Rubber Compression Molding
Compression molding is much like waffle making. The uncured rubber material is put in the molding press just like batter is poured into a waffle press. In both cases, the pressure and heat process the raw material into the finished product.
Compression molding is the most original method to manufacture rubber parts. It can produce a great range of products. The end products can be as small as 0.024 inches and as large as 30 inches in diameter.
Quick links to Rubber Compression Molding Information
Rubber Compression Molding Process
In compression molding, a hardened and stiff raw rubber is cured with heat and high pressure into a useful rubber part. It is a relatively simple process. The products manufactured by curing rubber are used in multiple industries and machinery. The process in detail is as follows:
- It starts with a piece of vulcanized rubber of desired shape and size. The shape and size are set according to the final product. The rubber part at this point of the process is called a preform.
- The preform is then put into the cavity of a mold. The mold is then closed.
- High heat and pressure in the mold press cause the preform to melt and flow into the mold cavity and acquire the shape.
- The cycle time can be adjusted for different materials used and end products.
- As the rubber part is cured, it is removed from the mold cavity for the next product cycle.
Rubber Compression Molding Equipment
Compression molding is a cost-effective process to mold rubbers because of the equipment and materials used. It is readily available and inexpensive.
Tools Required for Compression Molding:
- Checking Gauge
- Used to check the standard of the product.
- Molds and Mold Cavity
- Used to form the rubber into a desired shape and size.
Some may use fixtures to keep the workpiece in a particular position or orientation.
- Jigging
- Used to keep the tools in place.
- Molding Press
- Used to apply pressure and generate enough heat for the process.
Other tools may be needed to accomplish the job; for example, dies, punches, a hydraulic press etc.
Advantages of Rubber Compression Molding
The following are some of the advantages of using compression molding instead of other molding processes:
- It is a straightforward process to execute.
- The tooling and equipment required are very inexpensive.
- It is ideal to mold large parts and especially the parts which are thick in diameter.
- This method is a very economical choice for multi-color molds and insert molding.
- It has little tooling and set-up costs; hence it is very cost-effective for small to medium scale production runs.
Things to Consider When Choosing Compression Molding
When deciding on the type of molding technique, there are several aspects to consider. For that, you should ask yourself these questions:
- What is the size, shape, and orientation of your part?
- Which materials will you be using?
- How much does your piece weigh?
- How much volume do you need to produce, and in how much time?
Application of Molded Rubber Products
Molded rubber products offer utility in diverse fields. For example, medical facilities, the automobile industry, manufacturers using heavy machinery, precision mechanics, etc.
These are essential because they significantly reduce stress on equipment, minimizing the wear and tear in machines. This prolongs the life of expensive machines. Here are some examples of the molded rubber products:
- Self-Adhesive Bumpers
- Grommets
- Anti-Vibration Pads
- O-Rings
- Suction Cups
- Vacuum Lifters
- Compressor Mounts
- Extrusions
- Tubings