Platinum Cured Silicone Rubber

Synonym: addition silicone rubber Food grade silicone

Platinum cured silicone rubber, also known as addition silicone rubber or food grade silicone, usually there are two colors of translucent and transparent silicone rubber, but you can mix in a silicone pigments of your choice to add color. Both parts are liquid but part A contains the platinum catalyst. With a simple 1:1 (Weight or volume ) mixing ratio, this low-viscosity liquid can be mixed and poured with the utmost ease. at room temperature or by heat can be cured durable elastomer. This product produces no odor and nontoxic, FDA compliant.

Principle of Curing

In a platinum-based silicone cure system, also called an addition system (because the key reaction-building polymer is an addition reaction), a hydride- and a vinyl-functional siloxane polymer react in the presence of a platinum complex catalyst, creating an ethyl bridge between the two. The reaction has no byproducts. Platinum cured silicone’s can be cured quickly with heat, Platinum-cure silicone rubbers are critically sensitive to sulfur and will not cure under any circumstances when exposed.  


  1. Easy to use, Fast demold time
  2. Food Safe, non-toxic, no odor,FDA compliant
  3. Very good flowability and self de-airation
  4. Excellent tear and tensile strength
  5. No heat is generated during curing
  6. Exhibit good chemical, abrasion
  7. Cure without byproducts
  8. High elongation
  9. Low Shrinkage(≤0.1)
  10. Temperature Extreme resistant(-50~250℃)


Platinum Cured silicone are food grade silicones suitable for making baking molds and trays, ice trays, casting butter, chocolate and other applications used to produce food. Perfect for intricate detail moulds and castings requiring minimal shrink and long life. These silicones are commonly used in highly accurate prototyping and model making applications.

Platinum Cured silicones are suitable for making molds for baking, casting ice, butter or chocolate and other applications used to produce food. They are also used for making prosthetic and orthotic devices, skin safe appliances and effects, etc.  

How to Use

Step 1: Prepare the Original Molds

Make your original molds perfect. fix it on a board. And fix the original mold on a board , then used four piece of board to enclose the original molds.

Step 2: Applying A Release Agent

Although not usually necessary, a release agent will make demolding easier when pouring into or over most surfaces.

Step 3: Weighing

Determine the volume of silicone needed to fill your mold, weigh the same amount of part A and part B.

Platinum cured silicone require very accurate and careful mixing.

The mixing ratio of part A and part B can be by weight or by volume.

Step 4: Mixing

After dispensing required amounts of Parts A and B into mixing container (1A:1B by volume or weight), mix thoroughly making sure that you scrape the sides and bottom of the mixing container several times.

Mixing must be done thoroughly and evenly or you will be left with uncured parts, and if you are too vigorous, air bubbles can be a problem, unless you have a vacuum degassing chamber.

Step 5: Vacuum pumping(optional)

Although not necessary, vacuum degassing helps eliminate any entrapped air in pourable silicone rubber. After mixing parts A and B, vacuum material for 3-5 minutes at 29 inches of mercury, making sure that you leave enough room in container for product expansion.

Mix Parts A & B thoroughly, Place mixing container into vacuum chamber. Ensure a tight seal between lid gasket and chamber. Turn on vacuum pump. Close vacuum valve to enable air flow.  After silicone falls, vacuum for an additional 90 seconds. Do not over vacuum! Turn off pump. Relieve pressure in chamber by opening valve.

Step 6: Pouring

Pour in a thin unbroken stream into the lowest point in the cavity or mold. This will help break up some of the air entrapped during mixing.

Step7: Curing

Atmospheric temperature and humidity vary from season to season. In winter months the pot life and curing time will be nearly twice their summer values. Demould will be 4-6hrs depending on ambient temperature and humidity.

Do not cure rubber where temperature is less than 10°C, Because it will be hard to cure.


  1. Because no two applications are quite the same, a small test application to determine suitability for your project is recommended if performance of this material is in question.
  2. Platinum-cure silicone rubbers are critically sensitive to sulfur and will not cure under any circumstances when exposed. If compatibility between the rubber and the surface is a concern, a small-scale test is recommended. To prevent inhibition, one or more coatings of a clear acrylic lacquer applied to the model surface is usually effective. Allow any sealer to thoroughly dry before applying liquid silicone.
  3. Platinum cured silicones require very accurate and careful mixing.
  4. Mixing must be done thoroughly and evenly or you will be left with uncured parts, and if you are too vigorous, air bubbles can be a problem, unless you have a vacuum degassing chamber.
  5. Platinum can be accelerated with heat, but remember if you decrease the cure time, you will also decrease the work time!
  6. If you need to retard the cure speed, the only way to significantly slow down the reaction is to chill the components drastically before mixing.


Shelf life is 12 months from the date of production. Store material at room temperature (73°F/23°C). Storing material at warmer temperatures will also reduce the usable shelf life of unused material. Storage beyond the date specified on the Certificate of Analysis does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.


  1. The components A and B of Platinum cured silicone rubber have been approved by FDA, which are neither toxic nor harmful to human skin. Therefore, no special treatment precautions are required. If you want to wear gloves, Wear vinyl gloves only. Latex gloves will inhibit the cure of the rubber.
  2. Should accidental eye contact occur, wash thoroughly with water and consult a physician.
  3. Adult Supervision Required. Keep Out of the Reach of Children.