When you get or place an ordr of the sofa accessories -Sofa zig zag round spring,do you know how to test them?Let me tell you the method:
First,test the sizes,see the below of photo:
1.Diameter,means the thickness of the wire, ± 2mm
2. Length ± 0.5cm
3. Loop height ± 1mm
4.Loop width± 1mm
5.Arc height ± 20cm
If every point is in the range of acceptable,means spring size ok.
Second,see the surface,if the surface is smoothy,without big flaw,then it can be passed,or if your requirements is high,you can make the springs to make the salty pray test,as the following machine.If you don't have your own test machince,you can take them to the specialized agency,usually they will charge you 300-600RMB.
At last,the fatigue of test,you must use the professional machine to test,usually will test 50000 times continusously,if the Zig zag upholstery springs can't broken,the springs will be very goods elasticity.