1, Material preparation
The first step in pouring silicone rubber is to prepare the materials. Silicone rubber is usually composed of two components, A and B, which undergo a chemical reaction after mixing to form cured silicone rubber products. During the material preparation process, it is necessary to accurately weigh components A and B according to the formula ratio to ensure uniform mixing and avoid uneven performance or defects after curing. In addition, when preparing materials, attention should be paid to the storage conditions of the raw materials, such as temperature, humidity, etc., to prevent them from deteriorating or getting damp, which may affect the pouring effect.
2, Exhaust gas
Exhaust is one of the key steps in the silicone rubber casting process. After mixing components A and B evenly, they need to be placed in a vacuum tank for exhaust treatment. The main purpose of exhaust is to remove bubbles and volatile substances from the mixture, to ensure that silicone rubber does not have voids or bubbles during the pouring process, thereby affecting the quality and performance of the product. The exhaust time is usually determined based on the viscosity and bubble content of the mixture, and it is generally necessary to maintain a certain degree of vacuum for a period of time to ensure that the bubbles are completely expelled.
3, Pouring
Pouring is the process of injecting the exhausted silicone rubber mixture into a mold. Before pouring, it is necessary to pre treat the mold, such as cleaning, preheating, etc., to ensure that the silicone rubber is completely adhered to the mold surface, avoiding difficulties in demolding or surface defects of the product. During pouring, it is necessary to control the pouring speed and pressure to ensure that the mixture evenly fills the mold cavity, avoiding the occurrence of voids or bubbles. At the same time, attention should be paid to the pouring temperature, as temperatures that are too high or too low can affect the curing speed and performance of silicone rubber. During the pouring process, it is necessary to continuously observe the flow of the mixture in the mold and adjust the pouring parameters in a timely manner to ensure the integrity and quality of the product.
4, Waiting for solidification
After pouring, the silicone rubber mixture needs to wait in the mold for a certain period of time to solidify. Curing is the process of chemical reactions occurring between the molecular chains of silicone rubber to form a stable structure. The length of curing time depends on factors such as the type and formula of silicone rubber, pouring temperature, and the thermal conductivity of the mold. During the curing process, it is necessary to maintain a constant mold temperature to avoid adverse effects of temperature fluctuations on the curing process. At the same time, attention should be paid to pollution factors such as humidity and dust in the curing environment to prevent surface defects or performance degradation of the product.
5, Demoulding and subsequent processing
After curing is completed, the silicone rubber product needs to be removed from the mold, that is, demolded. Attention should be paid to the force and angle during demolding to avoid deformation or damage to the product. After demolding, further processing of the product is required, such as deburring, polishing, cleaning, etc., to improve the surface quality and aesthetics of the product. For certain products with special requirements, such as medical supplies or precision instrument components, stricter inspection and testing are required to ensure compliance with relevant standards and requirements.
6, Quality Control and Precautions
Quality control is crucial in the silicone rubber casting process. From material preparation to curing, every step requires strict control of operating conditions and parameters to ensure the quality and performance of the product. Meanwhile, the following points should also be noted:
Raw material quality: Select high-quality silicone rubber raw materials and adhesives to ensure the purity and stability of the raw materials.
Mold design: Reasonably design molds based on the shape and size of the product to ensure the accuracy and durability of the mold.
Operating environment: Keep the pouring environment clean and dry to avoid contamination of the product by dust and moisture.
Equipment maintenance: Regularly maintain and upkeep the pouring equipment to ensure its normal operation and accuracy.
Personnel training: Provide professional training to operators to improve their operational skills and quality awareness.
