Custom made silicone formulations

At Venair, we are continuously working on silicone formulations adapted to the customer’s different demands – a solution which develops its own polymerization silicone method based on basic silanes. A custom-made formulation of the silicone offers tailored products to the pharmaceutical, biopharmaceutical and food industry, among others, with unprecedented benefits which have not been seen on the market so far.

The process

To do this, the polymerizations are synthesized in the laboratory by different ring-opening polymerization catalysts, which can be altered during or after polymerization. Proceeding from a siloxane channel from a polycondensation process, using a vinylsiloxane, a part of the methyl groups are replaced by vinyl groups which results in polyvinyl siloxanes. The polymer will be the result of this process, whose properties will depend on the size of the polymer chain (polymerization degree, chain branching), the vinyl group content, the weight of the molecule, etc.

Polymer substituents to change properties

The synthesized polymers will have different properties, depending on the included substituents and their position. In the laboratory, the three types of polymers, which cover the biggest market, are synthesized with vinyl substituents, fluoropropyl substituents and phenyl substituents. The different polymer substituents can change the properties. For example, a phenyl substituent gives the silicone bigger temperature resistance, and a fluoropropyl substituent means that the final product has bigger resistance with regards to some dissolvent.

Polymer substituents to change mechanical properties of hoses

The mixing

Subsequently, we proceed to the mixing of the silicone, where necessary additives are added in order to modify the basic properties until we have a product, which complies with the customer's demand. This method makes it possible to change the properties of the final product with a clear objective: full adaptation to the customer’s needs.

Unprecedented benefits

In the manufacturing industry of silicone hoses and tubes, there are enormous advantages in regards to these new materials compared to regular silicones, both in terms of pure performance (heat resistance, chemical compatibility, flexibility, durability, etc.) and adaptation to the requirements of a particular industrial process. The development of custom made silicones also ensures consistency in the formulation of raw materials, which results in a stable product completely adapted to its use.

1. Maintaining flexibility at high temperatures

An example of the special formulation is that the silicone is able to maintain its flexibility after having been subjected to temperatures up to 300ºC. So far, this is an unprecedented product in the industry, which does not lose its elasticity nor generate breakage when it crystallizes. The silicone is synthesized from the first polymer. During the mixing process any additive necessary are added so that the final product’s physical properties maintain intact. The greatest achievement is the highly flexible conservation, even after two weeks of aging at 300ºC. After this process, hardness only increases 11 points, contrary to most of the silicones on the market, which increase more than 20. Furthermore, the elongation stays around 200 %.

A clear example of this incredible optimization of the flexibility of the product is Vena® Sil 650V.

2. Substantial prolongment of the hose useful life

The benefits obtained with this type of hose , which is exposed to high temperatures in the production process, are very remarkable. The material can prolong its useful life substantially in product transfer processes at high temperatures, because it preserves its flexibility and mechanical abilities without breaking.

Another example about this property can be found in the heated hoses made completely under client's temperature requirements.

3. Optimization of the compatibility with FKM materials

Another example of this specific development is the formulation of a silicone with adhesive properties in order to optimize its compatibility with FKM (flouroelastometro), a commonly used material in the inner layers in the hoses due to its chemical resistance, which has a low adhesion capability with the rest of the silicone layers that forms the hoses. This development makes it possible to reach a level of adherence that increases the value of the force required to disengage the materials by five times compared to a conventional silicone hose. The new silicone contains an additive that optimizes the union with the FKM, because the vulcanization is produced at the same time as the union is made between two layers.

You can check Vena® Vitosil to learn more about the compatibility with FKM.

4. Higher bending strength

In this way, we obtain a product with greater resistance to bending, as the layers are not separated by mechanical action, which gives the product more durability. FKM is a fluoroelastomer, and in some cases it has been indicated that the silicone is incompatible with FKM . The combination of this product and good silicone adhesion makes it possible to expand the applicability of Venair’s product range.

A clear example of this incredible optimization of the flexibility of the product is Vena® Sil 650V Lastic.

5. Improvements of the reistence and the chemical compatibility

Another central battlefield is the research aimed at improving the resistance and the chemical compatibility of the silicone oils or coolant and certain chemicals. In this regard, all sorts of tests are carried out, that is, tests concerning aging in extreme conditions, checks on working conditions and tests according to international regulations or to a customer’s specific regulations. 

To know more about our custom silicone formulations talk with our engineers and sales advisors, about the remarkable benefits about using this materials for a more optimal production process.

Discover more about the benefits of custom silicone formulations.