Suppliers of plastic recycling machines, recycling machine, plastic recycling machine, washing plant, recycling plant,shredders, waste recycling machines and granulators.
Plastic recycling is the process of recovering scrap or waste plastics and
reprocessing the material into useful products, sometimes completely different
from their original state. For instance, this could mean melting down soft
drink bottles then casting them as plastic chairs and tables.
Plasticsportal listing suppliers of plastic recycling
machines, recycling machine, plastic recycling machine, washing plant, recycling
plant,shredders, waste recycling machines and granulators.
Plastic recycling is the process of recovering scrap or waste plastics and
reprocessing the material into useful products, sometimes completely different
from their original state. For instance, this could mean melting down soft
drink bottles then casting them as plastic chairs and tables.
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Plastic recycling is the process of recovering scrap or waste plastics and
reprocessing the material into useful products, sometimes completely different
from their original state. Before recycling, plastics are sorted according
to their resin identification code. PET, for instance, has a resin code of
1. Processing When compared to other materials like glass and metal materials,
plastic polymers require greater processing to be recycled.Plastics have a
low entropy of mixing, which is due to the high molecular weight of their
large polymer chains. A macromolecule interacts with its environment along
its entire length, so its enthalpy of mixing is large compared to that of
an organic molecule with a similar structure. Heating alone is not enough
to dissolve such a large molecule; because of this, plastics must often be
of nearly identical composition in order to mix efficiently. When different
types of plastics are melted together they tend to phase-separate, like oil
and water, and set in these layers. The phase boundaries cause structural
weakness in the resulting material, meaning that polymer blends are only useful
in limited applications. Another barrier to recycling is the widespread use
of dyes, fillers, and other additives in plastics. The polymer is generally
too viscous to economically remove fillers, and would be damaged by many of
the processes that could cheaply remove the added dyes. Additives are less
widely used in beverage containers and plastic bags, allowing them to be recycled
more frequently. The use of biodegradable plastics is increasing. If some
of these get mixed in the other plastics for recycling, the recycled plastic
is less valuable. Many such problems can be solved by using a more elaborate
monomer recycling process, in which a condensation polymer essentially undergoes
the inverse of the polymerization reaction used to manufacture it. This yields
the same mix of chemicals that formed the original polymer, which can be purified
and used to synthesize new polymer chains of the same type. Du Pont opened
a pilot plant of this type in Cape Fear, North Carolina, USA, to recycle PET
by a process of methanolysis, but it closed the plant due to economic pressures.[citation
needed] Another potential option is the conversion of assorted polymers into
petroleum by a much less precise thermal depolymerization process. Such a
process would be able to accept almost any polymer or mix of polymers, including
thermoset materials such as vulcanized rubber tires and the biopolymers in
feathers and other agricultural waste. Like natural petroleum, the chemicals
produced can be made into fuels as well as polymers. Gasification is a similar
process, but is not technically recycling since polymers are not likely to
become the result. Recently, a process has also been developed in which many
kinds of plastic can be used as a carbon source in the recycling of scrap
steel. Yet another process that is gaining ground with startup companies (especially
in Australia, United States and Japan) is heat compression. The heat compression
process takes all unsorted, cleaned plastic in all forms, from soft plastic
bags to hard industrial waste, and mixes the load in tumblers (large rotating
drums resembling giant clothes dryers). The most obvious benefit to this method
is the fact that all plastic is recyclable, not just matching forms. But criticism
rises from the energy costs of rotating the drums, and heating the post-melt
pipes. Recycling of PET bottles Post-consumer PET is often sorted into different
color fractions. This sorted post-consumer PET waste is crushed, pressed into
bales and offered for sale to recycling companies. PET flakes are used as
the raw material for a range of products that would otherwise be made of polyester.
PVC recycling PVC- or Vinyl Recycling has historically been difficult to perfect
on the industrial scale. But within the last decade several viable methods
for recycling or upcycling PVC plastic have been developed. The most-often
recycled plastic, HDPE or number 2, is downcycled into plastic lumber, tables,
roadside curbs, benches, truck cargo liners, trash receptacles, stationery
(e.g rulers) and other durable plastic products and is usually in demand.
The white plastic foam peanuts used as packing material are often accepted
by shipping stores for reuse. In Israel successful trials have shown that
plastic films recovered from mixed municipal waste streams can be recycled
into useful household products such as buckets. Similarly, agricultural plastics
such as mulch film, drip tape and silage bags are being diverted from the
waste stream and successfully recycled into much larger products for industrial
applications such as plastic composite railroad ties. Historically, these
agricultural plastics have primarily been either landfilled or burned on-site
in the fields of individual farms. CNN reports that Indian Dr. S. Madhu of
the Kerala Highway Research Institute has formulated a road surface that includes
recycled plastic.[citation needed] Aggregate, bitumen (asphalt) with plastic
that has been shredded and melted at a temperature below 220 degrees C to
avoid pollution. This road surface is claimed to be very durable and monsoon
rain resistant. The plastic is sorted by hand, which is economical in India.
The test road used 60 kg of plastic for an approx. 500m long, 8m wide, two-lane
road. Since the US annually uses 100 million metric tons of plastic, it could
pave 1.67 billion km of single-lane road this way. Plastic recycling rates
lag far behind those of other items, such as newspaper (about 80%) and cardboard
(about 70%). Low national plastic recycling rates have been due to the complexity
of sorting and processing, unfavorable economics, and consumer confusion about
which plastics can actually be recycled. Part of the confusion has been due
to the recycling symbol that is usually on all plastic items. This symbol
is called a resin identification code. It is is stamped or printed on the
bottom of containers and surrounded by a a triangle of arrows. The intent
of these arrows was to make it easier to identify plastics for recycling.
The recycling symbol doesn’t necessarily mean that the item will be accepted
by residential recycling programs. In the UK, the amount of post-consumer
plastic being recycled is relatively low, due in part to a lack of recycling
facilities. Plastic Identification Code Seven groups of plastic polymers,
each with specific properties, are used worldwide for packaging applications
. Each group of plastic polymer can be identified by its Plastic Identification
code (PIC) - usually a number or a letter abbreviation. For instance, Low-Density
Polyethylene can be identified by the number 4 and/or the letters "LDPE".
The PIC appears inside a three-chasing arrow recycling symbol. The symbol
is used to indicate whether the plastic can be recycled into new products.
The PIC was introduced by the Society of the Plastics Industry, Inc. which
provides a uniform system for the identification of different polymer types
and helps recycling companies to separate different plastics for reprocessing.
Manufacturers of plastic products are required to use PIC labels in some countries/regions
and can voluntarily mark their products with the PIC where there are no requirements.
Consumers can identify the plastic types based on the codes usually found
at the base or at the side of the plastic products, including food/chemical
packaging and containers. The PIC is usually not present on packaging films,
as it is not practical to collect and recycle most of this type of waste.