PU Foam and its Varied Applications

There are in general two major types of Polyurethane Foams that are in use and in a variety of applications:
i) Flexible polyurethane foams and
ii) Rigid polyurethane foams.

Flexible polyurethane foams or Flexible foams as it is commonly referred to is high in demand due to a vast range of uses it can be put to. Flexible foam is generally used as cushioning material in mattresses, seating applications and other speciality applications. These can be very firm, soft or visco-elastic and are measured in terms of firmness, stiffness, or load-bearing capacity. Based on the needs of the application, some foams may need the addition of flame retardant agents to make it into a Fire Retardant foam or anti-microbial to make them a germ-free foam variant. Flexible PU foam can also be produced in the form of foam slabs in a continuous application. This type of foam is cut and fabricated to sizes and shapes as per usage demands. This type of foam usually is of low density. Another variant of Flexible foam called the Flexible moulded foam is produced using moulds that form the foam shape during cure. Typical applications include seating, transport and medical applications. This foam is usually of medium density. Flexible foam is also available in a variant which is known in the industry as Skin foam. This type of foam is produced the same way as moulded foam, but it forms its own tougher outer skin during the curing process. Typical applications for integral skin foam include armrests, steering wheels, shoe soles,etc.

Hard Foam or Rigid foams is a variant of PU foam that is generally used in construction like in the insulation of entry doors in buildings and in also in panels of appliances like 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 is also 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 and hard plastic parts (such as for electronic instruments).
A variant of Hard Foam sometimes referred to as Structural foams finds application in signage or chair backs. They often look similar to wood but unlike wood they do not rot or get affected by insects or affected by water.
Spray foam is one of the popular applications of Hard Foam. This type of foam can be sprayed on rooftops or in between wall studs to create a sealed building envelope, making it a preferred choice for energy efficiency construction and retrofits. Construction applications include house sheathing or concrete lifting. The foam is either sprayed or injected via a low-pressure gun delivery system.
Energy Absorbing Foam is yet another foam type of Rigid or Hard Foam which has wide ranging applications in dampening noise and vibration. In automotive applications such foams are used for acoustical and vibration dampening of doors, dashboards, and ceilings, etc.

PU foam Manufacturers can produce custom variants of PU Foams depending on the usage requirement