Rubber Molding


Custom Rubber Corp. is a leader in rubber molding parts and products that meet the specifics of our customers' needs. We provide exactly what our name suggests; Custom Rubber products. We have over a 95% customer retention rate and base our entire business on our Mission: Responsiveness ~ From Design To Delivery. Custom Rubber Corp. provides personalized and personal service and assistance every step along the way making the design and purchase of rubber molding parts easy.

Click Here to dowload our rubber molding informational PDF

How Do You Mold Rubber?

There are several different ways to mold rubber, including injection molding, transfer molding and compression molding. Each one involves shaping a raw rubber material into a final product using a mold of some sort. The ideal type of rubber molding for your product depends entirely on your material and intended application. The molding process can change dependent upon many factors including the type of material used. To help explain this, we've put together a quick introduction on the differences between natural and synthetic rubber.

Custom Rubber Corp. is constantly making investments in new equipment so that we can provide our customers with the most modern and efficient manufacturing and secondary operations available for rubber molding products.

Molding-related capabilities include:


What Additional Rubber Molding Services Do You Offer?

Custom Rubber Corp. offers an array of services that complement our core ability to respond to customers' inquiries and requests for molded rubber parts. Custom Rubber Corp. can go the extra mile with custom rubber molding products, including:

  • Cryogenic Deflashing: Tumbler and Shot Blaster
  • Slitting and/or Punching
  • Applying PSA or Adhesive
  • Secondary Bonding Rubber to Metal and/or Plastic
  • Trimming
  • Automated Vision and Laser Inspection Systems
  • Specialty Testing
  • Special Packaging
  • Customized Labeling per Customer Specifications

Click here to reach out for information on our secondary services.

Molding Colored Rubber

Custom Rubber can also produce parts that go beyond simple black homogeneous rubber parts.  We are experts in molding colored rubber, and have years of experience bonding rubber to metal and/or plastic. 

Click here to reach out for more information on our molding colored rubber services.

What is Rubber Injection Molding? 

Rubber Injection Molding is a process in which strips of rubber materials are fed into injection molding machines and cured. In most cases, it is the most efficient way to mold rubber. Rubber injection and injection-transfer molding start with more efficient material preparation. The material is mixed, typically in 500-pound batches, and then stripped immediately after being mixed, into continuous strips measuring approximately 1.25" wide and 0.375" thick. This strip is fed into a screw on the injection molding machines, which charges a barrel with a pre-defined amount of material. When the mold is closed, the material in the barrel is injected into the mold cavities and cured.

There are many advantages to Rubber Injection Molding:

  1. Complete elimination of pre-forms, a labor-intensive step that can introduce variability in pre-form weight and shape resulting in variability of the finished product (learn more about preforms under compression molding).
  2. Complete elimination of operator placement of pre-forms. In many cases, the operator has to strategically place the pre-forms in either the cavity (compression molding) or the pot (transfer molding) to ensure quality output.
  3. The injection screw pre-heats the material before forcing it into the cavities. This decreases the viscosity of the material, allowing it to flow more easily into the cavities. The other advantage is the potential for decreased cure time for two reasons:
  • More rapid cavity filling due to lower viscosity.
  • The material is well on its way to being cured as a result of the heat added during the screw charging and shear created during injection.

To learn more about Rubber Injection Molding, reach out to Custom Rubber Corp.

What is Rubber Transfer Molding?

Rubber Transfer Molding is the process of taking rubber compound or mixed raw material and making "pre-forms"  and then compressing the material, forcing it into a cavity where high pressure and temperature vulcanize the rubber to create a new shape. The advantages of transfer molding over compression molding can include:

  1. Fewer and simpler pre-forms because one pre-form can fill hundreds of cavities.
  2. Tighter dimensional tolerance control because the mold is not held open by excess material spilling out of the cavity parting line; all the excess hold the plunger open from the pot.
  3. Colored rubber parts benefit because pre-forms can be cut by hand from raw material sheets, significantly reducing the chance of contamination that can come from mechanical prep for compression molding or the injection screw and barrel in injection molding.

Custom Rubber Corp. has well over 100 years of institutional knowledge about rubber molding. Click here to reach out with questions on transfer molding.

What is Rubber Compression Molding?

Rubber Compression Molding is the process of taking rubber compounds or mixed raw material and making “pre-forms'' in the shape of the end product and loading them, typically by hand, into an open mold. The mold is closed, the rubber cured, and then demolded—typically by hand. Compression molding is different from transfer molding because the rubber is put directly into the cavities, then compressed rather than being compressed in the pot then transferred into the cavities. 

The first modern rubber product ever produced was compression molded in the home oven of Harvey Firestone in the 1890s. In many ways, not much has changed since as the process is considered to be cost effective. Indeed, compression molding rubber can be cost-effective if one or more of the following is true: 

  1. Compression molding tooling already exists.
  2. The quantity required is very low.
  3. The part’s cross-section is very large and it requires a long cure time.
  4. The material required is expensive and does not flow well.

 Custom Rubber Corp. has been compression molding since its founding in 1956 and has extensive experience in taking on existing tooling. Click here to reach out for answers to your questions on rubber compression molding.

Contact Custom Rubber Corp.

We specialize in meeting your business’s custom rubber molding needs and providing exceptional secondary services to deliver a full-scale, one stop shop. Click here to contact Custom Rubber for answers to your questions, more information on rubber molding services or to request a quote.