What is the difference between injection mold design and liquid silicone mold design?

The difference between injection mold design and liquid silicone mold design is not only reflected in material selection and molding process, but also in various aspects of mold design, manufacturing, use, and maintenance.

1、 Material selection and molding process:

Injection mold design mainly uses solid plastic particles as raw materials. These particles melt into a liquid state at high temperatures, and then the molten plastic is injected into the mold cavity through the high pressure of the injection molding machine. After cooling and solidification, the product is formed. The design of injection molds needs to consider factors such as plastic melt flowability, cooling rate, shrinkage rate, etc., to ensure the dimensional accuracy, appearance quality, and physical properties of the product. The design of liquid silicone molds uses pre mixed liquid silicone rubber (LSR), which is a two-component material that is typically mixed and maintained at a specific temperature before injection. LSR has good fluidity, fast vulcanization, excellent tear resistance, resilience, yellowing resistance, and thermal stability. The design of liquid silicone molds requires special attention to the material’s flow characteristics, curing process, and mold temperature control to achieve optimal product quality and production efficiency.

2、 Mold design and manufacturing

Injection mold design typically requires consideration of the flow, cooling, and solidification processes of the melt to ensure uniform cooling and dimensional stability of the product. The structure of injection molds is relatively complex, including mold core, mold cavity, gate, cooling water channel and other components, and the mold material needs to have high strength, high hardness and good wear resistance. The manufacturing process of injection molds includes mold processing, assembly, and debugging, which require high-precision processing equipment and strict manufacturing processes to ensure the accuracy and lifespan of the molds. The design of liquid silicone molds focuses more on the flow characteristics and curing process of the material. Due to the fact that LSR does not shrink in the mold, but usually shrinks after demolding and cooling, the influence of shrinkage rate needs to be considered in mold design to ensure the stability of product dimensions. In addition, the design of liquid silicone molds also needs to pay attention to the temperature control of the mold, usually using electric heating to evenly distribute the temperature field of the entire mold, in order to promote the uniform solidification of LSR. The manufacturing process of liquid silicone molds is relatively simple, but high-precision processing equipment and manufacturing processes are also required to ensure the accuracy and lifespan of the molds.

3、 Mold use and maintenance

During the use of injection molds, it is necessary to regularly clean the surface of the mold and the residue at the sprue to prevent plastic from solidifying inside the mold and causing damage to the mold. At the same time, the cooling water channel of the injection mold needs to be kept unobstructed to ensure uniform cooling of the product. The maintenance of injection molds includes lubrication, rust prevention, regular inspections, etc., to extend the service life of the molds. During the use of liquid silicone molds, it is also necessary to regularly clean the surface of the mold and the residue at the injection point to prevent LSR from solidifying inside the mold and causing damage to the mold. In addition, the temperature control system of the liquid silicone mold needs to be regularly inspected and maintained to ensure the accuracy and stability of the mold temperature. The maintenance of liquid silicone molds also includes cleaning, rust prevention, regular inspections, etc. to extend the service life of the molds.

4、 Product details and complexity

Although injection molding can produce fine details, it may not be able to produce overly complex or intricate geometric shapes due to the characteristics of plastic materials and the design capabilities of molds. Injection molding is more suitable for large-scale production of various plastic products, such as toys, containers, automotive parts, etc. Liquid forming can produce very fine details and complex geometric shapes, thanks to the good flowability and curing properties of LSR. Liquid forming is suitable for manufacturing precision, small, and complex silicone products, such as seals, medical equipment components, etc. Liquid forming has significant advantages in manufacturing complex shapes and fine details, which can meet customers’ high requirements for product accuracy and appearance quality.

5、 Cost and Production Efficiency

Although injection mold design requires high equipment investment, it can reduce the cost per unit of product in long-term production due to its high production efficiency and stable product quality. Injection molding is suitable for large-scale production and can fully utilize the production capacity of equipment to improve production efficiency. Although the equipment investment for liquid silicone mold design is relatively low, it may not have a significant cost advantage due to low production efficiency and significant fluctuations in product quality. However, with the continuous advancement of technology and the continuous improvement of processes, the application of liquid forming in the field of silicone molding is also constantly expanding and innovating. In the future, liquid forming is expected to play an important role in more fields, providing more possibilities for the production and application of silicone products.

6、 Innovation and Development in Mold Design and Manufacturing

With the continuous development of mold design and manufacturing technology, injection mold design and liquid silicone mold design are constantly innovating and improving. Injection mold design is developing towards high precision, high efficiency, and high automation to meet the market’s demand for high-quality plastic products. The design of liquid silicone molds pays more attention to the flow characteristics and curing process of materials, and improves the quality and production efficiency of products by optimizing mold design and manufacturing processes. In addition, with the application of new technologies such as 3D printing and intelligent manufacturing, mold design and manufacturing processes will become more intelligent, automated, and efficient. These new technologies will provide mold designers and engineers with more innovative design ideas and manufacturing methods, promoting the continuous progress and development of mold design and manufacturing technology.