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Plastic Recycling Processes
Described
RBL are one of the fastest growing plastic recycling companies
in the UK today. We have several plastic recycling facilities and
a network of recycling partners across the UK so we can arrange
collection of your plastic waste from wherever you are. If you have
obligations under the packaging waste directive. RBL are accredited
for the issue of PRNs.
RBL buy plastic waste for recycling and can also offer recycling
processes on a toll processing basis. Below you will find some brief
descriptions of the most common plastic recycling processes.
 Preparation
Plastic scrap or waste comes in all manner of shapes and sizes
such as plastic bottles, bottle crates, plastic pallets and
car bumpers and a variety of material
types. Often these plastic materials are not compatible
with each other when it comes to recycling so they have to be
identified and separated.
It is also necessary to strip off any extraneous materials such
as metal or foam which will hinder the recycling process at
a later stage.
It may also be necessary to clean the scrap (particularly if
the plastic waste comes from packaging applications such as
plastic milk bottles).
Size
Reduction
Before the plastic waste can be melted down and recycled into
plastic pellets for moulding into new products it must be reduced
in size. At its most basic this is a case of sawing large items
of scrap so that they will fit down the throat of the granulation
machines.
Shredding is a much more efficient way of reducing the size
of large scrap plastic items. A shredder basically consists
of a large tank that the scrap is fed into, at the bottom of
which are heavy duty rotating blades which quite literally rip
the plastic to shreds.
The output of the shredding process is irregular sized strips
of plastic which will be up to several inches in length (still
too big for the compounding process).
Finally comes granulation. Granulation is probably the most
common form of plastic recycling and there are many granulation
companies dotted around the UK.
The process again involes a set of rotating blades, but unlike
shredding the granulation process chips the plastic scrap. Grids
can also be used with the granulation machines to control the
size of the resulting regrind (also known as reground). Typically
plastic regrind has a diameter of about 10mm which is ideal
for the compounding process.
Blending
Blending is simply the process of creating a homogenous batch
of plastic and can be used at various stages of the plastic
recycling process. Material may be blended on arrival at our
recycling facilities to aid with testing of the plastic. Many
polymer types are incompatible and therefore we need to ensure
that incoming batches are not contaminated with different polymer
types.
We may also blend several batches of plastic regrind together
to create a homogenous batch of material to be extruded into
compound. This ensures that the finished batch of compound is
consistent throughout.
A blender is essentially a very simple piece of equipment, it
consists of a large container into which the plastic materials
are fed, the bottom of which is conical in shape to aid with
emptying the material out after the blending process is complete.
A vertical screw feeds the plastic to the top of the blender
where it then spays onto the sides of the blender where foils
further disperse the material.How long this process takes depends
on the quantity of material and the speed of the screw.
Compounding
/ Extrusion
The compounding process is similar to that of an injection moulding
machine. Plastic raw materials and additives are metered into
a hopper at one end of a barrel. This material is transported
along the length of the barrel by an Archimedes screw and is
melted by applying heat from external heater bands, as well
as the heat caused by friction / shear heat.
As the material moves along the screw, special sections of the
screw knead, mix and compound the plastic, additives and fillers
together. At the other end of the barrel, the melted plastic
is passed through a wire screen that filters out any residual
dirt, grit or other contaminants, and is then pushed through
a die plate.
As the material comes through the die plate, it is cut into
pellets and then cooled by quenching in water. It is then dried
and packed into a selection of different packaging types.
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RBL are specialists in all aspects of plastic recycling
if you have a requirement for plastic recycling processes
or need assistance with general or plastic waste management
then send us your details through our
contact address or call us on +44-1268-289422.
We also buy and sell all types of plastic in all forms, be
it plastic production scrap, post consumer or post industrial
waste, regrind, off-spec compound and recycled plastic compound.
If you are looking to buy or sell any plastics then please
contact us for competitive pricing
and payment terms.
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