What is the process of LSR injection molding?

The LSR injection molding process, as a high-precision and high-efficiency molding technology in modern manufacturing, is widely used in the production of precision parts that require waterproofing, sealing, and high stability. The core of this process lies in utilizing the unique properties of Liquid Silicone Rubber (LSR) material to achieve product molding and vulcanization through precision injection molding equipment.
1、 Material preparation
The first step in LSR injection molding process is material preparation. Liquid silicone gel is usually divided into two components: A gel and B gel, which need to be mixed in a strict 1:1 ratio. This step is crucial because the accuracy of the ratio directly affects the quality of the subsequent molded products. During the mixing process, a quantitative device is used to accurately control the ratio of the two types of rubber materials, and a static mixer is used for thorough mixing to ensure uniform mixing and no bubbles are introduced into the system.
2、 Measurement and Mixing
The mixed silicone material needs to be accurately measured by a measuring device and fed into the feeding system of the injection molding machine. The measuring device usually includes components such as a measuring pump and a supply bucket, which can ensure that the silicone material maintains a constant pressure and flow rate during transportation. The uniformly mixed silicone material is further mixed in a static mixer to achieve the best molding effect.
3、 Injection molding
Injection molding is the core process of LSR injection molding. At this stage, the mixed silicone material is high-pressure injected into the mold that has been preheated to the appropriate temperature. The design of molds needs to consider the shape, size, and precision requirements of the product to ensure the quality and consistency of the molded product. During the injection molding process, silicone material is subjected to high temperature and pressure in the mold, and begins to undergo vulcanization reaction, gradually solidifying and forming.

4、 Sulfurization and cooling
Sulfurization is a crucial step in the LSR injection molding process. In the mold, silicone material undergoes chemical reactions at high temperatures to form stable cross-linked structures, thereby achieving solidification. The duration of vulcanization depends on factors such as the type of silicone material, mold temperature, and product thickness. After vulcanization is completed, the mold needs to be cooled to reduce the temperature of the product and prevent deformation. During the cooling process, it is necessary to control the cooling rate to avoid internal stress and uneven shrinkage.
5、 Demoulding and post-processing
After the product has cooled to a certain temperature, the demolding operation can be carried out. Be careful and cautious when demolding to avoid damaging the product. After demolding, the product still needs to undergo a series of post-processing procedures, such as removing defects such as burrs and burrs, and conducting visual and dimensional inspections. For certain products with special requirements, further processing and assembly are required.
6、 Quality Control and Testing
The LSR injection molding process has strict requirements for product quality. Throughout the entire production process, multiple processes require quality control and testing. For example, the mold needs to be cleaned and inspected before injection molding; During the injection molding process, it is necessary to monitor parameters such as injection pressure and temperature; After vulcanization, it is necessary to inspect the appearance and dimensions of the product. Through these measures, it can be ensured that the LSR products produced have excellent performance and stable quality.
7、 Automation and Intelligence
With the development of technology, LSR injection molding process is gradually moving towards automation and intelligence. Modern injection molding machines are typically equipped with advanced control systems and sensors that can monitor various parameters in real-time during the production process and make adjustments as needed. At the same time, some high-end injection molding machines also have functions such as intelligent recognition and fault diagnosis, which can greatly improve production efficiency and product quality.
In summary, LSR injection molding process is a complex and sophisticated manufacturing technology. Through precise material preparation, measurement and mixing, injection molding, vulcanization and cooling, demolding and post-treatment, as well as quality control and testing, high-quality and high-precision LSR products can be produced. With the continuous advancement of technology and the continuous improvement of processes, LSR injection molding technology will be widely applied and developed in more fields.