The most general definition of Foam describes it as a substance that is formed by trapping gas bubbles in a liquid or a solid. Foam is a spongy mass which has various uses in the industry, among which the most common use is of its cushioning effect. When made to undergo chemical reactions with a Blowing Agent, all plastics form Foam. Foam may be used to package your costly electronic goods, when they are shipped out of the factory, it’s used to manufacture thermal insulators, it is used in mattresses and pillows, and it is used to make comfortable slippers for your feet.

A few examples of Foam plastics include Sponge, Food Box and Foam Sheet. These are foam produced from different types of plastic.

Here we study different types of foam available and try to compare them on the basis of quality.

Solid foam can be broadly classified into three types:

Open-cell Structure Foam: This foam contains pores which are connected to each other to form an interconnected network. This kind of foam has a comparatively lower density and a sponge-like appearance. Open-celled foam is used in football dummies. This kind of foam is used to fill chairs or bean bags.
Closed-cell Structure Foam: also named Crosslinked Polyethylene Foam this kind of foam doesn’t have a network of connected cells. It is a solid foam material. Normally this kind of foam has higher compressive strength due to its structure. This kind of foam has a higher dimensional stability, absorbs less moisture and has higher strength when compared to Open-celled foam. Its structure makes it have a harder surface feel, and makes it is better at absorbing impacts. In this type we have the Syntactic Foam – a special class of foam which contains hollow particles embedded in a matrix material.
Re-bonded foam - sometimes called bonded foam, it is recycled foam that is made by grinding old foam into small bits and bonding them back together. Rebonded foam is heavier foam with good impact absorbing qualities. It is nearly as soft as open celled foam.

The uses of foam in our life are many and varied. A few advantages of foam are listed below:

Foam-filled tires have been designed replace solid rubber and pneumatic tires. The biggest advantages of foam-filled tires are that they never become punctured. Another advantage of foam-filled tires deals with the tire pressure. Different kinds of foam are used to manufacture tyres and keep a constant pressure. These tires keep a constant tire pressure. One of the final advantages of foam-filled tires is the level of stability that they provide.
If Foam is used in insulation, it results in reduced HVAC loading. Heating and cooling costs decreased. Foam provides a draft free environment for improved indoor air quality, and reduces dust and airborne fibers. Lastly, foam insulation does not deteriorate with time and nor does it settle or compact into cavities.