OVERMOULDING PROCESS HAVING INTERMEDIATE HEATING STEP This invention is directed at an improved method of overmoulding aimed at reducing cycle times, improve interstitial bonding and reduce interstitial stress in sequential multi shot injection moulding of same or different material combinations, hard- soft overmoulding, application of coatings through injection process, applicable to thin to very thick parts, by way of example moulding of TIR Lens for LED automotive headlamp.

摘要

Abstract A method for manufacture of an overmoulded article made up of at least two parts, so arranged that moulding first part according to parameters that are adapted for fastest possible cycle time without having any regard to temperature required at 5 interface of second part moulding, cooling first part rapidly followed by heating face of the first part by application of heat before the said first part has completely cooled to room temperature, so characterized that at end of heating there exists at least three temperature zones in the first part namely zone 1, zone 2 and zone 3, the zone 1 closest to surface of the first part that was heated, the zone 3 near middle of thickness 10 of the said first part and the zone 2 is inter spaced between the zone 1 and the zone 3, temperature in zone is higher than temperature in the zone 2 and temperature in the zone 3 is higher than temperature in the said zone 2, followed by overmoulding a second layer on the so heated face thereby improving adhesion of second part and minimizing interstitial stress while achieving substantial reduction in overall cycle 15 time. Fig 9B Fig 9C E ~33141 -28 Fig 9D Fig 9E 30 Figure 9 Page 9 of 12