This document summarizes different types of plastics, their manufacturing processes, properties, and applications. It discusses the main plastics - high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). For each plastic, it describes the manufacturing process, physical and chemical properties, and common products made from that plastic. The core plastic manufacturing processes of injection molding, extrusion molding, and thermoforming are also summarized.

1. DESIGN METHOD
Research on
By Simiraaj. M.Design (2nd sem)
NIFT,Kannur.

2. What is plastic?
Plastics are a material that is made up mainly
of macromolecules, that can be made fluid by
the action of heating and pressurizing, and
that can be processed into end products with
any useful shape you want to make.

3. Types of plastic
• High density polyethylene (HDPE)
• Low density polyethylene (LDPE)
• Polypropylene (PP)
• Polystyrene (PS)
• Polyvinyl chloride (PVC)

4. High-Density Polyethylene
High-Density Polyethylene products
are very safe and are not known to
transmit any chemicals into foods
or drinks. HDPE products are
commonly recycled. Items made
from this plastic include containers
for milk, motor oil, shampoos and
conditioners, soap bottles,
detergents, and bleaches. It is
NEVER safe to reuse an HDPE
bottle as a food or drink container if
it didn’t originally contain food or
drink.

5. Manufacturing process
(1) SLURRY PROCESS : The Ziegler-
Natta catalyst, as granules, is mixed with a
liquid hydrocarbon (for example, 2-
methylpropane (isobutane) or hexane),
which simply acts as a diluent. A mixture of
hydrogen and ethene is passed under
pressure into the slurry and ethene is
polymerized to HDPE. The reaction takes
place in a large loop reactor with the mixture
constantly stirred (Figure 4). On opening a
valve, the product is released and the solvent
is evaporated to leave the polymer, still
containing the catalyst. Water vapour, on
flowing with nitrogen through the polymer,
reacts with the catalytic sites, destroying
their activity. The residue of the catalyst,
titanium(IV) and aluminium oxides, remains
mixed, in minute amounts, in the polymer.

6. • (2) Solution process : The second method involves passing ethene and
hydrogen under pressure into a solution of the Ziegler-Natta catalyst in a
hydrocarbon (a C10 or C12 alkane). The polymer is obtained in a similar way to
the slurry method.
• (3) Gas phase process :
A mixture of ethene and
hydrogen is passed over a
Phillips catalyst in a fixed bed
reactor (Figure 6).
Ethene polymerizes to form
grains of HDPE, suspended in
the flowing gas, which pass
out of the reactor when the
valve is released

7. PHYSICAL PROPERTIES
• Waxy
• Black
• Medium clutter
• Impression possible
• Joining by fusion
• Hard

8. Low-Density Polyethylene
Low-Density Polyethylene is sometimes recycled. It is a very
healthy plastic that tends to be both durable and flexible. Items
such as cling-film, sandwich bags, squeezable bottles, and
plastic grocery bags are made from LDPE.

9. Manufacturing process
• Low-density polyethylene (ldpe) is a thermoplastic made from petroleum. It was
the first grade of polyethylene, produced in 1933 by imperial chemical industries (ici)
using a high pressure process via free radical polymerization. The process is operated
under very high pressure (1000-3000 atm) at moderate temperatures (420-570 K) as
may be predicted from the reaction equation. This is a radical polymerization process
and an initiator, such as a small amount of oxygen, and/or an organic peroxide is
used.
• Ethene (purity in excess of 99.9%) is compressed and passed into a reactor together
with the initiator. The molten poly(ethene) is removed, extruded and cut into
granules. Unreacted ethene is recycled. The average polymer molecule contains
4000-40 000 carbon atoms, with many short branches.
• There are about 20 branches per 1000 carbon atoms. The relative molecular mass,
and the branching, influence the physical properties of LDPE. The branching affects
the degree of crystallinity which in turn affects the density of the material. LDPE is
generally amorphous and transparent with about 50% crystallinity. The branches
prevent the molecules fitting closely together and so it has low density.

10. Polypropylene
Polypropylene is occasionally
recycled. PP is strong and can
usually withstand higher
temperatures. It is used to
make lunch boxes, margarine
containers, yogurt pots, syrup
bottles, prescription bottles.
Plastic bottle caps are often
made from PP.

11. Manufacturing process
• Production of polypropylene takes place by slurry, solution or gas phase process,
in which the propylene monomer is subjected to heat and pressure in the
presence of a catalyst system. Polymerisation is achieved at relatively low
temperature and pressure and the product yielded is translucent, but readily
coloured. Differences in catalyst and production conditions can be used to alter
the properties of the plastic.
• Propylene is obtained, along with ethylene, by cracking naphtha (crude oil light
distillate). Ethylene, propylene, and higher alkenes are separated by low
temperature fractional distillation. From being a byproduct of ethylene in the
early 1950's, propylene is now an important material in its own right.

12. Physical properties
• Semi-rigid
• Translucent
• Good chemical resistance
• Tough
• Good fatigue resistance
• Integral hinge property
• Good heat resistance

13. Polystyrene
Polystyrene is a synthetic
aromatic polymer made from the
monomer styrene, a liquid
petrochemical. Polystyrene can
be rigid or foamed. General
purpose polystyrene is clear, hard
and brittle. It is a very
inexpensive resin per unit weight
polystyrene is commonly
recycled, but is difficult to do.
Items such as disposable coffee
cups, plastic food boxes, plastic
cutlery and packing foam are
made from PS.

14. Manufacturing process
There are three types of processes generally used - suspension, solution
and mass (bulk) polymerisation. The advantages of the solution route, which can be continuous
or batch operation, are low residual monomer content and high purity polymers. The suspension
route produces polymers of different molecular weights and can make specialist crystal and high
impact grades of polystyrene. The main advantages of the mass process are the clarity and
excellent colour of the resins produced.

15. Physical properties
Polystyrene is a colourless polymer that is
available in sheet and pellet form. It has poor
chemical resistance and weather ability. It is
also of low impact strength and has a glass
transition temperature.

16. Polyvinyl Chloride
Polyvinyl Chloride is
sometimes recycled. PVC is
used for all kinds of pipes
and tiles, but is most
commonly found in
plumbing pipes. This kind
of plastic should not come
in contact with food
items as it can be harmful if
ingested.

17. Manufacturing process
The chemical process for
making PVC involves three
steps: first, production of
the monomer, vinyl chloride,
then the linking of these
monomer units in a
polymerisation process; and
finally the blending of the
polymer with additives.

18. Manufacturing process of plastic products:
Depending on the type of products to be manufactured, different plastic manufacturing
processes are employed.
Injection moulding
Plastic extrusion
moulding
Thermoforming

19. Injection Moulding
• Material is introduced into the injection moulding
machine via a Hopper. The injection moulding
machine consists of a heated barrel equipped with a
reciprocating screw (driven by a hydraulic or electric
motor), which feeds the molten polymer into a
temperature controlled split mould via a channel
system of gates and runners. The screw melts
plasticises) the polymer, and also acts as a ram during
the injection phase. The screw action also provides
additional heating by virtue of the shearing action on
the polymer. The polymer is injected into a mould tool
that defines the shape of the moulded part. The
pressure of injection is high, dependant on the
material being processed; it can be up to one
thousand atmospheres. Tools tend to be
manufactured from steels, (which can be hardened
and plated), and Aluminium alloys for increased
cutting and hand polishing speeds. The costs
associated with tool manufacture means that injection
moulding tends to lend itself to high volume
manufacture.
Click link to watch video of injection mould:
http://www.bpf.co.uk/Data/Image/InjectionMouldingAnimation.swf
Telephone handsets, electrical switches,
syringes, DVDs, disposible razor are few
examples of products made.

20. Extrusion Moulding
• Plastic extrusion involves forcing melted
plastic through a die into a shape with a
fixed cross section. It’s an efficient way to
produce many shapes, and is essential in
both industrial and domestic product
applications. Since the plastic is melted from
a solid form and then resolidified, only
thermoplastics can undergo extrusion. The
properties of this type of plastic make it
good for recycling both scrap pieces
and post consumer goods.
• Products made are: pvc pipes, clear plastic
film, vinyl siding, insulation of electrical wire

21. Thermoforming
• Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming
temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or
"film" when referring to thinner gauges and certain material types, is heated in an oven to a high-enough
temperature that it can be stretched into or onto a mold and cooled to a finished shape. In its simplest
form, a small tabletop or lab size machine can be used to heat small cut sections of plastic sheet and
stretch it over a mold using vacuum. This method is often used for sample and prototype parts. In
complex and high-volume applications, very large production machines are utilized to heat and form the
plastic sheet and trim the formed parts from the sheet in a continuous high-speed process, and can
produce many thousands of finished parts per hour depending on the machine and mold size and the size
of the parts being formed.
Click link to watch : http://bpfmedia.emango.net/Thermoforming_RPC_BPF.swf
Disposable cups, containers,
blisters, clamshells etc are
few products

22. Physical property
PVC has high hardness and heat stability of PVC is very poor,
when the temperature reaches 140 °C PVC starts to decompose.
Its melting temperature is 160 °C. PVC is a polymer with good
insulation property. It is formed in flat sheets in a variety of
thicknesses and colors.
Application as : pipes, electric cables, signs, building material,
clothing, furniture, healthcare, plasticisers,

23. Chemical properties
material Color of
flame
odor drips Speed of
burning
remarks
HDPE Blue,
yellow tip
paraffin yes slow Floats in
water
LDPE Blue,
yellow tip
paraffin yes slow Floats in
water
PP Blue,
yellow tip
sweet yes slow Difficult to
get
scratch
PS yellow Illuminatin
g gas
yes rapid Dense
black
smoke
with soot
in air
PVC Blue,
yellow tip
fruity no Very slow Black
smoke
with soot

24. THANKYOU