Laminates or decors for furniture, windows or doors are often based on a plastic film which is embossed with a wood grain. The heart of an embossing line is the heating of the plastic web directly before the embossing calander. The surface of the foil should be soft enough for embossing, but the material must not suffer any heat damage. It pays off if the heat source can be precisely controlled.
Replacing ceramic emitters with modern infrared emitters from Heraeus Noblelight brought the decisive improvement at Renolit in Great Britain. The tailor-made infrared system enables faster production speeds and helps to save energy.
Infrared systems for more efficient heating prior to embossing
In embossing, a structure is pressed into a plastic sheet to achieve the desired feel and appearance. To achieve this, the surface must be minimally softened by heat and therefore, the plastic foil runs through a heat station. The desired structures are then pressed into the soft surface by passing the foil between steel rollers and a rubber roller as counter bearings.
In this case, it pays off if the heating takes place as close as possible to the embossing nip / embossing calander. This is because the longer the heating process takes, the more the complete foil web heats up, even in depth. This can lead to the soft film being undesirably pulled or stretched as it continues to run.
Short-wave infrared emitters are very powerful and, in contrast to conventional emitters, can heat the foils very quickly and in a targeted manner. Compact, powerful infrared modules require a smaller surface area than conventional, usually large-area heating solutions. This means less convective losses to the environment and thus significantly improved energy efficiency.
Modern infrared emitters enable precise control
Renolit produces laminates for kitchen, bedroom and bathroom furniture as well as foils for lamination on exterior window profiles and doors at its Cramlington site in the UK. An important element of the production process is the embossing line, as many of these PVC-based laminates are embossed with a wood grain.
When modernizing the existing embossing line, the company replaced the existing ceramic heating system with short-wave infrared emitters. These are arranged in individual cassettes to create heating zones that can be regulated independently of each other. The cassettes are arranged in such a way that they follow the contour of the plant. As a result, the heating is always at the same distance from the web and thus considerably more evenly than before.
This custom-designed system from Heraeus Noblelight enables precise control of the heat so that the energy is used very efficiently. The foil is quickly heated up to the set temperature, allowing higher production speeds.
In addition, the response time of the short wave emitters in seconds minimizes the risk of damage to the web, as the heating elements can be switched off immediately in the event of an unexpected band stopp.
The Application Center at Heraeus Noblelight
Heraeus Noblelight has been making Infrared and UV radiation available to industry and science for many years. The in-house Application Centre offers the possibility of carrying out practical tests with competent technical support. The tests are evaluated and discussed together with customers. The aim is to find the best type of emitter and the best configuration for the respective application - and thus to the heating or curing process – that precisely and efficiently matches the requirements.
Heraeus, the technology group headquartered in Hanau, Germany, is a leading international family-owned portfolio company. The company’s roots go back to a family pharmacy started in 1660. Today, the Heraeus group includes businesses in the environmental, electronics, health and industrial applications sectors. Customers benefit from innovative technologies and solutions based on broad materials expertise and technological leadership.
In the 2019 financial year, Heraeus generated revenues of €22.4 billion with approximately 14,900 employees in 40 countries. Heraeus is now one of the top 10 family-owned companies in Germany and holds a leading position in its global markets.