Sirmax Group presents GAPP technology at K, for injection molding without welding lines

The presentation of the patent

on Thursday 20 October at 5.00 pm

at stand C69, Hall 8B

Sirmax Group, an Italian company among the first producers in the world of thermoplastic granulates for all sectors of use – automotive, household appliance, power tools and household, electrical, electronic, construction, furniture -, presents at the 2022 edition of K an absolute news: GAPP (Gas-Assisted Push Pull) technology, innovation that allows injection molding of thermoplastic material without weld lines. Through Smart Mold, a university spin-off 50% owned by Sirmax, the group has developed an innovative system that eliminate weld lines in plastic products, significantly increasing their mechanical properties.

Sirmax Group will present GAPP on Thursday 20 October starting from 17.00, at stand C69, Hall 8B; the presentation, with Professor Giovanni Lucchetta of the University of Padua, will be followed by a drink time starting at 5.30 pm.

Specifically, GAPP favors the interpenetration of the weld line flow fronts in such a way as to modify the shape of the interface, promote the interdiffusion between the flow fronts and the realignment of the reinforcing fibers. Weld lines are one of the most critical structural defects in parts obtained by injection molding of fiber-reinforced thermoplastics. At a weld line, the reinforcing fibers adopt an orthogonal orientation with respect to the filling direction, which results in a significant reduction in the strength and rigidity of the molded part, adversely affecting its structural performance.

With GAPP technology, during the packing phase, pressurized nitrogen is used to displace the molten thermoplastic across the weld line interface without leaving any cavity in the molded part. Experimental tests showed that GAPP can increase a weld line strength by 240% for a polypropylene reinforced with 35% short glass fibers, almost reaching the compound nominal resistance.

The GAPP technology is added to the many others that Sirmax Group puts in place to give the end customer a customized product that is increasingly compliant with his needs. A globalized company, Sirmax supplies its products and technology in the same way to all parts of the world, through its 13 factories and its 5 Research & Development centers.