Molding method of molded surface fastener, molded surface fastener manufactured by the method, and molding apparatus thereof

Abstract

Molten resin material is continuously extruded from a first extruding hole extending in a width direction of a first extruding nozzle, and is passed through a second extruding nozzle which is arranged a front surface of the first extruding nozzle and has a second extruding hole at a position corresponding to the first extruding hole. The second extruding hole is a single extruding hole having a plurality of longitudinal rectangular openings arranged at the same pitch in the width direction, and a communicating section with which one end of the respective rectangular openings communicate, and the first extruding hole is a single extruding hole having coupling-element-molding openings arranged corresponding to the rectangular openings and a base-member-molding opening corresponding to the communicating section. Then, by relatively vibrating the first extruding nozzle and second extruding nozzle in the width direction so that the confronting extruding holes may mutually cross, a surface fastener is continuously molded, while individually molding the coupling element having a coupling head portion projecting forward and backward in a molding direction from one end of a stem portion standing on a surface of a sheet-like base member. At this time, each coupling element is approximately shaped like a parallelogram in its plan view.

What is claimed:  
     
         1 . A molding method of a molded surface fastener for continuously and integrally molding a sheet-like base member and a multiplicity of coupling elements, comprising the steps of: 
 (a) continuously extruding molten resin material from a first extruding hole extending in a width direction of a first extruding nozzle arranged on the downstream side in an extruding direction of the molten resin material via an extruding die of an extruding machine;    (b) passing the molten resin material extruded from the first extruding nozzle through a second extruding nozzle which is arranged at a front surface of the first extruding nozzle and has a second extruding hole corresponding to the first extruding hole; and    (c) relatively vibrating the first extruding nozzle and the second extruding nozzle in the width direction in such a way that the respective extruding holes facing each other mutually cross,    wherein one of the first extruding hole and the second extruding hole includes a plurality of longitudinal rectangular openings arranged in the width direction, and the other extruding hole has coupling-element-molding openings arranged so as to correspond to the rectangular openings.    
     
     
         2 . A molding method according to  claim 1 , wherein the first extruding hole has the coupling-element-molding openings, and the second extruding hole has the longitudinal rectangular openings, and a periphery of each of the longitudinal rectangular openings is formed to have a tapered surface gradually enlarged toward the downstream side in the extruding direction, and that the second extruding nozzle is vibrated on the front surface of the first extruding nozzle.  
     
     
         3 . A molding method according to  claim 1 , wherein the first extruding hole has the longitudinal rectangular openings, and the second extruding hole has the coupling-element-molding openings, and a periphery of the coupling-element-molding opening is formed to have a tapered surface gradually enlarged toward the downstream side in the extruding direction, and the second extruding nozzle is vibrated at the front surface of the first extruding nozzle.  
     
     
         4 . A molding method according to  claim 1 , wherein the first extruding nozzle and the second extruding nozzle in series are in close contact with the extruding die, and the molten resin material is directly extruded to the first extruding nozzle from the extruding machine.  
     
     
         5 . A molding method according to  claim 1 , further including the step of cooling the molten resin molding material which has passed through the second extruding nozzle.  
     
     
         6 . A molding method according to  claim 1 , further including the steps of: extruding the molten resin material from the extruding machine on a peripheral surface of a cooling cylinder rotating in one direction so as to mold a sheet-like molten resin layer on the peripheral surface; and introducing the sheet-like molten resin layer into the first and second extruding nozzles arranged facing the cooling cylinder on a downstream side of the molten resin layer.  
     
     
         7 . A molding method according to  claim 6 , further including the step of molding a plurality of anchor members integrally on opposite edge portions of the sheet-like base member where the coupling elements are not molded, by anchor-member-molding cavities formed on the cooling cylinder at right and left periphery portions in the axial direction thereof.  
     
     
         8 . A molding method according to  claim 1 , wherein each of the coupling-element-molding openings of one of the extruding holes is shaped approximately like T.  
     
     
         9 . A molding method according to  claim 1 , wherein each of the coupling-element-molding openings of one of the extruding holes is shaped approximately like Y.  
     
     
         10 . A molding method according to  claim 1 , wherein a tip of each head-portion-molding openings in the coupling-element-molding openings of one of the extruding holes is bent toward a base-member-molding opening.  
     
     
         11 . A molding method according to  claim 1 , wherein a vibration speed in said vibrating step is regularly changed.  
     
     
         12 . A molding method according to  claim 1 , wherein a vibration speed in said vibrating step is randomly changed.  
     
     
         13 . A molding method according to  claim 1 , wherein at least one of the coupling-element-molding openings among a plurality of coupling-element-molding openings arranged laterally side by side, are different from the other coupling-element-molding openings in height.  
     
     
         14 . A molded surface fastener having a sheet-like base member and a multiplicity of coupling elements continuously and integrally molded by the molding methods according to  claims 1  to  3 , wherein each of the coupling elements has a stem portion standing on a surface of the sheet-like base member and a coupling head portion projecting substantially forward in a molding direction from an end of the stem portion, and the coupling head portion has approximately a parallelogram cross sectional shape in its plan view, with long sides extending at a certain angle θ with respect to a molding direction, and each pair of the coupling elements mutually adjacently arranged in the molding direction assumes a mirror symmetrical form.  
     
     
         15 . A molded surface fastener according to  claim 14 , wherein said certain angle θ is 0°, and axes in projecting directions of the coupling head portions arranged in lines in the molding direction are on the same straight line.  
     
     
         16 . A molded surface fastener according to  claim 14 , wherein said certain angle θ is within range of 0°<θ≦90°, and an axis in a projecting direction of the coupling head portion extends at said angle with respect to a straight line connecting centers of the respective stem portions.  
     
     
         17 . A molded surface fastener according to  claim 14 , wherein a vertical cross section of the coupling element is approximately shaped like T.  
     
     
         18 . A molded surface fastener according to  claim 14 , wherein a vertical cross section of the coupling element is approximately shaped like Y.  
     
     
         19 . A molded surface fastener according to any one of claims  14 ,  17 ,  18 , wherein a tip of each coupling head portion is bent toward a surface of the base member.  
     
     
         20 . A molded surface fastener according to  claim 14 , wherein thickness of each stem portion in the molding direction thereof and a projecting length of each coupling head portion of the coupling elements, which are mutually adjacently arranged in the molding direction, are regularly changed in the molding direction.  
     
     
         21 . A molded surface fastener according to  claim 14 , wherein thickness of each stem portion in the molding direction thereof and a projecting length of each coupling head portion of the coupling elements, which are mutually adjacently arranged in the molding direction, are randomly changed in the molding direction.  
     
     
         22 . A molded surface fastener according to  claim 14 , wherein heights of the coupling elements from the base member to the top thereof, which are mutually adjacently arranged perpendicularly to the molding direction, are different.  
     
     
         23 . A molding apparatus of a molded surface fastener for molding a sheet-like base member and a multiplicity of coupling elements integrally by continuous molding, said apparatus comprises: 
 (a) a first extruding nozzle having a first extruding hole extending in a width direction thereof;    (b) a second extruding nozzle arranged at the front surface of the first extruding nozzle and having a second extruding hole corresponding to the first extruding hole;    (c) a vibrating means for relatively vibrating the first extruding nozzle and the second extruding nozzle in the width direction so that the corresponding extruding holes may mutually cross;    wherein one of the first extruding hole and the second extruding hole is an extruding hole including a plurality of longitudinal rectangular openings arranged in the width direction, the other extruding hole has a plurality of coupling-element-molding openings arranged corresponding to the rectangular openings.    
     
     
         24 . A molding apparatus according to  claim 23 , wherein the vibrating means has a crank mechanism connected to the first extruding nozzle and/or the second extruding nozzle through a link.  
     
     
         25 . A molding apparatus according to  claim 23 , wherein the vibrating means has a cam contact fixed to the first extruding nozzle and/or the second extruding nozzle, and a cam with which the cam contact are in contact.  
     
     
         26 . A molding apparatus according to  claim 23 , wherein the vibrating means has a control means for changing a vibration speed of the vibrating means.  
     
     
         27 . A molding apparatus according to  claim 23 , wherein the first extruding hole has the coupling-element-molding openings, and the second extruding hole has the longitudinal rectangular openings, and the periphery of the longitudinal rectangular opening is formed to have a tapered surface gradually enlarged toward a downstream side of an extruding direction thereof, and the second extruding nozzle is connected to the vibrating means.  
     
     
         28 . A molding apparatus according to  claim 23 , wherein the first extruding hole has the longitudinal rectangular openings, and the second extruding hole has the coupling-element-molding openings, and a periphery of the coupling-element-molding opening is formed to have a tapered surface gradually enlarged toward a downstream side of an extruding direction thereof, and the second extruding nozzle is connected to the vibrating means.  
     
     
         29 . A molding apparatus according to  claim 23 , wherein at least one of a plurality of coupling-element-molding openings arranged side by side laterally is different from the other coupling-element-molding openings in height.  
     
     
         30 . A molding apparatus according to  claim 23 , wherein the first extruding nozzle is arranged in series in a die of an extruding machine, and a cooling means for cooling molten resin molding material extruded from the second extruding nozzle, is arranged in front of the second extruding nozzle.  
     
     
         31 . A molding apparatus according to  claim 30 , wherein the cooling means is a cooling cylinder.  
     
     
         32 . A molding apparatus according to  claim 23 , wherein a cooling cylinder is in confrontation with a die of an extruding machine, and on a downstream side of a rotational direction of the cooling cylinder, the first extruding nozzle and the second extruding nozzle are arranged facing a peripheral surface of the cooling cylinder with a gap approximately equal to thickness of the base member.  
     
     
         33 . A molding apparatus according to  claim 32 , wherein anchor member molding cavities are formed at right and left periphery portions of the cooling cylinder in the axial direction thereof.  
     
     
         34 . A molding apparatus according to  claim 23 , wherein each of the coupling-element-molding openings of the extruding hole is approximately shaped like T.  
     
     
         35 . A molding apparatus according to  claim 23 , wherein each of the coupling-element-molding openings of the extruding hole is approximately shaped like Y.  
     
     
         36 . A molding apparatus according to  claim 23 , wherein a tip portion of a head-portion-molding opening in each coupling-element-molding openings of the extruding hole is bent toward a base-member-molding openings.