Apr 30, 2020 Viewed: 95 Tag: injection  

Defects often encountered in injection molding of transparent plastic parts

[Bubble]: Water and other gases mainly in the resin cannot be discharged (during the mold condensation process) or due to insufficient filling, the condensation surface condenses too quickly and forms a "vacuum bubble".


[Silver grain]: Due to the anisotropy of internal stress during the filling and condensation process, the stress generated in the vertical direction causes the resin to flow on the orientation, and the non-flow orientation has a different refractive index, resulting in glittering silk patterns. After expansion, the product may crack. In addition to the attention to the injection molding process and mold (see the table, the best product is annealed. For example, the PC material can be heated to more than 160 ℃ for 3 to 5 minutes, and then naturally cooled.)


[Poor surface gloss]: Mainly due to the large roughness of the mold, on the other hand, the premature condensation prevents the resin from copying the surface of the mold, all of which make the surface produce small unevenness and make the product lose its gloss. The method of overcoming is shown in the table.


[Vibration]: refers to the dense corrugations formed from the straight gate. The reason is that the melt viscosity is too large, the front end material has condensed in the cavity, and the material then broke through this condensation surface, causing the surface to tremble.


[White smoke]: Black spots: Mainly caused by plastic in the barrel, due to local overheating, causing the barrel resin to decompose or deteriorate. The method of overcoming is shown in the table. In order to clearly illustrate the measures taken to overcome these deficiencies, a table is provided for your reference.


[Whitening]: haze: mainly caused by dust falling into the raw material in the air or the moisture content of the raw material is too large.






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