A System of Products to Protect Valuable Tooling
Chem-Trend has developed a suite of products designed to work in concert with each other to make production molds for the composite industry more efficient and longer lasting. The “Release System” developed by Chem-Trend is applicable for molds made either of composites, or metal.
Addressing the Challenges of Molds Made From Composites
A composite mold that has just been constructed and pulled from its plug/master mold should, ideally, be allowed to “season” for several days before being put into production. “Seasoning” allows the polymer matrix to fully cross-link and to allow any residual solvents entrapped within the matrix to evaporate, leaving a mold surface that is as ready as possible to face the rigors of the molding process.
However, seasoning is not always possible due to production demands; therefore molds are often put into production before they are completely ready. A “green” mold (not fully seasoned) is much more vulnerable to both the chemical and mechanical attacks faced as a part of the molding process.
Chem-Trend has developed both mold sealers and mold primers to “assist” the mold (green and seasoned) in fighting off both mechanical and chemical attacks.
High Gloss Molds and Closed Mold “A” sides- Sealing
Molds destined to produce parts with a high gloss must be prepared with a blemish-free high gloss surface finish, since the surface of the mold is always “reflected” in the surface finish of the part produced. A high gloss finish to the mold surface indicates that there is either light, or no, mold surface porosity†. A mold sealer should be applied at this stage, followed by the appropriate release agent. The sealer ensures that if there is any porosity at all, it will be closed off, and the release agent will have a perfectly suitable surface on which it can adhere.
Non-cosmetic Molds and Closed Mold “B” sides – Priming/Sealing
Composite Molds destined to produce parts that are going to be post-mold treated – such as those to be painted, for example – are not normally prepared with a blemish-free high gloss finish. Mold “B” sides and “A” sides that are non-cosmetic in closed molding and vacuum bagging are usually in direct contact with the wet resin or the resin in the pre-preg. In these circumstances the mold surface is subject to extremely aggressive chemical, as well as mechanical (abrasion) attack. For these a mold primer should be applied, followed by a mold sealer and finished with the appropriate release agent when molding occurs.
The primer performs as a “heavy-duty” sealer, ensuring that the mold surface is totally isolated from the other components of the release system. The mold sealer and mold release agent are therefore free to perform their roles in the release process. An additional benefit is that the Chem-Trend primer, when fully cured, provides a perfectly reactive surface that promotes adhesion of Chem-Trend semi-permanent sealers and release agents.
A mold that has been taken out of production and repaired should first be given a thorough cleaning, and then repaired areas of the mold should be prepared as per a new mold. The whole mold should then be treated with the Chem-Trend release system (mold primer, sealer and release agent) when placed back into service.
It is not unusual for parts of a mold to have been “compounded”, where the surface has been abraded and either given the finish that is required, or returned to its original state of finish. In these cases all previous release agents used (or those transferred from the plug/master in the case of a new mold), have been sanded or compounded away to reveal a bare mold surface. In these instances a thorough cleaning with a Chem-Trend mold cleaner, using a wipe-on wipe-off technique, will ensure that the mold surface is perfectly clean and ready to receive the base-coat of the release system, setting up the necessary protection barriers for the mold.
Protecting Molds Made From Metal
Metallic molds, although not susceptible to the same chemical changes that take place within the matrix of a composite tool, nevertheless need protecting from chemical and mechanical attack, especially when new. Not all metallic substrates promote good adhesion of a typical semi-permanent sealer/release agent type of system. For these cases, a specially developed Chem-Trend primer can be employed that’s designed to bond or adhere to almost any known substrate. Once the primer is in place and fully cured, the release system can be applied as usual.
Treating a new, or repaired, metal mold with a full Chem-Trend semi-permanent release system, consisting of cleaner, primer, sealer and release agent, will ensure that the mold goes into production with the best possible chance of producing excellent parts starting with cycle number one. Chem-Trend sealers and semi-permanent release agents are specially formulated to adhere to substrates coated with a Chem-Trend primer, thus ensuring that the mold surface is properly protected and has the ability to provide multiple releases, saving time and money for your operation.
To learn more about the advantages your operation can gain by utilizing our industry leading products, and receiving our industry leading service, contact us.