The wood veneers are divided into two major groups: rotary cut veneer and sliced veneer. Sliced veneer is the most commonly used veneer in profile wrapping. The complexity of the core material dictates the quality of veneer to be used.
Manufactured fleece-backed veneer, as a fleece is glued on the back of the veneer. The veneer becomes more flexible due to the glued-on fleece.
The quality of symmetric and asymmetric finger-joint veneer is visible after the lacquering process. In the case of poor quality, two different pigmentations are visible. Different pigmentations are avoidable using veneer with an aluminium indicator.
Veneer with an aluminium indicator is always in roll form. An aluminium strip is applied at the joint between the veneer sheets. This type of veneer needs to be ordered with a specified sheet length within the roll of veneer. The sheet length needs to be 1’’ longer then the profile it will be applied to allowing for some length variations in the substrate. The advantage of the aluminium indicator is, that the finger-joint strip will not be placed on the profile and ruin its aesthetics. This is accomplished by using sensors on the machine to pinpoint the position of the aluminium indicator at the joint. The signal is used to position the substrate with the aluminium indicator in the veneer roll. Doing it this way, the beginning of the veneer sheet is certain to be synchronous with the beginning of the substrate.
Different paper types are available for profile wrapping. Paper for profile wrapping is usually made like a sandwich. It starts out with the base paper that is also referred to as the backer. The backer is available in different colours and different weights. The second layer is the decorative layer. The decorative layer can be of a solid colour or with a printed pattern. Usually 30g paper, this decorative layer is laminated to the base paper. The colour of the finished paper depends on the colour of the base paper. These papers can range from 30 to 300 g and more. Most commonly used papers are 60 or 80 g papers. They can be wrapped around very complex profiles and at the same time they are not as fragile as 30 g paper. Paper can be wrapped around sharp edges (with the exception of very heavy papers).
Laminates are decorative surface papers impregnated with melamine resins and then pressed over Kraft paper core sheets impregnated with phenolic resin. These sheets are then bonded at pressures exceeding 200 Kg/cm2 at temperatures approaching 150°C. Finished sheets are trimmed and the backs are sanded to facilitate bonding. Laminates are more difficult to wrap in comparison with wrapping paper, because papers are more flexible. The variety of laminates ranges from high-pressure to low-pressure to continuous laminates. There is a difference in the way theses laminates are manufactured as well as in the flexibility of the material. Sharp edges are not recommended. For the flooring industry the laminates are coated with aluminium oxide.
In case of profile-wrapping with laminates an extremely long wrapping zone is necessary. The temperature of the laminate, if corners are to be wrapped, must reach 300° C in the relevant area.
There are many different types of vinyl available. The most commonly used materials are hard / soft PVC and PP. Vinyl can be of a solid colour or have a printed pattern. Different topcoats are available for interior or exterior products.
No special requirements.
The vinyl has to be durable against ultraviolet rays. A special vinyl with a wood-like surface (veneer characteristics) and aluminium-like surface (aluminium characteristics) is available for exterior application, which is mainly used by the PVC window industry.
The newest development is a thermoplastic film for the decorative finishing of windows, doors and other building elements. The film is also suitable for regions with harsh climates, because of a higher weather and temperature stability. Also under difficult conditions the foil possesses outstanding colour and gloss stability. Before glue application, the processing temperature of “Renolit-Fast” has to be 80°C with strict tolerance levels.