Where foam fits in medical design

A variety of different chemistries and manufacturing processes can fine-tune characteristics in foam. Foams give engineers a range of different and customizable materials for designing medical equipment. Specially cut polyurethane foam is used in this oral swab so it isn't abrasive enough to harm patients' mouths and gums. Foam can be processed to change its structure and properties. Foam offers designers a full palette of potential materials. They can use it to absorb, seal, filter, wick, cushion, insulate, or support loads. And to solve even more application problems, you can heat it, compress it, and laminate it to change its characteristics. Foam plays a crucial role in surgery masks, cervical collars, thermal insulation and wound-care products, fluid regulators, and acoustic absorbers and dampers. This kind of versatility makes foam unique as a design material. And thanks to innovative fabrication techniques and the latest in polymer chemistry, foam can take on a wide range of different properties, including shape retention, water resistance or absorbency, porosity, density, and a myriad of physical characteristics. Variations on a basic recipe In its simplest form, flexible polyurethane foam — the most common type of foam — is the product of petro-chemistry and resins. More precisely, it's made of toluene diisocyanate, polyol and water. These ingredients are mixed, poured onto a linear conveyor, then left to "rise" and cure. Additives are blended in for specific characteristics such as retarding bacterial growth or flame, adding color, absorbing or repelling liquids, and inhibiting the effects of UV radiation. Once it cures, the foam consists of individual cells (also called pores) which have completely polymerized and solidified to form a skeletal structure. The cells can be open or closed. Open-cell foams, such as polyurethane ester and polyurethane ether, have interconnected cells with a thin membrane between the skeletal ribs and