Discover a range of techniques you can use in the laser processing of wood materials. Follow on to rediscover how you can achieve best results with mdf, wood veneer and all other wood types.
The laser processing of natural wood materials entails taking into account the varied characteristics of the wood materials such as high desity and resin content.
The more consistency in the coloring and grain of the wood material, the better the laser engraving result.
Review of suitable wood types
|Soft woods||Processing of these varieties of wood materials, such as balsa wood or poplar, call for a lower power level using the laser and can be cut and engraved much quicker. The engraving process produces a lighter outcome.|
|Hard woods||A more powerful laser power is suggested when laser cutting and engraving hard woods. These varieties of wood, such as oak or maple, are examples of dense woods. The engraving is usually more contrasting than on soft wood.|
|Coniferous woods||Processing these woods is much more complex than any of the other wood materials. Finding the material parameters is not easy due to the soft texture of the wood surrounding the outside. This therefore implies that these woods, such as larch or fir, are not suitable for laser engraving, mostly due to the high content of hard and uneven grains.|
|Veneers||Equivalent properties are found within these wood types. Veneered woods are made of real wood and therefore show the same engraving properties as solid wood panels.|
|Plywood||Plywood consists of at least three layers of wood whose grain is glued and pressed at an angle of 90°. Plywood is sold in various types of wood and is offered in different sizes. When laser cutting, the type of glue is important for laser processing. Select white-glued plywood panels or plywood panels made specifically for laser processing.|
|MDF (Medium density fiberboard)||MDF is a homogeneous wood-based material made of finely defibrated, mainly bark-free, softwood, which is gently pressed in the longitudinal and transverse directions. The surface and edges are smooth and firm. So MDF can be easily engraved and cut. However, it should be noted that the cutting edges become very dark during laser processing.|
Guideline for laser engraving:
Hard woods result in dark, soft woods in lighter, engravings.
Laser cutting guideline:
The drier and more resin-free the wood, the clearer the cutting border.
How to select the correct engraving parameters
The grayscale matrix feature allows you to promptly and easily determine the desired engraving parameters for your laser machine,
Suggestion: The more you defocus (z-offet: approx. 0.5 - 2 mm), the darker the engraving of the wood will be. Defocussing the laser beam increases the laser spot size, decreases the performance density and burns more wood instead of letting it pass directly into the gaseous form. The disadvantage is that details can be lost.
Determining the cutting parameters
You can test the cutting parameters by drawing a rectangle with two differently rounded corners. Send this graphic to the laser. For 3mm thick wood, start with high performance and a cutting speed of 2-5%. Reach your desired cutting quality by gradually reducing the speed.
Laser parameters for download
We have tested the optimum laser parameters for all types of wood from Trotec. You can find them in the JobControl® material database or download them here:
The sticky dust generated by the wood laser should also not stick to the engraving object. Simply glue an application tape onto the working surface. This serves as a short-term surface protection and can be easily engraved along with it. After laser processing, it is simply removed. Application tape is well suited for the engraving of larger areas and for cutting. However, it is not suitable for photo-engraving or very fine engravings, since many small parts have to be removed later. When selecting the application tape, be sure to use PVC-free material and that it is removable.
The right optics
Laser cutting wood is a sublimation process. Precise focusing and the choice of the right optics are therefore crucial. A distinction must be drawn between engraving and/or cutting. While engraving, please pay attention to the following: The finer the details, the shorter the focal length of the lens should be. As a rule, 1.5" or 2.0" lenses are suitable for almost any laser engraving on wood. The situation is different for cutting. The thickness of the material plays an important role here. The thicker the material, the longer the focal length of the lens used. For 1/8 inch thick wood we recommend the use of a 2" lens, for 1/4 inch thick we recommend a 2.5" lens.
The connection of compressed air is recommended especially for cutting wood. A small-diameter nozzle should be used to protect the lens. In addition, the small nozzle diameter directs the compressed air straight into the cutting gap. As a result, dust and gas are removed more quickly and the cutting quality is significantly improved.
Cleaning hardware and optics are important factors in woodworking. Wood dust is extremely sticky due to the resins and oils it contains, and dust tends to settle in the machine. So it is important to clean the machine regularly.
Suitable exhaust system
During laser engraving and laser cutting of wood, dust and gases are produced which must be properly extracted. So the use of a suitable exhaust system is essential.
Relief engraving on wood
Wood is a great material for relief engraving. In a relief engraving, grayscales are converted into different laser power levels, which produces three-dimensional engraving. You can engrave in several passes with relatively high performance, and then perform one or two cleaning passes to remove the smoke residue.
Inlays in wood
Wood inlays (intarsia) are also particularly popular with wood. In an inlay, different woods are laid on a flat surface in such a way that a smooth surface is created, which now contains differently colored and differently structured inlays. Usually the base material is engraved first, and then the material to be laid (usually veneer) is cut and inserted. For the veneer, make sure that the width of the laser beam (cutting gap) is adjusted. This means that the carrier must be slightly larger.