Remix each component (A & B) every time before using. Following applies to any version.
1. Mixing of the two components
Add 100 parts of BLUESIL RTV 3527 A to 100 parts of BLUESIL RTV 3527 B. The two components may be intimately mixed either by hand or using a low-speed electric or pneumatic mixer to minimize the introduction of air into the mixture.
After mixing parts A & B it is recommended to degas the product to eliminate the entrapped air introduced in the mixture. If the material is processed using an automatic dosing machine with a static mixer, both single parts can be degassed before mixing because air is usually not introduced in the mixture.
BLUESIL RTV 3527 A&B is degassed under a 30 to 50 mbar vacuum. When the vacuum is applied the product expands 3-4 times its initial volume and bubbles form on the surface. Once bubbles disappear, the mixture collapses back to its initial volume. To complete degassing simply wait few minutes before releasing the vacuum, then the product will then be ready to use.
Remark: pull and release the vacuum several times improves the degassing. For easier degassing only fill a recipient only to 1/3 of its height.
Pour the degassed mixed material slowly in a steady stream from one edge of the mould box so that the material flows evenly over the model minimizing the entrapment of air bubbles under the flowing silicone.
3. Cross linking
At room temperature (23°C) BLUESIL RTV 3527 A&B cures in the given setting time regardless of the mould thickness. For best results the mould should be allowed to fully cure for 24 hours before using it for production.
Room temperature curing assures the lowest possible shrinkage, if accelerated cure is desired, mild heat should be preferred. To minimize shrinkage cure the elastomer at maximum temperature of 60°C for 3-4 hours, higher temperatures will cause higher shrinkage.
Conversely at lower temperature polymerization is much slower: at 10°Cthe time necessary to complete cross-linking will be almost double the time at 23°C.
Be aware that contact with certain materials can inhibit the curing of this RTV:
- Natural rubbers vulcanized with sulphur
- Polycondensation RTV catalysed with metal salts
- PVC stabilizing agents
- Amine cured epoxies
- Sulphur containing clays.
In case of doubts it is recommendable to run a quick test with a small quantity of material in order to assess compatibility.
Take note that cross contamination due to not well cleaned tools or devices is frequently the main causes of inhibition. The best way is to use only dedicated gear when processing polyaddition RTVs.
|BLUESIL RTV 3527 B may be stored at a temperature below 40 °C/ 104 °F for up to 12 months from its date of manufacturing.||Please consult the Safety Data Sheet of this product.|
BLUESIL RTV 3527 B
BLUESIL RTV 3527 A&B is a two component, silicone elastomer which cures at room temperature by a polyaddition reaction (1:1 ratio).
Aiming at satisfying different application requirements BLUESIL RTV 3527 A&B is available in 3 color versions and a Quick Curing (QC) version.
2 Part RTV
- Excellent reproduction of details.
- High flowability and good mechanical properties.
- Excellent ink uptake and release.
- Good release properties with organic resins and gypsum.
- Possibility to choose longer (Standard version) or shorter working time (QC version) and different colours.
- Low linear shrinkage.
- No release of toxic substances during and after curing.
BLUESIL RTV 3527 A&B can be used for the production of printing pads or printing rollers with medium hardness.
The product finds application also in the production of molds for manufacturing copies in different materials (resins, gypsum, etc.) when good elasticity and medium hardness are required.
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