What is a Silicone Rubber
Silicone Rubber is a synthetic elastomer made up of silicone, carbon, hydrogen and oxygen. It is renowned for its exclusive amalgamation of physical and chemical properties. Some of these properties are temperature resistance, chemical resistance, etc. It is used in various industries for different purposes because of its ability to perform in difficult environments. There are two types of Silicone Rubber. They are:
- Solid Silicone Rubber
- Liquid Silicone Rubber
Solid Silicone Rubber
Solid Silicone Rubber is made up from raw materials of solidified silicone. It is produced by heating and rolling the raw material until it becomes malleable and can be given the desired shape. As the mould undergoes a vulcanizer and is pressed at high temperatures, it is possible to achieve the required hardness of the solid silicone rubber. It is used in aviation, construction and consumer industry.
Manufacturing Process of Solid Silicone Rubber
The process of manufacturing solid silicone rubber includes the following steps:
- Compression Moulding: During this step, the preformed solid silicone is kept in the mould cavity. Then, it is heated and pressured due to which the raw material takes the shape of the mould.
- Transfer Moulding: This process is quite similar to compression moulding but it utilizes a plunger to change the shape of the raw material according to the mould cavity.
- Extrusion: The last step of this manufacturing process is extrusion. Heating the solid silicone and using a shaped die is involved in this process. The shaped die helps in maintaining continuous lengths of precise profiles or cross-sectional shapes.
Characteristics of Solid Silicone Rubber
Below stated are some of the characteristics of solid silicone rubber:
- It is resistant to temperatures.
- It is resistant to chemicals.
- It is a non-sticky substance.
- It possesses excellent electrical insulation.
Application of Solid Silicone Rubber
Solid silicone rubber can be used for following applications:
- Gaskets, seals, washers, etc.
- Grippers, wheels, rollers and robotic products.
- Ducts, tubing and hoses that require high temperatures.
- Electrical Insulations and Thermal Protection.
- Shock Absorbers.
- Parts for food processing. (only if approved)
Curing for Solid Silicone Rubber
To cure the solid silicone rubber, a process named vulcanization is used. It is a chemical process that converts a rubber compound into a durable solid. This process is conducted on high-temperatures.
Liquid Silicone Rubber
Liquid Silicone Rubber is the liquid form of silicone elastomer. It is made by using a liquid injection moulding method. It can be produced in less time and with the use of minimum raw materials. It is used in the healthcare, automotive and food & product packaging industries.
Manufacturing Process of Solid Silicone Rubber
Liquid Silicone Rubber is manufactured using the injection moulding method. In this process, two components i.e., silicone polymer and any cross-linking agent are mixed in accurate amounts. This mixed liquid is straight a way injected into the mould cavity. The material then takes the shape of the mould. Liquid Silicone Rubber made using this method is popular for its accuracy and design. It becomes an ideal choice for creating highly detailed parts.
Characteristics of Liquid Silicone Rubber
Below stated are some of the characteristics of liquid silicone rubber:
- It can be vulcanized quickly.
- It possesses excellent fluidity.
- It is non-irritant to skin.
- It is safe for the environment.
Application of Liquid Silicone Rubber
- O-rings and seals,
- Moulded parts that require precision such as valves, connectors or nozzles.
- Healthcare appliances such as tubes and masks.
- Membranes, boots and automotive sensors.
- Thermal pads and electronic assembly.
- Lenses and encapsulants.
Curing for Liquid Silicone Rubber
Liquid Silicone Rubber is cured at less temperatures. This becomes an advantage for highly sensitive materials and requires shorter cycles of time in its manufacturing process.
Factors Distinguishing Solid Silicone Rubber and Liquid Silicone Rubber
| Solid Silicone Rubber | Liquid Silicone Rubber |
|
Applications |
|
| ● Used in production of day-to-day consumer products.
● Used for industrial and mechanical parts of the aviation and automobile industry. |
● Used in the manufacturing of food products.
● Used in healthcare products that come in direct contact with human skin. |
|
Appearance |
|
| ● Denser in nature and consists of fluidity. | ● Available in solid form. |
|
End Products |
|
| ● End products are less transparent.
● End products contain odour due to the existence of vulcanizing agents. |
● End products are more transparent.
● End products are odourless in nature. |
Viscosity of Solid Silicone Rubber and Liquid Silicone Rubber
- Solid Silicone Rubber: Solid silicone holds a higher viscosity which reduces its liquidity. However, this property helps the raw material in shaping and during the manufacturing process. Because of its solid nature, this type of silicone rubber can be cut and shaped very easily.
- Liquid Silicone Rubber: Liquid Silicone Rubber has less viscosity due to which it is flowable and does not need any pressure or long curing cycles. It also has a self-levelling nature which makes the distribution equal and results in consistent quality and reduction of defects.
How to Choose Between Solid Silicone Rubber and Liquid Silicone Rubber
Selection of correct silicone rubber depends on the type of purpose. For example, skincare and healthcare appliances require liquid silicone rubber as these are directly involved with the human skin whereas solid silicone rubber is used in manufacturing daily life products. There is a ton of variety of silicone rubber in the market. These also possess different characteristics. Thus, to choose between the correct form of silicone rubber, one must know the desired properties or the end products such as:
- Transparency
- Resilient to tear
- Resilient to water
- Resilient to high temperatures
- Electrical Conductivity
Take away
This is the brief explanation about the difference between solid silicone rubber and liquid silicone rubber along with their characteristics, manufacturing processes and applications. We hope this information will be effective for you. Please let us know through your valuable feedback and the suggestion in the drop box.