Laser cutting of wood and plywood is an excellent alternative to mechanical cutting methods for wood-based panels. With the thickness of the board or plywood sheet up to 10 mm, the laser quickly and efficiently copes with the task of straight-line cutting, figured and openwork cutting. And the engraving made by the beam can compete in quality with the handmade art carving, while the process itself is many times faster.
Properties and features of different types of plywood and wood species
Wood and wood products are easily cut with a laser beam, however, the quality of the cut is affected by the species, hardness of the wood and the moisture content of the material. Coniferous processing is easiest. Hardwoods are cut a little harder. The density of the wood itself plays a significant role – the harder the wood, the greater the beam power you have to choose. Soft wood, such as spruce, pine, poplar, aspen, is easy to cut with a laser, species characterized by high density – beech, oak, birch – are slightly worse. The presence of knots and other heterogeneities in the structure of the tree negatively affects the cutting process.
Plywood, like wood, has significant decorative potential and is easy to process. However, its behavior when interacting with a laser is affected not only by the properties of wood, but also by the presence of an adhesive component. In fact, plywood is a composite material – several layers of wood veneer connected by glue based on resin. The urea resin, which is part of the FC, has a low heat resistance and is safe. Phenolic resin in FSF plywood and bakelite varnish in FB release toxic substances when exposed to heat. Therefore, laser cutting for plywood of these types is not used (or is used extremely rarely).
The processing result also depends on the grade of plywood. The presence of a large number of knots in low-grade veneer (grade 4) makes it difficult to cut. But when using first-class material, not only the final product looks much more presentable, but the cutting process itself is much simpler.
Features of laser processing technology
Laser cutting occurs without direct contact of the cutting tool with the workpiece. The principle of operation is based on the ability of the laser to penetrate deep into the material, causing strong heating and burning of wood. A light beam passing through a system of lenses and mirrors acquires a fine focus. The laser head guided by the CNC moves over the workpiece along the path specified in the program. Depending on the radiation power, the laser cuts through the plywood or wood preform exactly to the depth set by the program. When cutting through material of large thickness, it is sometimes necessary to make several passes.
The ability to adjust the processing parameters in a wide range allows you to cut wood with different properties. The impact area of the beam is hundredths of a millimeter, which means that workpiece deformation is excluded. During processing, the slice is heat treated, so additional grinding is not required. Among the advantages of laser cutting when working with plywood and wood are precision cuts, clear internal angles, parallel edges. Not the last place is occupied by economical cutting – thanks to narrow cutting lines, parts on the sheet can be placed close to each other, with minimal indentation.
Subtleties of setting up laser equipment for working with plywood and wood
CNC plywood cutting can be done without operator intervention. But for the automatic operation of the equipment, it must be correctly configured. To get an excellent result, you must:
- have a well-designed management program;
- choose the right processing mode;
- correctly place the workpiece;
- clearly position the tool at the starting point of the processing.
At a power of 40-50 W, plywood 3 mm thick can be cut, while ensuring a cutting speed of up to 10 m /s. For through cutting (in one pass) of plywood 6 mm thick, use the power of 80-90 W, for 8 mm plywood – 100 … 130 W. With increasing power, the cutting speed increases. However, do not choose too high power indicators, as this can lead to carbonization of the edge of the workpiece. It is better to choose the appropriate ratio of radiation power and cutting speed empirically by testing a test sample.
The optical system is responsible for the quality of the radiation, which means that care and adjustment should be given attention. Mirrors and lenses should be clean and perfectly tuned. The task of mirrors is to form a stream from randomly moving particles, which is then focused using a lens into a narrow beam. Inaccurate optical adjustment can cause distortion of the beam path.
Where to get the cutting layout
In order for the finished product to fully meet the quality requirements (accuracy, purity of processing), it is important to pay attention to the preparation of the unitary enterprise, the basis of which is an electronic drawing. The finished layout can be found on the Internet, bought on specialized sites or from specialists involved in the development of vector models. To independently create a digital prototype of a workpiece or product, you must use one of the graphic editors (CorelDraw, AutoCAD, etc.) or a drawing program.
Drawing requirements:
- The model must be performed in full size.
- use minimum line thickness.
- Straight lines, curves need to be connected to a polyline.
- The contours must be closed, that is, they must be a single object.
- Double or overlapping lines are not allowed.
- To ensure maximum accuracy, it is worth considering the thickness of the laser beam, which, although small, still has its own value (0.1 mm).
The drawing should be saved in a format understandable to the machine, and then use the software included with the machine to create a processing algorithm. The control program indicates the point of origin, sets the cutting width, beam power, tool moving speed.
Non-obvious aspects when working with wooden workpieces. How to avoid marriage
With a homogeneous texture, such as solid wood, the laser copes well. The cutting speed of wood is 5-15 mm /s, depending on the thickness and species. With the temperature effect of the beam on the workpiece, the edges may darken. This is not always associated with excess power, rather depends on the properties of the tree itself. Hardwoods are most likely to acquire a dark shade, which can be removed by grinding. However, sometimes this not very positive feature of laser cutting of wood is used as an original feature, which allows you to express lines more clearly and clearly.
Plywood is the most moody among all wood-based materials. The reason for this is its layered structure. Veneer sheets in the inner layers may have knots, cracks, and glue may be placed unevenly. The thicker the plywood, the more layers of veneer-glue in its composition, and therefore defects are more common. That is why sheets with a thickness of more than 10 mm are undesirable to cut with a laser. Inhomogeneities in the form of knots, as well as an excessive amount of glue provoke undercut. These places have to be re-cut or cut at a reduced speed, which in turn can degrade the quality of the cut line. Sites where there is no glue, on the contrary, can burn.
Rejection of the cut line (dark cut, poor cutting) can be caused by incorrect transmission of the beam from the emitter due to improper optical settings. To prevent getting defective blanks, you need to check and correctly adjust the focal length, and possibly adjust the optical system.
Security
When laser cutting or engraving plywood , safety precautions should be followed. Failure to follow the instructions can result in personal injury. So, getting your hand in the area of the beam will cause skin burns. Poor maintenance of the machine, accumulation of dust and dirt can cause electrical breakdown and injury to the operator.
Despite the absence of a large number of chips and sawdust typical of mechanical processing, fine dust and gases are generated during laser cutting of plywood . These microscopic particles settle on the product, the lens, and can cause a deterioration in the quality of the cut, and in some cases, a cause of fire. The use of compressed air for blowing will allow time to remove litter from the cutting zone, avoiding negative situations.
It should be borne in mind that toxic fumes can be released during thermal exposure to the material. use the ventilation system to quickly remove combustion products from the room.
In general, before you press the “Start” button, be sure to check the serviceability and cleanliness of the equipment, the correct operation of the ventilation and cooling systems. And when the machine is running, use common sense, because any carelessness or inattention can cause an accident.
The use of laser cutting in various fields
Laser cutting of wood and plywood opens up the possibility of manufacturing flat products of complex configuration and elements of various designs. using a laser, you can perform not only contour cutting, but also turn an ordinary wooden blank into a masterpiece of carpentry. Plywood and wood products are used to decorate restaurants, bars, offices and home interiors. On the blanks cut from the sheet, you can apply any inscriptions, drawings, and even photo images.
Production of souvenir and gift products
Wooden souvenirs are in great demand. They keep the warmth of the tree and pleasant memories of the donor, place or event. To enhance the atmosphere of the holiday, wooden hashtags, miniatures that are used to decorate locations, a table in a restaurant or a festive cake will help. The plywood laser cutting technology technology allows you to create unique souvenirs and serial products. Original gifts require exclusive packaging, so one of the directions in the manufacture of souvenir products is the creation of gift boxes, branded wardrobe cases, bottle cases. However, souvenir products are not only gifts for loved ones or commemorative magnets, but also corporate paraphernalia, business gifts that also perform an advertising function.
Advertising business
Various designs are made of plywood, used in the design of points of sale, signs, serving items for cafes, bars, restaurants. Due to the ability to apply images and inscriptions with a laser, everyday objects made of wood or plywood are often used as promotional items. Original desktop appliances, business card holders, key rings, cup holders, calendars decorated with the company logo can be a useful gift to customers or business partners.
Furniture production
Due to its strength and elasticity, plywood is widely used for the manufacture of structural furniture parts. With the help of time-consuming processing, the plywood sheet is able to transform into the original design. This material not only does not limit the designer’s imagination, but also encourages creative experiments. The author’s furniture is born out of it – deck chairs, armchairs, benches, rocking chairs, coffee tables. However, the form is not always self-sufficient. Laser cutting of plywood allows you to make carved decorative elements: inserts in furniture facades, headboards, table tops, as well as decorative grilles, interior partitions and much more.