High-density foam vs low-density foam: differences

15.06.2021

In this article, we point out the differences between the low and high-density foam. These products are both made of LDPE (Low Density PolyEthylene) but they differ in their density [kg/m3] and thus, the use of these materials is not the same.

What is high-density foam?

Also known as thick foam, the high-density foam has almost twice the density of low-density foams. How to make high-density foam?  At Trocellen, we manufacture both, we always select the proper density by application and final usage.

Firstly, the components of the foam are getting mixed, and we gain a so-called matrix. This matrix has to be heated to have bubbles emerging. From these bubbles, thin layers are created. The proximity of these layers defines the category of foam, whether its low or high-density products.

Important to mention that the evaluation of “high” or “low” is a relative value. For example, in case of NBR rubber foam is referred to as low-density foam even if it’s 80 kg/m3. There is no exact value, the evaluation of “high” or “low” differs for every type of foams.

Example: the difference between high and low-density foams

Main differences between high and low-density foams:

  • Mechanical properties: high-density foam has greater mechanical properties (compressive stress resistance, tensile strength, tear strength, thermal shrinkage) then low-density foam.
  • Insulation properties: low-density foam has a lower λ-value then high-density foam (therefore it has better thermal insulation behavior).
  • Softness: low-density foam is much softer; they are ideal for sport mats or packaging infill.

High-density foam usage

Due to mechanical and thermal properties, main applications in which high-density foam can be used are:

  • Upholstery & couch cushions
  • High-density foam roller
  • Insulation panels
  • High-density foam mattress
  • Sport (e.g. yoga mattress)
  • Sport underlays (under sport machines)
  • Foamboard
  • Packaging foam
  • Insole shoes.

In order to use the foam correctly, you might need quality glue or proper adhesive backing for high-density foam, so you can stick the foam to its place (for example if you use it for insulation).

Custom cut high-density foam

High-density foams are easy to cut with the right method. This means that the foam can easily be customized and can be used in every shape needed. It is also applicable for vacuum forming and thermoforming, or even lamination.

Interesting feature, that high-density foam returns to its original state after compression. They can be also non-flammable materials.