Reasons and solutions for poor molding of silicone products.

Reasons and solutions for poor molding of silicone products. In the production process of silicone products, poor molding directly affects product quality and production efficiency. Common problems include material shortage, bubbles, warping, and lack of gloss on the surface, which often stem from deviations in raw material control, mold design, process parameters, and other aspects.

Shortage problem: dual test of raw materials and molds

1. Core reasons

Insufficient weight of raw materials: The cutting length of the raw materials is too short or the thickness is too thick, making it difficult to fill the mold cavity when flowing.

Mold design defects: excessive clearance between mold fits, unreasonable size of overflow holes, or deviation in raw material discharge position.

Poor flowability of raw materials: Prolonged storage can lead to reduced flowability or insufficient molding pressure.

2. Solution

Optimize raw material management: strictly weigh and control the amount of raw materials used to avoid cutting size deviations; Regularly replace raw materials with reduced liquidity.

Adjust the mold and process:

Reduce the clearance between molds and optimize the size of overflow holes.

Increase the molding pressure to ensure that the rubber material flows fully to the designated position.

Adjust the exhaust frequency and stroke to avoid premature vulcanization that may cause incomplete filling of raw materials.

Bubble Problem: The Art of Balancing Exhaust and Sulfurization

1. Core reasons

Insufficient vulcanization: Insufficient vulcanization time or temperature results in large residual bubbles on the rubber surface.

Gas entrapment: The exhaust design of the mold is unreasonable, or air is mixed into the raw materials.

Poor adhesion: Residual gas in the rubber metal bonding area, which shrinks and forms bubbles when pressurized.

2. Solution

Adjust vulcanization process: extend vulcanization time, increase vulcanization temperature, or adjust formula to accelerate vulcanization speed.

Optimize mold design: increase exhaust frequency, improve exhaust groove and overflow groove to ensure sufficient gas discharge.

Improve the mixing process: increase the temperature of the mixed rubber to avoid gas mixing; Break the bubbles on the rubber material before feeding.

Warping problem: Collaborative control of solidification and cooling

1. Core reasons

Incomplete curing: Insufficient curing conditions or improper molding process result in excessive material shrinkage.

Mold design defects: unreasonable ejection device or uneven cooling.

2. Solution

Optimize curing conditions: extend curing time, increase curing temperature, and ensure complete vulcanization.

Improve mold design: Redesign the ejector device to ensure that the product is evenly cooled before exiting the mold.

Use a shrink fastener: Use a shaper during the curing process to reduce warping and deformation.

Surface Matte: Precise Control of Mold Temperature and Release Agent

1. Core reasons

Abnormal mold temperature: The mold temperature is too high or too low, resulting in insufficient surface glossiness.

Release agent issue: Improper use of release agent or rough mold surface.

2. Solution

Adjust mold temperature: Set the appropriate mold temperature according to product requirements to avoid being too high or too low.

Optimize release agent: Choose the appropriate release agent to improve the surface smoothness of the mold.

Mold treatment: Chrome plating is applied to the surface of the mold to reduce surface roughness.

Other common problems and solutions

1. Matte surface

Reason: The mold temperature is too high or too low.

Solution: Determine the optimal mold temperature range through experiments to ensure stable curing process.

2. Adhesive mold problem

Reason: The surface of the mold is rough, improper use of release agent, or excessive pressing pressure.

Solution: Improve the surface smoothness of the mold, select appropriate release agents, and reduce the pressing pressure appropriately.

3. Mottled surface

Reason: Overheating of the mold caused pigment decomposition.

Solution: Reduce the mold temperature and curing temperature to prevent the pigment from decomposing due to heat.

The solution to the problem of poor molding of silicone products needs to start from multiple dimensions such as raw material control, mold design, and process parameter optimization. In the future, with the advancement of intelligent manufacturing and green manufacturing, the silicone products industry needs to further strengthen standardized management and technological innovation to meet the market's demand for high-quality products.