PLASTIC MATERIALS

Plastics

CLASSIFICATION OF PLASTICS

- THERMOPLASTICS

            When we heat them, they become soft, which allows them to be formed into different shapes.
            The heated and cooling process can be repeated many times.

                                 - PVC
                                 - PS
                                 - PE
                                 - PP
                                 - Methacrylate
                                 - Teflon
                                 - Cellophane
                                 - Polyamide (Nylon)


- THERMOSETTING  PLASTICS

             When heated, they become soft and can be shaped. When cooled, they cannot be remoulding by applying heat.

                               - Polyurethane
                               - Phenolic resins
                               - Melamine
                               - Polyester resins

- ELASTOMERS

                    Made by vulcanization: mixing sulphur and rubber, and heating to 160ºC.

                              - Natural Rubber
                              - Synthetic rubber
                              - Neoprene
                              - Silicone

FABRIC MATERIALS

Adam Knits

N

atural fibres are greatly elongated substances produced by plants and animals that can be spun into filaments, thread or rope. Woven, knitted, matted or bonded, they form fabrics that are essential to society.

Like agriculture, textiles have been a fundamental part of human life since the dawn of civilization. 

While the methods used to make fabrics have changed greatly since then, their functions have changed very little: today, most natural fibres are still used to make clothing and containers and to insulate, soften and decorate our living spaces. Increasingly, however, traditional textiles are being used for industrial purposes as well as in components of composite materials, in medical implants, and geo- and agro-textiles.

Plant fibres Plant fibres include seed hairs, such as cotton; stem (or bast) fibres, such as flax and hemp;leaf fibres, such as sisal; and husk fibres, such as coconut.	Animal fibres Animal fibres include wool,  hair and secretions,  such as silk.
Abaca - Coir - Cotton - Flax - Hemp - Jute - Sisal -	Alpaca wool - Angora wool - Camel hair - Cashmere - Mohair - Silk - Wool -

PLASTIC. CLASSIFICATION

There are two main types of plastics and these are named Thermoplastics and Thermosetting Plastics.

Thermoplastics are made up of lines of molecules with few cross linkages. This allows them to soften when heated and to be bent into a variety of shapes and forms. They become stiff and solid again when cold. This process can be repeated many times. The bond between the molecules is weak and become weaker when reheated, allowing reshaping. Thermoplastics tend to be composed of 'long chain monomers. They can be recycled.

Thermosetting Plastics are made up of lines of molecules which are heavily cross linked. It creates a rigid molecular structure. They may be heated the first time and shaped but they become permanently stiff and solid. They cannot be reshaped again. The molecules of these plastics are cross linked in three dimensions and this is why they cannot be reshaped or recycled

PLASTICS

                                    DEFINITION OF PLASTIC

Plastics are man-made materials. Plastics have taken the place of traditional materials like woods and metals.

Plastics differ from other materials largely because of the size of their molecules. Most materials have molecules made up of less than 300 atoms, plastics contain thousands of atoms. We call them Macromolecules.

Some plastics are derived from natural substances such as animals, insects and plants but most are man-made. These are named Synthetic Plastics. The first plastic based on a synthetic polymer was made from phenol and formaldehyde, with the first viable and cheap synthesis methods invented by Leo Hendrik Baekeland in 1909, the product being known as Bakelite.

Most synthetic plastics come from crude oil but coal and natural gas is also used. 

Monomers are chemical substances consisting of a single molecule. Thousands of these are linked together in a process called Polymerisation to form new compounds called Polymers. They are composed of organic condensation or addition polymers and may contain other substances to improve performance or economics. The vast majority of plastics are composed of polymers of carbon and hydrogen alone or with oxygen, nitrogen, chlorine or sulfur.

STONE AND CERAMIC MATERIALS

STONE: marble, granite, slate.
STONE BINDERS: plaster, cement, mortar, concrete.
CERAMICS: Baked clay, earthenware, heat resistant material, stoneware, porcelain.
GLASS
            - Shaping techniques: mould blowing, float glass making and lamination

FABRIC MATERIALS

Fabric materials can be natural or synthetic:

Natural:
- Vegetable origin: cotton, linen, hemp.
- Animal origin: wool, silk.
- Mineral origin: asbestos, metals.

Synthetic:
Nylon, polyester, rayon.

UNIT 3. MATERIALS. VOCABULARY

A

Ash

Aluminium

Ash

B

Birch

B eech

Branch

Bark

Broadleaf

Bronze

C

Chesnut

Copper

Cotton

Cork

D

Deciduous tree

E

Elm

Evergreen tree

F

Fir

G

Growth  rings

Gold

Glass

H

Heartwood

Hardwood

I

Iron

L

Leaf

Leaves

Leather

M

Metal

N

Needle

O

Oak

P

Pine

Poplar

Petroleum

Plastic

R

Roots 

Rubber

S

Stem

Seed

Steel

Sapwood

Softwood

Sap

Silver

Stone

Silk

T

Timber

Tree

Trunk

W

Wood

Wooden

Walnut

Wool

PROPERTIES OF MATERIALS

PROPERTIES OF MATERIALS

STRENGTH

The ability of a material to stand up to forces being applied without it bending,  breaking, shattering or deforming in any way. ELASTICITY The ability of a material to absorb force and flex in different directions,  returning to its original position. PLASTICITY The ability of a material to be change in shape permanently.  DUCTILITY The ability of a material to change shape (deform) usually by  stretching along its length. TENSILE STRENGTH The ability of a material to stretch without breaking or snapping. MALLEABILITY The ability of a material to be reshaped in all directions without cracking TOUGHNESS A characteristic of a material that does not break or shatter when receiving a blow or under a sudden shock. HARDNESS The ability of a material to resist scratching, wear and tear and indentation. CONDUCTIVITY The ability of a material to conduct electricity.

KINDS OF MEMORY IN COMPUTER

In computing, memory refers to the physical devices used to store programs  or data  on a temporary or permanent basis for use in a computer or other digital electronic device.

TYPES:

- RAM (RANDOM ACCESS MEMORY): Volatile memory is computer memory that requires power to maintain the stored information.
- ROM (READ ONLY MEMORY): Non-volatile memory is computer memory that can retain the stored information even when not powered. New contents can not be added. Used to store the instruction of routine type, permanent in nature and used to control or supervise the hardware.

COMPUTER´S VOCABULARY

1. Address	14.Dot	27.Memory	40.Spam
2.Address book	Download	Menu	Toolbar
3. Addressee	Email	Message	USB
4.Attach	Email Address	Network	User name
5.Backup	Erase, Delete	Password	Virus
6.Bandwidth	File	Print	Web page
7.Browser	Folder	Program	Website
8.Button	Home page	Save	Window
9.Click	Icon	Screensaver	48.Wireless
10.Cursor	Install	Search engine
11. Cut and paste	Key	Slash
12. Data	Keyword	Server
13.Desktop	26.Link	39.Software

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