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14 Mar 2007  -  United States

New mould sealer for marine moulding applications

Axel Plastics Research Laboratories, Inc. announces a new semi-permanent mould sealer, XTEND® XTR, developed to provide enhanced mould protection and extended release performance in marine moulding applications.

The new addition to AXEL’s product line is a solvent-based. wipe on/wipe off sealer, that yields a high gloss, streak-free surface and superior chemical resistance. Nancy Teufel, AXEL’s Global Product Manager, says, “Current low VOC gel coat formulations continue to trouble the marine market, with parts being more difficult to de-mould and fewer pulls being achieved before mould maintenance is required; the introduction of XTEND XTR mould sealer addresses both of these problems.”

Background
A major marine manufacturer has experienced difficulty in de-moulding parts since implementing a new low VOC resin system. Deck moulds, in particular, because of their steep draws and low draft angles, are very difficult to release and are frequently damaged in de-moulding, necessitating time-consuming and costly repairs. To forestall damage
to moulds, the manufacturer has mandated that mould release be re-applied after each pull on the difficult decks.

The trial 
A new deck mould was introduced into production. The mould was wiped with mould cleaner in preparation for application of two coats of XTEND XTR mould sealer. The sealer application was followed by four coats of release as per the manufacturer’s standard preparation protocols, and the mould was put into service. (NOTE: New moulds pose extra risks of sticking or difficulty in de-moulding, as they can contain significant amounts of free styrene).

The results
The first deck was pulled from the mould with ease and the mould was re-treated with release in accordance with the manufacturer’s break-in procedures for new tooling. After break-in, the mould was allowed to cycle through the production line. Unlike other moulds already in service, the mould treated with XTEND XTR mould sealer consistently released decks more easily. Based on the ease with which the parts were releasing, the manufacturer decided to apply touch-up coats of release after three de-mouldings rather than one, although they acknowledged that the mould was releasing so well that it was conceivable that they could simply continue to run it without re-application of release.

With the success of the new mould treated with XTEND XTR, the trial was extended, with several of the more problematic decks being selected for treatment with the sealer. The results in these trials substantiated the initial test, with each deck mould treated with XTEND XTR sealer providing easier release and longer service than those that had not used the sealer.

The conclusion
Based on the results of what were considered to be the most demanding mould release applications, the manufacturer is confident that the use of XTEND XTR mould sealer will keep moulds in service longer and reduce the incidence of costly and production-halting mold repairs.

While application of mould sealer is an additional step in this manufacturer’s operations, plant management feels that the small investment of time required to apply mould sealer is already offset by the reduction in time required to apply touch-up coats of release. Moreover, maintaining moulds in peak condition for longer is judged to be a paramount concern, and in this regard, XTEND XTR was judged to be a clear winner.

Source : Axel