The present invention relates to a method of manufacturing a hook-and-loop fastener which is integrally molded by injection molding and a hook-and-loop fastener.
As an example of a hook-and-loop fastener, there is a hook-and-loop fastener in which a base plate and plural engaging elements protruding from one surface of the base plate are integrally molded. There are various types of engaging elements and an example thereof is an engaging element called mushroom in that the engaging element has the similar shape as a mushroom.
As an example of a method of manufacturing the hook-and-loop fastener according to the related art including mushroom engaging elements, there is a method using a base mold for molding a base plate, a head mold for molding heads of mushrooms, and a destructively-detachable leg mold for molding pillar-shaped legs of mushrooms (Patent Document 1). In this manufacturing method, after injection molding is carried out using the molds, the destructively-detachable legs are melted with, for example, water to move the base mold and the head mold in a direction in which both are separated from each other to enable mold opening.
However, in the above-mentioned manufacturing method, a material other than a resin which is a molding material is essentially required for the destructively-detachable leg mold. In addition, it is necessary to consider how to dispose of the destructively-detachable legs melted with water after the molding.
It is therefore an object of the present invention to provide a hook-and-loop fastener manufacturing method and a hook-and-loop fastener in which a material other than a molding material does not have to be used as much as possible.
A hook-and-loop fastener manufacturing method according to an aspect of the embodiments of the present invention includes (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 of performing injection molding to form a molded product in which a pillar group which is a set of plural pillars and a base plate having a surface from which the pillar group protrudes are integrated into a unified body.
(2) The cutting step is a step of cutting a tip part of the pillar group to form a cut product in which a small pillar group which is shorter than the pillar group and the base plate are integrated into a unified body.
(3) The melting step is a step of melting a tip part of the small pillar group to form pillar body portions which are non-melted portions and engaging portions which are melted portions and which are thicker than the pillar body portions from small pillars constituting the small pillar group.
(4) The cooling step is a step of cooling the engaging portions to determine shapes of a plurality of engaging elements including the pillar body portions and the engaging portions, thereby forming a hook-and-loop fastener in which an engaging element group which is a set of the engaging elements and the base plate are integrated into a unified body.
In the melting step, it does not matter whether a heater as a heat source for melting the tip part of the small pillar group comes in contact with the small pillar group. When the heater comes in contact with the small pillar group, molten resin may be attached to the heater and may serve as a cause of defective products. Therefore, it is preferable that the melting step be as follows.
That is, the melting step includes arranging a heater with respect to the tip part of the small pillar group in a non-contact state.
It is preferable that an engaging portion of each engaging element of the hook-and-loop fastener manufactured according to this embodiment be as follows.
That is, each of the engaging portions includes an engaging face protruding outward from a tip of the respective pillar body portions over the whole circumference in a circumferential direction thereof.
An intersection angle between the engaging face and a side surface of the pillar body portion does not matter particularly, but is preferably as follows.
That is, an intersection angle between the engaging face and a side surface of the respective pillar body portions is equal to or greater than 90° and less than 150°.
A hook-and-loop fastener according to another aspect of the embodiments of the present invention includes a base plate and an engaging element group which are integrally molded by injection molding. The engaging element group includes plural engaging elements protruding from plural positions on one surface of the base plate in a thickness direction thereof. Each of the engaging elements has a laminated structure comprised of resin layers extending from the inside of the base plate, and includes a pillar body portion protruding from the one surface of the base plate in the thickness direction thereof and a semispherical engaging portion having an engaging face protruding from an outer circumference of a tip of the pillar body portion over the whole circumference. In the pillar body portion, the resin layers are formed in parallel along a length direction of the pillar body portion and in the engaging portion, the resin layers are formed radially from the tip of the pillar body portion.
In the hook-and-loop fastener manufacturing method according to the aspect of the embodiments of the present invention, a material other than a resin as the molding material does not have to be used essentially. Since the cut tip part of the pillar group can be collected and reused, it is possible to easily dispose of undesired substance which is generated in the manufacturing course.
By setting the heater not to come in contact with the small pillar group in the melting step, it is possible to reduce the cause of defective products.
The hook-and-loop fastener according to another aspect of the embodiments of the present invention has a configuration in which each engaging element is formed by laminating resin layers extending from the inside of the base plate and is manufactured by the hook-and-loop fastener manufacturing method according to the aspect of the embodiments of the present invention.
In the accompanying drawings:
An example of a hook-and-loop fastener 1 which is manufactured according to the present invention is a mushroom hook-and-loop fastener as illustrated in
The hook-and-loop fastener 1 according to the present invention is used, for example, as a male hook-and-loop fastener. In a more specific example, when two hook-and-loop fasteners engaging with each other are constituted by male and female hook-and-loop fasteners, the male hook-and-loop fastener may be constituted by the hook-and-loop fastener 1 according to the present invention and the female hook-and-loop fastener may be constituted by a hook-and-loop fastener in which plural loops as engaging elements protrude from a woven or knitted base fabric. When two hook-and-loop fasteners engaging with each other are constituted by male hook-and-loop fasteners, both of the two male hook-and-loop fasteners may be constituted by the hook-and-loop fastener 1 according to the present invention, or only one of the two male hook-and-loop fasteners may be constituted by the hook-and-loop fastener 1 according to the present invention and the other hook-and-loop fastener may be constituted by a hook-and-loop fastener manufactured using a manufacturing method other than the manufacturing method according to the present invention.
The base plate 2 is a plate as a base from which the engaging element group 3 protrudes and both surfaces in the thickness direction thereof are planar and are parallel to each other in this embodiment. Here, the shape and the thickness of the base plate 2 are not particularly limited in the present invention.
The engaging element group 3 includes plural engaging elements 31 protruding from plural positions on one surface of the base plate 2. The engaging element group 3 includes plural engaging elements 31 which are regularly arranged. In the drawings, the engaging element group 3 includes plural engaging element lines 31L each having plural engaging elements 31 arranged in a line and the plural engaging element lines 31L are arranged at equal intervals in a direction perpendicular to the extending direction of the lines. More specifically, in each engaging element line 31L, plural engaging elements 31 are arranged in a line at equal intervals. Regarding a relationship between neighboring engaging element lines 31L and 31L, one of plural engaging elements 31 and 31 constituting one engaging element line 31L is disposed between neighboring engaging elements 31 and 31 in the other engaging element line 31L. In other words, the neighboring engaging element lines 31L and 31L have a relationship in which the engaging elements 31 are arranged in a zigzag manner.
Each engaging element 31 includes a pillar body portion 31a and an engaging portion 31b protruding from the tip of the pillar body portion 31a. More specifically, in the drawing, each engaging element 31 includes a pillar body portion 31a having a cylindrical shape and an engaging portion 31b having a semispherical shape. In the present invention, the shape of the pillar body portion 31a is not particularly limited to the cylindrical shape and may be other shapes such as a prism shape, and, for example, the cross-section of the prism shape may be triangular, quadrangular, pentagonal, hexagonal, or other polygonal.
The engaging portion 31b has a shape in which a circular surface which is a bottom surface 31c of the semispherical shape is continuous from the tip surface of the pillar body portion 31a. When viewed in the extending direction of the pillar body portion 31a, as illustrated in the enlarged part of a one-dot chained line in
As illustrated in
As illustrated in
For example, as illustrated in
The molded product 1x formed through the injection molding step includes the base plate 2 and the pillar group 3x as described above. The pillar group 3x includes plural pillars 31x which are regularly arranged on one surface of the base plate 2 in the same arrangement as in the engaging element group 3.
The resin layers can be considered to indicate a flow of molten resin injected in the injection molding step. The molded product 1x illustrated in
The cutting step uses a jig 5, for example, as illustrated in
The reception opening 51a having a size slightly larger than the size of the base plate 2 is formed on the top surface of the lower jig 51. The depth of the reception opening 51a is set to be greater than the thickness of the base plate 2 and is set to be less than the total height of the molded product 1x (the sum of the thickness of the base plate 2 and the total height of the pillar 31x).
The upper jig 52 is a flat plate having substantially the same size as the size of the base plate 2, and the thickness thereof is set to be less than the total height of the pillar 31x such that the hole group 52a including plural holes 52b into which the pillars 31x of the pillar group 3x are inserted penetrate the upper jig 52 in the thickness direction thereof.
As illustrated in
As illustrated in
The melting step uses a heater 6 as illustrated in
In the cooling step, by cooling the engaging portions 31b which are at a high temperature immediately after the melting step, the engaging portions 31b are solidified and the shape of the engaging elements 31 each including the pillar body portion 31a and the engaging portion 31b is determined, thereby forming a mushroom hook-and-loop fastener 1. In the cooling step, the engaging portions 31b may be forcibly cooled by wind from a fan or the engaging portions 31b may be cooled naturally by leaving the engaging portions for a predetermined time.
In the above-mentioned example of the manufacturing method according to the present invention, a material other than the resin as the molding material does not have to be used essentially. The tip parts of the pillar group 3x hardly include impurities other than the molding material and thus can be collected and reused, and undesired substance which is generated in the manufacturing course can be easily disposed of. Since the heater 6 is disposed in a non-contact state with the small pillar group 3y, it is possible to reduce a cause of defective products.
In the above-mentioned example of the manufacturing method according to the present invention, the engaging elements 31 constituting the engaging element group 3 have an engaging portion 31b having a less-distorted semispherical shape.
As can be seen from the comparative example, in order to acquire an engaging portion 31b having an ideal semispherical shape as in the example of the hook-and-loop fastener according to the present invention, it is important that the resin layers are substantially parallel to each other along the length direction of the pillar 31x in the tip portion of the melted small pillar 31y. Since the outer layer of the resin layers forms the bottom surface 31c of the engaging portion 31b and the vicinity thereof, at least the outer layer preferably has a shape which is substantially parallel to the length direction of the pillar 31x over the whole outer circumference of the pillar 31x, and the inner layers of the resin layers are not particularly limited.
Another example of the method of manufacturing the hook-and-loop fastener 1 according to the present invention is different from the above-mentioned example in only the injection molding step as illustrated in
In the example illustrated in
In the example illustrated in
In the example illustrated in
The third drum 73 is disposed to be rotatable about the center of the cylindrical surface thereof. The third drum 73 has cavities 73a formed to form the pillars 31x similarly to the second drum 72.
The tip surface of the nozzle 7 is formed as a curved surface which is concave in an arc-like sectional shape. The curved surface is a surface having an arc-like sectional shape of which the diameter is larger than that of the third drum 73. The nozzle 7 is disposed with a gap from the cylindrical surface of the third drum 73 such that the center of the arc of the curved surface matches the center of the third drum 73.
In the example illustrated in
In the internal structure of the molded product 1x obtained through the injection molding step illustrated in
The present invention is not limited to the above-mentioned embodiment, but can be appropriately modified without departing from the gist thereof. For example, in the engaging element group 3 of the above-mentioned embodiment, the engaging elements 31 constituting the neighboring engaging element lines 31L are arranged in a zigzag manner, but the present invention is not limited to this configuration. In the present invention, the engaging elements 31 may be arranged at equal intervals vertically and horizontally.
In each engaging element of the above-mentioned embodiment, the engaging face protrudes from the outer circumference of the pillar body portion over the whole circumference in the circumferential direction, but the present invention is not limited to the engaging face formed over the whole circumference. For example, the engaging face may protrude from only a part of the whole outer circumference of the pillar body portion. More specifically, as illustrated in FIGS. 1, 2, and 3 of U.S. Pat. No. 6,678,924, the engaging element may have an engaging face in only a part of the circumference of the pillar body portion having a cross-like sectional shape, not the whole circumference, by forming a pillar to have a cross-like sectional shape, cutting an intermediate portion of the pillar, and then thermally melting the cut cross-section.
Number | Date | Country | Kind |
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2014-227050 | Nov 2014 | JP | national |
The present application is a divisional application of U.S. application Ser. No. 14/926,317, filed on Oct. 29, 2015 which claims priority of Japanese Patent Application No. 2014-227050, filed on Nov. 7, 2014 and entitled “Hook-and-Loop Fastener Manufacturing Method and Hook-and-Loop Fastener”, the entire contents of which are hereby incorporated by reference.
Number | Date | Country | |
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Parent | 14926317 | Oct 2015 | US |
Child | 16175909 | US |