Rubber as a material with high elasticity and excellent physical properties, plays an important role in our daily life. From car tires to seals, from medical devices to daily necessities, rubber products are everywhere. So, how are these rubber products made? This article will introduce the 3 Types of Rubber Molding in detail: compression molding, injection molding and transfer molding.
Rubber Compression molding is a traditional rubber molding method suitable for manufacturing rubber products with complex shapes and precise dimensions. In this method, unvulcanized rubber is placed in the mold cavity, and then pressure and temperature are applied to make the rubber flow in the mold and fill various parts of the mold until it is fully vulcanized.
How Rubber Compression Molding Works
The working principle of rubber compression molding is relatively simple. First, the rubber raw material (usually raw rubber or preformed rubber sheets) is placed into the cavity of the mold. Then, the rubber is compressed by mechanical pressure to fill every corner of the mold. Under the action of pressure and temperature, the rubber gradually vulcanizes to form the desired shape and size. Finally, the mold is opened and the molded rubber product is taken out.
Advantages of rubber compression molding
- High precision: Since the rubber is subjected to uniform pressure in the mold, products with precise dimensions can be manufactured.
- Wide applicability: Suitable for various products with complex shapes, such as seals, shock absorbers, etc.
Disadvantages of rubber compression molding
- Low production efficiency: Compared with injection molding, compression molding has lower production efficiency and is not suitable for mass production.
- High labor intensity: Manual operation is required during the operation, which is labor-intensive
Rubber Injection Molding
Rubber Injection molding is a modern rubber molding method, similar to plastic injection molding. It melts the rubber raw material at high temperature and then injects it into the cavity of the closed mold through the screw or plunger of the injection machine.
Working principle of rubber injection molding
The working principle of rubber injection molding is as follows: First, the rubber raw material (usually granular or powdered) is placed in the barrel of the injection machine. Then, the rubber is melted into a fluid state through heating and the rotation of the screw. Next, the molten rubber is injected into the closed mold cavity through the plunger or screw of the injection machine. In the mold, the rubber quickly cools and vulcanizes to form the desired shape and size. Finally, the mold is opened and the molded rubber product is taken out.
Advantages of rubber injection molding
- High production efficiency: It can realize automated production and is suitable for mass production.
- High product precision: Since the rubber is subjected to uniform pressure and temperature in the mold, the product has high dimensional accuracy.
- High material utilization: Injection molding has high material utilization and less waste
Disadvantages of rubber injection molding
- High equipment cost: Injection molding equipment is relatively expensive and the investment cost is high.
- High mold requirements: Precision molds are required and the mold cost is high.
The roots of rubber injection molding lie in the plastics sector. With enhanced precision in rubber manipulation, three key variations have been developed:
- Organic Rubber Injection Molding
- LSR (Liquid Silicone Rubber) Injection Molding
- Thermoplastic Rubber Injection Molding
Let’s delve into each of these specialized techniques.
Rubber Transfer Molding
Rubber Transfer molding is a method between compression molding and injection molding and is suitable for thermosetting rubber.
How rubber transfer molding works
The working principle of rubber transfer molding is as follows: First, the rubber raw material is placed in a container called a barrel. Then, the rubber is pushed into the mold through a transfer system (such as a piston). In the mold, the rubber is subjected to pressure and temperature, gradually vulcanizing to form the desired shape and size. Finally, the mold is opened and the molded rubber product is taken out.
Advantages of rubber transfer molding
- Wide applicability: Suitable for rubber products of medium size and complex shape.
- High product precision: Since the rubber is subjected to uniform pressure and temperature in the mold, the product has high dimensional accuracy.
Disadvantages of rubber transfer molding
- Relatively low production efficiency: Compared with injection molding, transfer molding has low production efficiency.
- High equipment and mold costs: Specific transfer systems and molds are required, which are costly.
Customized Rubber Molding Parts & Molds
Numerous enterprises and producers require distinctive components. As creators develop specialized equipment for particular applications, the challenge is to manufacture these innovations affordably and efficiently. Frequently, the answer lies in customization. This is where tailored rubber injection molding steps in.
Customized Rubber Molds & Parts Manufacturer
Integral to many operations is the precision of rubber molding—not just a temporary fix but a critical component. If you’re in search of tailored solutions or suppliers, we’re at your service. When it comes to bespoke parts, our team of specialists is ready to engage in a streamlined, three-step process:
- Clarify the Specifications: We’ll work with you to define the exact part you require, utilizing any existing blueprints you might have.
- Prototype and Fabricate: We’ll then create and manufacture the custom rubber component you specified.
- Rapid Delivery: Your bespoke part will be dispatched promptly.
We handle the entire process. For all your injection molding and custom rubber part needs, a simple call is all it takes: contact us now to get started and discover more. Visit our website to establish communication and gain further insights.
The three methods of rubber molding each have their own advantages and applicable scenarios. Compression molding is suitable for manufacturing products with complex shapes and precise dimensions, but the production efficiency is low; injection molding has high production efficiency and is suitable for mass production, but the equipment and mold costs are high; transfer molding is between the two and is suitable for products of medium size and complex shapes. Choosing a suitable molding method requires comprehensive consideration of factors such as the specific requirements of the product, production volume, and cost.
In the manufacturing process of rubber products, the choice of molding technology is crucial. Understanding the working principles, advantages and disadvantages of these molding methods can help us better choose the appropriate molding technology, improve production efficiency, reduce costs, and produce better quality rubber products. With the development of science and technology, rubber molding technology is also constantly improving. In the future, there may be more efficient and environmentally friendly molding methods, which will bring more possibilities for the manufacture of rubber products.
