Liquid silicone rubber (LSR) is a versatile manufacturing material that can be used across many industries. It is highly durable and can withstand a variety of environmental conditions. It is also very biocompatible, making it ideal for use in products that come into contact with humans such as skin, organ parts or prosthetics. It is also capable of withstanding a wide range of temperatures, from -60 degC to +250 degC, maintaining its mechanical properties and high-performance.
The chemical structure of liquid silicone rubber is composed of silicon and oxygen, creating an inorganic polymer called siloxane. This backbone can then be modified by adding a number of organic chemical groups that change the physical characteristics of the final material. These can include a wide range of additives, crosslinkers and fillers to achieve specific performance requirements.
Depending on the intended end-use, silicones can be cured with either heat or a combination of chemicals and heat to create a solid or semi-solid elastomer. Injection molding is the most common process used to manufacture LSR. During this process, pliable LSR is injected into a mold and heated to a temperature that initiates a chemical reaction that cures the elastomer, forming a strong, durable part with an exact geometry and dimensions. Injection molding of LSR is fast and allows for complex part designs with intricate features.
Medical-healthcare grade or class VI silicone that has been tested for biocompatibility is often used to produce parts like menstrual cups, baby bottle nipples and scuba mouthpieces. It can be molded into medical-grade seals for appliances such as bathing tubs, mattresses and shower curtains. It can even be used in long-term implantable medical devices.
These materials are also commonly found in consumer and industrial applications such as medical hoses, automobiles, electronics and clothing. They are often used in products that have to withstand high and low temperatures, as well as chemicals and humidity. They are also known for their excellent electrical properties and can be made conductive by adding a powdered filler such as carbon.
The versatility of silicones also makes them ideal for a number of other applications that require high-performance, durable materials. For example, they can be blended with other elastomers to improve their wear and tear, or with metals to make them more durable and resistant to high temperatures and harsh chemicals. They can also be pigmented to match color needs, including human skin tones.
In addition to its impressive mechanical properties, such as good elongation and high tear and tensile strength, LSR is also very soft with great flexibility. It is also easy to handle and ideally suited for injection molding with quick cycle times, which can help reduce costs and increase productivity. It is also able to be injected into very small features and tight spaces, which can open up new design possibilities for your next project.