Bubbles Introduced by Improper Mixing and Stirring

A large amount of air is entrained into the casting liquid during stirring. 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. Internal defects reduce the mechanical strength and density of the product, and have a particularly severe impact on products with pressure-bearing and sealing requirements.

(1) In terms of process speed: too fast a stirring speed forms vortices, speed parameters affect the synchronization of material flow state and reaction progress. (2) In terms of the mixing process: the stirring paddle is positioned too high or not submerged below the liquid surface, uneven mixing leads to inconsistent reactions or performance in various regions. (3) In terms of the mixing process: unreasonable stirrer design, uneven mixing leads to inconsistent reactions or performance in various regions.

(1) Formula adjustment: reduce the stirring speed to the minimum speed that does not produce vortices, adjust gradually and verify the effect, ensuring that other performance indicators of the product are not affected. (2) Material selection: use a vacuum stirring kettle, establish material selection evaluation standards and determine the optimal plan through comparative tests. (3) Formula adjustment: adopt planetary stirring to reduce air entrainment, adjust gradually and verify the effect, ensuring that other performance indicators of the product are not affected. (4) Process strengthening: let stand or vacuum degas after stirring is completed., increase the vacuum degree and ensure sufficient treatment time, and proceed to the next process only after confirming that bubbles are completely eliminated. (5) Preventive measures: establish standardized degassing and casting operating procedures, regularly train operators, and check the first piece of each shift to confirm no bubble defects.

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.