How to solve the problem of bubbles in silicone injection molded products?

During the production process of silicone injection molded products, occasional problems with bubbles appearing inside or on the surface of the product may occur. This not only affects the appearance quality of the product, but may also have adverse effects on its performance and service life. Therefore, mastering the solution to bubbles in silicone injection molded products is of great significance for improving product quality and production efficiency. This article will explore in detail the solutions to bubbles in silicone injection molded products from three aspects: the causes of bubble formation, measures to prevent bubble formation, and treatment methods after bubble formation.
1、 The causes of bubble formation
There are various reasons for the formation of bubbles in silicone injection molded products, mainly including the following aspects:
1. Material issue: The silicone raw material may contain impurities such as moisture and volatile substances, which are prone to volatilization and produce gas at high temperatures, thus forming bubbles. In addition, prolonged or improper storage of silicone raw materials may also lead to the deterioration of the materials and the generation of bubbles.
2. Injection molding process issue: Improper setting of parameters such as temperature, pressure, and speed during the injection molding process can easily lead to uneven filling of silicone in the mold or the formation of air bubbles. In addition, unreasonable mold design or defects on the mold surface may also lead to the generation of bubbles.
3. Operational issues: During the injection molding process, if the operation is not standardized or incorrect, such as too fast injection speed, insufficient injection pressure, improper mold temperature control, etc., it may lead to the generation of bubbles.
2、 Measures to prevent bubble formation
To prevent the formation of bubbles in silicone injection molded products, the following measures can be taken:
1. Strictly control the quality of raw materials: Select high-quality silicone raw materials and conduct strict testing and screening before use to ensure that the raw materials do not contain excessive moisture, volatile substances, and other impurities. Meanwhile, pay attention to the storage time and environment of the raw materials to avoid spoilage.
2. Optimize injection molding process parameters: Based on the actual situation of the product and the design characteristics of the mold, set reasonable parameters such as temperature, pressure, and speed during the injection molding process. Ensure that silicone is evenly filled in the mold to avoid air entrapment.
3. Improve mold design: Optimize the flow channel design and exhaust system design of the mold to ensure smooth flow and sufficient exhaust of silicone in the mold. At the same time, pay attention to the smoothness and accuracy of the mold surface to avoid defects on the mold surface that may cause bubbles to form.
4. Standardize operating procedures: Strengthen the training and management of operators to ensure that they can proficiently master injection molding processes and operating skills. During the operation process, strictly follow the process requirements to avoid errors that may cause bubbles.

3、 Treatment methods after bubble generation
If bubbles have already formed in silicone injection molded products, the following measures can be taken for treatment:
1. Repair method: For products with small surface bubbles and fewer quantities, repair method can be used for treatment. Fill and polish the bubble area with silicone material that is similar in color to the product, making it flat and consistent with the surrounding surface. This method is simple and feasible, but its effectiveness is limited and may affect the appearance quality of the product.
2. Rework method: For products with many or large bubbles, rework treatment is required. Put the product back into the mold for secondary injection molding or reprocessing to eliminate bubbles. This method can completely eliminate bubbles, but it is costly and may affect production efficiency.
3. Scrapping treatment: If the bubble problem in the product is severe and cannot be solved through repair or rework, it needs to be scrapped. Although scrapping may cause certain economic losses, it can avoid bringing unqualified products into the market and affecting the reputation of enterprises and consumer interests.
4、 Case analysis
The following is a case analysis of bubble problems in silicone injection molded products:
A silicone product factory encountered bubble problems while producing a silicone button. After inspection, it was found that the raw materials contain too much water and volatile substances, leading to the formation of bubbles. The factory has taken the following measures to address this issue:
1. Strictly screen and test the raw materials to ensure that their quality meets the requirements;
2. Optimize the injection molding process parameters and adjust parameters such as temperature, pressure, and speed to ensure that the silicone gel can be uniformly filled and fully vented in the mold;
3. Improve mold design, optimize flow channel design and exhaust system to ensure smooth flow of silicone and sufficient exhaust;
4. Strengthen the training and management of operators to ensure that they can proficiently master the injection molding process and operating skills.