Soft foam seals instead of TPE-seals in injection moulding tools
At the International Trade Fair K 2007 in Düsseldorf CeraCon was presenting an innovation

CeraCon and Sunstar are specialists for the application of foam seals and are showing a new application technology on the K exhibition in Düsseldorf for the first time. This new technology called S-FIT (Soft Foam Injection Technology) ensures that soft foam seals (e.g. Polyurethane seals) can directly be applied to the thermoplastic parts by a one-shot process inside the injection moulding tool.

Known issues about sealing by two-component injection moulding technology

Until now, seals on plastic parts are normally made by a two-component injection moulding technology. That means that subsequently to the thermoplastic process a TPE material is injected. The seal integrity of the parts produced by the 2K injection moulding technology does often not meet performance expectation. After a certain period of time and due to temperature influences traditional TPE seals are deforming plastically. The consequence of this deterioration is generally seal failure or leakage. In case of low ambient temperature the reduced elasticity of the TPE material also leads to leaking seals.

The advantages of CeraCon's S-FIT technology and Sunstar's soft foam material (Penguin Foam) are striking: Foaming up the sealing material (e.g. PUR) with pure air is creating a soft and elastic foam seal with thermosetting properties. The seal is compressible and has got good reset forces independent of the time under compression and independent of the ambient temperature (range from -40°C to +90°C).

Advantages of the new technology S-FIT

The new technology S-FIT demonstrates significant advantages compared to the traditional 2K injection moulding technology. Firstly, you do not have to buy a high priced 2K injection moulding machine to produce parts with S-FIT soft foam seals. Secondly, the technology is realised by a traditional machine with 1K-control and the external foam applicator "FOAMPLY M". The approved 2K tool and die technology is used for moulding and shaping. Commissioning/production start-up, is possible without producing defective goods - even after a longer period of downtime, e.g. after the weekend.

Approved FOAMPLY technology combined with Penguin Foam comes with S-FIT

Actually, CeraCon's application technology with Sunstar's Penguin Foam on plastic parts is no innovation. For several years, important suppliers to the automotive industry and manufacturers of other industrial products have already been producing their parts by using this technology. However, until now the applications have been realised by the so-called FIPFG technology (Formed in-place foam gaskets). Using this technology the single component foam is applied in a secondary manufacturing process to that of the plastic part. However, the heat curing mechanism of Penguin Foam means that immediate part assembly can be facilitated, after foam curing (e.g. 5 mins. at 80°C).

The revolutionary S-FIT technology ensures that soft and elastic foam seals can now be directly applied to the injection moulded part in a fully automated process. The time for foaming is often shorter than the time for cooling down the plastic part. A surface coating of the tool has the effect that there is no release agent necessary between the production cycles. Consequently, cycle times are shorter and productivity higher. Not only does this result in an economic advantage for the piece part costs, but also delivers a more streamlined manufacturing process with less demand on factory space. This reduces capital investment, as there is no secondary automation or labour requirement for seal application. Furthermore there are no additional licence fees to be paid.

On the K Exhibition (Stand no. G06 in hall 11) CeraCon and Sunstar were showing the new technology S-FIT in operation.


Please note our publications and the opinion of the press about S-FIT: