What's HCR Silicone and What's the Future of HCR Silicone?

HCR silicone, known as high consistency rubber, Heat-cured rubber, high temp vulcanizing (HTV),which is structurally different from the rubber elastomer in the conventional sense, it’s a kind of solid block of rubber as pre-cure material and which contains polymers with a high molecular weight and long polymer chains, and usually molded by heat compression molding.

HCR Silicone has good chemical inertness, good mechanical strength in a large temperature range, and excellent aging resistance.

HCR silicone can be formulated into different performances, colors and effects. Typical applications include automotive parts, office equipment parts, wire and cable, various profiles and food, medical and health products industries.

What is HCR silicone’s Advantages?

HCR Silicone Elastomers can be used at temperatures ranging from -50°C to +300°C, and can be used for a range of applications, especially within the automotive and aerospace industries.

HCR Silicone can have different colorings, and it's easy to have color change compared to Liquid Silicone Rubber.

HCR Silicone has excellent heat resistance at the same time it can still maintaining the properties of a low-temperature material.

HCR Silicone is kind of post-cured material, which has good outgassing test result.

Notes: Besides the main polymer suppliers,  HCR elastomers need to be mixed together with other ingredients, which is different from Liquid Silicone Rubber(LSR) and Room Temperature Vulcanizing (RTV), they can be found readily in a pre-compounded system.

HCR Silicone's current situation and future

Among the market of silicone products, HCR high consistency rubber product’ quantity is large, and with the new demand for wordwidel economic development and technological advancement, silicone rubber has a large expansion space. Although the production and sales of hot vulcanized silicone rubber products are large, the market competitiveness of high-end products is not strong. To improve the technical level of high consistency silicone rubber products, we should first start from improving the quality of raw rubber products.

How to improve the qualtiy of high consistency silicone rubber material’s quality?

We can analyse the correlation between the composition, structure and properties of silicone rubber raw rubber, the current production process and technical defects of existing products, to propose practical technical measures.

What’ the reason of quality defects of hot vulcanized silicone rubber?

• Influence of raw material impurity components

• Polymer volatiles

• Effect of polymer molar mass size and distribution

• Effect of polymer hydroxyl groups

• Effect of polymer vinyl content and distribution on properties of vulcanizate

• Effect of trifunctional chain links in raw rubber

HCR Silicone's Production equipment and operating conditions

After years of production and operation assessment, the thermal vulcanized silicone rubber raw rubber production mainly adopts the following three processes:

1. The polymerization reaction material is intermittently dehydrated through the dehydration tank - compounding ingredient - the static mixer is continuously polymerized - the flasher is continuously deducted Molecular substances - packaging;

2. Polymerization reaction materials are dehydrated by dehydration kettle - polymerization reactor batching, batch polymerization - flasher continuous depletion of molecular substances - packaging;

3. Reactor dehydration, batching - continuous polymerization of pipeline reactor - The flasher continuously depletes the molecular matter - packaging.

Technical measures to improve the quality of hot vulcanized silicone rubber:

• Production process and formula

• Improve the purity of raw materials

• Scientifically regulate polymer volatiles

• Regulating the molar mass and distribution of polymers

• To reduce or eliminate polymer hydroxyl groups

• Regulating polymer vinyl content and distribution

• Avoid raw rubber polymers to form trifunctional links

• Increase the variety of silicone rubber raw rubber