Compression Molding
——Compression Molding is the original production method for molded rubber. It is a useful molding process for forming bulky parts, bellows, grommets, gaskets, seals and O-rings, etc. It is a widely used, efficient, economical production method for many products particularly low production volumes of medium to large parts, materials with a high cost and applications that demand extreme hardness. The process involves compressing preformed rubber in a mold with a press. During the compression process, rubber is forced into the mold cavity to form the final product.
Advantages
Short set-up time, easy to change material's hardness & colors quickly.
02
Compression Molding is the only way to produce silicone products at Marble Colors.
The tolerance can be controlled at 0.02-0.1mm by using good steel material, good located pins, and good mold-making equipment.
Compression Moulding ProsCompression molding is cost economic than rubber transfer molding and LSR injection molding, and the compression molding process is quite simple when compared to LSR injection molding. (It is a low-cost process and can be used for both low & high volume production.)
Material
EPDM, NBR, SBR, NR, Silicone(VMQ), Neoprene(CR), HNBR, XNBR, FKM, FFKM, FVMQ, FLAS, PTFE, PU, ECO, IIR, ACR, etc...
Surface Treatment
With compression molding, we can make surface as matte, texture, common polishing, mirror polish, laser engraving, power coating, printing, segmented colors and mixed colors. You can find effect of different surface treatment from below picture.VRP highly welcome custom surface treatment for silicone rubber parts.
Factors To Consider In Rubber Compression Mold Design
1. Weight
Because heavier molds need more energy, their weight may affect how well a product is produced.
As a result, the mold’s design should work to reduce weight while yet preserving the required structural integrity.
2. Flexibility
The mold design should be adaptable to accommodate various part designs and forms. Applying interchangeable inserts, versatile tooling, or movable mold cavities can accomplish this.
3. Vibration Dampening
Vibration-dampening elements should be incorporated into the mold design to lessen the effect of machine vibration on the quality of the finished product.
The use of shock absorbers or the integration of vibration-absorbing materials can accomplish this.
4. Mechanical Properties
It can make it more likely that the mold will be able to adapt to the physical characteristics of the material and generate high-quality pieces.
This a long side the properties such as strength and hardness.
5. Mechanical Properties
It can make it more likely that the mold will be able to adapt to the physical characteristics of the material and generate high-quality pieces.
This a long side the properties such as strength and hardness.
6. Pressure Required
The mold’s design should consider the force necessary to compress the rubber substance inside the mold chamber appropriately.
7. Thermal Decoupling
To avoid excessive heat transfer between the rubber substance and the mold, the mold design should consider thermal decoupling, which can result in flaws and lower the quality of the finished product,
8. The integration of insulating materials or the usage of cooling channels can accomplish this.