Patent ID: 9597823
Date: 2017-03-21
CPC Classifications: A44B,B29C,B29L,Y10T

Claim:
1. An insertion block intended to be disposed in a mould for forming an object to be moulded to form a hook field in one piece with the moulded object, comprising at least one first plate, having on its upper edge at least one cut-out having a shape complementary to a series of hooks and issuing out of the two opposite lateral surfaces of the plate and of its upper edge, and at least two second plates sandwiching the at least one first plate therebetween, to form a cavity having said shape complementary to said series of hooks, delimited by lateral walls formed by the two second plates and issuing out of the upper edge of the first plate via an opening, the plates being clamped together, characterized in that the plates are fixed to each other by a “diffusion bonding” process, and in that there is formed in at least one of the plates at least one auxiliary recess which is intended to form, when the plates are against each other, at least one aeration channel communicating on the one hand with at least one part of the at least one cavity and on the other hand with the exterior of the insertion block formed by the plates disposed one against the other, wherein the aeration channel(s) has/have a stepped cross-section formed by a first part having a small cross-section and a second part having a larger cross-section than the small cross-section, wherein the small cross-section is intended to effect the communication with the head part of the cavity having a shape complementary to the hooks such that air can pass into this cross-section but not thermoplastic material, and the large cross-section permits quick venting of the air which passes from the small cross-section into the large cross-section, itself in contact with the outside.