Plastic Fabrication

!±8± Plastic Fabrication

Plastics Guide a how to

The first man made plastic was invented in 1862 by Alexander Parkes named Parkensine it was a cellulose based Plastic.

Bakelite was the first fully artificial made plastic which was manufatured in 1907 by Leo Baekeland a chemist in New York. It was a resin called Bakelite. The earliest plastic.

Bakelite

A term often used to retell a hard, dense, laminated plastic material made by applying heat and pressure to layers of paper, glass cloth or cotton fabrics impregnated with various artificial resins. These materials have good mechanical drive and dimensional stability with excellent dielectric properites. Used in a range of areas such as in electrical final boxes, aircraft cable pulleys, bearings, gears and transformers, etc.

Avalable In: Sheet from 0.8mm - 100mm thick. Rod & tube from 4mm .

Since then many other Plastics have been invented or discovered. In normal these are:

Nylon:

The most base engineering thermoplastic in use today. manufactured for engineering in any grades, mainly Type 6 and 66. Most base throughout is Type 6 which has an excellent aggregate of toughness, mechanical drive and impact resistance. Glass filled, black Mos2, graphite and special lubricated grades are also available. Used for technical parts, bushes, bearings, gears, wear pads, rollers, pulleys, etc.

Available In: Sheet from 0.5mm - 100mm thick in varying sizes. Rod from 5mm - 500m. Tubes are ordinarily cast to order.

Pvc:

Non-corrosive, chemical and oil resistant. Pvc has excellent electrical insulating properties and is self extinguishing. Used for electrical parts, laboratory equipment, photographic and chemical tanks, fume cupboards, etc. Easy to cut, shape, weld and fabricate. Maximum temperature for use 60°C.

Available In: Sheet from 1.5mm - 70mm thick. Rod from 6 - 200mm.

Polyethylenes:

Hdpe: High Density Polyethlenes are unyielding to a wide range of chemicals. They have excellent insulation properties, almost no moisture absorption and maintain their properties even at low temperatures. Hdpe is ideal for cutting boards in food processing areas. The most base grades used in engineering are Uhmwpe and Hmwpe.

Uhmwpe: Ultra High Molecular Weight Polyethylene has the highest impact drive and best abrasion resistance of any thermoplastic today. Self lubrication, ideal for wear strips, etc. Used widely in the food and containers industries for guide rails, rollers, scraper blades, star wheels, feed worms, chute linings, etc.

Hmwpe: High Molecular Weight Polyethylene provides a good compromise in price and properties for normal engineering use. Used in many similar applications to Uhmwpe, but where abrasion resistance is not critical.

Available In: A range of sheet from 1.0mm - 100mm thick in natural, black & green. Rod from 10 -250mm .

Polycarbonate:

Virtually unbreakable.

The toughest glazing material known today, polycarbonate has an impact drive 250 times greater than glass of equal thickness. Used primarily for all kinds of safety, vandal unyielding and theft deterrent glazing. Some base uses include machine guards, window shields for cranes and forklifts, protection visors, riot shields, etc. Used for glazing in schools, bus shelters, factories and buildings, sports complexes, etc.

Available In: Sheet from 1mm up to 12mm thick. Rod & Tube also available.

Acrylic:

Commonly known as Perspex®, Acrylic is an ideal replacement for glass in many areas. It is widely used for signs, lighting, protection glazing, machine guards, instrument covers, display units, windows for aircraft, boats and caravans, cab glazing for tractors and other machinery. Acrylic has outstanding weathering potential with exceptional clarity. Less than half the weight of glass, yet up to 15 times more unyielding to breakage.

Available In: Sheet from 1.5mm to 50mm thick in a range of sizes and colours. Opal acrylic available for signs and light boxes, Prismatic for light covers and skylights. Clear rod up to 150mm . Tube form 6mm Od to 500 mm Od.

Teflon:

Offering superb properties.

Commonly known as Teflon®. Ptfe has the best chemical resistance of any plastic. Very high heat resistance, highly good electrical properties combined with a very low coefficient of disagreement make it a unique material. Used for bearing pads, gaskets, packing rings, insulators and many chemical plant components. Also produced with glass, carbon or bronze fillers to heighten mechanical properties.

Available In: A range of sheet, rod and tube, skived Ptfe tape, plain and etched. Ptfe coated glass cloth is also available for heat sealing applications.

The above are only a few of the base plastics used in a wide range of applications in our modern day.

Plastics have evolved a long way, nowadays we use Polycarbonate all over the world in many factories as machine Guards.

Acrylic is used in almost every shop as display cases, stands, lightboxes, cake stands, Point of Sale Displays, etc...

Polyethylenes of various grades along with food grade are now used in many facets of the engineering arena. Uhmwpe has an espcecially high co-efficient of disagreement and excellent wear properties.

Acetal is widely used for precision machined components with excellent dimensional stability and good creep resistance.

Polypropylene is mainly used in the fabrication of Chemical Tanks as it has excellent chemical resistance properties.

Point Of Sale Display Stands:

Acrylic is widely used for Point of Sale Displays as it is easy to build and once flame polished using hydrogen & oxygen it looks like glass.
With use of special solvents the fabricator is able to achieve a halt that is required to build Museum Displays.

Cnc Routing

Nowadays most materials are able to be Cnc Machined.

Common Plastics that can be Cnc Routed are:

Acrylic at 2 meters per/min
Polycarbonate at 2.5 meters per/min
Polyurethane using a spiral cutter using multipass option and routing at 1.8 meters per/min
Hdpe routing at 3.5 - 4.0 meters per/min
Pvc at 2.5 meters per/min
Nylon depends on thickness as is tougher to route generally 2 meters per/min.