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Twin screw extrusion: a benefiting solution for specialty compounds and complex masterbatches
Clextral has acquired extensive expertise in plastics technology (polymers), particularly in the implementationœ of technical compounds (or compounds with specific properties) based on polyolefins, polyamides, ABS, etc., and complex master batches.
This experience is the fruit of collaborations with leading firms in the chemical or plastic transformation fields
Twin screw extrusion technology for compounding and masterbatches
Advantages of Clextral twin screw extrusion for the production of compounds and master batches:
• Optimum product quality
• Dedicated screw profiles, ensuring high mixing quality and effective pigment dispersion
• Pigments can be pre-mixed with the polymer, fed by individual dosers or injected at subsequent stages in the polymer mixing process
• A powerful kinematics transmitting high torques to create maximum shearing, ensuring a homogeneous mixing. The short contact times protect heat-sensitive materials.
• Process flexibility
• The opening sleeve allows immediate access to clean and reconfigure the screws, reducing down times between batches
• Channels are designed for a rapid change
• Self-cleaning screws facilitate cleaning for colour changes.
• "True" surface screw elements prevent the infiltration of material between the screw sections
Turn key production lines for compounding & masterbatches
Special compounds:
The twin screw technology allows extruding granules with complex compositions by incorporating in the base matrix up to 5 or 6 components, which explains the name "compound" given to these granules.
These compounds have special characteristics and are increasingly being used to elaborate a wide range of elements used in the automotive industry, the packaging industry, or the household appliance industry, for example.
The obtained compounds are semi-finished products, which will then be used to produce differently shaped parts in injection presses, injection blow machines, film, profile section, synthetic fibre or other lines.
Masterbatches:
Master batches are pigment concentrates of organic or inorganic (mineral) origin (30 to 80%) used diluted in the virgin polymer : phtalocyanin blue, rubin red, titanium dioxide, iron oxide, etc.
The powder polymer (PE, PP) is pre-mixed with the pigment and waxes to improve dispersion.
Advantages of Clextral twin-screw extrusion for the production of master batches:
• The Clextral twin screw extruders offer appropriate characteristics to obtain high-quality pigment concentrates with specific properties.
• Machine cleaning is facilitated for colour changes : opening sleeve, special line, reed granulation
• Additional pigments, lubricants, stabilisers and other agents may be gravity fed through additional openings or injected in liquid form at various stages along the sleeve. Volatile components are extracted by vacuum degassing modules.
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