Surface Bubbles/Voids on the Product

Spherical or elliptical voids appear on the surface layer and inside of the casting liquid. This defect is usually discovered after the product is demolded or during cross-section inspection, and is mostly concentrated in thick-walled areas or at the end of resin flow. This defect affects the appearance quality of the product and reduces the market competitiveness of the product.

(1) In terms of the mixing process: air is entrapped during resin mixing and stirring and is not fully degassed, uneven mixing leads to inconsistent reactions or performance in various regions. (2) In terms of the mold: or poor degassing of the mold surface, the mold structure or condition directly affects the flow and molding of the material in the cavity. (3) In terms of materials: the volatile content or moisture in the raw materials exceeds the standard, vaporizing at molding temperatures to form bubble sources. (4) In terms of the process: air is entrained during filling or pouring, and venting/degassing measures are insufficient. (5) In terms of the mold: the cavity venting structure design is unreasonable, and gas cannot be effectively discharged.

(1) Process optimization: extend the vacuum degassing time until bubbles are completely eliminated, determine a reasonable time based on product wall thickness and material characteristics, balancing production efficiency and quality. (2) Process strengthening: increase the degassing vacuum degree, increase the vacuum degree and ensure sufficient treatment time, and proceed to the next process only after confirming that bubbles are completely eliminated. (3) Formula adjustment: reduce the stirring speed to reduce vortices, adjust gradually and verify the effect, ensuring that other performance indicators of the product are not affected. (4) Formula adjustment: adopt bottom feeding to reduce air entrapment., adjust gradually and verify the effect, ensuring that other performance indicators of the product are not affected. (5) Preventive measures: establish a complete process control standard and quality inspection system, and regularly review process data for continuous optimization.

The essence of this problem is that gas is not effectively removed during the casting '2079851475616104453, and it needs to be solved collaboratively from three aspects: degassing process, casting method, and venting design.