Silicone rubber is extruded to make a wide range of products. This includes solid or sponge tubing, rods, gaskets, seals, etc. The following image shows a typical silicone extruded profile of a tube.

Manufacturing Silicone Extruded Profiles
To produce silicone extruded profiles, rubber is forced continuously through a die. This die helps it to forms into a desired cross-sectional size and shape. Silicone rubber ideally must be extruded at room temperature. A vital point about the silicone rubber extrusion is that temperatures may not be allowed to go beyond 54°C during the process of extrusion. This is to ensure protection against scorching and loss of the vulcanizing agent.
A screw extruder used for manufacturing silicone extruded profiles must contain the following equipment:

• A screw specifically designed for silicone rubber.
  
  
• A Feeding roller that is attached to screw by a gear or that is driven separately in the intake zone.
  
  
• Extended barrel, according to the length of the screw. The barrel should preferably be hard metal plated.
  
  
• A breaker plate fitted with recess for holding screens.
  
  
• Spider flange or a crosshead
  • For holding a mandrel for the formation of inside diameter during the making of tubing.
    
    
  • For holding die holder and allowing radial adjustment for centring.
  
  
• Universal die holder
  
  
• Plate or coin die
  
  

What Constitutes A Good Die Design A good die design should incorporate the following things: Absence of "dead spots" There should be no”dead spots” to catch or hold the rubber as it move towards the die. If some amount of silicone rubber is trapped in the extruder for a prolonged period, there may be the potential risk of frictional heat causing vulcanization. This would give rise to problems of restricted flow and rough extrusions. Uniform flow There should be uniform flow of silicone rubber through out the die. Care must be taken for sharp corners in the die as they are inclined to produce excessive drag. This runs the risk of having rough edges on the extrusion. Flexibility Dies should be designed in a manner to leave scope for easy corrections or adjustments.

Features of Silicone Extruded Profiles
The silicone rubber extruded profiles show the following features:

• A low compression set
• Excellent thermal insulating properties
• Resistance to fire
• No toxicity as approved for use in food contact applications
• Good elasticity
• Can resist temperatures up to 500°F
• Resistance to Ozone
• Flexibility for custom profiles
• Anti adhesive
• Wide range of durometer or hardnesses

Applications of Silicone Extruded Profiles
Silicone Extruded profiles have a variety of industrial applications. Some of the most popular applications include the following:

• Fluid mixing tank seals
• Mixer seals in food manufacturing
• Bladder seals
• Lighting enclosure seals
• Seals for windows
• Environmental chamber seals
• Seals for oven and microwave
• Refrigerator/freezer seals
• Seals in automobile applications
• Oven and microwave seals

Silicone Extruded Profiles for Core Healthcare Products Silicone extruded profiles can be processed for making thin-wall, tight-tolerance ID/OD tubing for use in medical applications. Some of the products include: ID/OD tubing with 1.5" diameter Multilumen Microlumen Drain tubing Gaskets Wound drains Urinary catheters