Silicone products common quality problems and solutions: burrs, bubbles, lack of glue, deformation

Silicone products common quality problems: first look at the phenomenon, and then look for root causes

Many of the defects in silicone parts are related to Mold venting, temperature and time parameters, raw material and mold condition Related. The following is organized by "Phenomenon → Common Causes → Direction of Improvement", so that you can analyze the problem and explain it to the public.

1) Raw edges (flying edges)

Phenomenon: Excessive thin edge at the parting line location.

• Common causes: mold clearance, excessive pressure, mold wear, uneven venting
• Improvement direction: Optimize mold fit and exhaust, control process parameters, and establish mold repair and maintenance mechanism.

2) Bubbles/voids

Phenomenon: Surface bulges or internal voids that affect appearance and strength.

• Common causes: insufficient venting, gas/water content of raw materials, insufficient process time
• Improvement direction: strengthen the exhaust design, optimize the mixing and pretreatment, adjust the vulcanization time.

3) Lack of glue/short shot

Phenomenon: Localized underfill and missing edges.

• Common causes: poor runner/gate design, insufficient temperature, insufficient material fluidity
• Improvement direction: optimize the gate and runner, adjust the temperature and pressure, and do structural optimization if necessary.

4) Deformation / Warping

Phenomenon: Deformation after demolding or after placement, poor assembly.

• Common causes: uneven cooling, improper demolding, material shrinkage and structural asymmetry
• Improvement direction: optimize the mold and process, improve the demolding tooling, and adjust the structure thickness if necessary.

5) Surface strains/scratches

Phenomenon: Exterior surfaces have pull marks or scratches.

• Common causes: mold release friction, poor mold surface condition, assembly or packaging friction
• Improvement direction: optimize the surface treatment of the mold, improve the release and packaging methods

6) Large size fluctuations

Phenomenon: Significant size variation within the same lot or from lot to lot.

• Common causes: raw material batch differences, process parameters drift, mold state changes
• Improvement direction: lock down key parameters, establish first article/walk-through inspection, clarify CTQ size sampling inspection

Advice on communicating quality issues (more customer friendly)

• Describe the phenomena and effects first (appearance/assembly/sealing)
• Give initial range of causes (exhaust/parameters/mold/material)
• Provide verifiable actions (re-inspection, re-testing, trial production comparison)