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Our company One of the world's leading manufacturers
of latex foam components -
Our products A large range of mattress cores,
toppers and pillow cores -
Our concerns Ecologically balanced & sustainable
way of production
Tested quality
Latexco strives to objectify the definition of sleeping comfort that in the first place is a personal and therefore subjective perception. We test different comparable criteria which are relevant to sleeping comfort by means of standardized tests.
There are 3 basic parameters that define sleeping comfort:
Density is mass per unit volume, a value expressed in kg / m³ and determined through the weighing of a standardized sample (ISO 845). Typical densities of latex lie between 55 and 85 kg/m³. In other words, the density expresses the quantity of material used and therefore the durability (the more material is used, the more durable).
Hardness is the resistance against pressure. Hardness and density (mass per unit volume) of a foam mattress are interrelated. As the density decreases, a growing loss in hardness arises after repeated loading.
2 Methods:
Standard ISO 2439 states that the ILD-hardness (Indentation Load Deflection) equals the force required to load the mattress core till 25%, 40% or 60% compared to its original thickness with a circular plate of 50 square inches or 322 cm².
Latexco uses the CLD-hardness (Compression Load Deflection) according to standard ISO 3386, which is the counter pressure (= force per surface) in Pascal when 25% of the mattress core is pressed in with the same stamp. Notice that 1 kPA (kilopascal) equals 10 g/cm² (gram per square cm).
Resilience or elasticity is measured by the "ball-rebound"-test (ASTM D3574). In this test, a steel ball is dropped from a certain height on the material and afterwards the rebound is measured in % compared to the predetermined height. The resilience of regular PU-foams is situated between 40 and 50 %. HR-foams have an elasticity of 50 to 60% and latex foams of 60 to 70%. Slow recovery foams have “0” elasticity!
There are also a few parameters which are derived from the first 3:
Hysteresis is a value (in %) expressing the amount of energy absorbed by the tested material (being latex or other core material) during the test. An ideal hysteresis value lies between 20 and 30%. Latexco latex mattresses tested according to LGA (EN 1957) generally show a hysteresis value between 20 and 30%. The standard blend mattresses tend to give a +25 -30 % result, the natural mattresses (being even more resilient) tend to have a 20% result.
The test: a stamp (of 355mm Ø) is driven into the tested material with a force that gradually builds up to 1000 Newton (corresponding to a body weight of +/- 100kg), while the loading curve is registered. Afterwards the force is gradually released during which the de-loading curve is registered. This produces a banana-shaped curve. The smaller the area between the loading and de-loading, the more slender the banana curve, the less energy is absorbed by the material.
The conclusion: The higher the absorption of energy by a mattress, the more muscle strength (energy) the person asleep will need to change its position and the lower the quality of his sleep. Mattress cores which are too hard however have too low a hysteresis, which results in no energy being absorbed by the mattress and the person sleeping 'above' the mattress. This also excludes a stable body position.
An important precondition of comfort is that the mattress core feels soft at first, but offers increasing resistance as it is compressed further. The comfort index or SAG factor is a measure of this attribute derived from the hysteresis curve. The SAG factor is the ratio between force needed to realise 65% compression of the mattress with a stamp and the force needed to realise 25% compression with the same stamp. The higher the index, the better the mattress supports the body equally. The sag factor for regular PU-foams is about 2 and for the more resilient HR-foams (High Resilient) about 3. Latex foam performs obviously better with a sag factor up to 4 for standard latex and up to 5 for the unique Innergetic latex.
It is important that the hardness and the resilience of the foam should be preserved over a longer period of intensive use. The durability can be tested in 2 ways: a static fatigue test compressing the foam over a period of time under exigent circumstances, or the dynamic fatigue test during which the foam is repeatedly compressed to imitate the load bearing during a normal life span (10 years).
For the first test, the static fatigue test, the compression set is determined by ISO 1856 by compressing a foam sample 75% during 22 hours under a temperature of 70°C and then calculate the loss in height in terms of percentage. Good foams lose height less than 15%.
The more relevant test however is the dynamic fatigue test. This test, according to ISO 3385 standard, loads a foam sample of 40 by 40 cm 80,000 times with a weight of 75 kg (a force of 750 N). Afterwards, the loss in height and in hardness is determined in terms of percentage compared to the original value.
Another dynamic fatigue test is done according to the testing method of EN 1957 (ecolabel directive 98/634/EG). In this test, a roller-shear with predetermined dimensions and a weight of 140 kg is rolled 30,000 times up and down the mattress. Afterwards thickness and hardness after 100 cycles are compared to the end results. The hardness is determined as the average incline at 210 N, 275 N and 340 N in the load deformation curve.
Tests run by the German Institute LGA in 1997 following the project EN 1957 yielded results of about 3 mm loss in thickness and 3 % loss in hardness for a latex mattress core. More recent tests in 2004 again proved the excellent durability of latex products by Latexco in general and especially of the unique Innergetic mattress with only 0.6% loss of height and only 1% loss of hardness.
Equal pressure distribution is another factor important for qualitative sleeping comfort. The pressure distribution of a mattress can be measured by an X-sensor pressure mapping system.
Good pressure distribution helps combating pain in parts of the body where peak pressure can occur (heel, shoulder, hips) and guarantees good blood circulation. Medical literature speaks of oppression of the capillary blood vessels when local peak pressure values exceed 5kPa or 38 mmHg.
Tests on latex mattresses showed that 99% of the measured points are lower than 38 mmHg, which proves the good pressure distribution qualities of latex.
There are 3 basic parameters that define sleeping comfort:
Density is mass per unit volume, a value expressed in kg / m³ and determined through the weighing of a standardized sample (ISO 845). Typical densities of latex lie between 55 and 85 kg/m³. In other words, the density expresses the quantity of material used and therefore the durability (the more material is used, the more durable).
Hardness is the resistance against pressure. Hardness and density (mass per unit volume) of a foam mattress are interrelated. As the density decreases, a growing loss in hardness arises after repeated loading.
2 Methods:
Standard ISO 2439 states that the ILD-hardness (Indentation Load Deflection) equals the force required to load the mattress core till 25%, 40% or 60% compared to its original thickness with a circular plate of 50 square inches or 322 cm².
Latexco uses the CLD-hardness (Compression Load Deflection) according to standard ISO 3386, which is the counter pressure (= force per surface) in Pascal when 25% of the mattress core is pressed in with the same stamp. Notice that 1 kPA (kilopascal) equals 10 g/cm² (gram per square cm).
Resilience or elasticity is measured by the "ball-rebound"-test (ASTM D3574). In this test, a steel ball is dropped from a certain height on the material and afterwards the rebound is measured in % compared to the predetermined height. The resilience of regular PU-foams is situated between 40 and 50 %. HR-foams have an elasticity of 50 to 60% and latex foams of 60 to 70%. Slow recovery foams have “0” elasticity!
There are also a few parameters which are derived from the first 3:
Hysteresis is a value (in %) expressing the amount of energy absorbed by the tested material (being latex or other core material) during the test. An ideal hysteresis value lies between 20 and 30%. Latexco latex mattresses tested according to LGA (EN 1957) generally show a hysteresis value between 20 and 30%. The standard blend mattresses tend to give a +25 -30 % result, the natural mattresses (being even more resilient) tend to have a 20% result.
The test: a stamp (of 355mm Ø) is driven into the tested material with a force that gradually builds up to 1000 Newton (corresponding to a body weight of +/- 100kg), while the loading curve is registered. Afterwards the force is gradually released during which the de-loading curve is registered. This produces a banana-shaped curve. The smaller the area between the loading and de-loading, the more slender the banana curve, the less energy is absorbed by the material.
The conclusion: The higher the absorption of energy by a mattress, the more muscle strength (energy) the person asleep will need to change its position and the lower the quality of his sleep. Mattress cores which are too hard however have too low a hysteresis, which results in no energy being absorbed by the mattress and the person sleeping 'above' the mattress. This also excludes a stable body position.
An important precondition of comfort is that the mattress core feels soft at first, but offers increasing resistance as it is compressed further. The comfort index or SAG factor is a measure of this attribute derived from the hysteresis curve. The SAG factor is the ratio between force needed to realise 65% compression of the mattress with a stamp and the force needed to realise 25% compression with the same stamp. The higher the index, the better the mattress supports the body equally. The sag factor for regular PU-foams is about 2 and for the more resilient HR-foams (High Resilient) about 3. Latex foam performs obviously better with a sag factor up to 4 for standard latex and up to 5 for the unique Innergetic latex.
It is important that the hardness and the resilience of the foam should be preserved over a longer period of intensive use. The durability can be tested in 2 ways: a static fatigue test compressing the foam over a period of time under exigent circumstances, or the dynamic fatigue test during which the foam is repeatedly compressed to imitate the load bearing during a normal life span (10 years).
For the first test, the static fatigue test, the compression set is determined by ISO 1856 by compressing a foam sample 75% during 22 hours under a temperature of 70°C and then calculate the loss in height in terms of percentage. Good foams lose height less than 15%.
The more relevant test however is the dynamic fatigue test. This test, according to ISO 3385 standard, loads a foam sample of 40 by 40 cm 80,000 times with a weight of 75 kg (a force of 750 N). Afterwards, the loss in height and in hardness is determined in terms of percentage compared to the original value.
Another dynamic fatigue test is done according to the testing method of EN 1957 (ecolabel directive 98/634/EG). In this test, a roller-shear with predetermined dimensions and a weight of 140 kg is rolled 30,000 times up and down the mattress. Afterwards thickness and hardness after 100 cycles are compared to the end results. The hardness is determined as the average incline at 210 N, 275 N and 340 N in the load deformation curve.
Tests run by the German Institute LGA in 1997 following the project EN 1957 yielded results of about 3 mm loss in thickness and 3 % loss in hardness for a latex mattress core. More recent tests in 2004 again proved the excellent durability of latex products by Latexco in general and especially of the unique Innergetic mattress with only 0.6% loss of height and only 1% loss of hardness.
Equal pressure distribution is another factor important for qualitative sleeping comfort. The pressure distribution of a mattress can be measured by an X-sensor pressure mapping system.
Good pressure distribution helps combating pain in parts of the body where peak pressure can occur (heel, shoulder, hips) and guarantees good blood circulation. Medical literature speaks of oppression of the capillary blood vessels when local peak pressure values exceed 5kPa or 38 mmHg.
Tests on latex mattresses showed that 99% of the measured points are lower than 38 mmHg, which proves the good pressure distribution qualities of latex.
Latexco N.V., Sint-Amandstraat 8bis - 8700 Tielt (BE), Tel. +32(0)51401431 - Fax +32(0)51405566 - info@latexco.com | all branches