Robert Don Whitman

Polymer-Polyols in the Development of High Resiliency Foams

The development of more reactive polyether polyols realized during the 1960’s was instrumental in the design of molded flexible urethane foams that cured more rapidly. As the technology improved and polyols with even higher reactivity evolved, systems were devised whereby foam parts could be demolded quickly at ambient conditions. Such a process looked particularly attractive in molding applications because the conventional process in vogue at the time (hot molding) required substantial amounts of energy and time for adequate foam cure. Because the new systems cured adequately in molds at ambient temperatures, they were given the designation high resiliency &dquo;cold-cure&dquo; foam. High resiliency &dquo;cold-cure&dquo; foams prepared even during the infancy of the new technology gave dramatic improvement in properties related to comfort, durability, and flammability. For example, resiliency characteristics were significantly enhanced with a concurrent increase in the 65/25

Infiluence of Polymer Structure on High Resiliency Urethane Foams

The first reaction usually occurs between aromatic diisocyanates and relatively high molecular weight triols to produce urethane linkages. These groups confer the chemical build-up of flexible polyether chains to the polymer network and provide the elastomeric properties of the foam. The reaction between the diisocyanates and water occurs stepwise through amine intermediates to produce disubstituted ureas and generate carbon dioxide for expansion of the foam. A continuous matrix of solid urethane polymer with cellular structure is developed when the reactivities for the above reactions are in a proper balance. A judicious choice of catalysts and surfactants is necessary to ensure that the polymerization of the crosslinked network

New Furniture Foam Test Methods

During the past few years, rigid polyurethane foams have gained considerable prominence in usage by furniture manufacturers. High-density molded rigid polyurethane foams can provide surface qualities similar to wood products and physical properties adequate for numerous functional applications. Many decorative articles and structural components presently are being fabricated from rigid polyurethane foam materials. Such products can be mass produced without the requirement that a skilled craftsmen provide careful attention to each individual article or section. In addi-

A Rapid Demolding Process for High Resilience Polyurethane Foam

tributed to improvements in foam physical properties, as well as in the process itself. HR foams are produced from high molecular weight polyols containing a high ratio of primary to secondary hydroxyl groups [1]. These highly reactive polyols are typically combined with polymer polyols to yield HR foams with a wide range of load bearing properties [2,3] . The process is faster and simpler when compared to the production of conventional hot-

Formulating Principles For High-Density, High-Resilience Slabstock Urethane Foam:

continuing growth of high-density, high resilience slabstock foam in the marketplace attests to its ability to meet these fundamental requirements. Historically, the furniture and bedding markets for high quality cushioning materials have been dominated by latex foams. These products typically exhibit comfort and cushioning qualities which result in outstanding performance characteristics. However, latex foams tend to be undesirable due to their unusually high densities, relatively low tear resistance values, and tendencies to oxidative deterioration. Filled urethane foams also provide many of the excellent properties associated with latex foams. Generally, these foams are prepared with high levels of particulate inorganic materials, such as calcium carbonate, silica or barium sulfate, and usually are formulated with low water levels. These filled urethane foams also suffer from unusually high density disadvantages, low tear resistance properties and are difficult to process within normal production capabilities. High-density, high-resilience foams do not exhibit the disadvantages noted for these other cushioning products. High resilience slabstock foam densities are generally lower than those obtained for latex or filled urethane foams and the formulations for these foams may be processed readily by current slabstock foam production equipment. In addition, the oxidative stability of these foams is excellent