Hard Foam

Hard foams work with the basic principle of creating a network of closed cells through which density is reduced, as the bulk is replaced by air pockets.

It is closer to the properties of Styrofoam but is much more pliable and flexible. Styrofoam can easily be broken if bent but hard foam will not split or break when bent. Hard foam has closed cells so it will not absorb liquids. This foam is preferred by packaging designers as it does not absorb liquid.

Hard foam has closed cell structure and has better insulation properties then many other insulation materials. It is widely used in building cold rooms and for insulation of piping and tanks in industrial / mining applications. Heat generated from curing fibreglass does not affect hard foam thus enabling fibreglass lamination. Hard foam is also widely used for marine buoyancy. One cubic metre of 35kg/M³ polyurethane foam would have a positive buoyancy of 965kg. Hard foam is used extensively by sculptors and artisans to create shapes as it can be easily carved, sanded in to difficult shapes quickly

The hardness of foam is a measure of the firmness or stiffness of foam under load bearing. Hardness is measured when a piece of foam is compressed to 40% of its thickness, and is the force required to achieve compression. The hardness of foam should not be mistaken for the quality of the foam; it is merely the firmness of the foam.

 

Major factors that favour hard foam are

• Durability – hard foam has higher density which implies a longer lifetime.
• Support – Firmer the hard foam better the support to the spine.
• Keeps your body straight and provides a natural spine position.
• It helps in reducing pressure on the circulatory system of the body.
• By preventing collapsing of your lower back and helps to inhale more oxygen.
• Supportive to body props that are using a body pillow or knee pillow is not a problem.
• Though a little uncomfortable in the beginning but it can be adapted easily.
• The hard foam mattress helps keep your body straight and the spine neutral while you are sleeping. And due to this, the pressure on your internal system gets reduced and your body maintains a better flow of functions and efficient blood circulation throughout the night to give you a better sleep.

 

Application

Hard foams are used between metal or plastic walls/sheets of most refrigerators and freezers, or other surface materials in the case of thermal insulation panels in the construction sector. Its use in garments is growing: for example, in lining the cups of brassieres. Hard foam is also used for mouldings which include door frames, columns, balusters, window headers, pediments, medallions and rosettes.
Hard Foam formulations cover an extremely wide range of stiffness, hardness, and densities.

Hard foam is widely used in high resiliency flexible foam seating, hard foam insulation panels, microcellular foam seals and gaskets, durable elastomeric wheels and tires, automotive suspension bushings, electrical potting compounds, seals, gaskets, carpet underlay, and hard plastic parts (such as for electronic instruments).