Trelleborg tackles thermoplastic-thermosetting elastomer bonding issues with multicomponent assemblies

2 min read

Trelleborg Sealing Solutions is an exponent of multicomponent technology, a technique that creates a single component from multiple assembled parts.

The process can significantly lower the total cost of ownership for customers, while giving them the design latitude to create better products, it says.

Recognising a demand in the marketplace for thermoplastic to thermosetting elastomer-bonded multicomponent solutions, Trelleborg Sealing Solutions has invested in a Multicomponent Development Center. Now able to provide fully tested and validated options, Trelleborg enables customers to reap the many benefits of multicomponent technology in more applications.

Multicomponent technology involves the bonding of two or more materials to create a single, often complex, component that would otherwise entail the assembly of numerous parts. As well as sealing, innovative designs can build in adjacent functions, such as structure, housing, and support. Converting an assembly into a single component gives significant technical and commercial benefits. It alleviates risks associated with assembly and overcomes any issues related to tolerance stack-up, blind assembly or secondary operations. When replacing metal parts within an assembly, the components become corrosion-resistant, according to Trelleborg.

Until now, bonding thermoplastic to thermosetting elastomer, or rubber, with the necessary strength has not been possible. Established ways to produce multicomponent parts already exist for bonding plastic to thermoplastic elastomer and plastic to liquid silicone rubber (LSR). The base for these is always an engineered plastic, which withstands the heat required for overmoulding.

In addition, for bonding plastic to thermoplastic elastomer and plastic to LSR, material suppliers offer compounds specifically for bonding and can provide information on the bonding performance of the materials. However, for thermosetting elastomers there is no information available, especially as compounds can be proprietary.

The task of the Multicomponent Development Center was to investigate bonding of thermoplastic to thermosetting elastomer materials and the best methods to create secure bonds, considering surface properties and material processing. The Center has defined a one-step process bond between thermoplastic and thermosetting elastomer materials without pre-treatment, adhesives, surface preparation or any other additional steps. This creates a process described as ‘exceptionally reliable’ and which can include a high level of automation with integrated visual or functional quality checks.

Having already validated nearly 50 different material combinations, the Center continues testing to build a database of possible combinations, and to test specifically to customer requirements.

Borg adds: “Multicomponent technology allows production of components that cannot be produced by any other method, pushing the limits of manufacturing innovation. It brings tangible benefits to equipment manufacturers in many sectors, helping them to meet design goals, such as making products smaller and more compact, light weighting, increasing robustness, and improving inherent quality, while lowering total cost of ownership.

“To fully take advantage of all that multicomponent technology offers, it is best to involve us from early in the concept stage of product development. That allows us to understand the application, overall assembly, where the component fits and possible production challenges. We also look at all typical parameters for a sealing application, such as process media, temperature range, tolerances, and critical sealing surfaces. Considering every aspect creates a better product, not only from a user’s point of view but from a design for manufacturing one; at an early stage optimising the product for serial production in high volumes.”

Thermoplastic-to-thermosetting elastomer bonding adds to Trelleborg’s established range of plastic-to-thermoplastic elastomer and plastic-to-LSR material combinations.