Carpet Cushion (pad) Terms

A

Additive - A material used to modify the properties, processing, or end use of a base polymer. The amount of additive used is usually expressed in parts per hundred (by weight) of the total resin n the polymer formulation.

Antioxidants - Materials which when added to a flexible polyurethane foam formulation improve the resistance of the foam to oxidative type reactions, such as scorch resulting from high exothermic temperatures.

Auxiliary Blowing Agent (ABA) - An additive used in the production of foam which supplements the primary blowing agent (water), and can be used to make foam softer or lighter. Compounds used to produce gases to expand, or blow, flexible polyurethane foam during production. Auxiliary blowing agents are low temperature boiling solvents, such as methylene chloride, acetone, hydrochlorofluorocarbons, and isopentane.

B

Ball Rebound -A test procedure (ASTM D3574) used to measure the surface resilience 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 resilience value.

Basal Cells - Larger, irregular cells found just under the surface skin of a molded foam part.

Board Foot - A unit of foam measurement equal to a square foot of material one-inch in thickness.

Bonded Urethane Foam (rebond) - Bonded foam cushions which are referred to as rebond are made by combining shredded or chopped pieces of scrap through a fusion process into a single sheet of material. Many grades of bonded cushion are considered to be among the best performing and highest quality carpet cushion products.

Bonding - Performed through adhesives or through a heat processes like flame lamination (also known as flame bonding) which bonds the foam to a fabric or other material (film, etc.) by melting one surface of the foam with a flame source and quickly pressing it to the other substrate before the melted material resolidifies.

Bottom Out - Lack of support under full weight load. This characteristic is often found in low-density foam. This term is very subjective, as a cushion may bottom out with a heavy person, and be very comfortable to a lighter-weight individual. Specifying a cushion with a higher density can reduce the problem.

Bun - A segment of foam cut off from continuously produced slabstock type of foam.

C

CFD (Compression Force Deflection) - A measure of the load bearing ability of a foam. It is the force exerted against a flat compression foot larger than the specimen to be tested. The value can be expressed at 25%, 40%, 50% and/or 65% compression (ASTM D3574). Note: Previously called “CLD (Compression Load Deflection

Colorant - Dyes or pigments added to impart color.

Conventional Prime - This is the basic prime cushion and represents the basic industry technology. It is much softer with many air-filled compartments with multiple open windows, which are formed by the surrounding network of elastic struts. This product will not perform as well as the better prime products.

Cushion Thickness - With cushion, thickness does not mean density. Thickness is the measurement of the product from one side to the other as the product has been manufacturer for use. Thickness is shown as a fraction or an inch or in its decimal equivalent, i.e., 5/32″, 7/16″, 1/2″, 9/16

D E

Densified Prime - This cushion provides a unique under foot feel. With densified prime the vertical compression is limited by the oriented cell thickness. The basic concept in densified prime is that vertical struts are stunted and the cell shape is flattened in directional orientation. The vertical compression is limited by the oriented cell thickness at a specified firmness. This is accomplished through controlling the foam rising action through mechanical or chemical technologies.

Density of Foam Style Cushions - A cushions density is equal to the weight of one cubic foot (12″ x 12″ x 12″) of foam.

Density of Foam Style Cushion Testing - To determine density a one cubic foot (12″ x 12″ x 12″) of foam is weighed. The weight of this cubic foot is reported as (x) pounds per cubic foot. This is a reasonably accurate test that is reporting the materials actual substance, in this case the substance being the density. The higher the density the better the support characteristics of the product.

Density per cubic feet - Total weight of material measuring one cubic foot, (12″ x 12″ x 12″) In theory, all cushion can be stated in density per cubic foot and in weight per square yard.

Discoloration - The gradual yellowing of foam due to a photochemical reaction. It is faster in sunlight than in artificial light, although it occurs in both. Fresh foam may discolor in the center of the block as a result of thermal or chemical events. Discoloration does not affect the physical properties of the foam.

Double Stick Cushions - A variety of cushions from sponge to needlebond synthetics have been produced for these installations. On double stick installations it is important that the carpet manufacturers specification for carpet cushion has been adhered to.

F

Felt Cushion (See fiber cushion)

Fiber Cushions (Felted) - Varieties of this type of cushion are produced from both natural and synthetic fibers. Natural fibers include animal hair, jute, hair & jute blends and rubberized hair and/or jute. Synthetic fibers include such as nylon, polypropylene and polyester. These cushions are most commonly used under commercial carpet and some berber carpet. They are made in widths up to 12′ and in weights from 32 to 85 ounces per square yard.

Frothing - A foaming technique in which air or other gases that are mechanically whipped into the polyurethane mixture using a high-shear mixer prior to the foam reaction.

G

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 foam product

Grafted Prime - In this cushion part or all of the conventional polyol is substituted with a special polyol. This special polyol, referred to as a polymer polyol, graft polyol or copolymer, contains minute polymer particulate of styrene and other monomers which extends the harness range beyond that of conventional prime. With the exchange or addition of these reinforced polyols the hardness range of a grafted prime is extended far beyond that of the conventional prime products.

H

Hair Cushion (See fiber cushion)

Hard Spots - Resin - Spots that are hard like a marble are generally from the resin used in the bonding process. A spot that is hard enough to be felt is generally considered a defect. The proper correction is to remove the spot. A pad should not require replacement unless the spots are excessive.

Hard Spots - Skin - These are shiny, narrow hard pieces that come from the outside of some foam buns. An inexpensive pad will likely contain more skin than a better variety. Skin spots are a characteristic of many bonded urethane cushions and it is common for manufacturers not to consider them a defect unless they are large enough and hard enough to cause discomfort when walking in bare foot.

High Resilience (HR) Foam - This is a variety of polyurethane foam produced using a blend of polymer or graft polyols. High resilience foam has a less uniform (more random) cell structure different form conventional products. The different cell structure helps add support, comfort, and resilience or bounce. High resilience foams have a high support factor and greater surface resilience than conventional foams and are defined in ASTM D3770.

I J K L

IFD (Indentation Force Deflection) 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, typically 15 inches square or larger, to a stated percentage of the sample’s initial height. Common IFD values is generated at 25 and 65 percent of initial height. (ASTM D3574.) Note. Previously called “ILD (Indentation Load Deflection)”.

Isocyanate is a shorthand name for the family of diisocyanates, which are one of the two major ingredients in the chemical process by which polyurethane foam is made.

Jute Cushion (See fiber cushion)

Log Production Process - This involves developing the urethane in a cylinder shape referred to as a log. These polyurethane logs are peeled into the desired thickness, much like you peel plywood veneer from a log.

M N

Mechanically Frothed Urethane Foam - Frothed urethane foam cushions are made from a process originally developed to apply cushioned backings to carpet. Air bubbles are introduced by mechanically beating the chemical solution. The solution is solidified by heat and than fabricated into sheets of a predetermined thickness. A facing material is laminated to one side to provide stability and a surface for the carpet to be stretched across. Urethane foam cushioning is applied to a sheet of nonwoven material, forming a carpet cushion product with a typically higher density and firmer feel.

Mildew Problems - Slow seepage or flood that goes undetected or uncured for several days may result in mildew. Fiber pads suffer this problem. Rubber & foam are impervious, but they must still be removed because they retain water and the fact that carpet backings are also liable to suffer from mildew.

O

Oxidation Problems - Rubber & foam pads depend on the sealing off of floor & carpet surface to prevent undue oxidation. Areas with bad air pollution (NO2) (03) intensify problems. Fiber pads are impervious to this problem.

Ounces per square yard - Total weight of the ounces in on square yard (9 square feet).

P Q R

Peeling - The process whereby thin sheets of foam are cut from a cylinder of foam. Similar to plywood peeling.

Polymer - Organic substance composed of repeating chemical units built up into large molecules.

Polyol is a primary chemical in the formulation of foam. It is usually a glycerin-based product with three reactive hydroxyl groups. When mixed with diisocyanates and other specific ingredients, it produces the reaction that causes flexible polyurethane foam to form.

Polyurethane - Generally, a polymer connected by urethane groups. Urethane linkage and its supplements result from the reaction of polyol with isocyanate.

Prime Carpet Cushion - The carpet cushion industry denotes a group of cushion products that are made from slabstock polyurethane foam as prime. These products include conventional prime, grafted prime, and densified prime

S T U V

Scrim - A material attached to cushion so that carpet can be easily stretched across it.

Slab Stock - Flexible polyurethane foam that is made by continuous pouring of mixed liquids into a conveyer, creating a continuous loaf of foam.

Slabstock Production Process -This is a continuous process where the reacting foam chemical mix is dispensed on to a moving conveyer belt. The expanded foam develops in long flat loafs or buns (normally six feet wide). The buns are slit to its desired size, much like you would slice a loaf of bread.

Slitting - The process where sheets of foam are cut from a rectangular foam block.”

Sponge Rubber Cushion - Sponge cushion is manufactured with both synthetic and natural rubber along with other chemicals that include both oils and fillers. The mix expands when air is mixed into the batch by chemical means and is formed into either a flat or rippled slab. A material is bonded to the surface and this adds stability and provides a surface that the carpet can be stretched over. These cushions are made in widths up to 12′ and in weights between 41 and 120 ounces per square yard.

Flat Sponge (Slab Rubber) has a flat surface without the ripples.

Rippled Sponge (Waffle Rubber) has a rippled or waffled surface.

W X Y Z Sponge cushion is manufactured with both synthetic and natural rubber along with other chemicals that include both oils and fillers. The mix expands when air is mixed into the batch by chemical means and is formed into either a flat or rippled slab. A material is bonded to the surface and this adds stability and provides a surface that the carpet can be stretched over. These cushions are made in widths up to 12′ and in weights between 41 and 120 ounces per square yard.

Walk-on Testing - This is a standardized test that is used to evaluate installed residential carpet system performance. While this test can be used to evaluate different styles of carpet over a particular control system it can also be used to compare the affects of different types of carpet cushion on the composite floorcovering system. The complete protocol for this test is available through the Polyurethane Foam Association.