*NEWS*CANON:HOW THEY RECYCLE PLASTICS

[Anonymous]

Developed to Promote the Use of Recycled
Plastics

Almost all the housing materials of office
automation equipment are made of plastics.Canon began its project to develop
recycling technology for the plastics of office automation equipment in
1992.

In general terms,collected plastic materials have dirt and
deterioration, and the additional heat history to which they are subjected
during the recycling process means that it is not easy to maintain recycled
materials at a level of quality high enough for reuse in their original
application. In particular, recycled plastics are avoided for use as exterior
housing due to the unappealing appearance and the difficulty in meeting the
strict requirements of applicable electric safety standards (UL).

The
sandwich molding technology was developed as a method of resolving this issue.
This is the first technology in the world to allow use of recycled plastic for
exterior housing.

Part of Copying Machine Where Recycled Plastic Is Used

Exterior Power Box of Inkjet Printer Where Recycled Plastic Is Used

Using Recycled Plastics for Core
Layers

The main plastics employed by Canon for its
products include PC+ABS alloy, PS, ABS and Noryl resins. In sandwich molding,
the PC+ABS alloy resin that is used as a material in the housings of many of our
products is recycled for reuse in copying machine housings.

Following
the processes of grinding/powdering, foreign matter removal and
cleaning, PC/ABS resin separated from used products is generally
kneaded with virgin stock compounds (sometimes special additives are
added to recover physical properties)and reprocessed into pellets for
reused as molding. However,Canon’s sandwich-molding method does not
knead the resin with virgin plastic compounds; instead, it utilizes
this resin for the core layers of molding after grinding/powdering,
foreign matter removal and cleaning. These core layers are then
sandwiched between virgin stock skin layers. This method solves the
problem of physical appearance being ruined by the possible
contamination of foreign objects and irregular color tones. In
addition, we have successfully reduced recycling costs, because there
is no need to count on materials suppliers.

Additionally, while it was difficult to inject the core plastic compound
uniformly into the thin layer, Canon has achived 30% of content of core being
injected into 3.0mm of thickness.

We have also completed development of a
recycle grade material employing Noryl and HIPS resins retrieved from used Canon
products, and have Utilized it for various parts of office automation
equipment.

Example of Sandwich Molding (MMP
Sandwich Molding at Kobe Steel, Ltd.)

A special plate to inject recycled plastic flakes is installed at the original nozzle tip of an injection-molding machine. The injected flakes are then sandwiched between virgin stock skin layers from both sides so that they does not escape or overflow, but spread uniformly. Using conventional recycling methods, it was difficult to inject the core plastic compound uniformly into a thin-wall work piece. However, the Canon method has achieved a 30% content of core (recycled) materials at 3.0 mm thickness.

As shown above, ingenuities
have been introduced in the mold geometry and injection conditions so that a
large volume of core material can be injected consistently. Because the recycled
material is sandwiched between the virgin materials,the problem of ruined
physical appearance resulting from the contamination of foreign objects or
irregular color tones is avoided.

[Author]

February 21, 2005 at 9:50 AM