How it is made Plastic Chair? Erdi Karaçal Mechanical Engineer
UNIVERSITY OF GAZIANTEP
HOW IT IS MADE
Chairs are about status, power, and control.
Origins of the chair started with the throne.(taht)
Single-person seats with a back were important status symbols in ancient
Mesopotamia and Egypt, as well.
Obviously our chairs today are completely different from ancient Egyptian
thrones, but the throne-like properties of chairs have been the key
historical factors behind their rise.
Until the nineteenth century, Chairs were used by
rich people.That changed with the Industrial
Revolution. Suddenly chairs were being made cheaply
in factories and more people could afford to sit like the
At the same time, labor was being settled: as
workers moved from agriculture to factories and
offices, laborers spent more and more time sitting in
those newly mass-producible chairs.
Until the centuries chairs were produced by using wood or
iron as a raw material.
After the discovery of oil Chairs have been produced by
using petroleum products.
We can see many types of chairs in our daily life
People use chairs for sitting.We can use them in many
places. For example in our house,at cafe, restaurant and etc
During I talk about chairs You are also sitting on them.Maybe we
can not be aware of that point but the product of chair is
important part of our life…
Reasons of Using Plastic Chair
*The price of plastic chair is cheaper than others,it is very
useful and its weight is lighter than others.
*We can recycle it.
*They can be cleaned easily.
*Also transportation of plastic chair is easier than others.Due
to the design of the plastic chair they can be combined
*Main reason is ; We can produce plastic chair more quickly
As a result, People commonly use Plastic Chair..
Polyethylene terephthalate is our raw material to produce plastic
chair.It is also called as PET which the name of pet bottles comes
from there.This material is thermoplastic which means that we can
recycle it easily.
Pet has good corrosion of thermal radiation.İf we placed in direct
sunlight they can with stand there for a very long time (five years
Pet is resistant againts solvents.Therefore Products of Pet can be
easily cleaned by using solvent.
Pet has high mechanical strength.When we consider the product
of chair strentgh is important so Pet is our raw material to produce
Manufacturing Process of Plastic
Is there anybody want to say how it is made plastic
Can we produce chairs as totally one part or we should
assemble of its parts.
Injection molding is a manufacturing process for producing parts by
injecting material into a mold. Injection molding can be performed with
a host of materials, including metals, glasses, elastomers , confections,
and most commonly thermoplastic and thermosetting polymers.
Material for the part is fed into a heated barrel, mixed, and forced into a
mold cavity where it cools and hardens to the configuration of the
cavity. After a product is designed, usually by an industrial designer or
an engineer, molds are made by a mold maker (or toolmaker) from
metal, usually either steel or aluminum, and precision-machined to form
the features of the desired part. Injection molding is widely used for
manufacturing a variety of parts, from the smallest components to entire
body panels of cars.
Parts to be injection molded must be very carefully designed to
facilitate the molding process; the material used for the part, the desired
shape and features of the part, the material of the mold, and the
properties of the molding machine must all be taken into account. The
versatility of injection molding is facilitated by this breadth of design
considerations and possibilities.
The industry expanded rapidly in the 1940s because World War II created
a huge demand for inexpensive, mass-produced products.In 1946, American
inventor James Watson Hendry built the first screw injection machine,
which allowed much more precise control over the speed of injection and
the quality of articles produced.This machine also allowed material to be
mixed before injection, so that colored or recycled plastic could be added to
virgin material and mixed thoroughly before being injected. Today screw
injection machines account for the vast majority of all injection machines.
In the 1970s, Hendry went on to develop the first gas-assisted injection
molding process, which permitted the production of complex, hollow
articles that cooled quickly. This greatly improved design flexibility as well
as the strength and finish of manufactured parts while reducing production
time, cost, weight and waste.
The plastic injection molding industry has evolved over the years from
producing combs and buttons to producing a vast array of products for
many industries including automotive, medical, aerospace, consumer
products, toys, plumbing packaging, and construction.
Mold or die are the common terms used to describe the tool used to produce
plastic parts in molding.
Since molds have been expensive to manufacture, they were usually only used
in mass production where thousands of parts were being produced. Typical
molds are constructed from hardened steel, pre-hardened steel, aluminum,
and/or beryllium-copper alloy. The choice of material to build a mold from is
primarily one of economics; in general, steel molds cost more to construct, but
their longer lifespan will offset the higher initial cost over a higher number of
parts made before wearing out.The standard method of cooling is passing
a coolant(usually water) through a series of holes drilled through the mold
plates and connected by hoses to form a continuous pathway. The coolant
absorbs heat from the mold (which has absorbed heat from the hot plastic) and
keeps the mold at a proper temperature to solidify the plastic at the most
efficient rate. Aluminum molds can cost substantially less, and when designed
and machined with modern computerized equipment can be economical for
molding tens or even hundreds of thousands of parts. Beryllium copper is used
in areas of the mold that require fast heat removal or areas that see the most
shear heat generated. The molds can be manufactured either by CNC
machining or by using electrical discharge machining processes.
A clamp is a fastening device to hold or secure objects tightly
together to prevent movement or separation through the application of
inward pressure. In the United Kingdom and Australia, the
term cramp is often used instead when the tool is for temporary use
for positioning components during construction and woodworking;
thus a G cramp or a sash cramp but a wheel clamp or a surgical clamp.
There are many types of clamps available for many different purposes.
Some are temporary, as used to position components while fixing them
together, others are intended to be permanent. In the field of animal
husbandry, using a clamp to attach an animal to a stationary object is
known as "rounded clamping." A physical clamp of this type is also
used to refer to an obscure investment banking term; notably "fund
clamps." Anything that performs the action of clamping may be called
a clamp, so this gives rise to a wide variety of terms across many fields.
Although technically not a clamp, gripping elements mounted on the
buckets of heavy duty equipment are referred to as clamps too.
How are Plastics Recycled?
– Separating Plastics by Type
– Cleaning & Disinfecting Plastic
– Grinding up Plastic Flakes
– Melting Plastics Down & Reducing Them to
– The Born Again Plastics