Apple is developing a new injection molding technology to improve the watertight seal of mobile phone housings.
In a U.S. patent application published today, adhesive is placed in pores of an anodized aluminum phone housing. A thermoplastic layer is then insert molded on top of the metal. The plastic and the adhesive are cured simultaneously, improving bond strength.
The pores in the metal are created by etching, laser etching, aggregate blasting, or nano-molding. The pores are at least one micron in depth or width and are irregularly shaped. The plastic can be transparent or decorated with graphics.