Light or illuminated boards allow or facilitate the use of wood and derived boards where weight plays an important role or where large thicknesses are sought without falling into the inconveniences that a solid board could bring (weight, handling, transport, loss of mechanical properties …) .
Types of light plates
There are several techniques and materials that allow you to obtain boards of greater lightness. Here, we will focus on the most common classes of lightweight boards.
All of these techniques for reducing the weight of a board are based on two methods, which can even be combined: obtaining hollow structures or using less dense materials.
- Hollow structures.
- Honeycomb or carpeted interior panels.
- Other hollow structures. On the market it is possible to find hollow alternatives for a honeycomb structure, although they are not as frequent. For example, grids made of MDF veneers, rows of wooden slats, veneers in curved or spiral shapes, etc.
- Density reduction.
- Low density fiberboard. Wood fibers allow the manufacture of slabs of various densities depending on the pressure used during manufacture.
- Use of light compounds or synthetic polymers such as polystyrene or expanded polyurethanes as fillers.
- Something common a few years ago and which fell out of use was the use of products of agricultural origin as a filler (linen, straw, etc.). The disadvantages of this option are due to the fact that a considerable reduction in weight is not achieved, only about 20%, and also the resulting panel has limited mechanical characteristics.
Alveolar or Flooded Board
O composition Common for honeycomb plates is a sandwich structure like the following:
- Soul or interior. It consists of a cardboard structure shaped like a honeycomb. Therefore, they are also known as honeycomb plates. It is essential to allow ventilation of the soul, so the gaps are connected. This technique is not the only one, in the past others were used, but this was imposed and is what is found on the market.
- Frame, Frame. Structure or frame that finishes off the edges of the board. The frame is usually made of solid wood, or of the same material with which the faces are made, such as MDF (medium density fiberboard).
- Wood veneer faces and thin plates (3-4 mm) are used for the faces and edges of the plate. Various materials can be used: MDF (the most common), plywood or agglomerate.
- Decorative coatings. Various coatings can be used: melamine, natural wood veneer, HPL laminate … It will depend a lot on the use that will be made of the panel.
- Finishes. When the board offers suitable surfaces, several types of finishes can be applied. Mainly varnishes for plywood and lacquers for MDF.
Its hollow structure makes it difficult to use some types of hardware. For example, screws and nails do not offer the same resistance when nailed or screwed in this type of plate as in a solid, therefore, the use of adhesives and / or plugs may be necessary.
They are intern use. They were not designed to be used outdoors and, if that were the case, their useful life would be significantly reduced.
Mechanical properties. Although it is very complex to provide accurate data, due to the enormous variability of the product, it is pertinent to comment that they offer good resistance to flexion taking into account its density. Thus, honeycomb boards are used as shelves, where they must support weight on many occasions.
Although they may have thickness between 32 and 100 mm, the usual ones are 38, 50, 60 mm.
Other properties such as final density, humidity, dimensional stability, durability, sound insulation or thermal conductivity depend on the final combination of the materials used, therefore, there are no guide values for the set of this type of boards. Therefore, one should consult the documentation provided by the manufacturer for each type of plywood board.
One of the great disadvantages of the alveolar boards is the difficulty that they can present to the edge. Sometimes, the faces are not thick enough to ensure good adhesion when gluing the edge. In addition, when manipulated, this area is particularly weak.
Low density fiber board
The essence of this type of board consists of obtaining a fiber board, similar to MDF, although with a lower density, about 300-400 kg / m3 versus 650 kg / m3 on average of an MDF.
For low density fiber board MDF veneers can be added on the sides to offer a more resistant surface, suitable for the application of finishes and as a support for decorative coatings such as melamine paper or natural veneer.
The density is not the same throughout the thickness of the plate, it increases as we approach the faces.
The result is a stable and light board (weight reduction of approximately 30-40%), with good mechanical characteristics and easy handling.
It is sold in thicknesses ranging from 30 to 60 mm.
The main disadvantage is the loss of adhesion that some types of hardware or fixings can present.
Lightweight composite or polymer-based plates
The great advantage of this type of plate in relation to the previous ones is that improve its mechanical characteristics and add properties such as thermal and acoustic insulation. Although, on the other hand, its price is significantly higher and the weight reduction achieved is more limited.
The interior of this type of plate is generally a mixture of wood particles or fibers together with some kind of light polymer. For faces are used mdf sheets 3-4 mm, which offer an ideal surface for the application of a wide variety of finishes and decorative coatings.
The final average density of this type of slab is generally between 475 and 525 kg / m3 depending on the final thickness. The thicker it is, the lower the density.
The thicknesses or thicknesses between which these light polymer-based plates are found are between 16 and 50 mm.
Uses of light plate
Illuminated plates are used exclusively for carpentry and interior furniture. For example: doors and cabinets, tables or desks, shelves, partitions or interior partitions, furniture for fairs and stands, decoration …