RTV silicone rubber for make mold

RTV silicone rubber for make mold 

Features
Good flowability and long working time
Medium hardness 
High tear and tensile strength
Easy de-mould from complex replica parts
Acid and alkali-resistance
Low linear shrinkage

Application
RX-725  is suited for reproduction of cement molding, concrete stones, artificial stones, plaster molding, figures, art objects, decoration molding, GRC products, gypsum products, resin products ,PU molds. etc..

Description
RX-725 mold making silicone rubber is a two-component material silicone rubber,consisting of Part A base silicone and Part B organic tin curing agent,cures at room temperature by a condensation reaction.These materials can be cast into the cured silicone mold:plaster,polyurethane,PU,GRC,cement,resin,polyester,wax etc..

Standard Datasheet of  RTV silicone rubber for make mold 

Gel-type Components  A   B
Appearance  (liquid)  transparent : White 
Mixing ratio :  100 :2
Viscosity (Pa.s)   : 25000

Hardness shore A:    27±1

Shrinkage  rate(%): ≤0.2 
Pot life(25C) (mins) : 30-40
Curing time (mins):    24h
Tensile strength (Mpa) : 3.6
Elongation at break (%):  560

Tear strength shore A: 36

How to make the silicone mold
The surface of the original should be clean and free of loose material.If your products with thin flower patterns ,and especially with porous substrates,pls use a suitable mold release agent such as soap water,detergent,waseline or petroleum jelly.

Mixing
Please weight 100 Part A base and 2 parts of organic tin Curing Agent in a clean container.Thoroughly stir Part A base silicone before use, as filler separation may occur upon prolonged storage. Mixing Part A and Part B evenly until part B completely dispersed in the base. Hand or mechanical mixing can be used,but do not for an extended period of time or allow the temperature to exceed 35°C. Mix suitably small quantities to ensure thorough mixing of base and curing agent.

It is strongly recommended that entrapped air be removed in a vacuum chamber,allowing the mix to completely expand and then collapse. After a further 1—2 mins under vacuum,the mix should be inspected and can be used if free of air bubbles. A volume increase of 3—5 times will occur on vacuum de-airing the mixture. So a suitably large  container should be chosen.

Pouring the mixture and curing
Pour the mixed Part A base silicone and part B organic tin curing agent as soon as possible onto the original,avoiding air entrapment.The catalyzed material will cure to a flexible rubber within 6 hours(or faster by different mixing ratio or room temperature),we advice you de-mold after 24 hours ,it is will improve the replicate times of silicone mold.

Storage
When stored at or below 30°C in the original unopened containers,SILASTIC RX-725 Base and Curing agent have a usable life of 12 months.from the date of production.After 12 months stock,pls use the Stir to mixing the Part A silicone for some mins, then the silicone can be use again,no influence for other performance.

Packing
1kg/drum,5kg/drum,20kg/drum,25kg/drum or 200kg/drum of Part A base silicone rubber.
0.25kg/bottle,1kg/bottle and 10kg/bottle of Part B organic tin Curing Agent.

Note
This product is neither tested nor represented as suitable for medical or pharmaceutical uses. Not intended for human injection. Not intended for food use.

Any questions about the iterm,please don't hesitate to contact Ms Taylor Liu

Tel: +86-755-89212380

Mob: +86-18938867522

Skype:taylordl828