Abstract: A two-shot inverse mould design of mobile phone's case was developed, which was aimed at both pre-clamping system of 1st shot mould and ejection system mounted in stationary half of 2nd shot mould. Both gate mark and ejecting mark were avoided through a process platform. The demolding force of the creative friction locker was calculated against part's shrinkage .The moldflow simulation of the two-shot injection was made and reviewed. The inverse mould had overcome the defect of gas spraying mark emerged in normal sequence of two-shots injection and made the mass molding stable in high quality.

Key words: mobile phones case, two-shot inverse mould, ejection system, design