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Static problems associated with plastic products such as thin films not only cause processing problems
in manufacture as well as use in the converting industry, but also adversely affect performance during
usage. To achieve long term performance, anti static characteristics should remain during the entire
life span of the product, but conventional anti static agents provide solutions that are temporary.
Non-permanent anti static agents are typically hygroscopic in nature and are basically less compatible
with polymers. Their migration to surface generates anti static behaviour in the plastic products. Water
absorption of the anti static agent makes it conductive. Typically these non-permanent anti static agents
have low molecular weight and are chemicals like glycols, sulphonates or amides.
Permanent anti static agent agents are usually based on polymers and therefore have high molecular weight.
During processing, they form a continuous network within the polymer matrix that requires being anti static
in property. It starts functioning immediately and does not require depending upon migration to surface. This
also helps to retain anti static property over a long time.
Typically permanent anti static agents are based on polyamide or polyester and
are therefore non-compatible with non-polar polyolefins.
Dupont has recently developed a new type of permanent anti static agent based on ethylene copolymer
called Entira AS MK 400. Due to its polyolefinic nature it has excellent compatibility with polyolefins.
This new type of permanent anti static agent is not only compatible with PE, PP and EVA, but also works
well with engineering polymers like polyamide as well as ABS.
This new permanent anti static agent has a potential market in the areas of:
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Multi layer films |
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Multi layer extrusion blow moulded containers. |
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PE pallet stretch hood |
Multi layer products offer a special advantage for permanent anti static agent because the agent does not
require any migration to external surface. Presently this grade of anti static agent works best in environment
having higher humidity. Dupont is endeavouring to develop grade that can be effective even at lower humidity levels.
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