EN 1957-2012 pdf download.Furniture – Beds and mattresses – Test methods for the determination of functional characteristics and assessment criteria.
5.7 Equipment for recording the load/deflection curves
The equipment for recording the load/deflection curves shall be a loading pad (5.6) and a testing machine capable of applying a vertical downward load up to 1000 N.
The travel speed for both loading and unloading shall be (90 ± 5) mm/minute.
Load and height with reference to a fixed datum shall be measured.
The accuracy of the height measuring system shall be ± 0,5 mm or better.
The accuracy of the load measuring system shall be ± 1 % of the max load (1000 N) or better.
The equipment shall be so that horizontal forces do not influence the measurement.
5.8 Equipment for the durability test
The equipment consists of a roller with dimensions and a shape illustrated in Figure 3 and a mechanism capable of relative horizontal movement of the roller on the unit surface.
The roller surface shall be hard, smooth and without scratches or other surface defects.
The total rolling system shall apply a load of (1400 ± 7) N measured In the static condition.
The roller shall have a rotation moment of inertia of 0,5 kgm2 ± 0.05 kgm2. The roller shall be free to pivot along its longitudinal and lateral axis relative to the horizontal.
The roller shall be capable of following the surface of the mattress, and it shall be free to move up and down to follow the mattress surface.
The forces on the roller shall act horizontally (see 7.2) at the centre point. The motion shall be approximately sinusoidal (within ± 10 %) and symmetrical along the longitudinal symmetry axis of the unit. The frequency shall be (16 ± 2) cycles per minute.
Special attention shall be given to tears in seams, seam splits, displacement or lumpiness in filling materials, broken springs, protrusion of the springs as well as holes and tears in ticking material in the mattress surface inflicted by the durability test. Internal inspection shall be carried out only at the end of the test and after all measurements have been taken.
7 Test methods
7.1 General
When mattress, bed base and frame (if applicable) are supplied together as a bed set, they shall be tested together. All tests and measurements shall be done on the complete unit standing on the floor surface (5.1).
Where a mattress is supplied separately, it shall be tested for durability with the standard test bed base for mattress (5.3) with side support profile (5.4).
If necessary, the same support profile shall be used for complete units. For the assessment of the load/deflection curves, the mattress shall be placed on the table/test board (5.5).
7.2 Durability test
The test shall be carried out with the roller apparatus (5.8).
Before beginning the test, adjust the roller mechanism so that:
a) The driving forces act horizontally ( 0°, + 20) when the roller rests on the centre line of the sleeping area.
b) The length of travel of the roller shall be 250 mm on either side of the longitudinal centre line of the sleeping area and perpendicular to its longitudinal axes.
The test unit shall be rolled for 100 cycles before initial measurements are taken.
The test shall be carried out for a total of 30 000 cycles and shall not be discontinued except to take measurements.
One cycle includes one travel back and forth.
7.3 LoadIdeflection curve
The load/deflection curve shall be obtained using the equipment specified in 5.6 and 5.7.
Hardness measurement shall begin within 5 mm from moving the mattress from the standard climate (see
4.1).
The Initial measurement shall be taken after 100 cycles of durability test (see 7.2 or clause 9).
The measuring point shall be in the centre of the roller tested area, as well as at the load application point of the edge test (see Clause 9), The measuring procedure shall be as follows:
a) Before carrying out any measurements, the test item shall be allowed to recover for at least 5 h in the standard climate (see 4.1).
b) Preload the measuring point with 1000 N and unload. Repeat the preload and unload sequence a further 2 times, with the time between each preload cycle not exceeding 30 s. The measurement shall begin within 30 s of the end of the last preload cycle.
EN 1957:2012 (E)
c) The measurement shall consist of paired observations of deflection and load, whilst the load is increased upto 1000 N.
When logging data for the load deflection curve, there should be no less than 250 points from 0 to 1000 N. From 0 to 450 N, the distance between the points should not be more than 2 N. When calculating the slopes, this can be done by taking 5 points above and 5 points below each measuring valve and calculating the slopes by linear regression.
It may be of interest to record the Hysteresis curve by taking loadldeflection measurement with the load decreasing from 1000 N to 0.
8 Evaluation of characteristic parameters
8.1 Determination of height loss.EN 1957-2012 pdf download.