Author: Haroon Khalil

Functions of a matrix are as follows: Thermosetting resins are the most common type of matrix. These resins have the property of reacting chemically under certain time and temperature conditions. Epoxy resins are the most widely used thermosetting resins. Polyester, vinyl ester, phenolic, bismaleimide, epoxy novolac, polymide, etc., are the other matrixes. Composites may be…

The following are the functions of reinforcing fibres: Three most commonly used reinforcing fibres are: (a) glass fibres, (b) carbon and (c) aramid. Glass fibres are the heaviest which provide high flexibility. Carbon is the strongest and heavier. Aramid has moderate stiffness. When more than one reinforcing material is used, that material is called hybrid…

Composite materials are formed by combining two or more different materials to utilise their virtues and minimising their deficiencies. These materials are also called as composites. Depending on the requirement, tougher and lighter materials may be combined. Materials utilised retain their physical and chemical properties independently in the finished product. The composites comprise of the…

Plastics may be classified into two broad groups based on their behaviour with respect to heat, viz., thermo plastics and thermoset plastics. 1. Thermo Plastics These are the plastics which become soft when heated and become hard when cooled. These plastics can sustain repeated softening and hardening for indefinite time. Old scrap and worn-out materials…

Plastics are basically organic substances which may be natural or synthetic resins in origin with or without moulding compounds. Synthetic resins are phenol, formaldehyde, cellulose, vinyl, alkyd, etc. The moulding compounds are catalysts, filters, hardeners, lubricants, pigments, plasticisers, solvents, etc.

1. Conventional Types Based on composition and properties, the conventional glass may be classified as soda lime or crown glass, flint glass, and Pyrex or heat-resistant glass. (i) Soda Lime or Crown Glass The composition by weight, in general, is sand 75 parts, lime 12.5 parts, soda 12.5 parts, alumina 1 part and waste glass…

Properties of glass are mainly governed by the factors such as composition of constituents, state of the surface, thermal treatment, dimensions of the object, etc. Glass has been popular and useful due to the following properties:

The main constituents of glass are silica, sodium or potassium carbonate, lime, manganese dioxide, cullet and colouring materials. 1. Silica Silica is the principal constituent of glass. Silica alone when fused at a very high temperature would give a good glass on cooling. However, it is essential to add some quantity of alkaline materials along…

Glass may be defined as a hard, brittle and transparent or translucent material. Technically glass is any substance or combination of substances which has solidified from the liquid state without crystallisation.