- Resilience / Ball Rebound
The resilience of a polyurethane foam is measured according to ISO 8307:2007. In this test a steel ball (standard, with known weight) is dropped from a pre-determined height, over a polyurethane foam. This test is used to obtain the percentage of rebound, which is a measurement of the returned energy of the foam.
- British Standard BS5852
This standard was developed by the British Standards Institute and is used to measure the degree of flammability of furniture, fabrics and fillings according to different ignition sources.
- Open Cell
Open cells are cells that are part of the polyurethane foam structure and that are broken thus allowing air flow through the material.
- Closed Cell
Closed Cells are part of an intact membrane structure that can reduce or eliminate air flow in foam.
Compression-set is 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".
Comfort is the ability of a structure (pillow / mattress / topper) to mold to the body, avoiding the concentration of pressure points, relieving and distributing the force exerted on them providing relaxed sensation of wellbeing, without any pain or other unpleasant feelings.
- Foam pad
A foam pad is a segment of a polyurethane foam block cut / laminated, from a Slab Stock production.
The density of a polyurethane foam is defined as the weight per volume of foam. The standard unit to express the density is kg/m³. For example, if a foam has 40kg/m³ of density, this means that 1 m³ of foam weights 40 kg.
Durability reflects the continuity of foam characteristics over its lifetime and may be estimated through a laboratory test called Dynamic Fatigue.
The hardness of a flexible polyurethane foam, measures its resistance to penetration and compression. To characterize the hardness of the polyurethane foam, a kPa range (KiloPascal) or N (Newton) is commonly used. This range is used in different tests according to the standards ISO 3386-1:1986/Amd 1:2010 and ISO 2439:2008.
Elongation refers to the percentage that a specially shaped sample will stretch from its original length before breaking (Test by the standard norma ISO 1798:2008).
- Open Cell Structure
The structure of an open cell polyurethane foam is permeable so that gases and fluids can pass through the foam. Walls and some cells were broken.
- Dynamic Fatigue
Dynamic fatigue is a measure of the tendency of foam to soften under cyclic stresses. Fatigue of foam samples can be measured by cyclically compressing and relaxing a flexible polyurethane foam sample and measuring its change.
A gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are a dispersion of molecules of a liquid within a solid in which the solid is the continuous phase and the liquid is the discontinuous phase.
- Porosity / Air Flow
Porosity is the measurement of the air flowing through a sample of polyurethane foam.
- Slab Stock
Slab stock is flexible polyurethane foam made by the continuous pouring of mixed liquids onto a conveyor, creating a continuous loaf of foam.