30 Aug 2023

Panel World is Successfully Using Vacuum Assisted Injection for Refrigerated Truck Panels

UNIDO, the United Nations Industrial Development Organization, funded a demonstration project to assess the technical and economic advantages of Vacuum Assisted Injection (VAI) in plants producing polyurethane discontinuous panels. The project was carried out at Panel World, a family-owned business covering 2,500m² of manufacturing space in South Africa that produces polyurethane panels, using PU foam blended with pentane.

Together, with the help of Manni Presse, we retrofitted Panel World’s existing predominantly-manual foaming plant. The new technology would allow them to use pentane as a blowing agent instead of HCFC-141b and a vacuum during foam injection and polymerization.

The tests demonstrated VAI’s success in terms of foam distribution and quality improvements. These results offer a new opportunity for converting and retrofitting old production equipment to process pentane instead of outdated HCFCs and HFCs.

The project’s objectives

The project had to meet a number of objectives. In retrofitting Panel World, we would need to demonstrate the benefits of applying VAI to replace HCFC-141b with pentane in terms of insulative properties. The technology would have to be easy to apply and replicable, so that could be applied to other foaming plants.

In addition, the project would also have to show the advantages in terms of safety, employee health and environmental sustainability. A lower cost structure would also need to be possible via shorter foaming time, lower foam density, and lower thermal conductivity.

Benefits of VAI technology

  • 40% less demolding time, 25% higher plant efficiency, 25% less energy used for production
  • Up to 10% lower applied foam density
  • Improved thermal insulation: up to 5% compared to pentane expanded foam without a vacuum
  • Higher foam quality, aspect, and dimensional stability

Reduced pressure means a better foam

To demonstrate VAI’s technical and financial advantages, Panel World’s existing dedicated equipment and technology had to be modified.

For this project we supplied one of our EasyFroth premixing units and an A-Compact dosing unit while our innovative partner, Manni Presse, provided the necessary foaming press set up to use pentane and equipped with VAI hardware. Pentane, a natural substance, was the preferred blowing agent, representing an environmentally safe and sustainable technology.

Before foaming, a controlled vacuum is applied between the press platen where the pre-assembled panel is positioned. Reduced pressure applied during injection and foam expansion, facilitates an even distribution of the polyurethane foam.

To test for consistency in density distribution, compressive strength, thermal conductivity, and foam stability, each panel was divided into three equal segments along its length. Test samples were then cut from the center of each segment.


If you are interested in learning more about this technology, make sure to stop by UTECH Middle East this September 5 – 7, 2023. We will be in Hall 7, Booth J25 of the Dubai World Trade Center in the United Arab Emirates ready to answer all of your questions.

What our solution includes

  • Penta EasyFroth 20 pre-mixing unit
  • A-Compact high-pressure dosing unit
  • FPL mixing heads
  • 8.5m Manni press set up for pentane with 2+2 polymerization cavity system, equipped with VAI hardware
Manni VAI Truck Panel