Mechanical Properties of EPS

EPS is an exceptionally versatile packaging material. It can be moulded into any shape or size – as intricately delicate or as large and solid – as you require.

Some important facts about the mechanical properties of EPS are:

  • Varying the density of the bead in the EPS mould gives you a range of different strengths and performances. EPS can be moulded in densities from 12 – 60 grams per litre – 60 grams per litre is similar to a soft pine wood – depending on the levels of stress that you expect the package to undergo and the fragility of the goods you are packaging.

  • Extra components such as wood, plastic or metal can be moulded into the pack to add extra strength for large objects such as washing machines or for multiple stacking in the warehouse.

  • Being 98 per cent air, EPS is extremely lightweight. A thin wall package around 5 mm thick might weigh less than 4 grams; a thick wall pack about 150 mm thick could weigh over 2Kg.

  • EPS is unaffected by damp, moisture and heat and its soft surface protects against damage and dirt. If further strengthening or resistance is required, EPS can be given abrasion resistant, waterproof coatings.

  • A water-based coating can be applied to give EPS anti-static properties.

  • EPS packs may be self coloured or may be coated with colour prior to the moulding stage giving full or pastel shades respectively.

  • Your logo and branding can be moulded in or silk-screen or flexographically printed onto EPS boxes and trays.

  • Flame retardant additives can be used in EPS. And, it is worth noting that in combustion, the amount of carbon monoxide and particulates given off by EPS is a small fraction compared to that given off by wood or cardboard.

Compressive stress at 10% compression, and flexural strength of moulded articles made from EPS foam as a function of moulded density; DIN 53421, 53423

EPS Expanded Polystyrene packaging - Average compressive stress, flexural strength, KPa

Tensile strength of moulded articles made from EPS foam as a function of moulded density; DIN 18164

EPS Expanded Polystyrene packaging - Average tensile strength, kPa