Polyurethanes are made from two main raw materials - isocyanates and polyols, both of which are derived from crude oil. The chemical reaction begins after mixing these two process-ready liquid components of the system with various auxiliary materials, such as catalysts, blowing agents and stabilizers.
The history of polyurethanes goes back several generations. At first, there was a technology to produce rigid (rigid) foams, then soft foams, and finally semi-rigid foams.
Most importantly, it demonstrates good thermal parameters - it can resist a wide range of temperatures (from -200°C to +135°C). The average thermal conductivity PUR foam has a density of 0.026 W/m2 and the most favorable apparent density after curing of rigid foam is usually 35-50 kg/m³.
The greatest advantage of PUR foams is their excellent thermal insulation properties. PUR foam is also resistant to relatively high loads as well as to fungi and molds. Therefore, it is undoubtedly the ideal material for any construction and renovation work, such as thermal and acoustic insulation, as well as - in the case of flexible polyurethane foams - assembly and sealing.
PUR foam has perfect adhesion to both vertical and horizontal surfaces and has a porous structure. The porous material has cavities inside. Porosity is a property that tells us the volume and number of pores with a certain diameter. Polyurethane foam also has a short processing time and retains its chemical neutrality after curing.
Polyurethane Foam Tray
Polyurethane (PU) is a common polymer used to make foam, especially for furniture, but also for packaging. It has an elastic open-cell structure and is relatively soft, providing a wide range of properties that are particularly suitable for delicate and lightweight items or items that are very sensitive to vibration.
Polyethylene (PE) is a closed-cell, non-absorbent foam that is resistant to mold, mildew, rot and bacteria, and is highly resistant to chemicals. Medium-weight polyethylene foam provides excellent protection for products with moderate to low brittleness.
With the right design, it can also protect lighter, more fragile products. It is an excellent foam for positioning and cushioning. PE is available in extruded and laminated sheets. PE is available in a wide range of thicknesses, densities and colors. Recycled PE is one of the most commonly used foam packaging materials.
Cross-linked polyethylene foam is a high-density, closed-cell foam that is characterized by a firm hand, water and chemical resistance. Cross-linking of polyethylene is a chemical or irradiation process that links all polymer molecules together through stronger chemical bonds.
XLPE has many of the same properties as polyethylene foam and is ideal for protecting "A" grade surfaces due to its non-abrasive properties. xlpe is widely used in packaging for medical products and devices because it produces very limited particulates. Due to the high-end look and feel of the material, XLPE is often used in multi-part presentation kits. Most PU and PE and some XLPE foams can be used in antistatic formulations.
EPE Thermal Foam
Expanded polyethylene (EPE) and expanded polypropylene (EPP) - also known as beaded foam - are produced by "bursting" or expanding small beads of polymer and fusing them into a mold under temperature and pressure.
EPE is safe for Class A surfaces, and both EPE and EPP are widely used in automotive and packaging applications where durability, multiple impact resistance and other demanding performance challenges must be met.
These foams also have very low compression creep and will return to their original shape after continuous loading. Both EPP and EPE provide superior cushioning capacity at half the density compared to other materials. It may be a good material for many packaging applications because it can be used less than traditional PE or cross-linked polyethylene (XLPE), and it is also recyclable (XLPE is not).
Choosing a packaging partner with knowledge and experience in the properties of various foams can improve your packaging. At MUNKCARE, our design team can help you determine the right type, quantity and density of foam to ensure your product always arrives safely. More details, contact us now.
