English Abstract

New Bonding Technology for Dissimilar Materials

Kohshi MIOKI
Shinichi HIROTA
POLYPLASTICS CO., LTD., Fuji, Shizuoka, Japan
Nippon Gomu Kyokaishi,(2017),90(5),268-273 General Review in Japanese

Recently, it is increasing that double-shot molding technology using some engineering plastics is required particularly for molding parts such as sensors and connectors in automobile and electronics fields.
There are two major constraints in conventional double molding technology: (1) difference in melting temperature or softening temperature between primary and secondary materials, and (2) compatibility between primary and secondary materials. These limitations are obstacles to adopt double shot molding technology for joining molding parts with similar materials or dissimilar materials.
Joining mechanism of conventional double shot molding is fusing primary material by heat transfer and shear from secondary material flow. By changing from the fusion joining mechanism to use of a physical anchor, we thought it would be possible to overcome the aforementioned constraints and join between even if dissimilar materials.
As a result, we developed a technique that adopted laser etching on surface of primary material to remove resin and expose the glass fibers which then acts as an anchor for the secondary molding material. We named this process AKI-Lock® (Advanced Knitting Integrated Lock) and introduce its various features.

Keywords: Double Molding, Dissimilar Material Joining, Laser Treatment, Physical Anchor, Airtightness