Glossary of Terms

A2LA - American Association of Laboratory Accreditation - a non-profit, professional membership society committed to the success of laboratories through the administration of a broad-spectrum, nationwide laboratory accreditation system and a full range of training on laboratory practices taught by experts in their field. Rubberlite’s lab is accredited.

Accelerated Aging - A test method to represent extended aging of material in a shorter amount of time. For cellular rubber it is the process of artificially increasing time to measure physical property changes. This usually involves exposure to air at an elevated temperature.

Acrylic Adhesive - A pressure-sensitive adhesive formed by the polymerization of acrylic ester monomers. These adhesives exhibit high temperature resistance, excellent U.V. resistance, good plasticizer resistance and good aging characteristics.

AFMA - American Furniture Manufacturers Association. A voluntary organization of furniture manufacturers dedicated to fostering the growth and development of the furniture industry and improving the effectiveness and efficiency of furniture manufacturers. AFMA was formed from the merger of the National Association of Furniture Manufacturers and the Southern Furniture Manufacturers Association.

ANSI - American National Standards Institute. An organization that verifies that standards developed by other organizations have met the requirements for due process before approval as an American National Standard. The use of American National Standards is voluntary.

ASTM - American Society For Testing and Materials. An organization devoted to the establishment of standard methods and procedures for testing materials.

Acoustical Flexible Polyurethane Foam - Foam designed to attenuate, or dampen vibrations or sound waves.

Air Flow - A measure of the ease with which air will pass through a foam sample. (Test Method ASTM D3574)

Aliphatic - Class of organic chemical compounds containing carbon, having an open chain molecular structure.

Anti-Oxidants - Materials which when added to a flexible polyurethane foam formulation improve the resistance of the foam to oxidative type reactions, such as scorch.

Anti-Static Flexible Polyurethane Foam - Foam that has been impregnated with electrically conductive materials to prevent static electricity buildup or promote static dissipation. It is used primarily in packaging applications, such as electronic components.

Aromatic - Class of organic chemical compounds characterized by having a benzene, or six membered, ring molecular structure. Toluene diisocyanate is an aromatic organic compound.

Auxiliary Blowing Agents - Compounds used to produce gases to expand, or blow, flexible polyurethane foam during production. Most auxiliary blowing agents are low temperature boiling solvents, such as chlorofluorocarbons, methylene chloride, methyl chloroform, acetone, hydrochlorofluorocarbons, and isopentane.

BIFMA - Business and Institutional Furniture Manufacturers Association. An association of manufacturers of business or institutional furniture dedicated to the development of voluntary product safety and performance standards and test methods.

Back Foam - Flexible polyurethane foam used for other than seat cushioning, usually of a lower density than seating foam.

Ball Rebound - A test procedure used to measure the surface resiliency of flexible polyurethane foam. The test involves dropping a steel ball of known mass from a predetermined height onto a foam sample. The rebound height attained by the steel ball, expressed as a percentage of the original drop height, is the ball rebound resiliency value. (Test Method ASTM D3574)

Barrier Material - A barrier placed between a cover fabric and filling materials to slow heat transfer and flame spread to the filling material.

Blemish - An imperfection occurring in a cellular rubber product. It is usually circular in appearance and does not go completely through the material. Sometimes referred to as a dimple.

Blend Materials - Various polymers used in the manufacture of cellular rubber materials that are blended together to give a product a wide range of resistance properties.

Blocks - A cut-off segment of the continuously produced flexible polyurethane foam being made by the slabstock technique. In some cases this block would have top, bottom, and side skins intact and have cut surfaces only on the ends. In other cases, the skins may be removed by in-line trimmers, leaving a smooth rectangular block.

Blowing - The process by which flexible polyurethane is foamed during production. The majority of blowing is accomplished in polyurethanes by adding water to the polyol/toluene diisocyanate reaction. Water reacts with the toluene diisocyanate to produce carbon dioxide gas bubbles that expand the polyurethane as it polymerizes. Auxiliary blowing agents are high volatility liquids that, when added to the polymerizing liquid, tend to boil and produce large quantities of gas. The gas produces bubbles as the polymerization takes place, expanding the liquid resin before it solidifies. Common auxiliary blowing agents include CFC's and methylene chloride.

Blowing Agent - Various chemicals used in the manufacture of cellular rubber products that cause the material to expand by giving off a gas when they are exposed to heat.

Board Foot - Unit of measurement in the flexible polyurethane foam industry equal to a square foot of material one inch in thickness.

Boardy - Flexible polyurethane foam with a stiff or rigid feel, generally indicated by high 25% IFD values.

Bolster - A loose pillow, flexible polyurethane foam and/or fiber filled, that is not attached to the upholstery frame.

Bonded Foam - Flexible polyurethane foam crumbs or shredded flexible polyurethane foam that has been rebonded to form a salable product.

Boston Chair Test - Boston Fire Department test method to measure performance of flexible polyurethane foam padding materials when exposed to a fairly severe flaming ignition source. This test is a full scale composite test. Ignition source is four double sheets of newspaper crumpled inside a paper grocery bag.

Boston Foam - Flexible polyurethane foam filling or padding material that will meet the requirements of the Boston Fire Department chair test.

Bottom Out - The lack of support by a flexible polyurethane foam under full load. This term is very subjective, as a foam may bottom out with a heavy person, and be very comfortable to a lighter-weight individual.

Breathability - See Air Flow.

British Standard BS-7176 - British standard specification for resistance to ignition of upholstered furniture when tested according to BS-5852. This standard sets the specifications for ignition source resistance levels for low, medium, and high risk occupancies.

British Test BS-5852 - British Standards Institute test method for the ignitability of upholstered composites by open flame or smouldering cigarette sources. BS-5852 is a small scale composite test of material combinations. Open flame ignition sources range from a match equivalent butane flame up to a nominal 126 gram wooden crib. Additionally, a smouldering cigarette is used as an ignition source.

Buffed - Flexible polyurethane foam pieces that have been shaped or contoured by removal of foam using abrasive or "buffing" methods.

Bun - See Blocks. Generally, buns are longer than blocks, approximately equal to or greater than 60 feet in length.

CFC-Free Foam - Flexible polyurethane foams that have been made without the use of chlorofluorocarbons as auxiliary blowing agents.

California 117 Foam - Flexible polyurethane foam filling material or padding that will meet the requirements of the California Bureau of Home Furnishings' Technical Bulletin No. 117.

California Technical Bulletin 116 -California Bureau of Home Furnishings test method for cigarette ignition resistance of residential upholstered furniture. This is a small scale composite test.

California Technical Bulletin 117 -California Bureau of Home Furnishings test method and requirements for open flame and cigarette resistant materials used in residential upholstered furniture construction. Cal-117 is a small scale component test. Ignition source is either an open flame gas burner as specified by Federal Test Method Standard No. 191, Method 5903.2 or smoldering cigarettes meeting the cigarette specification of DOC FF4-72.

California Technical Bulletin 133 -California Bureau of Home Furnishings test method and requirements for open flame resistance of seating furniture for use in public occupancies in seating areas of ten or more seats. Cal-133 is a full scale composite test in which physical design and construction material combinations can affect the test outcome. Ignition source is five double sheets of newspaper or a specially designed gas burner as specified in the test method.

Capability (Process) Index, Cp or Cpk - A statistical measure used to describe the capability of a process to produce a product (output) within specification tolerance limits. The index is a measure that indicates high or low process variability. Note: Where k is a constant number of subgroups of a given size.

Carbon Dioxide Blown Foam -Flexible polyurethane foam in which all the gas for expanding the foam is carbon dioxide generated by the chemical reaction between water and the isocyanate material.

Carrier - When referring to double-coated pressure sensitive adhesive, it is the thin medium to which the adhesive is anchored to on both sides. One of the most common carriers is Mylar.

Catalyst - A chemical that changes the rate of reaction of a chemical process, but is not consumed or produced during the reaction.

Cell - The cavity remaining in the structure of flexible polyurethane foam surrounded by polymer membranes or the polymer skeleton after blowing is complete.

Cell Count - The number of cells per linear inch or centimeter, expressed as pores per inch or pores per centimeter.

Cell Size - The average diameter of the cells in the final flexible polyurethane foam product, often measured in micron units.

Cellular Rubber - Low-density rubber products containing a cellular structure. The cells may either be open and interconnecting or closed and not interconnecting; a generic term for materials containing many cells (either open or closed, or both) dispersed throughout the mass.

Chemically Blown - A term applying to a cellular material in which the cells are formed by gases generated from thermal decomposition or other chemical reaction. In other words and in most cases, a powdered chemical that is added to a rubber mixture which, when exposed to a certain temperature, turns into a gas and causes the foam to expand.

Chlorofluorocarbon (CFC) - Chemical compounds that are chlorine and fluorine substituted alkane hydrocarbons. CFC's are commonly used as auxiliary blowing agents for foams, refrigerants, aerosol propellants, and cleaning agents.

Clickability - The ability of a flexible polyurethane foam to recover from the pinching effects of die-cutting.

Closed Cell Rubber - A rubber product produced by a specific manufacturing process that utilizes gas forming ingredients in the rubber compound or by subjecting the compound to a high pressure gas such as nitrogen. Closed cell rubber is defined as a product whose cells are totally enclosed by its walls and hence not interconnecting with other cells. This unique physical property enables closed cell rubber to function as an excellent seal for moisture, dust, air, gas, smoke, noise, etc.

Coarse Cell Structure - A term used to describe the appearance of expanded cellular rubber when the individual cells are larger and/or spread apart further than normal. Sometimes incorrectly referred to as Open Cell.

Cold-Cure Foam - See high resiliency foam.

Combustion Modified Foam - Flexible polyurethane foams manufactured by using additives containing fire suppressants such as chlorine, bromine, phosphorus, antimony oxide, or some combination thereof, with or without hydrated alumina or melamine.

Combustion Modified High Resilience Foam (CMHR) - High resilience flexible polyurethane foams that have been modified for better flammability behavior by the addition of various flame retardants.

Compression Force Deflection (CFD) - The determination of the resistance to compression of a flexible polyurethane foam sample when the entire surface area of the sample is compressed. Test method is described in ASTM D3574.

Compression Rate - See Support Factor.

Compression Set - A permanent partial loss of initial height of a flexible polyurethane foam sample compression due to a bending or collapse of the cell lattice structure within the foam sample. Large percentages of compression set will cause a flexible polyurethane foam cushion to quickly lose its original appearance with use, leaving its surface depressed or "hollowed out".

Cone Calorimeter - Small, "bench-scale" calorimeter characterized by its inverted cone shape used to determine heat and smoke release rates for various materials when exposed to radiant heat. This is a small scale component test piece of equipment.

Constant Deflection Compression Set -Test used to determine the amount of foam recovery from a static or fixed compression. Test method is described in ASTM D3574.

Conventional Flexible Polyurethane Foam -Polyether type polyurethane foams made by the basic manufacturing process with no additives.

Conventional California or FR Foam - Conventional flexible polyurethane foams to which fire retardants have been added.

Converter - One that is employed in changing a raw material into another form of product.

Convoluted - A fabrication process in which flexible polyurethane foam is cut while compressed non-uniformly to produce a surface with a multicontoured texture. This texture gives the foam a different surface feel, or apparent softness.

Cross-linking - The bonding of molecules into a structure. This gives the polymer increased strength resulting in superior properties. Crosslinking can achieved by either physical (irradiation by an electron beam) or by chemical means.

Cure - For cellular rubber, the time period and temperature in which various chemical reactions (e.g. cross-linking) occurs. This phase of a process is critical as too much time will produce an over-cured product and too little time will produce an under-cured product.

DOT MVSS-302 - Department of Transportation Motor Vehicles Safety Standard in which the test sample is ignited in a horizontal position by a calibrated gas flame for 15 seconds. Burn length, time and speed are determined and sample is classified by the outcome. This is a small scale component test developed for automotive interior materials.

Deflect - To compress, usually by a specified amount or percentage.

Delamination - The undesirable separation or buckling of the release liner from an adhesive layer usually in the parallel direction of the web. Most often found during high humid conditions causing the paper to grow.

Densified - A material that has been made more dense by permanently compressing a unit mass into a smaller volume.

Densified foam - Sometimes called felted foam, it is foam that has been permanently compressed through a precisely controlled thermal setting process.

Density - The mass of a substance divided by its volume. In the United States, density is accepted as the weight of a substance divided by its volume. Foam density is often expressed as pounds per cubic foot or kilograms per cubic meter. (Test Method ASTM D3574)

Dish - Description of what occurs when a weight is placed on the center of a cushion and the corners of the cushion rise up in response.

Double-Coated - A pressure-sensitive adhesive consisting of a carrier with similar or dissimilar adhesives applied to both surfaces.

Double Tee - See Tee.

Durometer - An instrument used to measure hardness of elastic materials. Durometer is also used to reference a scale of hardness; ie, a low durometer implies a soft material.

Dynamic Flex Fatigue - See Fatigue.

ECH - Epichlorohydrin. A polymer used in the manufacture of cellular rubber. Its primary characteristics are resistance to swell when exposed to fuel and high temperature resistance up to 325ºF.

Elastomer - Polymers which resist and recover from deformation produced by force, similar in behavior to natural rubber.

Elephant Skin - Surface creasing effect due to lateral resistance of a stiff, thick flexible polyurethane foam when compressed parallel to its face.

Elongation - The percent that a specially shaped sample will stretch from its original length before breaking. (Test Method ASTM D3574)

Environmentally Safe - Flexible polyurethane foam processed with no auxiliary blowing agents.

EPDM - Ethylene Propylene Diene. A polymer used in the manufacture of cellular rubber. It has excellent resistance to sunlight, ozone and heat, and good resistance to alkalis and acids.

EVA - Ethylene Vinyl Acetate. It is generally used as a co-polymer in polyolefin foams resulting in greater resilience and higher tensile and tear performance.

Exotherm - The heat released as a by product of some chemical reactions. Flexible polyurethane foam producing reactions are exothermic.

Expanded Rubber - A term reserved for closed-cell compounds that are made by incorporating gas-forming ingredients in the rubber compound or by subjecting the compound to high-pressure gas, such as nitrogen. These materials are manufactured in sheet, roll, strip, molded, and special shapes by molding or extrusion.

Extrusion - Material that is formed by being forced through a shaping orifice as a continuous body.

FIRA - Furniture Industry Research Association - A voluntary British organization of interested parties involved in flammability research, creating methods of testing and establishing specifications for flammability performance of upholstered furniture.

Fabricator - One that constructs a finished product by combining, assembling or processing a raw material.

Fatigue - A tendency to soften under cyclic stresses. Fatigue of foam samples can be measured by cyclicly compressing and relaxing a flexible polyurethane foam sample and measuring its change in IFD.

Feel - See Hand. Felted - Flexible polyurethane foam that has been densified by heat and compression for use as a vibration dampening or shock absorbing material.

Felted - Flexible polyurethane foam that has been densified by heat and compression for use as a vibration dampening or shock absorbing material.

Filled Flexible Polyurethane Foam - Flexible polyurethane foams that have inorganic materials, such as marble dust, barium sulfate, graded sand or clay added to the foam during polymerization to increase foam density. These inorganic fillers are not chemically bonded into the foam polymer. They are instead mechanically trapped within the molecular structure of the polymer. Substantial amounts of filler may increase the foam's support factor, but may be detrimental to resiliency, strength, or durability.

Filler - The inorganic materials added to foam to increase foam density.

Finger Nail - A quick, general test for boardiness or stiff surface feel flexible polyurethane foam. A finger nail pressed into a foam sample that leaves a definite impression that does not quickly recover indicates a boardy foam.

Fire Retardants - A material that, when added to flexible polyurethane foam, will cause the foam to be more difficult to ignite or burn less rapidly or lose less weight during a fire than without that material.

Flammability - The characteristics of a material that pertain to its relative ease and relative ability to sustain combustion.

Flat Top - A block or bun of flexible polyurethane foam that is essentially flat on the top surface when poured, as opposed to having an arched top when allowed to free rise.

Flex Fatigue - See Fatigue.

Flexible PUF - Flexible polyurethane foam.

Fluid Immersion Test - The submersion of a piece of cellular rubber in Fuel B (similar to Jet Fuel). The foam is weighed before and after and the test measures the amount of fuel absorbed by the material. The lower the % of mass gain, the better the resistance to petroleum based fuels.

Foam - A product, either flexible or rigid, that has been produced by the internal generation of a gas in a fluid medium that is polymerizing while expanding in volume. The final result is either an open or closed-cell product.

Graft or Polymer Polyol - Polymers with active hydroxyl groups that have other organic groups or polymers "grafted" to the polyol molecule. These grafted organic compounds serve to reinforce the strength or modify other properties of the flexible polyurethane product.

Guide Factor - GF = 25% IFD divided by density determined after one minute rest.

Guts - Flexible polyurethane foam that has adequate support under load and does not "bottom out" is said to have "guts".

HCFC's - Non-fully halogenated chlorofluorocarbons that are used as substitutes for CFC's in foam blowing. Theoretically, HCFC's have a lower ozone-depletion potential to the environment than do "hard" fully halogenated CFC's.

Hand - Hand is the feel of the surface of flexible polyurethane foam when rubbed lightly. Stiff or hard feel is poor hand. Good hand is described as a springy, velvet feel.

Hardness - The resistance to indentation, as measured under specific conditions.

Hardness Index - Synonym for the 50% IFD value. Some furniture designs are for a maximum 50% indentation while some are for only a 20% indentation, ie., chairs versus bar stools.

High Resilience (HR) Foam - Flexible polyurethane foam that has a very rapid recovery from extreme compression and a fairly linear increase in resistance to compression per unit of penetration. (See ASTM D-3770).

Hook - A wedge shaped foam extension on cushion units used to make cushions conform to the shape of a back.

Humid Aging - An accelerated aging test under conditions of high humidity and temperature. ASTM D3574 describes the test method.

Hydrolytic Degradation - The degradation of flexible polyurethane foam by hydrolysis or disassociation by water under conditions of constant exposure. The humid aging test method was developed to attempt to measure the effects of hydrolytic degradation.

Hydrophilic - An affinity for water.

Hydrophobic - A repellency for water.

Hysteresis - The ability of a flexible polyurethane foam to return to its original support characteristics after it is compressed. Hysteresis = (25%)

IFD initial - 25% IFD after compressing 65% of initial height)/25% IFD initial * 100.

IAFF - International Association of Fire Fighters.

Indentation Force Deflection (IFD) - A measure of the load bearing capacity of flexible polyurethane foam. IFD is generally measured as the force (in pounds) required to compress a 50 square inch circular indentor foot into a four inch thick sample no smaller than 24 inches square, to a stated percentage of the sample's initial height. Common IFD values are generated at 25 and 65 percent of initial height. Reference Test Method ASTM D3574.

Indentation Load Deflection (ILD) - See Indentation Force Deflection.

Indentation Modulus - IM = (40%IFD-20%IFD)/20%IFD. The force required to produce an additional 1% indentation between the limits of 20% IFD and 40% IFD determined without the one minute rest. The slope of this line represents the resistance of the cell struts to post buckling. The slope of the linear portion of the stress-strain curve is defined as the indentation modulus.

Indentation Residual Deflection Force (IRDF) -A test method used with seating foam to determine how thick the padding is under the average person. The amount of deflection is determined by measuring the thickness of the pad under fixed force of 4.5 Newtons, 110 N, and 220 N on a 323 square centimeter circular indentor foot.

Initial Hardness Factor - IHF = 25%IFD/5%IFD determined without the one minute rest. This ratio defines the surface feel of a flexible foam. Soft surface foam will have a high IHF value, while stiff or boardy surface foams will have a low IHF value.

Initial Softness Ratio - See Initial Hardness Factor.

Interior Density - The density of a foam sample at its center. Generally, a foam will form a density gradient, with the highest density being at the outer, or skin surface, and the lowest density being at the core of the foam sample.

JIPFSC - Joint Industry Polyurethane Foam Standards Committee. A voluntary standards organization formed under the auspices of the American Furniture Manufacturers Association, dedicated to the development of flexible polyurethane foam standards, guidelines, test methods, classifications, and definitions for the furniture industry.

K Factor - A measure of the thermal conductivity of heat insulation expressed as BTUs/sq. ft. Lower values indicate better insulating materials.

Lamination - A fabrication process bonding two foam types, or a foam and another substrate, using an adhesive.

Latex Foam - A latex rubber foam product not related to flexible polyurethane foams.

Leveling - The process of taking raw material rubber products and skiving thin cuts of material from it until the rubber is uniform in thickness.

Life Safety Code - A collection of specifications and test methods relating to fire safety in buildings and structures compiled by the National Fire Protection Association.

Loop Splitter - A mechanical splitter which allows continuous slitting of long buns of foam.

MDI - An abbreviation for 4,4-diphenylmethane diisocyanate, it is often mixed with toluene diisocyanate in the production of molded flexible polyurethane foam cushions.

Maxfoam - A foam manufacturing process utilizing a trough and fall plate system for efficient foam manufacturing. See Varimax Melamine.

Melamine Foam - Flexible polyurethane foam incorporating melamine powder as a filler primarily as a fire retardant.

Methylene Chloride - A non-flammable, low-boiling chlorinated hydrocarbon solvent used as an auxiliary blowing agent in flexible polyurethane foam production.

Modulus - See Support Factor.

Modulus Irregularity Factor - MIF = 2 * 20%IFD - 40%IFD. The MIF is the extrapolated intercept of the stress axis, or y axis, of the linear portion of the stress-strain curve. If the MIF is zero, the indention modulus is essentially constant, and the stress-strain curve is linear and passes through the origin. If the indentation modulus varies at low levels of strain before reaching a constant value at above approximately 10 per strain, the MIF will either be a positive or negative value. The degree of deviation of the MIF from zero describes the shape of the lower end of the stress-strain curve, and thus the performance of cushioning for some seating applications.

Modulus of Compression (MOC) - See Support Factor.

Molded Foam - A cellular foam product having the shape of the mold cavity in which it was produced.

MVSS-302 - Motor Vehicle Safety Standard. This specification (302) describes test procedures used to determine the burn rate of parts, portions of parts, and composites used as interior trim parts in passenger cars, multipurpose passenger vehicles, trucks and buses.

NFPA - National Fire Protection Association.

NFPA 260 - National Fire Protection Association test method for determining resistance to cigarette ignition for materials used in upholstered furniture. This test is a small scale composite test. Ignition source is a smoldering cigarette.

NIST - National Institute for Standards and Technology, formerly the National Bureau of Standards.

Natural Rubber - Derived from botanical sources, primarily from the Heavea brasiliensis tree.

Neoprene (CR) (NEO) - Polychloroprene. A synthetic rubber discovered by the Du Pont Company in 1931. It is a polymer composed of carbon, hydrogen and chlorine. Its features include resistance to petroleum based fluids and flame resistance.

Nitrile Rubber (NBR) - Emulsion copolymers of Butadiene and Acrylonitrile in varying proportions. This chemical is used in the manufacture of expanded rubber primarily for its resistance to swelling in oils and solvents.

OSU Calorimeter - Calorimeter developed at Ohio State University for determination of heat and visible smoke release rates for various materials when exposed to different levels of radiant heat. The test method for using the OSU calorimeter is published under ASTM E-906, and is a small scale component test.

Oozing - Concerning PSA’s, refers to the condition where the sides of a roll become sticky or tacky due to the flowing out of adhesive between the layer of tape.

Open Cell Material - A rubber product produced by a specific manufacturing process that utilizes a chemical blowing agent that expands the mass during the vulcanization process. Open cell rubber is defined as materials whose cells are not totally enclosed by its walls and open to the surface, either directly or by interconnecting with other cells. The primary characteristics are that water, air or gas can pass through, much like the way water is absorbed by a dish sponge. This type of material is also excellent for padding and cushioning applications where low compression set is required.

Organotin Catalysts - A family of organic tin compounds used as catalysts in flexible polyurethane foam production that have a specific influence on the rate of the gelation reaction. Members include stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, and dibutyltin diethyl hexoate.

Over-cure - For cellular rubber, the time period or temperature in which various chemical reactions which occur (e.g. cross-linking) last too long. The result is blisters, too tight of a cell structure, voids along the edges, etc. This problem is most apparent on the edges of a material.

Ozone Resistance - The ability of a material to resist sunlight and/or outdoor exposure.

PFA - Polyurethane Foam Association. A trade association of the manufacturers of flexible polyurethane foam and their suppliers of goods and services.

Permeability - The rate at which a liquid or gas can penetrate into or through a flexible polyurethane foam. Usually associated with airflow, a measure of the openness of the foam.

Pieced - Flexible polyurethane foam that has been glued together from two or more smaller pieces. Commonly seen in cushioning to create special shapes or use up small pieces produced during fabrication.

Plasticizer - Chemical additives in a flexible polyurethane foam formulation that generally serve to increase the flexibility of the foam structure.

Plasticizer Migration - Loss of plasticizer from an elastomeric compound. It often migrates to the surface of the material where it is absorbed by another product or evaporates. This process causes the material to lose its flexibility and can contaminate other products.

Polyester - A family of organic polymers characterized by the presence of ester groups O " R-C-O-R within the molecule. Polyesters can be prepared to have reactive hydroxyl groups and thus can be used as a polyol in the preparation of urethane foam. Esters are more susceptible to hydrolysis than are ethers.

Polyether - A family of organic polymers characterized by the presence of ether groups R-O-R within the molecule. Polyethers can be prepared to have reactive hydroxyl groups and thus can be used as a polyol in the preparation of polyurethane foam. Ethers are less susceptible to hydrolysis than esters.

Polyethylene - A thermoplastic composed of polymers of ethylene.

Polymer - In dealing with sponge rubber, this is a large molecular chain made up of two or more monomers. These monomers are polymerized or chemically reacted to form a material that is significantly different than either of the two base monomers from which it was made.

Polymeric Foam - See High Resilience Foam.

Polyol - A chemical compound having more than one reactive hydroxyl group within the molecule. Polyol usually refers to a glycerine based product with three reactive hydroxyl groups.

Polypropylene - Any of various thermoplastic resins that are polymers of propylene. Propylene is a flammable gas derived from petroleum hydrocarbon cracking and used in organic synthesis.

Polypropylene Glycol - A propylene based diol having two reactive hydroxyl groups per propylene unit.

Polyurethane - Any of various thermoplastic or thermosetting resins, widely varying in flexibility, used in tough chemical-resistant coatings and in adhesives, foams, and electrical insulation.

Polyurethane Fillers - See Fillers.

Pores Per Inch (ppi) - Unit for expressing cell count of a foam.

Porosity - The presence of numerous small cavities within a material. See Air Flow.

Pounding Fatigue - Accelerated fatigue aging of flexible polyurethane foam by cyclicly compressing samples to a specified percentage of their original height and releasing for a specified number of repetitions.

Preflex - The practice of compressing a flexible polyurethane foam sample once or twice to a predetermined thickness before determining IFD.

Pressure Sensitive Adhesive (PSA) - A term used to designate a distinct category of adhesive tapes which in dry (solvent free) form are aggressive and permanently tacky at room temperature and adhere to a variety of surfaces without the need of more than finger or hand pressure. They require no activation by water, solvent or heat and have sufficient cohesive strength so they can be handled with the fingers.

PUF - Polyurethane Foam.

PVC - Polyvinyl chloride. A polymer used in the manufacture of expanded rubber. This compound is inherently fire retardant because of its high chlorine content.

Rate of Heat Release (RHR) - The quantity of energy released in a given amount of time from a burning sample, used in flammability studies. Units include BTU/hour, calories per second, joules per second, or watts. Values are determined by calorimetry, including cone calorimetry or the Ohio State University furniture calorimeter.

RE - Terminology derived from the ASTM-D-1056-65 specification. The R stands for cellular rubbers made from natural rubber, synthetic rubber or rubber-like materials, alone or in combinations where specific resistance to the action of petroleum based oils is not required. The E is a designation for closed-cell material.

Rebonding - The process of adhering flexible polyurethane foam crumbs or shredded foam back together again to make a salable product. Rebonded foam is often used for carpet padding.

Recovery - The return to original dimension and properties of a flexible polyurethane foam sample after a deforming force is removed.

Reinforced Foam - See Filled Flexible Polyurethane Foam.

Resiliency - The ability of a surface to spring back to its original shape after being deformed and released. The resiliency of flexible polyurethane foam is measured using the ball rebound test.

Reticulated Foam - Flexible polyurethane foams characterized by a three-dimensional skeletal structure with few or no membranes between strands. Reticulated foams are generally used as filters, acoustical panels, and for controlled liquid delivery.

RO - Terminology derived from the ASTM-D-1056-65 specification. The R stands for cellular rubbers made from natural rubber, synthetic rubber or rubber-like materials, alone or in combinations where specific resistance to the action of petroleum based oils is not required. The O is a designation for open-cell material.

Roller Shear - Procedure that fatigues a flexible polyurethane foam specimen dynamically at a constant force, deflecting the material both horizontally and vertically. See ASTM D- 3574

Roll Goods - Flexible polyurethane foam that has been peeled or slit from a foam "log" and rolled onto a core for handling purposes. Rolled foam sheets are commonly used for large area padding, such as carpet padding.

Rubber - A material that is capable of recovering from large deformations quickly and forcibly, and can be, or already is, modified to a state in which it is essentially insoluable (but can swell) in boiling solvent.

Rubber Based Adhesives - An adhesive made from one or more synthetic or natural elastomers and tackifiers to produce a pressure-sensitive adhesive. These adhesives are characterized by having higher quick tack and adhesion than acrylics, however, they lack aging and weather resistance.

SBE - Terminology derived from the ASTM-D-1056-65 specification. The SB Designation stands for cellular rubbers made from synthetic rubber or rubber-like materials having oil resistance with low swell. The E is a designation for closed-cell material.

SBR - Styrene-butadiene rubber. A polymer used in the manufacture of expanded rubber. It is very economical and possesses no unique chemical resistance properties.

SCE - Terminology derived from the ASTM-D-1056-65 specification. The SC Designation stands for cellular rubbers made from synthetic rubber or rubber-like materials having oil resistance with medium swell. The E is a designation for closed-cell material.

SPI - Society of the Plastics Industry. A national organization of companies and individuals in the plastics industry that is oriented toward developing industry standards and test methods.

Scorch - Discoloration in center of foam buns due to oxidation of the polymer during manufacture.

Seam - The splice line formed by two or more separate pieces of flexible polyurethane foam that have been bonded together.

Seat Foam - Flexible polyurethane foam used for seat cushions.

Section Density - Density of a flexible polyurethane foam taken from the cross section of a bun with top and bottom skins intact.

Self-Extinguishing - A somewhat loosely used term describing the ability of a material to cease burning once the source of flame has been removed.

Shelf Life - The period of time that a product can be stored under specific conditions and still remain suitable for use.

Shiners - Light reflected from intact cell walls, noticable on the cut surfaces of flexible polyurethane foam. A large number of shiners, or shiny spots, indicates a foam with many closed cells.

Shredded Foam - Flexible polyurethane foam that has been mechanically torn into small pieces or crumbs, for the purpose of creating a loose filling material.

Shrinkage - An inadvertent dimensional decrease of cellular structure without an actual breakdown or collapse of the cell. This characteristic is relatively common in all cellular rubber and plastic products. The primary cause is the equalization of pressure from the manufacturing process to normal atmospheric pressures.

Silicone - A rubber made from silicone elastomers and noted for its retention of flexibility, resilience, tensile strength and wide temperature range.

Silicone Foam - Organosilicon polymers that are expanded or blown during the polymerization of silicone rubber.

Silicone Surfactant - Complex organosilicon compounds that exhibit surface active properties when used in polyurethane foam formulations. These compounds add stability to the liquid foaming mixture so that collapse of bubbles is retarded and flowability is increased.

Skin - The higher density outer surface of the flexible polyurethane foam slab, resulting from surface cooling during polymerization.

Skive - To shave or cut off the surface of a rubber material in a horizontal manner. Sometimes referred to as splitting which means to divide sharply or cleanly into layers.

Slitting - The action of cutting material to width.

Slab Stock - Flexible polyurethane foam made by the continuous pouring of mixed liquids onto a conveyor, creating a continuous loaf of foam.

Splits - Horizontal tears or rips in the side of the flexible polyurethane foam block, either intermittent or continuous along the side of the slab, commonly caused by excessive speed of the blowing reaction or too steep an angle of rise.

Sponge Rubber - A cellular rubber consisting predominantly of open cells made from a solid rubber compound. These products are manufactured in sheet, roll, strip, and molded or special shapes. Sometimes referred to as foam rubber.

Static Fatigue - The loss in load bearing properties of a flexible polyurethane foam sample under constant compression of 75% for 17 hours at room temperature. See Test Method ASTM D-3574

Static Force Loss - See Static Fatigue.

Stripping - A product and/or process of producing a long, narrow piece of material that is uniform in width. Sometimes referred to as slitting.

Substrate - The surface to which a pressure-sensitive tape, fabric, foam, etc. is applied.

Support Factor - Support Factor = 65%IFD/25%IFD determined after one minute of rest or recovery. When based on 25% IFD values, the support factor indicates the 65% IFD values that will be attained by the foam. Seating foams with low support factor are more likely to bottom out under load.

TDI - An abbreviation for toluene diisocyanate, TDI is one of the two primary reactants involved in the production of flexible polyurethane foams.

Tear Strength - The ability of a piece of flexible polyurethane foam to resist propagation of a cut made in the sample. Reference ASTM D-3574

Tee - Horizontal extension on the front edge of cushion that extends in front of arms or stumps of chair or sofa frames.

Temperature Range - The minimum and maximum temperature that a material can be exposed to before the physical properties and/or appearance begins to move out of their specification range.

Tensile Strength - The pounds per square inch of force required to stretch a material to the breaking point. Reference ASTM D-3574

Thermal formable - To change the shape and/or structure of a material using heat and a suitable mild structure.

Tight Foam - Flexible polyurethane foam with many closed cells, resulting in low air flow measurements.

Tolerance - The permissible deviation from a specified value of a dimension.

Transfer Tape - An unsupported pressure-sensitive adhesive on a release liner that has been release coated on both sides.

UFAC - Upholstered Furniture Action Council. A voluntary furniture industry association organized to conduct research into more cigarette resistant upholstered furniture.

UL - Underwriters Laboratories. An independent, non-profit organization testing for public safety. UL is chartered to establish, maintain, and operate laboratories for the examination and testing of devices, systems, and materials to determine their relation to hazards to life and property.

UL-94 HBF - Underwriters Laboratories test method in which the test sample is ignited for one minute with a calibrated gas flame. Sample is classified by burn time, length, and glowing combustion time after the flame is removed. This is a small scale component test.

UL-94 HFI - Test method similar to UL-94 HBF, with the additional requirement that no flaming drippings are allowed which would ignite cotton placed below the test specimen.

UL-1056 - Underwriters Laboratories test method for the ability of upholstered furniture to resist rapid heat release when subjected to a flaming ignition source. UL-1056 is a full scale composite test in which physical design and material combinations may affect the test outcome. Ignition source is a nominal 340 gram wood crib.

Under cure - For cellular rubber, when the time period in which various chemical reactions occurring (e.g. cross-linking) does not last long enough. The result is a loose cell structure, a mushy appearance, etc. This problem is most apparent in the center of a material and this area will often collapse after skiving.

Urea - Urea is a by product of the water-toluene diisocyanate reaction during flexible polyurethane foam production. The urea forms short length polymer cross links between the long polyurethane chains, which adds firmness to the foam.

Urethane - A colorless, crystalline substance used primarily in medicines, pesticides, and fungicides. Urethane is not used in the production of urethane polymers or foams. The urethanes of the plastics industry are so named because the repeating units of their structures resemble the chemical urethane.

Varimax - A foam manufacturing process utilizing Maxfoam technology with the addition of moveable sidewalls for greater processing flexibility.

Vertifoam - A foam manufacturing process utilizing Maxfoam principles where the direction of foaming is vertical.

Vinyl - A chemical derived from ethylene and used as a basic material for plastics that are typically tough, flexible, shiny and often used for coverings and clothing.

Voids - The presence of numerous small cavities within a material.

Vulcanization - An irreversible process during which a rubber compound, through a change in its chemical structure, e.g. cross-linking, becomes less plastic and more resistant to swelling by organic liquids. The result is that elastic properties are improved or extended over a wide range of temperatures. Vulcanization can be carried out under numerous conditions but it usually involves heat.

Water Absorption Test - The process of submerging a piece of cellular rubber in distilled water and exposing it to increased atmospheric pressure. The foam is weighed beforehand and afterwards. The test measures the amount of water absorbed by the material. The lower the %, the less water the material absorbs.

Water Blown Foam - Flexible polyurethane foam in which the gas for expansion is carbon dioxide generated by the reaction between water and an isocyanate material. All flexible polyurethane foam is waterblown, although auxiliary blowing agents are often used to obtain special physical properties.

Wedge - See Hook

Z Suffix - A suffix within ASTM-D-1056 used for special requirements. The test methods and values are to be arranged between the manufacturer and the purchaser.