RTV-2 Silicon Rubber

Features-RTV silicone rubber material for concrete molds making

1. Two-parts, flowable liquid silicon & curing agent.

2. It gets cured at room temperature 250C within 3-5 hours.

3. An exceptional fluidity and good operability, easy to be demolded.

4. Good tensile strength and tear strength, low shrinkage.

5. Suitable for both brushing and pouring methods of operations for medium & large sized molds making.



Usage-RTV silicone rubber material for concrete molds makingSilicon rubber for PU/poly resin products, unsaturated resin products, plaster, candles and gypsums crafts, toys, soap, statuary, casting molds making, etc.

Model
630#

Appearance
white

Mixing proportion of curing agent (%)
5%

Operating time (mins 25 0C )
20-40

Curing time(hours 25 0C)
3-5

Hardness (Aý?
30ý?

Density ( g/cm 3 )
1.08

Viscosity (Mpas -25 0C)
27000~32000

Tensile-strength(kgf /cm2 )
ý?0

Tear-strength (kgf /cm )
ý?0

Elongation-break(%)
ý?450

Retractility(%)
ý?.3




Users Instructions-RTV silicone rubber material for concrete molds making

RTV- 2 molding silicone rubber (silicon) and silicon are generally named as two-part room temperature sulfurated silicone rubber, which features an exceptional fluidity and good operability. When mixed with 4%- 5% curing agent, they can still be operable within 35 minutes, but it will be formed after 3-5 hours. With a favorable resistance to deformation, high temperature, acid & alkali, and expansion, silicon flexible molds are used for mold duplication and delicate mold making for poly crafts, resin crafts, lighting and candle crafts, etc.

This product is a white or red flowable liquid with a hardness of 28-32Aý?when it gets cured. For molds making of large-sized products, multiple-piece molding methods is required. Meanwhile you will need silicon rubber with a higher hardness. Conversely, soft silicon is indispensable for molds with complicated patterns and delicate details. The amount of curing agent admixture depends on your requirements. Pls add more for a speedy drying process and a fast releasing and less on the other hand.
(Notes: Normally we do not recommend you to add any silicon oil. For special soft mold or molds with complex pattern or fine details, 5%-10% silicon oil can be added to condition the flexibility of the mold for convenience of release)



Mixing Ratio for Silicon Rubber & Curing Agent and the reaction time (Under room-temperature-25 0C)
1,Added with 2% of curing agent, silicon can still flow within 2 hours, mold can be released in 7-8 hours.
2,Added with 3% of curing agent, silicon can still flow within 1 hours, mold can be released in 6-7 hours.
3,Added with 4% of curing agent, silicon can still flow within 40-50 minutes, mold can be released in 5-6 hours.
4,Added with 5% of curing agent, silicon can still flow wtithin 30-40 minutes, mold can be released in 3-5 hours.



Technical Guidelines-RTV silicone rubber material for concrete molds making

Stir the base (Part A) well beofre use (except when depending on machine ).
Shake the catalyst container (Part B) well before use.
This is a 100 Part A to 5 Part B mixing ratio by weight.Weigh the desire amount of base into a clean mixing container.
Weight the proper amount of catalyst into the container. Mix the base and catalyst together by stirring with a stick until a uniform color is obtained. Scrape the container walls and bottom well to insure a thorough mix.
Though it is often unnecessary to deair the material due to its low viscosity some may choose to do so. If so,place the container into a vacuum chamber and evacuate the entrapped air from the mixture using a vacuum pump capable of achieving 29 inches of mercury vacuum.The mixture will rise, crest and then collapse in the contanier. Interruption(bumping) of the vacuum may be necessary to prevent overflowing the container. Keep the mixture under full vacuum for 2-3 minutes.
Bleed air slowly into the vacuum chamber. When the chamber is at atmospheric equiplibrium,remove the cover plate and take out the container.
Pour the deaired material slowly in a steady stream from one end of the mould so that the material flows evenly over the pattern. This should minimize emtrapment of air bubbles under the flowing material. A 'ready' mold may be poured firstly over the pattern, which will also help reduce the possibility of entrapping air on the pattern and in the cured rubber.A mold release agent may be applied on the pattern first to improve release.
Allow the rubber to cure for 2-4 hours at 24C before removing the cured rubber mold from the pattern. Heat acceleration not recommended with this product.
For best results, allow the mold to air cure an additional 24 hours before using it in production.
Shelf Life-RTV silicone rubber material for concrete molds making

Twelve(12) months from date of shipment when stored under 250C in the original sealed packages.





We can provide you the best quality rtv silicone rubber with competitive price and free demold technology.