Does compressing and rolling compromise the quality of foam?
Why compress and roll?
The increase in the cost of transportation has led customers and suppliers to rethink the shipping format of foam. This is when the idea of compressing and rolling foam came about. This practice allows for the reduction of space occupied by the material in the truck where it is transported as well as in the warehouse where it is stored. Consequently, there has been a reduction in the cost of transport, since it is possible to allocate more material in it, as long as the authorized weight limit is respected (as this implies a tax or impediment of transport). Thus, compressing and rolling foam has become common among manufacturers.
What effects does this have on the foam?
Technically, compressing and rolling can cause structural and mechanical alterations in the foam. However, this depends on its properties and quality.
A good quality foam should maintain its properties over time, under correct use. To measure the resistance of the foam to compression, we check its compression set (static fatigue), which measures, the loss of thickness of a foam sample after a prolonged compression, as a percentage - about 22h according to the test performed.
Compression is an imposed deformation that causes changes in foam. Since the impact of compressing and rolling foam depends on the compression to which it is subjected, the compression set value helps predict its behavior so that we can determine which foams can or cannot be compressed. Foams with lower compression set values often offer better performance responses.
One of the changes that can occur with the winding and compression of the foam is the loss of thickness. When compressed, the foam does not recover its initial thickness immediately. It takes up to 48 hours to recover.
Compression can also cause changes in the hardness of the foam. A foam subject to compression and rolling will lose hardness. However, the foam does not lose quality because it retains its structure.
It is also important to consider the time within which materials will be subject to this compression and rolling. Foam should not be compressed and rolled for more than 3 months.
The temperature to which the materials will be exposed is another factor to consider. We know that hot and humid climates make the foam recovery process difficult. In the case of some viscoelastic foams, cold weather also makes handling difficult as the foam becomes apparently harder when subjected to lower temperatures.
Nevertheless, the rolling process itself has an influence on the quality of the foam, since, if poorly done, it can affect its performance.
Overall, considering the cost/benefit ratio for both parties (manufacturer and buyer), compressing and rolling is the best option provided that the indications described are respected. The loss of quality may be almost non-existent.