Rubber moulding: materials, techniques, items

If you represent a technical company or are looking for customised rubber articles, you know how extensive the world of rubber moulding can be. However, you may not know the details of the techniques, materials and infinite possibilities for customisation that these processes offer.


In this article, we look into the methods and materials that we have been using at GB for almost 50 years to produce seals and items in rubber.

Rubber moulding techniques; compression and injection

Our range of machines can produce customised parts with both horizontal and vertical injection, compression and injection-compression technologies.

  • The injection method involves thermoplastics or polymers being injected at high pressure into the mould. These materials then solidify, creating the items.

  • The compression technique, on the other hand, involves placing the rubber inside a heated mould and then pressing it into its new shape. At GB we have presses of up to 650 tons!

  • Injection-compression moulding combines both techniques; the material is injected into the semi-closed mould and then compressed.


These techniques are not alternatives; the most suitable method will be defined according to the article to be made, the material chosen and the characteristics required.

Rubber moulding materials at GB

Before discussing the items that can be produced by rubber moulding, let us take a brief look at the materials. Elastomers, thermoplastics or moulded materials can all be used for moulding.


However, it is possible that during the design process of the customised article, it emerges no materials with the appropriate chemical and physical properties exist. Over time, to fill this gap, we have developed new materials adapted to customer needs and in line with regulations, with the support of specialised external R&D laboratories.


This means that the number of materials is potentially endless!

However, the main materials used today in the rubber moulding industry – and thus also by our company – are:


  • various groups of elastomers (ACM, EPDM, FKM, ECO, VMQ, FVMQ, CR, HNBR, IIR, NBR, NBR-PVC, SBR, NR, AU).
  • thermoplastics (ABS, PA6, PA6.6, PA6.6 FG, PBT, PC, POM, TPE, TPU).


In addition to these, there are also materials overmoulded with metals, nylon, rubberised cotton material and high-tech fibres for products that serve as high-pressure seals. 

Rubber articles and customised parts; the possibilities offered by moulding

Rubber moulding allows the creation of a wide range of articles. At GB, we specialise in customised parts, offering co-design and production activities.

Below are the most common categories of items made by rubber moulding:

  • Membranes – with special gas-compliant raw materials and compounds
  • Bellows – various shapes, sizes and thicknesses, with materials requested by clients and conforming to application standards
  • Frames – frames for the automotive, lighting and electronics sectors
  • Washers – made by moulding a shaped tube that is then cut in the lathe department – with in-house designed lathes
  • Overmoulded items
  • Special O-rings


All these products can be custom-made in our company with fully personalised specifications and specially designed materials.

GB for your custom-made rubber articles

When it comes to rubber moulding, we know our stuff; this has been our field of expertise since 1976. The quality of our products is guaranteed by an established and growing international client base and by quality assurance through IATF 16949 certification for the automotive sector.


What makes our company truly special is our in-house design and the possibility of creating new materials according to the technical characteristics required.


GB is also the parent company of the GB Group, which includes GBL and GBS, which respectively specialise in fluid-power and hydraulic seals and moulds for rubber and thermoplastics.


Being such a specialised industrial group leads to collaboration and the sharing of know-how both within and beyond the GB Group, making us ever more efficient and innovative.

Does your company need fully personalised and quality-guaranteed custom rubber items? Contact our Technical Department or request a quotation.