While choosing extruders for different types of rubber there are many choices available. Some of the popular types of extruders are hot feed, cold feed, and mixing extruders. In case of rubber extruders unlike thermoplastic extruders, rubber must be fed in strips to the machine. Consequently the rubber should be extruded without premature curing. The image given below shows a typical silicone rubber extruder.


Rubber extruders can be used to produce a number of shapes. Some of the popular shapes are:

• Medical tubing
• Industrial tubing
• Sheet
• Profile
• Rod
• Wire insulation
• Preform treads
• Sidewalls
• Bead apex compounds
• Wedges and filler components

Advantages of Rubber Extruder
The major advantage of using extruders is their ability for easily forming and shaping the rubber compounds. This proves particularly useful in preparation for other steps in the manufacturing process, or to actually form the desired final product with a comparatively simple equipment. Other advantage being relative ease in the maintenance of the machines and good life expectancy.

Types of Rubber Extruders
Primarily there are three types of rubber extruders that are popularly available. They are the following:

• Hot Feed Extruder
  In case of hot feed extruder the rubber compound needs to be preheated before it is being fed into the extruder. Hot feed extruders are suitable for the manufacturing of strips, tubes, moulding blanks, tyre thread etc.
  
  
  
• Cold Feed Extruder
  In case of cold feed extruder the screw design is more aggressive and designed to accept cold rubber compounds. Increasingly these days hot feed rubber extruders are replaced by the smaller, compact cold feed extruders. But one of the disadvantage(if it is) of cold feed extruder is the cost which is on a siffer side. Cold feed extruders are ideal for profiles, tubes, tyre treads, bead covering, fire hoses, blanks, slugs and other technical extrusions.
  
  
  
• Mixing Extruder
  The third category of mixing extruder comes with different screw pitches and typically has pins that are inserted into the shaft. This enables to introduce a violent flow and mixing.