Without Adhesion Promotor

VESTAMID® and rubber

Wherever rubber parts must be durably fastened or fixed, composites consisting of a hard component and an elastomer have proven extremely useful. The hard component was traditionally metal, but to reduce weight metal components are increasingly being replaced by suitable plastic parts wherever possible. For our patented plastic-rubber composite process we offer specially developed VESTAMID® D molding compounds.


Replacing metal by plastic parts has two additional advantages: Plastics do not corrode, and they can be efficiently processed by injection molding into parts of highly complex shape. Production of metal parts of similar complexity is extremely time- and labor-intensive; the use of plastics in the design of complex components therefore gives design engineers and parts developers considerably greater freedom.

Bonding without Adhesion Promoters

For durable functioning of composites, particularly under dynamic load, strong bonding between the hard and soft components is of prime importance. This is usually achieved by the use of adhesion promoters. Combinations of all standard rubber grades with most metals and suitable plastics are possible. Apart from the additional work steps needed for application of the adhesion promoter, the process requires measures for protecting against emissions of the solvents generally used, and for their environmentally correct disposal.

By contrast, the plastic/rubber composites patented by Evonik (K&K composites) do not use adhesion promoters: The specialty molding compounds allow strong and durable bonding to suitable rubber mixtures without the need for special pretreatment. Composites of this type are found in a wide variety of applications, for example as shock-absorbing bearings in the chassis of motor vehicles, in switch cams, and as reinforced seals in engines and machines.

The following VESTAMID® molding compounds have been specially developed for plastic/rubber composites:

  • VESTAMID® DX9321 - contains 20% glass fibers, impact modified
  • VESTAMID® DX9323 - contains 35% glass fibers impact modified
  • VESTAMID® DX9325 - contains 40% glass fibers, impact modified
  • VESTAMID® X7099 - contains 20% glass fibers