of the two male-part surface zippers can consist of the surface zipper 1 according to the present invention and the other surface zipper can consist of a surface zipper manufactured by a manufacturing process different from the manufacturing process according to the present invention.

[0020] The base plate 2 is a plate that serves as a base from which the engagement element group 3 projects, and in this embodiment both surfaces are flat and parallel to each other in their thickness direction. In the present invention, the shape and thickness of the base plate 2 are not particularly restricted.

[0021] The engagement element group 3 comprises a plurality of engagement elements 31 that project from a plurality of positions on a surface of the base plate 2.

[0022] The engagement element group 3 comprises a plurality of engagement elements 31 arranged regularly. In the figures, the engagement element group 3 comprises a plurality of engagement element rows 31L, each of which has a plurality of engagement elements 31 arranged in a row, and the plurality of engagement element rows 31L are arranged at equal intervals in a direction perpendicular to the direction of extension of the rows. More precisely, in each engagement element row 31L, a plurality of engagement elements 31 are arranged at equal intervals in a row. Regarding a relationship between adjacent engagement element rows 31L and 31L, one of the plurality of engagement elements 31 and 31 that constitutes an engagement element row 31L is arranged between adjacent engagement elements 31 and 31 of the other engagement element row 31L.The adjacent rows of engagement elements 31L and 31L have, in other words, a relationship in which the engagement elements 31 are arranged in a zigzag pattern.

[0023] Each engagement element 31 comprises a column body region 31a and an engagement region 31b projecting from the apex of the engagement body region 31a. More precisely, in the drawing, each engagement element 31 comprises a column body region 31a with a cylindrical shape and an engagement region 31b with a hemispherical segment shape. In the present invention, the shape of the column body region 31a is not specifically limited to a cylindrical shape and can have other shapes, for example, a prism shape, and, for example, the cross-section of the prism shape can be triangular, square, pentagonal, hexagonal, or polygonal in some other way.

[0024] The intervention area 31b has a shape in which a circular surface, which is a lower surface 31c of the spherical segment shape, is continuous from the tip surface of the column body area 31a. As can be seen in the enlarged part in the dashed line in Fig. As shown in Figure 1A, looking in the direction of extension of the column body region 31a, the outer circumference (the outer circumference of the lower surface 31c) of the engagement region 31b is larger than the outer circumference of the column body region 31a over its entire circumference in the circumferential direction, and the outer circumference of the engagement region 31b and the outer circumference of the column body region 31a are so-called concentric. Accordingly, the engagement region 31b is thicker than the column body region 31a.

[0025] As in the Fig. 1A and Fig. As shown in Figure 1B, the lower surface 31c of the engagement area 31b has a ring shape that projects outwards from the outer circumference of the column body area 31a and serves as an engagement surface that engages with engagement elements of another surface zipper. It is preferred that the engagement surface 31c is planar in one of its parts. Since, as shown in Fig. As shown in Figure 5B, the engagement surface 31c is a plane extending in a direction substantially perpendicular to the side surface of the column body region 31a, and the column body region 31a extends in a direction substantially perpendicular to a surface in the thickness direction of the base plate 2. A surface in the thickness direction of the base plate 2 and the engagement surface 31c are substantially parallel to each other. In other words, the angle of intersection θ between the engagement surface 31c and the side surface of the column body region 31a in the illustrated example is 90°, as shown in the enlarged area of ​​the dotted line in Figure 5B. Fig. The angle of intersection is shown in Figure 1B and is preferably greater than or equal to 90°. The upper limit of the cutting angle θ is less than 180°, preferably less than 150° in view of the product performance, and more preferably less than or equal to 135°.

[0026] As in the Fig. Figures 2 to 4C illustrate an example of a manufacturing process for the surface zipper 1 according to the present invention, comprising an injection molding step in which a molded part 1x is formed, wherein a column group 3x, comprising columns forming the engagement element group 3, and the base plate 2 with a surface from which the column group 3x projects, are integrated into a single body; a cutting step in which a cut product 1y is formed, wherein a group of small columns 3y, which is shorter than the column group 3x, and the base plate 2 are integrated into a single body by cutting the tip region of the column group 3x; a melting step in which the shape of the engagement element group 3 is formed by melting the tip region of the group of small columns 3y; and a cooling step in which the surface zipper 1 is formed by cooling.

[0027] For example, the injection molding step, as in Fig. Figure 2 shows a mold 4 comprising a stationary mold 41 and a movable mold 42, which open and close relative to each other in the vertical direction. In this example, the stationary mold 41 is assumed to be located at the top and the movable mold 42 at the bottom. The mold 4 includes a cavity 43 corresponding to the shape of the molded part 1x, and an access 44 that connects to the cavity 43 as a recessed area in a contact surface 4a between the stationary mold 41 and the movable mold 42. The cavity 43 is formed by an uneven surface of the mold 4 (more precisely, an uneven surface (hereinafter referred to as the "cavity surface") with a shape corresponding to the shape of the molded part).The stationary mold 41 and the movable mold 42 are connected to an injection molding machine (not shown) such that they are vertically opposed to each other, and the movable mold 42 is arranged to be vertically movable. The injection molding step is carried out by injecting molten resin into the cavity 43 of the mold 4. Examples of the molten resin include polypropylene, polyacetal, and nylon, and polypropylene can preferably be used to form the engagement area 31b in an ideal hemispherical shape.

[0028] The molded part 1x formed by the injection molding step comprises the base plate 2 and the column group 3x, as described above. The column group 3x comprises a plurality of columns 31x, which are regularly arranged on a surface of the base plate 2 in the same arrangement as the engagement element group 3. Fig. 5A is a photograph depicting a sectioned surface viewed with a polarizing microscope when the molded part 1x is cut along a plane parallel to the longitudinal direction of column 31x. This photograph shows the internal structures of base plate 2 and column 31x, and a layered structure of resin layers extending from the interior of base plate 2 in the projection direction of column 31x (towards the tip of column 31x) can be confirmed.A multitude of resin layers are arranged one above the other; more precisely, a multitude of layers are arranged in the thickness direction in a region of the base plate 2 that differs from a region that is continuous with the base of the column 31x, and the multitude of layers are arranged in the radial direction of the column 31x in a region (an intermediate region and a region near the base) below the tip region of the column 31x. In the base plate 2, the resin layers are bent to be lifted into the column 31x in the vicinity of the base of the column 31x.

[0029] The resin layers can be seen as indicating a flow of molten resin injected during the injection molding step. This is in Fig. 5A, the molded part 1x shown is made of black resin to make the flow of molten resin easy to observe, and the flow of molten resin (resin layers) can be seen through a variety of white and black lines in the Fig. 5A and Fig. 5B can be understood. A white line and a black line correspond to a resin layer. Based on the shapes of the layers, one can consider that the molten resin flows from the area corresponding to base plate 2 into the area corresponding to column 31x, rises directly from the area corresponding to the base of column 31x to the area corresponding to the tip of column 31x, collides with the surface of the cavity forming the tip of column 31x, is gently bent after the collision, sinks, and finally fills the cavity. In other words, the layers in the middle area of ​​column 31x have shapes that are parallel to the longitudinal direction of column 31x (shapes that extend in the longitudinal direction).Based on this shape, it can be seen that the molten resin is in a laminar flow when it cools and solidifies in the middle region of column 31x. On the other hand, the layers in the tip region of column 31x have shapes that curve towards the base (base plate 2) of column 31x, with the area around the tip of column 31x representing a reversal point. From this shape, it can be seen that the molten resin is in a turbulent flow when it cools and solidifies in the tip region of column 31x.

[0030] The cutting step uses a template 5, e.g., as shown in the Fig. Figures 3A to 3C are shown. The template 5 comprises a lower template 51, in which a receiving opening 51a for receiving the molded part 1x is formed, and an upper template 52, in which a hole group 52a, into which the column group 3x is inserted, is formed. The majority of the molded part 1x is received in a space formed between the lower template 51 and the upper template 52, and the tip area of ​​the column group 3x projects upwards out of the upper template 52.

[0031] The receiving opening 51a, with a size slightly larger than the size of the base plate 2, is formed on the upper surface of the lower template 51. The depth of the receiving opening 51a is greater than the thickness of the base plate 2 and less than the total height of the molded part (the sum of the thickness of the base plate 2 and the total height of the column 31).

[0032] The upper template 52 is a flat plate of essentially the same size as the base plate 2, and its thickness is less than the total height of the column 31x set, so that the hole group 52a comprises a plurality of holes 52b into which the columns 31x of the column group 3x are inserted, and penetrate the upper template 52 in its thickness direction.

[0033] If, as in Fig. As shown in 3A, where the mold part 1x is taken up in mold 5, the tips of the columns 31x of the column group 3x protrude upwards from the upper template 52. The upwardly projecting tips of the columns 31x are areas (areas formed by the molten resin that rose, was then gently bent, and then sank) where the resin layers are bent into a U-shape, as shown in the photograph of Fig. 5A is shown.

[0034] As in Fig. As shown in Figure 3B, the tip regions of the columns 31x are cut by sliding an edge of a cutting device C over the upper surface of the upper template 52. Accordingly, the tip regions of the columns 31x are cut as shown in Figure 3B. Fig. As shown in 4A, the product is cut along a virtual cutting line L that is parallel to the surface of the base plate 2, from which the column group 3x projects, forming a cut product 1y. The cut product 1y is then, as shown in Fig. Figure 3C shows the cut product 1y, taken from template 5. The cut product 1y comprises a group of small columns 3y, which is shorter than the overall height (projection height) of the column group 3x, and the base plate 2 with a surface from which the group of small columns 3y projects. In the tip regions of the plurality of small columns 31y that form the group of small columns 3y, the resin layers are arranged such that they are substantially parallel to each other in the longitudinal direction of the columns 31x.

[0035] The melt cutting process uses a heating device 6, as in Fig. Figure 4B represents the heating device 6. The heating device 6 is arranged such that it is separated from the tips of the group of small columns 3y of the cut product 1y in the upward direction in which the small columns 31y project. That is, the heating device 6 is in a non-contact state with the tip region of the group of small columns 3y. Since the heating device 6 has a flat plate shape and is arranged parallel to and opposite the base plate 2, the heating device 6 is equidistant from the tips of the small columns 31y of the group of small columns 3y and is adjusted to heat the small columns 31y uniformly. By heating the tip regions of the small columns 31y at a high temperature for a predetermined time using the heating device 6, the tip regions of the small columns 31y are melted.Accordingly, a column body region 31a, which is an unmelted region, and an engagement region 31b, which is a molten region, are formed from each small column 31y. To melt only the tip regions of the small columns 31y and not to add the heat of the heating device 6 to other regions, the cut product 1y is, for example, immersed in water, and only the tip regions of the small columns 31y of the group of small columns 3y protrude from the water and are then heated. Accordingly, the tip regions of the small columns 31y are melted, and the molten resin is cooled at the water surface and does not simply flow downwards from the water surface. As a result, the lower surface 31c of the engagement region 31b is likely to be parallel to the upper surface of the base plate 2, and the engagement region 31b is likely to have a spherical segment shape with less deformation.

[0036] In the cooling step, the engagement areas 31b, which have a high temperature immediately after the melting step, are solidified by cooling, and the shape of the engagement elements 31, each comprising the column body area 31a and the engagement area 31b, is determined, thereby forming a mushroom-head surface zipper 1. In the cooling step, the engagement areas 31b can be forcibly cooled by wind from a fan, or they can be cooled naturally by being left unattended for a predetermined time.

[0037] In the manufacturing process described above according to the present invention, essentially no material different from the resin needs to be used for the mold material. The tip areas of the column group 3x contain hardly any impurities other than the mold material and can therefore be collected and recycled, and unwanted material generated during the manufacturing process can be easily disposed of. Since the heating device 6 is arranged in a non-contact state with the group of small columns 3y, it is possible to reduce one cause of defective products.

[0038] In the above-described example of the manufacturing process according to the present invention, the engagement elements 31, which form the engagement element group 3, have an engagement area 31b which has a less deformed spherical segment shape. Fig. Figure 6 is a photograph showing a state when the mushroom-head surface zipper 1, which is manufactured according to the example of the manufacturing process according to the present invention, is observed with an optical microscope, wherein the engagement area 31b of each engagement element 31 has a spherical segment shape and its lower surface 31c is almost parallel to a surface of the base plate 2. Fig. Figure 5B is a photograph depicting the state when a sectioned surface 4, obtained by cutting the mushroom-head surface zipper 1, produced according to the manufacturing method of the present invention, along a plane parallel to the longitudinal direction of the column body region 31a, is observed with an optical microscope, allowing the internal structures (resin layers) of the base plate 2 and the column 31x to be seen. From these images, it can be seen that the layers extend radially from the tip of the column body region 31a, and the multitude of layers in the cross-sectional photographs are layered in the circumferential direction. More precisely, the layers in the vicinity of the lower surface 31c (engagement area) of the engagement region 31b extend along the lower surface 31c.

[0039] Fig. Figure 7 is a photograph depicting a state in which a mushroom-head flat zipper according to a comparative example is observed with an optical microscope. The flat zipper according to the comparative example is not subjected to the cutting step of the present invention, and the tip regions of the columns 31x are in the Fig. The state depicted in Figure 5A is molten. That is, the surface zipper according to the comparative example is produced by the injection molding step, the melting step, and the cooling step. In this case, the turbulent flow of the molten resin in the molten tip region of each column 31x influences the shape of the engagement area 31b after the melting step, and the engagement area 31b has a deformed shape, like a dented sphere. In particular, the underside of the engagement area 31b has a shape that is convexly curved upwards towards the side of the base plate 2 in a spherical shape. Accordingly, an engagement area 31b with this shape cannot exhibit an engagement force (coupling force) like a mushroom-head surface zipper.

[0040] As can be seen from the comparative example, in order to obtain an engagement area 31b with an ideal hemispherical shape, as is the case in the example of the surface zipper according to the present invention, it is important that the resin layers in the tip region of the molten small column 31y are substantially parallel to each other along the longitudinal direction of the column 31x. Since the outer layer of the resin layers forms the lower surface 31c of the engagement area 31b and its surroundings, at least the outer layer preferably has a shape that is substantially parallel to the longitudinal direction of the column 31x over the entire outer circumference of the column 31x, and the inner layers of the resin layers are not particularly constrained.

[0041] Another example of the manufacturing process for the surface zipper 1 according to the present invention differs from the example described above only in the injection molding step, as described in the Fig. 8A and Fig. 8B represents.

[0042] In the Fig. The example shown in Figure 8A is a mold 4 arranged at a distance below a nozzle 7 of an injection molding machine. The mold 4 comprises a first roller 71 and a second roller 72. The first roller 71 and the second roller 72 are arranged such that they face each other, with a distance corresponding to the thickness of the base plate 2 positioned between them. The surface of the first roller 71 is a smooth, unblemished cylindrical surface. On the other hand, cavities 72a for forming the columns 31x of the column group 3x are formed on the surface of the cylindrical surface around its entire circumference. Each cavity surface forming a cavity 72a is concave, with a closed area corresponding to the apex of the column 31x. The first and second rollers 71 and 72 are each rotatably arranged about the centers of their cylindrical surfaces.

[0043] If in the Fig. Figure 8A shows the first and second rollers 71 and 72 being slowly rotated while molten resin is injected from the nozzle 7 between the first roller 71 and the second roller 72. The molten resin that is poured between the first roller 71 and the second roller 72 forms the base plate 2 and flows into the cavities 72a of the second roller 72 to form the columns 31x, and a continuous molded part 1x is discharged outwards with the rotation of the second roller 72.

[0044] In the Fig. In the example shown in Figure 8B, a shape 4 is formed by a nozzle 7 of an injection molding machine and a third roller 73, which is arranged at a distance with respect to the molten resin injected by the nozzle 7.

[0045] The third roller 73 is rotatably arranged around the center of its cylindrical surface. The third roller 73 has cavities 73a which are designed to form columns 31x, similar to the second roller 72.

[0046] The tip surface of the nozzle 7 is designed as a curved surface with a concave, arcuate cross-sectional shape. The curved surface has an arcuate cross-sectional shape whose diameter is larger than that of the third roller 73. The nozzle 7 is positioned at a distance from the cylindrical surface of the third roller 73 such that the center point of the arc of the curved surface coincides with the center point of the third roller 73.

[0047] If in the Fig. In the example shown in Figure 8B, when the third roller 73 is slowly rotated while molten resin is injected from the nozzle 7 to the third roller 73, the molten resin that is filled between the nozzle 7 and the third roller 73 forms the base plate 2 and flows into the cavities 73a of the third roller 73 to form the columns 31x, and a continuous molded part 1x is ejected outwards as the third roller 73 rotates.

[0048] In the through the in the Fig. 8A and Fig. In the injection molding step 8B, the resulting internal structure of the molded part 1x consists of resin layers in the central region of column 31x that are parallel to the longitudinal direction of each column 31x. Accordingly, the molded part 1x is formed by the cutting, melting, and cooling steps, as described in the example above, into a mushroom-headed surface zipper. Each engagement element of the surface zipper has an engagement area with a spherical segment shape.

[0049] The present invention is not limited to the embodiment described above, but can be suitably modified without departing from its core. For example, the engagement elements 31, which form the adjacent rows of engagement elements 31L, are arranged in a zigzag pattern in the engagement element group 3 of the embodiment described above, but the present invention is not limited to this arrangement. In the present invention, the engagement elements 31 can be arranged vertically and horizontally at equal intervals.

[0050] In each engagement element of the aforementioned embodiment, the engagement surface projects from the outer circumference of the column body area over its entire circumference in the circumferential direction, but the present invention is not limited to the engagement surface being formed over the entire circumference. For example, the engagement surface can project from only a portion of the entire outer circumference of the column body area. More precisely, the engagement elements, as shown in the Fig. 1, Fig. 2 and Fig. 3 of US Patent No. 6,678,924, depicted, having an engagement surface only in a part of the circumference of the column body area, which has a cruciform cross-sectional shape, but not over the entire circumference, by forming a column such that it has a cruciform cross-sectional shape, cutting a central area of ​​the column and then thermally melting the cut cross-section.

Claims

[1] Manufacturing process for a surface zipper with: an injection molding step in which injection molding is carried out to form a molded part (1x) in which a pillar group (3x), which is a set of a plurality of pillars (31x), and a base plate (2) having a surface from which the pillar group (3x) protrudes, are integrated into a unitary body; a step of receiving the molded part (1x) in a space formed between a lower template (51) and an upper template (52) of a template (5), wherein a tip portion of the column group (3x) protrudes upward from the upper template (52); a cutting step in which the tip portion of the column group (3x) is cut off by sliding an edge of a cutter (C) over an upper surface of the upper template (52) to form a cut product (1y) in which a group of small columns (3y) shorter than the column group (3x) and the base plate (2) are integrated into a unitary body; a step of removing the cut product (1y) from the template (5); a melting step in which a tip portion of the small column group (3y) is melted to form column body portions (31a) which are non-melted portions and engagement portions (31b) which are melted portions and which are thicker than the column body portions (31a) of the small columns (31y) constituting the small column groups (3y); and a cooling step in which the engaging portions (31b) are cooled to determine shapes of a plurality of engaging elements (31) including the column body portions (31a) and the engaging portions (31b), thereby forming a surface slide fastener (1) in which an engaging element group (3), which is a set of the plurality of engaging elements (31), and the base plate (2) are integrated into a unitary body. [2] A manufacturing method for a surface slide fastener according to claim 1, wherein the melting step comprises disposing a heater (6) with respect to the tip portion of the small column group (3y) in a non-contact state. [3] A manufacturing method for a panel slide fastener according to claim 1 or 2, wherein each of the engaging portions (31b) includes an engaging surface (31c) projecting from a tip of the respective column body portion (31a) in its circumferential direction over the entire circumference. [4] A manufacturing method for a surface slide fastener according to claim 3, wherein an intersection angle (θ) between the engaging surface (31c) and a side surface of each column body portion (31a) is greater than or equal to 90° and less than 150°. [5] A surface slide fastener comprising a base plate (2) and an engaging element group (3) which are integrally formed by injection molding, using a mold (4) having a fixed mold (41) and a movable mold (42) which are designed to be opened and closed relative to each other in a vertical direction, wherein the engagement element group (3) comprises a plurality of engagement elements (31) projecting from a plurality of positions on a surface of the base plate (2) in the thickness direction thereof, wherein each of the engagement elements (31) has a layered structure consisting of resin layers extending from the interior of the base plate (2) and comprising a columnar body portion (31a) projecting from one surface of the base plate (2) in its thickness direction and a spherical segment-shaped engagement portion (31b) having an engagement surface (31c) projecting from an outer periphery of a tip of the columnar body portion (31) over the entire circumference, and wherein the resin layers in the column body portion (31a) are formed in parallel along a length direction of the column body portion (31), and wherein the resin layers in the engagement portion (31b) extend radially from the tip of the column body portion (31a), and the resin layers are layered in a circumferential direction in a cross section.

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