Types of Insulating Materials

There are several types of insulating materials either available in natural form or manufactured in the convenient size and shape from natural materials. So these are broadly classified into two groups as follows:

(i) Natural insulating materials

(ii) Insulating materials manufactured from natural materials.

i. Natural Insulating Materials

Some materials which are already available in nature and posses good insulating property are cotton, animal hair, wool, asbestos, silica, rock or slag, saw dust,wooden shavings, cork etc. Many times these can be used directly by filling in the space between double walls of refrigerated space. But, sometimes a binder is mixed in some of the natural materials to apply them in the shape of plaster coverings.

ii. Manufactured Insulating Materials

These are manufactured from naturally available insulating materials. Some of these materials are as discussed below:

a) Cork Board: These are manufactured by drying the cork and then pressing to shape by baking at moderate temperatures. On baking, the natural gum binds the mass together leaving the air cells in it. These may be available in varying thickness. These are commonly used in cold storage of dairy plant.

b) Thermocole: It is an outstanding insulating material used in cooling application.Its closed cell structure gives it excellent resistance to moisture. It also has good mechanical strength.

c) Kopak: It is a silky fiber taken from Caba tree. It is manufactured in the form of slabs which are light in weight. It can also be used in its loose form.

d) Celotex: It is produced from sugarcane.

e ) Insulating Wool: - Some insulating materials are melted and blown by air into fibrous form so as to give insulating material in the form of wool. This wool contains too much air space, which increases its insulating property.