Common problems in the production of phone cases

The following are common problems and solutions in the production of phone cases, analyzed based on the characteristics of different materials and processes:
1、 Defects in injection molding process
Surface issues
Color difference: caused by uneven dispersion of pigments or fluctuations in injection molding temperature.
Silver lines/burnt marks: The raw material contains moisture or the injection molding speed is too fast.
Sharp edges (burrs): The gap between the molds is too large or the locking force is insufficient.
Structural issues
Shrinkage marks: uneven wall thickness or insufficient pressure maintenance, requiring optimization of the cooling system.
Fusion line: Poor fusion of two streams, injection speed needs to be adjusted.

2、 Production issues with silicone shells
Appearance defects
Bubbles/pockmarks: Insufficient sulfurization exhaust or impurities mixed in raw materials.
Scratches: Improper demolding operation or rough mold surface.
Dimensional and hardness deviation
Size deviation: Insufficient mold accuracy or unstable vulcanization time.
Hardness mismatch: incorrect proportion of vulcanizing agent or improper temperature control.

3、 Materials and Health Risks
Poor quality raw materials issue
Recycling plastics: containing plasticizers and heavy metals, long-term exposure can be harmful to health.
Industrial adhesive: Excessive formaldehyde, resulting in a pungent odor.
Dyeing agent risk
Excessive lead: Cheap dyes may cause chronic poisoning.

4、 Other process challenges
TPE encapsulation delamination: Insufficient cleanliness of the substrate surface or mismatched adhesive.
LCP injection molded casing: Improper screw parameter settings or insufficient drying.

Solution suggestions
Mold optimization: Using hard mold steel (such as S136) to improve lifespan.
Process adjustment: Control the injection molding temperature, pressure, and holding time.
Strengthen quality inspection: Regularly detect the content of harmful substances.