Originally Published EMDM January/February 2003
INDUSTRY NEWS
Flexible Moulded Foam Has Good Memory |
| The Bayfit 582 viscoelastic polyurethane foam system from Bayer Corp. allows manufacturers to customize the rate of recovery in moulded products such as cushions and padding. |
A state-of-the-art memory-foam material recovers its shape much more slowly than ordinary foams. The Bayfit 582 polyurethane foam system from Bayer Corp. (Pittsburgh, PA, USA) can be used to produce flexible, moulded products with viscoelastic properties that can be tailored to the manufacturer's requirements.
"Currently, there are very few polyurethane foam systems that offer a viscoelastic formulation as an option," says Rich McHale of the polymers and chemicals communications department at Bayer Corp. "The viscoelastic performance—the length of time it takes the foam to return to its moulded shape—can be adjusted to a manufacturer's needs. It is based on MDI [diphenylmethane diisocyanate ] chemistry," he says.
Tailored to manufacturers who are experienced with MDI–based polyurethane formulations, Bayfit 582 is supplied ready for processing. It is a full polyurethane system, consisting of an MDI-based isocyanate component and a polyether polyol component. The viscoelastic properties of the system can be customized to attain a manufacturer's desired rate of recovery following compression. Additionally, the indentation force deflection of the system can be adjusted to achieve a consistency ranging from very soft to very firm.
The Bayfit 582 system produces low-resilience, cold-cure-moulded polyurethane foams with low to medium load-bearing properties and excellent elongation, the company reports. It processes with standard mould releases and tooling similar to that used with conventional high-resilience polyurethane foam systems. It is suitable for moulding both small and large parts. In addition, the system can be pigmented in a variety of colors.
While its strength is nowhere near that of metal or rigid thermoplastics such as polycarbonate or ABS, Bayfit 582 could serve as an alternative to some other shape-memory materials. "It depends on the physical-property requirements of the application," says McHale.
The Bayfit 582 system brings a unique feel and slow shape-recovery performance to a variety of products, including medical devices. "Devices that involve frequent or long-term human contact, such as armrests for wheelchairs and physical therapy equipment, ergonomic padding, patient-positioning aids, and other similar products, could benefit from padding moulded with this viscoelastic material," says McHale.
Although the system currently is available only in North America, Bayer Corp. has shared its formulation with the company's business that serves Europe, the Middle East, and Africa, the firm reports. As a result, this system may become available in Europe in the near future.
For more information on the Bayfit 582 system, contact Bayer Corp., 100 Bayer Rd., Pittsburgh, PA 15205, USA; phone: +1 412 7772500; fax: +1 412 7773899; Internet: www.bayer.com/polymers-usa.
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