HT 33 – Addition-cure RTV silicone

Silicone liquid rubber RTV2 HT 33 Transparent Zhermack - addition silicone for moulds

Clear RTV2 Silicone for flexible moulds and concrete casting

HT 33 Transparent Zhermack is a two-component silicone rubber RTV2 with vulcanization through addition, designed for flexible moulds. The system consists of two components, BASE and CATALYST, which are mixed in the ratio 1:1 And it vulcanizes at ambient temperature.

Silicone has a fluid consistency, is pourable and, after vulcanization, has a hardness of 33 Shore A. The combination of dimensional stability, reproduction accuracy and mechanical strength makes it suitable especially for moulds, artificial stone, concrete casting and jewellery applications.

Recommended applications

According to Zhermack technical documentation, HT 33 Transparent is recommended for:

• making flexible moulds;
• Concrete moulds and concrete castings;
• artificial stone and decorative elements cast;
• jewellerywhere the precision of reproduction and mechanical strength are important.

In concrete applications, HT 33 can be used for the production of molds for reproduction of elements such as reconstructed stone, decorative elements and other cast pieces, depending on the geometry of the model and the production process used.

Practical advantages of HT 33 Silicone Transparent

• Simple mixing ratio 1: 1 - BASE and CATALYST weigh in equal amounts.
• Fluid and pourable consistency - facilitates the distribution of material over the model and the penetration into its geometry.
• hardness 33 Shore A - allows obtaining a flexible mould with a relatively robust consistency.
• Good reproductive accuracy - the important feature for moulds and models with details.
• Dimensional stability and durability - important properties for repeated use of a mould.
• High mechanical strength - vulcanized silicone has a traction resistance of 5 N / mm ² and an elongation at break of 460%.
• Wide range of temperature after vulcanisation - the properties of vulcanised silicone are guaranteed between -40 ° C and + 200 ° C

Main technical characteristics

• Type: silicone RTV2 two-component, with added vulcanization
• Appearance: translucent
• BASE mixing ratio: CATALYST: 1:1
• Density at 23 ° C: 1,09 g / cc
• Vascosity of the mixture: 7500 cP
• Working time / Pot Life at 23 ° C: 20 minutes
• curing time at 23 ° C: 210 minutes
• hard after 24 hours at 23 ° C: 33 Shore A
• Traction resistance: 5 N / mm ²
• Landing at break: 460%
• Break resistance, Die B: 20 N / mm
• Volcanised Silicone use temperature: -40 ° C to + 200 ° C

Important: Technical values are provided by the manufacturer as indicative values and should not be used for the development of specifications without checking the applicable technical documentation.

Working time and curing time

At standard temperature 23°C, HT 33 Transparent has a working time / Pot Life of about 20 minutes And a curing time about 210 minutescalculated from the beginning of mixing the two components.

Temperature directly influences these times. At temperatures above 23 ° C, working time and curing time shall be reduced. At temperatures below 23 ° C, both times increase considerably.

Completing a multi-step mould

If the prepared material is not sufficient to complete the mould, the first layer may be allowed to strengthen. Additional amount of HT 33 can be applied maximum 24 hours after the first layer has been cured. According to the manufacturer, the second layer adheres to the first without altering the final result.

Best TOOLS Recommendations

To achieve reproducible results, weigh the two components separately and respect ratio 1: 1. Resuspend BASE and CATALYST prior to dosing and use clean and dry containers.

For molds with many details or for works where air bubbles can affect the final surface, degassing under vacuum is recommended by the manufacturer.

Complementary products that can be useful in the process of making molds:

• precision scale - for the correct dosage 1: 1 of the components,
• mixed containers - for controlled preparation of silicone;
• Mixture spatula - for mixing the components,
• Vacuum equipment - to degas the mixture and reduce air bubbles;
• Sulphur-free modeling plastic - for the preparation of certain models and the construction of the moulds, when the chosen process requires compatible plasticine.

Common questions about HT 33 Transparent

Conclusion

HT 33 Transparent Zhermack RTV2 is an addition-cure, pourable silicone with a hardness of 33 Shore A, designed to make flexible moulds. Simple mixing ratio 1: 1, fluidity, stability of mechanical properties and applicability for concrete moulds, artificial stone and jewellery recommend it for processes in which reproduction accuracy, mechanical strength and mould durability are important.