Belt calenders: Performing well under pressure

Laminted Textile for Home Decoration

Pressure is one of the distinct parameters, along with temperature and contact time, that you can change in your belt calendar to achieve the best outcome. This also applies when laminating two or more layers of textile using thermoplastic adhesives.

Our LFC models apply two different kinds of pressures:

  1. A belt is stretched around the heating drum and the textile substrates run between them. This type of pressure on the textile is relatively low and ensures an efficient transfer of heat.
  2. A pressure roller inside the silicone belt applies a much higher nip pressure.

What is an example of laminated product?

If you’re laminating a foam and a woven fabric together, the thermoplastic adhesive in between must reach a specific melting point before it starts to bind the two substrates. In our calenders, the belt will apply constant pressure, pushing the substrates to the heated drum, while the top layer – and the adhesive – are steadily warmed up.

When the thermo-adhesive reaches its melting point, the laminating pressure is applied. It’s important to get this just right; if this pressure is too low, the thermoplastic adhesive will remain as a layer between the two substrates.

If there is too much pressure, however, the adhesive will be pushed too deep into the substrates and will not be able to establish the bonding.

Left to right: high pressure, good pressure, low pressure
Left to right: high pressure, good pressure, low pressure

Is it possible to laminate without a pressure roller?

The short answer is yes, but to achieve a perfect bonding, you will need much more heat and contact time to activate the thermoplastic adhesive, which will lead to higher energy consumption.

If you would like to know more about Klieverik’s laminating and coating calendars, feel free to contact us at info@klieverik.com. We can offer unwinding and winding equipment, cooling rollers, accumulators, web cutting equipment, and more. And we’ll happily help you decide which calendar is best for you.