Bemould Plastic News

We will periodically update Bemould's latest updates, sharing our work experience with all the person in need ,and to answer the most common topics and questions that come up when working on new plastic part designs.

Defects -- injection molding of transparent plastic parts

 Sunday, 05 September 2021

[bubble]: water vapor and other gases mainly in the resin cannot be discharged (during mold condensation) or the condensation surface condenses too quickly due to insufficient mold filling to form a "vacuum bubble. Bemould injection mold factory

[crazing]: due to the influence of internal stress anisotropy in the process of mold filling and condensation, the stress generated in the vertical direction makes the resin flow oriented, while the refractive index is different from that of non flow orientation, resulting in flash silk lines. When it expands, cracks may appear in the product. In addition to paying attention to the injection molding process and mold , it is best to anneal the product. If the material can be heated to above 160 ℃ for 3 ~ 5 minutes, and then cooled naturally.) 

[poor surface gloss]: it is mainly due to the large roughness of the mold. On the other hand, it condenses too early, so that the resin can not copy the state of the mold surface. All these make the surface slightly uneven and make the product lose luster. See the table for the overcoming methods. 

[ripple]: it refers to the dense ripple formed from the straight gate as the center. The reason is that the front material has condensed in the mold cavity due to the excessive melt viscosity, and then the material breaks through the condensation surface, resulting in ripple on the surface. See the table for the overcoming methods. 

[white smoke]: black spot: it is mainly formed by the decomposition or deterioration of the barrel resin due to local overheating of the plastic in the barrel.

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