URETHANE INDUSTRY GLOSSARY - R

A shortened form for refrigerant 12 which is a neutral (non- trademark) name sometimes used to describe fluorocarbon 12, (dichlorodifluoromethane) a very low temperature boiling liquid commonly used as a frothing agent for urethane foam.

An abbreviation used to represent Rubber Manufacturers Association Test which is an indentation load deflection test used to rate cushions and mattresses for load carrying ability. The term is rarely used, the preference being for IFD test. The Test Method is described in ASTM D 1564-63T.

A term which refers to the large, irregular, normally elongated gas pockets usually found in frothed foam. Their size can be minimized by careful manipulation of the mixing chamber pressure, the percent of R-12 used in the formula, the type of chemicals used, etc. They are also called worm holes.

The ability to change and regulate the ratio or proportion between 2 or more fluid components . This introduces versatility to a machine, enabling it to be used with several different formulations. A fixed ratio machine can be built that will work with only one formula under precise operating conditions, but these are rarely requested. raw materials-a term often used to describe the chemical ingredients used in manufacturing urethane foam. The term is generally applied to the chemicals as received from the chemical manufacturers prior to any premixing.

A manufacturer of one or more of the basic chemicals used in the urethane foam industry.

A general term that can be used for any of the raw materials or intermediates used in the manufacture of foam.

The balance between the relative reaction rates of gas generation (blowing) and gelation (polymerization). This is quite important in the production of urethane foam, as a formula with too rapid generation of gas may cause collapse or splits; while a formula with too rapid a gelation rate will become closed celled in the case of flexible foams, or may tear apart by internal cracks in the case of rigid foams. See blowing reaction, gelation reaction and polymerization reaction for further information.

Is a term used to describe the process of adhering small particles of foam (crumb) back together again to make a saleable cushioning product. Several processes are available, some using latex adhesives, others using a foaming adhesive based on the urethanes, some requiring heat to cure or to dry, others curing at room temperature, some producing an inferior product, others producing a product superior to 'virgin foam' in many ways. A typical Application of rebonded foam is for rug underlays.

A seldom used term describing a device used for spreading the mixed liquids in a uniform pattern in molds or on conveyors. They are also called traversers or spreaders.

A term which refers to the practice of continuously pumping the metered fluids back to the machine tanks during the "off" portion of a foam production cycle. The 'on-off' valving in the mixing head serves merely to divert this continuously metered flow either into the mixing chamber or back to the machine tanks. There are three different degrees of recirculation defined as follows: Full recirculation all the way to the mixing head and back with little or no volume of non-recirculated material between the diverting valve and the mixing chamber, partial or short recirculation in which the diverting valve is located at some distance from the mixing chamber, resulting in a relatively large volume of non-recirculated material between the valve and the mix chamber, and non-recirculate in which there is no return line at all and the pump is either stopped during the 'off portion of the cycle or the pump is equipped with an internal bypass that operates when a valve is closed in the line between the metering pump and the mixing head.

A fluid control device usually consisting of a housing, a spring loaded diaphragm and a means for adjusting the spring tension. This can be used to control either the upstream or downstream pressure.

A term sometimes used as a synonym for hysteresis or sometimes as a synonym for the settling that occurs after peak foam use.

A drive motor, usually for a mixing head, that is located at some distance from the mixing head itself and transmits power by means of a flexible shaft drive or some other method.

A powerful pleasant smelling chemical which is added to a formulation to mask the unpleasant odors sometimes associated with Amine catalysts or even the polyols on occasion. There are a wide variety of scents available and if used properly, reodorants can perform a valuable service.

The ability to produce the same result at repeated intervals. This is a very important consideration in buying chemicals or machinery, since lack of reproducible control over any production variable can result in the production of poor quality foam.

A measure of the 'rubberiness' or elasticity of the product, in compression. One of the methods for measuring this is the 'Ball Rebound Test'.

Foam that has a very rapid recovery from extreme compression and a fairly linear increase in resistance to compression per inch or centimeter of penetration.

A term used as a general term describing the unsaturated polymers or monomers used in the paint industry, in particular those in the polyester family. It is occasionally applied to the polyols used in urethane foam.

Is a heater, usually in-line, that is in the fluid circuit, (either polyol or isocyanate stream).

The process of removing residual membranes or cell windows from the foam structure so that only a skeletal web-like network remains. There are several techniques involved and there are many patents in the field.

Very low density urethane foams characterized by a three-dimensional skeletal structure of strands with few or no membranes between the strands, containing up to 9701, or more of void space. They are made by treating an open-cell foam structure with a dilute aqueous sodium hydroxide solution under controlled conditions so that the thin membranes are dissolved, leaving the strands substantially unaffected. Ultrasonic vibrating is sometimes used to assist the solution process. These foams are used in filters for air-conditioners, automobile carburetors, air cleaning systems; and in acoustical panels, humidifiers and various household products.

Is the study of flow and deformation of matter.

Like structures formed at the joint between adjacent bubbles in a foam which becomes open-celled. The ribs are usually reinforced by the remains of the cell membranes in good quality foam.

See flow lines.

Those foam products which can be classified as having a firm stiff behavior and can be said to exceed their elastic limits with compressions or elongations greater than 10%. There are many other plastic based rigid foams than polyurethane foam. The most common of the other types are polystyrene foam, epoxy foam, polyethylene foam, phenolic foam, and urea-formaldehyde foam. Rigid foams may be thermoplastic or thermosetting.

The time interval between the liquid mixture being poured into the mold and the completion of expansion of the foaming mass.

A usually non-powered conveyor that is constructed of a series of tubes suspended at each end by a shaft and bearings which are fastened to a rail on each side. The rails are parallel to the direction of movement; the axis of the rollers are perpendicular to the direction of movement, but the surface of the rollers rotates in the direction of travel when a product is pushed on top.

A slang word referring to the appearance of the froth being discharged from a letdown nozzle. When all variables are in proper adjustment, the discharging material often takes on the round slightly fuzzy appearance of a manila rope dangling in air.

A term sometimes used to describe a mixing blade or impeller.

A term sometimes used to describe the machine tanks that form part of the metering system in order to distinguish them from bulk storage or premix tanks.

The time during which the foam machine was actually in operation to make foam. Recirculation time is excluded.