uk head office

0845 674 4747

Silicone Engineering > Blog > Archives for June 2015

Blog

Find out how Silicone Engineering’s knowledge and expertise in the industry provides explanations and answers to all your silicone questions.


Difference between platinum and peroxide curing?

When we talk about platinum or peroxide curing in the silicone world, curing is when the silicone rubber is chemically cross-linked by means of the addition of a peroxide or platinum curing agent. The curing agents differ chemically to give the end product, in this case silicone, different properties. Here we look at the positives and negatives of each system to make it clearer when deciding on what silicone material you require for your application.

 

Peroxide Cured Silicone

Positives

Easier to process – needs

silicone questions

Open and closed cell silicone sponge differences?

It is important when choosing any form of silicone sponge to understand the difference between open and closed cell. Confusing the two could lead to failure of a seal or gasket in application.

Open Cell Sponge

Open cell basically means that each cell, or if you like bubble, is openly connected to the next cell. These cells are not complete closures therefore water, moisture and dust can very readily make their way into the cell structure.

A good example of an open cell sponge

What Makes Rubber Stretchy?

There is one thing that all rubbers, natural and synthetic, have in common – they are all stretchy. In essence that’s what makes rubber, rubber!

But what exactly makes it stretchy. The answer to this is entropy.

Entropy is a state of disorder. There is an important law of physics called the Second Law of Thermodynamics which says that a system will move from a state of order to disorder. We have all seen this in everyday life. For example a room

What is the shelf life of a silicone product?

Standards that give shelf lives for elastomers, group different types into categories. BSI SO2230 puts silicone into Group C which has the lowest sensitivity to ageing effects and gives silicone an initial ten years shelf life.

After this it needs to be tested in some way to prove that it is still “fit for purpose”. Fit for purpose usually means that the material still meets the manufacturers original specification although it can be very difficult to test an extruded or moulded

How easily does silicone stick to different surfaces?

Silicone Adhesion

We often get asked a number of questions relating to silicone sticking to other surfaces and substrates. As simple as it may seem, the answer is often more difficult depending on the types of materials involved in the adhesion process. Here we will try to explain the basics of silicone and its adhesive properties to other surfaces.

Once cured, silicone can be extremely difficult to stick to surfaces. Silicone rubber will almost always need some form of adhesive to enable them

Page 1 of 3 pages

© 2017 Silicone Engineering All rights reserved