KR100985906B1 - Method for Making Mushroom-Type Hook Strap and Mushroom-Type Hook Strap Made Thereby - Google Patents

Abstract

Disclosed is a method of making a mushroom hook strap for mechanical tightening. In the first step of the method, a hook strap is formed as a component in which a plurality of hook preforms each have a substantially V-shaped free end. Then, in the second step of the method, the V-shaped free end of each hook preform has a higher filling ratio with the loop strap, a longer life, and a mushroom that can provide a reliable and omni-directional uniform tightening function. It is deformed into a polygonal head by two calendar rolls to form a shaped hook strap.

Mechanical Tightening, Free End, Loop Strap, Hook Strap, Loop, Hook

Description

Method for Making Mushroom-type Hook Strap and Mushroom-type Hook Strap Manufactured by It {Method for Making Mushroom-Type Hook Strap and Mushroom-Type Hook Strap Made Thereby}

The present invention relates generally to a method of manufacturing a hook strap for mechanical tightening, and more particularly, to a method of manufacturing a mushroom hook strap for mechanical tightening and a mushroom hook strap produced thereby.

Hook and loop fasteners are a well-known form of fastening and are widely applied in a variety of applications, such as clothing, hats / caps, and sporting goods, that are required to fasten two items together. Hook-and-loop tightening consists mainly of a hook strap with a plurality of plastic hooks formed thereon and a loop strap with a plurality of fabric loops formed thereon and for filling / disengaging hooks on the hook strap and loops on the loop strap. Fastening / unfastening function is provided.

1 provides a thermoplastic 1 into a plastic extrusion machine 2; Extruding the melted thermoplastic polymer 1 from an extruder into a plurality of die cavities 4 formed in the outer periphery of the forming roller 3; Cooling the forming roller 3 to form a hook strap 7 on which a plurality of standing stems 6 are formed; Stripping of the hook strap from the forming roller 3 by the stripping roller 5; And a free end of the stand to a temperature above the pour point of the thermoplastic reason for shaping the stems with the hook strap and the hook having the desired shape through a nip formed between a pair of shaping rollers. The manufacturing method of the hook strap which generally includes supplying the shape roller which contacts the base which heats the said is.

Figures 2 and 3 show the structure of the two shown mushroom hook straps, respectively, where Figure 2 shows an arrangement of mushroom hooks (Fig. 2b) which are circular heads formed from cylindrical stems (Fig. 2a); FIG. 3 shows an arrangement of mushroom hooks (FIG. 3B) that are elliptical heads formed from square bars (FIG. 3A). Although these two mushroom hooks may both provide some tightening / bearing functionality, they both have defects. For example, when filling the mushroom-shaped hook, the circular head shown in FIG. 2 with the fabric loop on the loop strap, the flat perimeter of the circular head of the hooks cannot provide sufficient clamping force without providing protrusions that can be filled with the fabric loop. Because of the drawbacks, the effective filling rate is relatively low. In addition, mushroom hooks, which are circular heads, can provide effective filling only when the head of the hooks is fully inserted into the fabric loop forming the padlock-shaped filling. However, although this lockup type of fill provides a solid fill, the fabric loops will normally be destroyed by the hooks during the separation operation between the hook strap and the loop strap, and the number of fill / unlock operations will increase. As you increase the percentage of broken loops, the tightening capacity will drop rapidly or even loosen the tightening capacity after several filling / unwinding operations. As a result, the effective life of these round head mushroom hooks is relatively short.

The end of the main centerline of the mushroom hooks that are oval heads shown in FIG. 3 can form an effective filling with the fabric loops and thus provide a higher filling ratio and greater clamping force than the circular head mushroom hooks. However, since these types of hooks can form an effective fill with the fabric loops only at the ends of the main centerline of the elliptical head, effective clamping force is provided only in the direction parallel to the main centerline of the elliptical head. The effective filling into the loop in a direction perpendicular to the main centerline of the oval head is much less than in the parallel direction. In other words, the tightening function provided by this type of hook and loop tightening is not an omnidirectional uniform tightening function but a directional tightening function. Therefore, the filling between this type of oval head, mushroom hooks and loops, may be subject to unintentional loosening if subjected to external influence forces in a certain direction (such as perpendicular to the main centerline of the elliptical head). This type of hooks can cause insufficient reliability problems.

In view of the above disadvantages / problems associated with the mushroom hook straps shown, there is provided a method for the manufacture of mushroom hook straps which can provide a reliable and omni-directional uniform tightening function with a higher filling ratio with the loop straps. There is a need.

It is therefore an object of the present invention to provide a method of making a mushroom hook strap which has a higher filling ratio with loop loops, has a longer life, and can provide a reliable and omni-directional uniform tightening function. This object can be achieved by a mushroom hook strap manufacturing method for mechanical fasteners. This method

The forming roller providing at its outer peripheral surface a plurality of substantially Y-shaped forming cavities and a rotating forming roller provided therein;

Providing an extruder having an extrusion die disposed extruded close to the outer periphery surface of the rotating forming roller having a gap formed therebetween;

Supplying the thermoplastic to the extruder and dissolving the thermoplastic in the extruder to extrude the dissolved thermoplastic into a plurality of substantially Y-shaped molding cavities and through the extrusion die onto the outer periphery surface of the rotational roller;

A plurality of hook preforms are molded thereon, and each preform is formed on a substantially Y-shaped molding cavity and on the outer periphery surface of the rotating forming roller to form a hook strap having a substantially V-shaped free end. Cooling the thermoplastic material with a cooling device in the field;

Removing the hook strap from the forming roller; And

Providing a hook strap through a nip formed between a pair of calendar rolls, wherein the calender rolls contacting the V free ends of the hook preforms form a polygonal head shape with the V free ends of each hook preform. Heating to a temperature above the plastic deformation temperature of the plastic material to deform the mold, thereby forming a mushroom hook having a polygonal head.

According to one aspect of the invention, the inner comprising two crossed arms of the V-shaped free end of the hook preform is parallel to the direction in which the hook strap is fed through the calender rolls.

According to another aspect of the invention, the mushroom hook strap is produced by the method described above.

 Aspects and objects of the present invention other than the above will become apparent by the description of the present specification in conjunction with the accompanying drawings.

For a more complete understanding of the invention and its advantages, reference is made to the following description given in conjunction with the accompanying drawings.

4 and 5, preferred embodiments of the method of the present invention and mushroom hook straps made thereby are described to illustrate the present invention.

4 is a diagram describing an apparatus 10 for producing an inventive mushroom hook strap in accordance with one aspect of the present invention. The apparatus 10 mainly comprises a rotational molding roller 20, an extrusion machine 30, a stripping roll 40 and a pair of calendar rollers 50 and 52. The forming roller 20 includes a plurality of substantially Y-shaped forming cavities 22 formed on its outer peripheral surface and a cooling device (not shown), such as the cooling water circulation system provided herein. The molding extruder 30 includes a dissolution chamber 32 for dissolving the plastic material, which is surrounded by a heating coil 33. The extruding machine 30 also includes a feed tank 34 disposed at one end of the dissolution chamber 32 and an extrusion die 36 operating coupled to the other end of the dissolution chamber 32. The extrusion die 36 is disposed protruding close to the outer periphery surface of the rotary forming roller 20 with a gap formed therebetween. This gap may vary by moving the extrusion die 36 relative to the outer periphery surface of the rotational molding roller 20.

When carrying out the method of the present invention, a thermoplastic (eg polyethylene) is first provided to the feed tank 34 through which the thermoplastic is fed into the extrusion machine 30. The thermoplastic material is dissolved by the heating coil 33 in the dissolution chamber 32 (eg, the temperature in the dissolution chamber is heated to 235 ° C.). The molten thermoplastic is then discharged through the extrusion die 36 onto the outer periphery surface of the rotational molding roller 20 and into a plurality of substantially Y-shaped molding cavities 22. After the thermoplastic material on the outer periphery surface of the rotating forming roller 20 and in the plurality of substantially Y-shaped forming cavities 22 is cooled and solidified by the cooling device of the forming roller 20, the hook strap 60 is formed. A plurality of hook preforms 64 are stripped from the forming roller 20 by a stripping roll 40 and the hook strap 60 is formed as a component on the backing 62 and the backside 62 for the purpose of forming a plurality of hooks. It includes. The hook strap 60 is then fed along a nip formed between calendar rolls 50 and 52.

In the embodiment shown in FIG. 5, each preform 64 is shaped into a polygonal peg (such as a polygonal nail as shown in the figure) and includes a major portion 66 and a substantially V-shaped free end 68. do. In addition, in the embodiment shown in FIG. 5, the plane comprising the crossed arms of the V-shaped free end of the hook preform 64 is in the direction D in which the hook strap 60 is fed along the calender rolls 50 and 52. Parallel

The calender roll 50, which contacts the V-shaped free end of the hook preform 64, is heated and maintained to the plastic deformation temperature of the thermoplastic. For example, when polyethylene is used as the thermoplastic, the calendar roll 50 is heated and maintained to 130 ° C. In addition, the nip is formed between the calender rolls 50 and 52 and this nip is less than the sum of the thickness of the back side 62 and the height of the preform 64 so as to substantially the stem of the hook preform 64. It can be adjusted to be equal to the height of the portion (66). As such, while being fed along the calendar rolls 50 and 52, the V-shaped free end 68 of the preform 64 is plastically shaped as a polygonal planar head 68 ′, as shown in FIG. 5. Will be transformed into

Since the hooks of the hook strap manufactured by the method of the present invention have a polygonal planar head 68 ', a plurality of protrusions may be used to form an effective fill with loops of the loop strap. And therefore higher filling ratios may be provided. Also, since the hooks of the hook strap of the present invention fill the loops of the loop strap with protrusions of the polygonal planar head, the loops will not be damaged during the unwinding operation, thus providing a longer life for the hook strap. In addition, the polygonal planar head of the hooks of the hook strap of the present invention provides protrusions in substantially all directions to fill the fabric loops of the loop strap, so that the hook strap of the present invention has a substantially uniform filling function in all directions. Can provide.

Although the invention has been described above in accordance with its preferred embodiments, this does not mean that the scope of the invention is limited to the specific structure and operational steps described above. Indeed, various modifications and variations exist within the spirit and principles described above. For example, an auxiliary cooling device, such as a cooling fan, can be used to provide additional cooling effect with hook straps on the outer peripheral surface of the forming roller 20 in order to provide additional cooling effect with the forming roller 20 in the diametrically opposite position of the extrusion die 36. Can be placed in relation to

It will be apparent to those skilled in the art that many modifications may be made to the disclosed structures / steps without departing from the scope of the present invention. Accordingly, the spirit of the appended claims includes all such changes and modifications that fall within the spirit and scope of the invention.

1 is a diagram describing an apparatus for manufacturing a traditional hook strap.

2A and 2B are enlarged schematic perspective views showing the structure of one of the mushroom hooks.

3A and 3B are enlarged schematic perspective views showing the structure of other mushroom hooks.

4 shows an apparatus for manufacturing a mushroom hook strap of the invention according to one aspect of the invention;

5 is an enlarged schematic perspective view showing the structure of the hook preform before and after being provided through calendar rolls.

Claims (6)

The forming roller providing at its outer peripheral surface a plurality of substantially Y-shaped forming cavities and a rotating forming roller provided therein; An extruder having an extrusion die which protrudes close to the outer periphery surface of the rotating forming roller and has a gap formed therebetween and which is arranged to be adjustable by moving relative to the rotating forming roller Providing a; Supplying the thermoplastic to the extruder and dissolving the thermoplastic in the extruder to extrude the dissolved thermoplastic into a plurality of substantially Y-shaped molding cavities and through the extrusion die onto the outer periphery surface of the rotational roller; A plurality of hook preforms are molded thereon, and each preform is formed on a substantially Y-shaped molding cavity and on the outer periphery surface of the rotating forming roller to form a hook strap having a substantially V-shaped free end. Cooling the thermoplastic material with a cooling device in the field; Removing the hook strap from the forming roller; And Providing a hook strap through a nip formed between a pair of calendar rolls, wherein the calender rolls contacting the V free ends of the hook preforms have a polygonal plane Heating to a temperature above the plastic deformation temperature of the plastic material to deform into a head shape, thereby forming a mushroom hook having a polygonal head, wherein the polygonal planar head fills the fabric loops of the loop strap. A method of making a mushroom hook strap for mechanical tightening wherein the nip is adjusted to be substantially equal to the height of the stem portion of the hook preform such that the nip is formed to provide protrusions substantially in all directions. The method of claim 1, A method of making a mushroom hook strap for mechanical tightening parallel to the direction in which the hook strap is fed through the calender rolls, the inner comprising two crossed arms of the V free end of the hook preform. delete The method of claim 1, Stripping step is a method of manufacturing a mushroom hook strap for mechanical tightening is performed by a rotary stripping roll. The method of claim 1, A method of making a mushroom hook strap for mechanical tightening, further comprising providing an auxiliary cooling device external to the forming roller to provide additional cooling to the outer peripheral surface of the rotating forming roller. A mushroom hook strap for mechanical tightening having a polygonal planar head that provides protrusions in a substantially forward direction made using the method according to claim 1.

Images