Semi-Permanent Release Agents for Thermosetting Resins
Especially Cast Polymer applications (Cultured Marble, Solid Surface and other fiberglass open molds)
The GruberCare MR series of Mold Release products has been researched and developed to meet all of the regulations in solvent use throughout North America, the European community, and other industrialized countries of the world.
GruberCare MR products do not contain any CFC's (chlorofluorocarbons), chlorinated, aromatic or toxic solvents. The active ingredients are fully-curing, solvent resisting polymers of extremely high thermal stability which, although constructed differently, will perform satisfactorily when applied and used on top of most other crosslinking polymer systems.
These products are neither silicone, wax, nor PVA. They are highly cured reactive polymers which form extremely hard, thin films when cured, giving the following benefits:
- Multiple Releases
- Release at temperature up to 475°C
- No mold build-up
- No transfer onto moldings
- Saves labor due to multiple release capabilities
- Lower mold maintenance costs
- Enhances ease of release
- Savings in ecological effects due to reduced solvent use and multiple release properties
- Overall cost savings
The GruberCare MR Series of semi-permanent release agents and related products include:
GruberCare™ MR Sealer
A Sealer for use in combination with GruberCare MR GP, and MR Hi-TEC products. It should be used to prevent styrene emission or migration from new molds and eliminate surface porosity of metallic molds.
GruberCare™ MR GP Multi-Release System
MR GP multi-release system yields high gloss moldings. Purposefully formulated for reinforced polyester resins or high-gloss moldings using gelcoats.
For special applications where rapid curing, high gloss and slip properties are required. Excellent for metallic molds or molds of high surface porosity. Purposefully formulated for rotational molding and phenolic resin molding.
MR Mold Release - Technical Characteristics
| Specific Gravity: |
0.78 kg/1t (approx) |
| Odor: |
Mild |
| Physical Appearance: |
Colorless |
| Flash Point: |
MR Sealer: 28°C
MR GP: 28°C
MR HI-TEC: 04°C
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| Coverage: |
Approximately 800-1000 Square Feet/Gallon |
Mold Preparation:
Mold surfaces must be clean and free of any other non-crosslinking release agents or resin build-up from previous processing, otherwise GruberCare MR products will have poor film formation and give unsatisfactory release performance. Clean mold with any suitable solvent which provides thorough cleaning without any residual film. Take care not to damage polyester molds (especially if less than seven days old).
Preparation of New Molds:
Newly produced molds ("green" molds) contain excessive levels of unreacted styrene which are attracted to other styrene molecules as in gel coats. The barrier built between this attraction is extremely important during the first few cycles of a new molds' service. Polymer releases are effective barriers against styrene migration, however, close attention should be paid to applying at least four (4) thorough coats of GruberCare MR Sealer to the new molds prior to an equal number of GruberCare MR GP or MR HI-TEC release. Allow each coat to cure completely as instructed. Perform a tape test on multiple locations of the mold surface to confirm sufficient film formation and that the continuity and completeness of the GruberCare MR film has been achieved. The ease of release of the tape will demonstrate the performance of the release film coating.
Application of Release Films
All GruberCare MR products have to be applied using a clean, lint-free cotton cloth or by airless spraying. For the most effective performance, always use the "wipe on/spray on" technique, applying just enough product to "wet" the mold surface. Then "wipe off" using a dry, lint-free cotton cloth. Wipe off should be done very gently and the mold surface coated with the GruberCare MR products should have a smooth, uniform appearance.
There is little difference in the application of the various products. You will notice that more application time is available with GruberCare MR products without resultant streaking. Only the HI-TEC evaporates quickly for use on rapid production molding. There are some references to go by when deciding which of the products best suits your needs:
- Gloss Finish --> Use MR GP
- To maintain a matte finish --> Use HI-TEC
To fill microscopic porosity of new resin or metallic molds, first apply four (4) coats of GruberCare MR Sealer with a 15 minute cure time between applications to ensure that solvents have completely flashed off, then wait for approximately 60 minutes for a complete cure before applying GruberCare MR Release System.
To Begin Application
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Apply 4 coats of MR Sealer with a 15 minute cure time between coats, then wait 60 minutes for a complete cure for maximum performance. When using MR HI-TEC you will notice faster evaporation of solvents by comparison. The cure rate of the Hi slip polymer is also more rapid, allowing for the mold to be put in use, approximately 15 minutes after the final coat is applied.
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To speed up the process, heat up the mold to around 80-120F for 15-20 minutes, taking care to increase the temperature gradually, then apply 4 coats of whichever GruberCare MR Release Products are using. Be sure to keep the film uniform: apply uniformly in areas of a few feet square feet at a time rather than the entire mold. The technique is to wipe on the release to "wet out" the area of application and then wipe off gently with a separate dry, lint-free cotton cloth.
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To increase the number of releases, condition the mold when molding begins by applying one coat of release after the first 2 or 3 parts, then continue production until the first signs of release difficulty occur, at which time another coat of should be applied.
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When release problems start to occur, apply one or two coats of release again, allowing 10 minutes between coats. Wait for 40-60 minutes before continuing molding if possible. Although it is possible to mold after only 12-16 minutes providing all solvents have dried off and a good surface is obtained. This can be quickly checked using a simple masking tape test.
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Note: Always re-seal the cans after use. GruberCare products are moisture.
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