The following are the core techniques for blue laser engraving to help improve precision, efficiency, and the quality of finished products:
First, determine the light source. Currently, there are two types: infrared and blue light. Then, determine the parameters.
Blue light is used more frequently, for wood and plastic, while infrared is generally used for metal.
First, determine the general classification. For example, the Siser Brick 600 thermal transfer vinyl material used falls into the plastic category. For this, you can refer to the acrylic consumable parameters provided on the official website for testing.
If the effect is too light, increase the power or decrease the speed appropriately. If it is too dark, decrease the power or increase the speed. You can print multiple times. Then, use engraving techniques such as:
a. Surface Preparation: Wood: Sand until smooth; Acrylic: Remove the protective film (to prevent sticking during high temperatures); Leather: Choose low-oil leather such as vegetable tanned leather, and lightly spray with water before engraving.
b. Increase the exhaust air during engraving and clean the surface dust after engraving.
c. After metal engraving, perform laser engraving parameter cleaning.
Finally, use the material matrix for multi-parameter verification.
Blue laser is characterized by a small focused light spot (high precision), a small heat-affected zone, but relatively weak penetration, making it suitable for the following materials that require targeted treatment:
Applicable materials:
Wood (softwood, hardwood, plywood), acrylic (especially light-colored), leather, paper, plastic (ABS, PP, etc.), fabric (cotton, linen), glass (requires coating assistance), stone (only surface scratching).
Materials to Avoid: PVC (produces toxic gases during carving), metal (cannot be carved without coating and requires special metal marking liquid), and dark/highly reflective materials (poor absorption of blue light, resulting in poor results).
Material Pretreatment:
Wood: Sand to smooth (reduce burrs), remove surface oil stains (can be wiped with alcohol), and dark-colored wood can be coated with a layer of light-colored primer (enhance contrast).
Acrylic: Tear off the protective film (avoid high-temperature adhesion). If there are white edges after engraving, the surface can be pre-wiped with alcohol.
Leather: Choose types with low oil content, such as vegetable-tanned leather, and lightly spray water before carving (to prevent overheating and charring).
The parameters are the key to determining the effect and need to be adjusted according to the material thickness, hardness, and engraving requirements (taking LightBurn as an example):
Power:
Fine carving (such as text, patterns): Power 30%-50% (to avoid burn-through or blackening of edges).
Deep carving (such as wood relief): Power 60%-90% (hardwood requires higher power, while softwood requires lower power to prevent carbonization).
Light-colored materials (such as white acrylic): Power can be increased by 10%-20% (weak blue light absorption); Dark-colored materials: Power is reduced by 10%-20% (prone to overheating).
Speed:
Precision first (e.g., detailed patterns): Speed 500-1500 mm/min (slow speed ensures sufficient action of the light spot).
Efficiency first (e.g., large area filling): speed 2000 - 4000 mm/min (to avoid pattern blurring caused by excessive speed).
Empirical formula: Power is inversely proportional to speed (when power increases, speed must be correspondingly increased to avoid local overheating).
Line Interval:
Fine pattern: 0.05-0.1mm (dense lines, clear details, time-consuming).
Large area filling: 0.1-0.3mm (sparse lines, high efficiency, suitable for rough style).
Principle: Not less than the diameter of the laser light spot (the light spot after blue light focusing is approximately 0.1-0.2mm; too small a spacing will result in overlapping ablation).
Engraving Mode Selection:
Vector engraving (Vector): Suitable for lines and text (fast speed, sharp edges), requires converting the design to vector format (.svg,.dxf).
Bitmap carving (Raster): Suitable for photos and grayscale images (note the resolution, recommended within 300 dpi, as too high a resolution will increase processing time).
Layered carving: Complex patterns are divided into multiple layers with different power/speed settings (e.g., text uses high-precision parameters, while the background uses high-efficiency parameters).
Path Direction Optimization:
Avoid "back-and-forth cross paths": Set "unidirectional scanning" in the software (to reduce pause burn marks during direction changes).
Carving along the material grain: Set the path of wood along the grain direction to reduce burrs and irregular ablation.
Canary Release Image Processing Techniques:
Use Photoshop or GIMP to convert the image to an 8-bit grayscale image (the stronger the black-and-white contrast, the clearer the carving levels).
Appropriately increase contrast (to avoid blurry canary release transitions), and reduce brightness (to prevent light-colored areas from failing to appear).
Focus Calibration:
Blue laser focusing requires high precision, so be sure to use the focusing ruler provided with the device or the "autofocus" function (a focal length error of 0.5mm may lead to a significant decline in performance).
Different material thicknesses require refocusing: for example, when changing from wood (5mm thick) to acrylic (3mm thick), the height of the laser head needs to be adjusted.
Blowing and Smoke Exhaust:
Turn on auxiliary blowing (moderate air pressure): blow away the smoke and dust generated by carving (to avoid secondary burning caused by smoke and dust adhering to the material surface).
Enhanced smoke extraction: Especially when carving wood or leather, smoke can contaminate the lens (regularly wipe the laser head lens with lens paper).
Ambient Temperature and Stability:
The working environment temperature should be controlled between 15-30℃ (too low temperature may cause the laser power to decline, while too high temperature affects the heat dissipation of the equipment). 。
Fixing materials: Fix with clamps or double-sided tape (to prevent material movement during engraving, which may cause pattern misalignment), and lightweight materials (such as paper) can be covered with a glass platen.
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Problem |
Cause Analysis |
Solution Tips |
The edges of the engraved pattern are blackened |
Excessive power / Too slow speed |
Reduce the power by 5% - 10% and increase the speed by 500 - 1000 mm/min |
The pattern has jagged edges / is unclear |
Excessively large scanning interval / Too fast speed |
Reduce the interval to 0.05 - 0.1 mm and decrease the speed |
There is white frost on the material surface (acrylic) |
Secondary burning caused by laser reflection |
Wipe with alcohol immediately after engraving, or reduce the power |
There are burrs in wood engraving |
The material is not polished / Engraving against the grain |
Polish to above 200 mesh and set the path along the grain direction |
Uneven engraving depth |
Uneven material / Incorrect focusing |
Level the material and recalibrate the focal length |
Gradual change carving: Use the "Power Mapping" function in LightBurn to make different brightness levels of the canary release image correspond to different powers (achieving a gradual change in depth).
Reverse carving effect (acrylic): Carve on the back of the acrylic and view from the front (power needs to be reduced to avoid punching through, suitable for making signs).
Multicolor overlay: First engrave the light-colored material, then fill the grooves with paint, and wipe the surface to form a colored pattern (e.g., wood + acrylic paint).
In blue light module engraving, the core purpose of "multiple engraving" is to compensate for the energy shortage, material limitations, or effect defects of single engraving, and achieve more ideal depth, clarity, or layering by superimposing engraving actions. The specific scenarios requiring multiple engraving need to be comprehensively determined based on material characteristics, engraving objectives, and equipment performance. The following are the detailed classifications and operation logic:
When the carving target is to penetrate thick materials (such as thick acrylic, solid wood blocks) or create a three-dimensional relief effect, if excessive depth is pursued in a single carving, it is likely to cause "edge chipping" (such as acrylic cracking), "charring" (severe carbonization of wood), or "pattern deformation" (excessive energy concentration) of the material. In this case, "layered multiple carving" must be used to gradually progress.
Thick material penetration (e.g., 5mm acrylic cutting / deep engraving): If the engraving depth is set to 5mm in a single pass, the energy of the blue light module may not be evenly transmitted to the bottom of the material, resulting in over-melting of the upper layer and incomplete cutting of the lower layer. It is necessary to split according to "total depth ÷ number of layers" (e.g., 5mm divided into 3 passes, 1.5 - 2mm each time), and clean the slag / debris on the material surface after each engraving to ensure that the energy of the next engraving is not blocked by residues.
Three-dimensional relief effect (such as wood relief, acrylic convex pattern): Multiple carving operations need to be planned according to the "layered depth" of the design (for example, if the relief protrusion is 2mm, it should be carved in 2 passes, 1mm each time), and each carving operation must strictly align with the pattern coordinates (it is recommended to use the "positioning function" of the equipment or calibration with marking points) to avoid misalignment of the relief edges caused by interlayer offset.
The wavelength of blue light (400 - 480nm) has "low absorption efficiency" for dark-colored and highly reflective materials - dark-colored materials (such as black plastic, dark walnut) absorb some blue light, but the single energy is insufficient to cause obvious changes in surface color/ texture; highly reflective materials (such as mirror stainless steel, electroplated plastic) reflect most of the blue light, and the single engraving mark is almost invisible, requiring multiple engravings to enhance "visual contrast".
Engraving on dark plastic/wood: After a single engraving, the color of the text has a small difference from the base color of the material (e.g., engraved black plastic remains light gray). 2-3 repeated engravings are required to allow the material surface to repeatedly absorb energy, gradually forming a deeper color (e.g., light gray → dark gray → nearly black), thereby enhancing the clarity of the text.。
Highly reflective material marking: For example, when engraving a logo on a mirror-finished stainless steel surface, a single engraving can only leave a very faint "hazy trace". It requires 4-6 engraving passes, with each pass allowing the blue light to slightly abrade the material surface (destroying the reflective layer), gradually forming a non-reflective engraving mark, and finally making the logo clearly visible.
If the power of the blue light module itself is low (e.g., <5W), or if the parameters are set incorrectly during the first engraving (e.g., the power is set too low, the engraving speed is too fast), resulting in the single engraving effect being far below expectations (e.g., shallow engraving marks, faint patterns), there is no need to readjust the parameters and start engraving from the beginning. Instead, you can directly repeat the engraving multiple times on the original pattern to gradually make up for the energy deficit.
Example: For the original parameters "power 50%, speed 100mm/s", the engraving effect is poor. There is no need to modify the parameters; simply repeat the engraving 2 - 3 times, which is equivalent to increasing the total energy to "50%×3", and can significantly deepen the engraving marks (provided that the material tolerance is sufficient, such as plastic and wood).
Note: If "slight carbonization" (such as blackening of the wood edge) has occurred during the first carving, it is not recommended to continue carving multiple times to avoid expanding the carbonized area.
It is essential to ensure "precise positioning": The core prerequisite for multiple carvings is "complete alignment of the patterns in each carving"; otherwise, issues such as "ghosting" and "misalignment" (e.g., offset of text strokes) may occur. Suggestions:
Use the device's "Absolute Position Carving" (set a fixed origin before carving and return to the origin before each repetition);
If the device does not have a positioning function, you can make a "cross mark" on the edge of the material and manually align the marked points before each engraving.
Control material temperature to avoid overheating: Multiple engraving operations can cause local temperature accumulation in the material (especially plastics and resins), which may lead to material deformation, melting, or combustion. Recommendations:
Each carving interval is 3-5 seconds (for small materials) or use a fan to blow towards the carving area (forced heat dissipation);
When performing layered carving on thick materials, clean the surface slag after each layer of carving (to avoid the continuous effect of residual heat).
Test on a small scale first, then proceed with formal engraving: The "tolerance times" vary for different materials (e.g., 3 times may be too deep for soft plastic, while 5 times may still be too shallow for metal). It is necessary to first test 2 - 3 times on the edge of the material to determine the optimal number of repetitions, and then proceed with batch engraving to avoid wasting materials.
When one or more of the following situations occur, multiple carving attempts should be prioritized:
① After a single engraving, the engraving depth < target depth (e.g., 0.3mm instead of the required 1mm);
② The contrast between the pattern and the base color of the material is low, making it unclear to the naked eye;
③ Fine details (text, texture) are missing or blurred;
④ The material has high hardness/density and large thickness, making it impossible for a single energy pulse to penetrate.
By adopting the approach of "small amounts multiple times + precise positioning + heat dissipation control", the engraving ability of the blue light module can be maximized, avoiding poor results caused by equipment limitations or material issues.
The advantage of blue laser lies in precision machining, with the focus on controlling thermal effects and optimizing paths. Beginners are advised to first test parameters on scrap materials (record the optimal power/speed combination) and gradually accumulate machining experience for different materials. If more specific parameter references are needed for a certain type of material (such as walnut, transparent acrylic), further instructions can be provided!