The laboratory tests that form the basis for Testfakta Verified Quality and Performance™ are carried out by SP Technical Research Institute of Sweden in Borås (SP) and the Ergonomie Institut München (EIM) in Germany.
The main elements of the test are ergonomics/comfort (EIM) and endurance and strength/durability (SP).
1. Testing of the bed’s spring characteristics (elastic properties)
2. Testing of the bed’s pressure distribution properties (contact pressure)
3. Testing of the bed’s elasticity and support for the shoulders
4. Testing of the bed’s elasticity and support for the body
5. Testing of the bed’s breathability
6. Testing of the bed’s heat-insulation characteristics
All of the test stages, with the exception of stages A5 and A6, are carried out both with and without a mattress topper. Test stages A3 and A4 are carried out for three different body types: smaller/lighter person (approximately 155 cm tall and 50-55 kg), medium/medium-heavy person (approximately 175 cm tall and 70-75 kg) and larger/heavier person (approximately 185 cm tall and 85-90 kg).
The spring characteristics show how firm or soft the bed’s springs are and how the bed adapts to the body’s heaviest contact points. Measurements are taken in the bed’s zones for shoulders, hip, lower back and heels at three different pressures (100 N, 200 N and 300 N) and given as an average in mm of flex.
Pressure distribution properties state how the mattress surface distributes and reduces pressure from a particular part of the body. This value can be attributed both to the surface (cover) of the mattress (mattress topper or bed base) and the material (stuffing) directly below the surface, as well as to the mattress topper core and the bed’s springs combined with the covering material. Measurements are taken in the bed’s zones for shoulders, hips, lower back and heels and given as an average in N/cm.
Elasticity and support for the shoulders states how much the bed yields beneath the shoulders. For side sleepers, the springs under the shoulders should yield enough to let the shoulder sink into the mattress, and thereby help the spine maintain a straight line between the lower back and the nape of the neck. For back sleepers, the springs should provide enough support to stop the shoulders/upper back sinking down too far and causing a curving of the upper part of the spine (nape of the neck).
The test is performed with two different indenters: one for the back-sleeper position with an area of 400 x 200 mm and one for the side-sleeper position with an area of 200 x 100 mm. The indenters are loaded with different pressures to simulate three different body types: 100 N for a smaller/lighter person, 200 N for an average/medium-heavy person and 250 N for a larger/heavier person. The measurement is given in mm of flex.
Elasticity and support for the body states the springs’ ability to support the natural ‘S’ shape of the spine. For back sleepers, pressure from the springs should provide adequate support to the different parts of the body (support for the lumbar region and flexibility/support for the pelvis/bottom and shoulders) in order to maintain the natural contours of the spine. The test is carried out with an indenter shaped like the body’s contours from the bottom to the neck (length 600 mm and width approximately 250 mm with a curve depth of approximately 25 mm). The indenter is loaded with different pressures to simulate three different body types: 350 N for a smaller/lighter person, 450 N for an average/medium-heavy person and 500 N for a larger/heavier person. The measurement shows the support for the lumbar region and is given in newtons.
The bed’s breathability states the bed’s ability to wick moisture/sweat away from the body. Breathability is tested using a dummy that secretes moisture/sweat like a normal sleeping human. The dummy is placed under a standard duvet and measurements are taken continuously over a seven-hour period at a room temperature of 21°C. Breathability is based on the measured value after seven hours and given in per cent as relative humidity.
The bed’s heat-insulation ability states the bed’s ability to retain body heat. Insulation ability is tested using a dummy with a body temperature equivalent to that of a normal sleeping human. The dummy is placed under a standard duvet and measurements are taken continuously over a seven-hour period at a room temperature of 21°C. Insulation ability is based on the measured value after seven hours and is given in degrees Celsius.
1. Fatigue testing of the spring characteristics
2. Fatigue testing of bed, frame and base
3. Fatigue testing of the sides of the bed
4. Impact testing of bed, frame and base
5. Fatigue testing of adjustable mechanism and motors
6. Static load in folded position
7. Impact testing in folded position
Fatigue testing of the spring characteristics is carried out by subjecting the beds to 45,000 roll cycles by a cylinder weighing 140 kg. The fatigue test corresponds to the load that beds are exposed to over approximately 10-12 years’ normal use.
Fatigue testing of bed, frame and base is conducted by subjecting the beds to 20,000 pressure cycles with a force of 1,000 N. The pressure loading is carried out in the centre of the bed and at the short and long sides of the bed.
After the fatigue tests have been carried out for the spring characteristics, bed, frame and base, measurements are taken for loss of height (settling in mm) and changes in the bed’s firmness index (spring characteristics on a 10-point scale). The settling is measured after the bed has recovered (five hours after the fatigue testing has finished).
Fatigue testing of the sides of the bed is conducted by exposing both long sides of the bed to 25,000 pressure cycles with a force of 1,000 N. This test simulates the stress the bed is subject to when someone sits on the edge. After the fatigue tests have been carried out for the sides of the bed, measurements are taken for loss of height (settling) at the sides of the bed.
Impact testing of bed, frame and base stimulates higher stresses, such as those that occur when children jump on a bed. In the test a 35 kg weight is dropped from a height of 30 cm in six different places on the bed, 10 times in each place.
After the fatigue and strength testing is complete, the beds are split open and inspected for any damage to the springs/battens and pockets, intermediate layers (foam layer over the spring system), bed frame and bed slats.
B5 – B7
1. The head end is raised 15 cm and the foot end 10 cm.
2. Static load of 90 kg for 10 seconds. 10 times for each corner and 10 times in the ‘bend of the bed’ formed when the ends are raised. The load is applied 20 cm diagonally in from each corner and 20 cm in from each long side in the ‘bend of the bed’. The static load corresponds to the load of a heavier person sitting on the bed.
3. Testing of the edge (90 kg) at the same points as the static load (500 pressure cycles in each corner plus 500 pressure cycles each side of the ‘bend of the bed’). The load corresponds to a person weighing 90 kg sitting on the bed.
4. Function check after testing of the bed is complete.
5. Fatigue testing where the bed is raised and lowered 1,000 times at the head and foot ends. The bed is given a load that corresponds to a person weighing 120 kg.
6. Repeat the static load, testing of the edge and subsequent function check in accordance with points 1 to 4 above.
The results from the different test stages are scored on a scale of 1 to 5, where 5.0 is the best and 3.0 is a pass/average. The scoring and weighting of the various stage results are carried out in consultation with the laboratories that have performed the tests.
The scores for the different test stages are weighted together for a total score as follows:
A. Ergonomics and comfort characteristics 60%
With mattress topper 50%
Without mattress topper 25%
B. Endurance and strength/durability bed and frame 40%
Beds with a spring interior, continental beds and mattresses without a frame (40%)
Adjustable beds (60%)
To meet the requirements for Testfakta Verified Quality & Performance™, the tested bed must achieve the following score: