Polyurethane Foam: History, Manufacture and Testing
Polyurethane foam has been around for over 80 years, firmly establishing itself as the most versatile and customisable foam material. Pioneered in 1937 through a chemical reaction of polyols and isocyanates, polyurethane foam now dominates the industry, with over 725,000 tonnes produced each year in the US alone.
How polyurethane foam is manufactured
That rate of production relies on a meticulous manufacturing process. The liquid components are poured onto a conveyor belt and immediately react, transforming into a familiar foam-like material in a form known as slabstock. At this stage manufacturers can create moulds for specialist shapes and components of varying dimensions, and additives that yield desired properties – from flame retardants to waterproofing chemicals – are included.
Shaping and reformulating foam
Polyurethane foam can also undergo additional processes towards the end of manufacture to alter its structure and performance. If not initially made in the desired shape with a mould, it can be shaped using lasers, water jets, hot wires and various cutters. In specialist cases, such as "convoluted" foam, compression processes develop the required egg-box shape. For more complex reformations, polyurethane is frequently combined with other materials and fibres through bonding processes like melting and powder laminating, significantly restructuring the foam and transforming its characteristics.
Testing and standards
Such a long history has only been achieved through consistently high standards. To maintain quality, polyurethane foam undergoes dynamic testing – starting with a basic flex-fatigue test, which calculates durability through repetitive compressions, before progressing to more complex tests such as hysteresis, which measures how well a foam regains its original shape once misshapen. The range is broad, from roller shear and tear resistance to resilience and airflow.
Keeping standards high across the vast polyurethane industry is no mean feat, and governing bodies play a key role. ASTM International, for example, is commended for the resources it offers for standard testing procedures, including airflow, indentation/compression force deflection and resilience, and all reputable manufacturers now produce products that adhere to ISO 9000 standards – a quality management framework ensuring foam meets statutory and regulatory requirements. Our guides to how memory foam is made and responsible foam production explore the manufacturing side further.
At eFoam, we're passionate about upholding the high standards of the polyurethane sector. For more information, please email info@efoam.co.uk or contact us, and one of our specialist advisers will be happy to help.
Frequently asked questions
When was polyurethane foam invented?
Polyurethane foam was pioneered in 1937 through a chemical reaction of polyols and isocyanates. It has been around for over 80 years and is now the most versatile and customisable foam material, with large volumes produced each year.
How is polyurethane foam manufactured?
Liquid components are poured onto a conveyor belt, where they react and transform into a foam-like material known as slabstock. Additives such as flame retardants or waterproofing are included at this stage, and moulds can produce specialist shapes. Foam can then be shaped with lasers, water jets, hot wires and cutters.
How is foam quality tested?
Polyurethane foam undergoes dynamic testing, starting with a flex-fatigue test (durability under repeated compression) and progressing to tests such as hysteresis (how well it regains shape), roller shear, tear resistance, resilience and airflow. ASTM International provides standard procedures, and reputable manufacturers meet ISO 9000 standards.
