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Manufacturers often make several different products
on the same equipment. To achieve consistently good quality of different
products, the equipment is required to be clean and free from the
previous product processed. The products could be different and
could vary in various aspects; colour, resin, formulations or melt
viscosity.
While good planning of the manufacturing operation
could help in reducing the production of waste material that is
generated between the change from the first to the next product,
a complete clean up of the equipment would be required for changeover
to a very critical product. The production loss due to complete
clean up is quite significant and negatively contributes, heavily
to the Profitability of the compounding operation.
There is, however, an alternative method available,
that could reduce the downtime of processing equipment. Special
compounds known as "Purging Compounds" are commercially
available. This compound is used to remove either colour, resin
or formulation before a changeover or shutdown of the compounding
line. Even if the shutdown is required, the cleaning of equipment
with the Purging Compound reduces downtime very significantly.
There are essentially 3 types of Purging Compounds
available :
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Chemical Purging Compound; this type of compound contains a chemical
that reacts with the compound when soaked for some time at elevated
temperatures. The chemical cleaning can be very efficient. Only
the harmfulness of bye-product gas, that is inevitably generated,
could cause some damage to the compounding barrel/screw. |
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The second type of Purging Compound utilizes the mechanical scouring
action of inert fillers that are blended with either universal resin
or with specific resin system. These abrasive fillers could cause
wear on the screw/ barrel on long usage. |
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There is another type of Purging Compound that uses the principle
of mechanical cleaning using non-abrasive granules. These granules
are soft from outside but are solid inside. Their mechanical action
helps in cleaning the equipment without wearing screw/barrel. These
non abrasive Purging Compounds provide the optimum benifits of cleaning
the system without affecting the screw/barrel and are therefore
the best purging compounds that are commercially available in the
market. |
For more information on Purging Compounds, Please
click here
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