Silicone products are widely used in the market, such as silicone buttons, silicone mobile phone cases, silicone key chains, silicone gifts, etc. However, during the production process of silicone products, some defects may occur due to factors such as raw materials and operations. Products, such as bad air bubbles, how do the bad air bubbles in silicone products occur? Is there a way around this?
White bubbles or small white spots appear on the silicone products after molding, which are wind and air traces. It means that the bubbles are bad. After tearing or cutting the bubbles with a knife, you can see that the inside of the bubbles is honeycomb (sponge) and feels soft and sticky. Let’s focus on the solution to the bad bubbles of silicone products?
1. Causes of low vulcanization temperature: The vulcanization temperature is usually set at 160-200 degrees Celsius when the silicone product is formed. The vulcanization temperature of silicone products is low, resulting in bubbles after molding of silicone products
2. The vulcanization time is too short Reason: The length of the vulcanization time determines whether the silicone product can be completely vulcanized. If the vulcanization time is too short, it will not cause the silicone product to become soft after molding, and it is more likely to cause surface air bubbles. Solution: extend the vulcanization time of silicone products.
3. The structure of the mold is unreasonable
Causes: The unreasonable design of the molding mold for silicone products will also cause air bubbles in the molding of silicone products. For example, the arrangement of products in the mold, the way of partitioning, the way of mold parting, and the design of the size of the mold will all cause bad bubbles. Solution: replace the mold
4. Raw material cutting method and discharge method Reasons: The discharge is arranged between the key and the key of the silicone product. At this time, if the pressure is applied, the raw material will flow into the bottom of the key from the side of the key and gradually fill the entire key, so that The internal air overflows the mold with the filling of raw materials Solution: adjust the cutting thickness of raw materials when cutting raw materials to specifications
Solution:
1. Increase high molding temperature
2. Put the empty mold into the machine and heat it for a period of time before operating it. 5. The reason why the vulcanization temperature is too high: when the molding temperature is too high, the silicone material on the surface has already begun to form during the process of mold clamping and pressure, and the air at this time has already begun to form. It’s hard to get out if it’s trapped inside, so it creates forming bubbles.
Solution: The temperature is lowered during molding. 6. Insufficient exhaust causes: After the raw material of silicone products is placed in the molding mold, air will be brought in, and it is impossible for the air to integrate with the raw material of silica gel. If the air is not discharged, It will cause bubbles on the surface of the silicone product after molding. Solution: Open the mold after clamping and pressurizing to facilitate the discharge of air in the mold. This process is exhaust. We need to set the distance and times of mold opening according to different products, which is what we often call the exhaust stroke and the number of exhaust. Usually the exhaust stroke is generally set at 0.6~1.2cm, and the number of exhaust Generally, it is set to 1~3 times. There is no fixed value for the specific setting. It needs to be tested repeatedly according to the structure and size of the product to achieve the best effect. Summary: Bubbles are generated during molding of silicone buttons, which will affect the appearance of the product at least. If bubbles appear on some functional structures, it will affect the function and service life of silicone products. Therefore, when the silicone product factory is molding the silicone product, it is necessary to pay attention to avoiding the occurrence of bad air bubbles in the silicone product, so as to avoid the impact of the bad air bubbles in the silicone product on the factory.
Post time: May-23-2023