plastics

Grade 8

What is plastics?

• Plastics are man-made materials. Today plastics are used in almost every phase of modem living. Some of the advantages of plastics are lightness, range of color, special physical properties, and ability to be mass produced

What plastics is used to make?

• Dinnerware and electric switchboxes are examples of the wide range of definite shapes made from plastics. Other examples are flexible film; sheeting, such as shower curtains and upholstery; airplane and automotive parts; internally lighted signs; coatings on textiles and paper; and many household gadgets. Plastics can be used to bind together such ma terials as fibers of glass, sheets of paper, or wood. These materials form boat hulls, air plane wing tips, and automobile bodies. Some modern automobiles have more than 300 in dividual plastic parts

Type of plastics

• The two general classifications (groupings) of plastic materials are thermoplastic and thermosetting. Thermoplastic materials soften when heated, and harden when cooled. They can be made soft or hard again and again.

• Thermosetting materials harden into permanent shape when put under heat and pressure .Once they are hard they can never be softened again

Examples of Plastics

• The type’s thermoplastics are Acrylic, cellulosics, nylon, polyethylene and vinyl . Melamine and urea, phenolic and polyesters are thermosetting plastic types.

Examples of thermoplasticsType of plastic Plastic group Uses

Cellulosics thermoplasticToys , lamp shades , partition ,shelf covers, storage boxes, ice crushers, juicer bowls ,vacuum parts, tool handles pipes ,spectacle frames

Nylon thermoplastic Slide fasteners, combs , brushes and bristles, baby dishes , funnels , salad spoon and fork ,washer ,gaskets

Polyethylenethermoplastic

Squeeze bottles, ice trays, toys, storage boxes, flashlights , wiring, pipe, kitchen- ware (Can be film, semi rigid, rigid, or coating)

Polystyrenethermoplastic

Canisters, storage boxes, wall tile, picnicware, toys, refrigerator door, liners and bins radio, phonograph, and air conditioner, housings light fixtures

Vinylthermoplastic

Raincoats, upholstery, tile, inflatable, curtains, toys, luggage, baby pants and pads, records (Can be film, sheeting, semi rigid, rigid, coating)

Acrylic thermoplastic Bowls, trays, partition, roofing, handbags, eye glasses, light fixtures, table appointments, bookends, dresser sets , window glazing ,picture frames

Examples of thermosetting plastics

Type of plastic Plastic group uses

Melamine thermosetting Dinnerware , table and counter tops ,cutlery handles, buttons ,housings for shavers and appliances

Urea Thermosetting Buttons, bottle tops , electrics plugs, wall plates

Phenolic Thermosetting Appliance handles and bases, TV and radio cabinets, telephone, pot handles, lightplugs and switches, wall paneling, furniture drawers, game counters, pen stands

Polyesters Thermosetting Luggage, awnings, roofing, partitions, chairs, light panels, lamp shades, fishing rods (The plastic is combined with strengthening material)

Differences between thermoplastics and thermosetting plastics

Property Thermoplastics

Thermosetting plastics

Action of heat They soften on heating and set on cooling every time

They set on heating and cannot be resoftened.

Expansion due to heating

They expand very much on heating.

Their expansion is only marginal due to heat.

Differences between thermoplastics and

thermosetting plastics Property Thermoplastics Thermosetting plastics

Type of moulding They are processed by injection moulding.

They are processed by compression moulding.

Scrap recovery Scarp can be reused. Scarp cannot be reused.

Advantages of plastic:

• Advantages of plastic:• Plastic are light in weight.• They can be easily moulded and have excellent finishing.• They possess very good strength and toughness.  They

possess good shock absorption capacity.• Plastic are corrosion resistant and chemically inert.• They have low thermal expansion of co-efficient and

possess good thermal and electrical insulating property.• Plastic is very good water resistant and possess good

adhesiveness.• Plastic is strong, good and cheap to produce.

Advantages of plastic:

• Plastic is a recycling process and it does not decompose.

• Plastic bottles can be reused and restored over again and again.

• Plastic is one of the unbreakable.• Plastic is an odourless.• Plastic is used for building, construction,

electronics, packaging (gladwrap) and transportation industries.

• Used to make - Water bottles, pens, plastic bags, cups etc.

Advantages of plastic:

• Plastic are Very cheap to make.

• Durability

• Strength

• Chemical resistance.

• Advantages of plastic are used to produce another product.

• Used to reduce soil and wind erosion.

Disadvantage of plastics:

• Plastic is a nonrenewable resources.

• Plastic is softness.

• causes CANCER

• Disadvantage of plastics are embrittlement at low temperature.

• Disadvantage of plastics are deformation under load.

Disadvantage of plastics:

• Disadvantage of plastics are low heat resistant and poor ductility.

• Disadvantage of plastics are combustibility.

• Produces toxic fumes when it is burnt

• It is a recycle process, but it is very costly.

Video • How is Plastic Made? http://www.youtube.com/watch?v=6eCt0VDg-Kc• Plastic Manufacturing Processes http://www.youtube.com/watch?

v=jYkKBUFORco• How it's made - plastic bags http://www.youtube.com/watch?

v=ix5inj6gvWs• How it's Made Plastic Cups and Cutlery

http://www.youtube.com/watch?v=WlYHC8hqjjY• How Plastic Bottles are Made http://www.youtube.com/watch?

v=T01i_vp2mJE