URETHANE INDUSTRY GLOSSARY - G

The net weight loss of chemicals during foam production, determined by subtracting the total weight of foam produced from the total weight of chemicals used. In most cases this refers only to the carbon dioxide generated in a water blown formula . In some cases it is used to refer to evaporation and eventual loss of the fluorocarbon. To avoid confusion the type of gas loss should be specified.

A thin coating of a high quality polyester plastic applied to the surface of a mold prior to filling the mold with foam. The foam adheres to the gel coat so that the part, when removed from the mold is finished.

An expression of the stability of the foaming mass. This is at least partly dependent on the increasing viscosity of the liquid. A foam with high gel strength would be very stable and could withstand more shearing stresses in molding than could a formulation with low gel strength.

The speed with which the chain extension and cross linking reactions are occurring in the foaming mass. This rate of reaction must be balanced with the rate of gas generation so that gelation occurs just after peak foam rise in order to achieve the best quality product. See reaction balance.

The increase in viscosity of the foaming mass caused by the polymerization of the liquid chemicals. See polymerization reaction.

Foams or formulations that are capable of being used in a wide variety of Applications without modification while still attaining a reasonably high level of physical properties.

Is the generic terms for polyols having a functionality of 2, also termed diols.

A term used to refer to a machine used to produce small foam particles from foam trim. These devices are also called shredders, cutters and hammer mills. See crumb.

An extra thermostat in the electrical circuit of a heating system, used as a safety control over the maximum temperature of the heating source.