| In standard rubber
processing, all materials scrapped post curing are treated as waste. |
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| Using HSM processing,
these materials can be processed and returned to the main material
stream. |
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| Typical fluoropolymer scrap from
an injection moulding process. |
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| EPDM door sealing strip
scrap. Note the steel reinforcing and the foamed upper geometry. |
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| Nitrile gasket scrap. This
material is left over from the punching process during which small flat
washers are produced. |
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| The following process
steps are critical to recycling: |
 | collection: scrap materials can be
collected from a number of points within the process. The
decision on whether or not to separate the materials at source will
depend on the variation in types of material being processed and their
relative volumes and values. This will also influence the size
of containers and the frequency of collection.
For many, a re-education of the operatives involved is also required
to ensure that the scrap is treated as a valuable material and not a
waste stream. |
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| p materials are presented in a
number of forms, ranging from granulate and powders through to metres
of extrudate. In extreme cases, size reduction may be required
to ensure accurate metering to the HSM process.
Materials can also be contaminated or contain a mixture of polymers
either due to the product / process design or as a result of the
collection process. In such cases, a sorting or
cleaning of materials may be required.
Materials may contain metal or fabric reinforcing layers. In
such cases, separation is required, which can be either manual
or automated.
In most cases, inspection of the incoming materials is
recommended to maintain quality levels and reduce the possibility of
the introduction of foreign matter. |
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| HSM processing: the
HSM process can be adjusted automatically for each batch processed to
ensure optimum processing. A range of processing parameters can
be stored as recipes and activated for each batch and the critical
parameters can be stored for stored reference or quality verification. |
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| post processing: dependant
on the characteristics of the materials processed and the target
process to which it is to be returned, a number of options exist for
the material form. This could range from milled strip or sheet
to extruded chord or powdered granulate. During post processing,
the materials can be weighed, packaged and labelled to suit the
downstream process. |
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| Delivery and usage: the
standard approach to recycled materials within the rubber industry is
to treat them as a filler (compatible at best). Many HSM
processed materials can be treated as compounds and combined with
virgin stock on the mixer dump mill. If this is acceptable, then
additional savings can be made on capital equipment as the effective
output of the mill room will be increased by the volume of materials
recycled. |
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| Recycled FKM materials.
These are 100% HSM processed materials that have been sheeted off a
mill. They can be used to manufacture new product or combined with
virgin compound to manufacture the original product. |
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| The
benefits of HSM processing include: |
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| increased production capacity |
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| materials cost reduction with acceptable materials
performance |
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| reduction (elimination) of factory waste and
associated charges |
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| one process capable of handling most material types |
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| quality controlled processes with no change in
compound ingredients |
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| enhanced environmental credentials |
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