During the liquid silicone rubber injection molding process, flash, short shots, and bubbles are relatively common process issues. These problems may be related to material viscosity, mold structure, venting design, and injection parameters, and require systematic troubleshooting combined with on-site conditions.

Flash is typically related to mold fit clearance, injection pressure, and material flowability. If the mold parting surface fit is insufficient, or injection pressure is too high, the compound readily overflows from gaps to form flash. Products with lower viscosity have stronger flowability, imposing higher requirements on mold precision and process control. Short shots may be caused by insufficient injection volume, high runner resistance, poor venting, or excessively slow injection speed. For products with complex structures, thin walls, or long runners, focus should be placed on whether the mold filling process is smooth.

Bubble problems are commonly seen in cases of insufficient degassing, excessively fast injection speed, or uneven mold temperature. Liquid silicone rubber may entrain air after mixing; if degassing time is insufficient, bubbles will remain inside the product. Excessively fast injection speed can also cause air entrapment, causing the compound to wrap air during cavity filling. Optimizing vent groove design and adjusting injection speed and holding parameters help reduce bubble defects.

To address the above issues, it is recommended to make coordinated adjustments from both material viscosity and process parameters. Higher-viscosity products are suitable for scenarios requiring reduced flash, but demand higher injection pressure; lower-viscosity products offer better mold filling but require more precise molds and more stable process control. Our company provides liquid silicone rubber products of different viscosity grades and can recommend suitable grades based on customers' mold structures and molding processes.

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