Insofar as laser cutting is concerned, wood can be separated into two distinct groups:
- Natural timber from various species of tree. For example, maple or cherry wood.
- Man-made wood manufactured by bonding wood pulp, fibers or shavings. For example, MDF or plywood
All natural timbers can be cut by a CO2 laser at the 10.6µm wavelength. Limitations only apply with regard to thickness and the degree of charring that is acceptable to the customer.
Special versions of laser cutting machine are made for specific wood cutting applications such as, for example, laser cutting plywood for label dies. However, for the purpose of this article we are referring to a typical benchtop format laser cutter <100w.
For most industries laser cutting anything beyond 12mm natural timber and 9mm plywood produces an undesirable result because the feed rate (speed of cut) combined with optical limitations causes the wood to adversely burn.
When laser cutting wood the rate of laser fume extraction, particularly underside extraction and air assist delivered through the nosecone, can never be too much. When vaporised, wood produces a very dense fume that if not immediately evacuated from the cutting line will rise into the path of the beam and absorb laser power, significantly dropping the feed rate of the cut and in turn accelerating the degree of charring at the edge of the cut
High amounts of debris from laser cutting wood can also contaminate laser optics causing them to fail prematurely and also cause HAZ (Heat Affected Zone), which is an undesirable staining to the edge and surfaces of the material.
In machines where the design of extraction is poor, surface HAZ can be minimised by first applying a low-tack, paper based tape to both surfaces of the wood. The tape acts as a masking barrier, attracting the contamination. After laser cutting the paper is removed and the wood surface underneath is clean.
Natural timber has a tendency to warp, which is challenging for laser cutting as this causes the beam to defocus, producing undesirable results. Therefore, if the application calls for laser cutting of natural timber it is best to process the material as soon as possible after receiving it from the mill.
Man-made or engineered woods can contain resins that are actually designed to be fire retardant. This is unhelpful when trying to burn through the wood with a laser cutter! Therefore, if the application calls for using a form of engineered wood it’s wise to be very selective about the exact type of material you use. For example, plywood is most commonly available in a WBP or exterior grade. The resins used to bond this type of plywood are among the least laser friendly and will resist the laser cutting process, accelerating HAZ.
Interior grade plywood, sometimes called white glue plywood, is among the most laser friendly plywood’s. Not as commonly available as exterior grade, interior grade should be used as a preference for laser cutting if the job specification allows it as the resins in the material will vaporise much cleaner.
An often overlooked aspect is that of the surface finish of wood prior to laser cutting. If the part to be laser cut is the finished item then the surface should always be sealed/finished before it is laser cut. This reduces HAZ and any HAZ present can be wiped off with a slightly damp cloth. If however the material is to be post processed, such as sanding for example, then pre-sealing the wood is not absolutely necessary as the HAZ will be removed during post processing.
At Lotus Laser Systems we manufacture a wide range laser, marking and engraving solutions ideally configured for laser cutting and laser engraving wood. Our experts would be happy to recommend which configuration best suits your application.
Watch our systems at work
Below are just a few videos of our systems laser engraving different types of wood.
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Lotus Laser Systems Blu125 200w DC laser cutting 5mm oak
http://lotuslaser.com
In this video we show how Blu125 200w cuts 5mm thickness solid oak wood quickly, cleanly with virtually zero contamination of the focus carriage
When combined with a high flow extract to atmosphere system a machine like this can cut for many weeks if not a few months without any lens contamination.
In this video the machine is using a 4" f/l lens, which is a compromise between surface contamination of the material and reduced maintenance. Using a 2.5" f/l lens would provide lower surface contamination as would blocking off the areas of the bed that are not covered.
In this video we did not block off the open areas of the table as we want to show how well the fumes area extracted from the underside port
Here at Lotus Laser Systems we have extensive experience in laser marking within a range of industries and applications
For more information on how we can help you please visit our website and get in touch.
Please view our full range of machines at https://www.lotuslaser.com/all-machines/ -
Lotus Laser Systems Blu100 and Meta CO2 cutting and marking Bamboo badges
http://lotuslaser.com
Laser Cut bamboo Blu100 DC and Laser Mark bamboo CO2 Meta C1. In this video we used the Blu100 DC to cut 5mm thick bamboo and engraved it with our Meta C1 CO2 laser. Our Blu100 DC is 80w machine and one of the best selling models for cutting apps. Included in the package is the rod dot positioning device, nosecone, 2'' lens, lotus cut software, air assist with onboard pump, lamella cutting table and Chiller. As you can see in the video the cutting takes only a few seconds and has no charring because of the premium extraction system in the bed. The marking on bamboo and acrylic badge by Meta C1 Co2 laser is another example of superior quality. Enjoy the video.
Here at Lotus Laser Systems we have extensive experience in laser marking within a range of industries and applications
For more information on how we can help you please visit our website and get in touch.
Please view our full range of machines at http://lotuslaser.com/machines
Suggested Systems
At Lotus Laser Systems we manufacture a wide range laser, marking and engraving solutions ideally configured for laser cutting wood. Below are just a few of those we suggest for this application. Please do contact us if you would like to find out more.
Specifically sized to minimise material waste, the Blu100 is our best selling CO2 laser cutter. This machine covers the vast majority of typical work for a machine of this type.
Meta-C is our flagship system designed for seriously heavy commercial and industrial users. The features built into Meta-C help it deliver the best functionality and performance in its class.
Specifically sized to minimise material waste, the Blu100 is our best selling CO2 laser cutter. This machine covers the vast majority of typical work for a machine of this type.With its huge 1250x900mm work area and a massive 100w of CO2 laser power, Blu125 is the ideal laser cutter to ensure that almost no job is too large or too long in process time maximising margins, giving the freedom to create more challenging designs as well as increasing the number of users that can gain access to the laser cutter during a single day.