How to Laser Engrave and Cut Polyimide (Extruded and Cast)

A 355 nm laser system is the best tool for engraving or cutting polyimide (PI or Kapton) with a laser. The most prominent type for this wavelength is an Nd: YAG laser. It combines high accuracy with fast cutting or engraving capabilities. A powerful laser beam is directed upon the substance in both circumstances. It leads to the evaporation or melting of the PI. The result is going to be highly precise cutting edges and good reproducibility.

The optimum power, speed, focal length, and airflow level are strongly dependent on the thickness of the Kapton plate that must be cut or engraved. The rule of thumb is: The thicker the plate, the higher the laser power and the lower the speed.

Listed below are the five steps on how to Laser Engrave and Cut Polyimide (Extruded and Cast)

Choose the right laser power – about 30-40 W for cutting and 4-6 W for engraving.
Focus the laser beam onto the surface.
Choose the right laser speed – about 12.5 mm/s.
Work with low to medium airflow – too much flow, and the Kapton does not melt sufficiently.
Ensure that the airflow covers the whole area of the Kapton plate.

Table of Contents

How to Laser Cut and Engrave Extruded Polyimide?

Listed below are the eight steps to laser cut and engrave extruded polyimide.

Prepare the material. Make certain that the extruded polyimide is clean and free of dirt. Cut the material to the project’s specifications.
Set up the laser cutter. Follow the manufacturer’s instructions to set up the laser cutter and ensure the unit is correctly calibrated.
Adjust the laser settings. Set the laser power and speed settings based on the thickness of the extruded polyimide and the required cutting and engraving depth. A low power level is ideal for engraving, whereas a higher power setting is necessary for cutting.
Test the settings. Test the laser settings on a tiny piece of extruded polyimide to check that the required results are obtained before continuing with the project.
Load the design file. Insert the design file into the laser cutter’s computer program and make changes.
Laser cut and engrave. Put the extruded polyimide on the laser cutter’s bed and start the laser cutting and engraving procedure. The laser cutter is going to cut or engrave the extruded polyimide according to the pattern specified in the design file.
Remove the material. Extruded polyimide must be carefully removed from the laser cutter’s bed once the laser cutting and engraving have been completed.
Clean the material. Use a soft cloth or brush to remove any dirt or residue left over from the laser cutting and engraving operation.

How to Laser Cut and Engrave Cast Polyimide?

Listed below are the eight steps to laser cut and engrave cast polyimide.

Prepare the material. Verify that the polyimide that has been cast is clean and free of debris. Size the material appropriate for the purpose.
Install the laser cutter. Set up the laser cutter according to the manufacturer’s instructions and ensure the unit is calibrated correctly.
Change the laser settings. The thickness of the cast polyimide and the necessary depth for cutting and engraving should be taken into account when adjusting the laser settings. It is advised to use a low power level for engraving, while a higher power setting is necessary for cutting.
Test the settings. Make sure the laser is set up correctly by practicing on a scrap of cast polyimide to get the required results before moving further with the project.
Load the design file. Prepare the design for cutting with a laser cutter by loading the design file into the cutter’s software and making any required modifications.
Laser cut and engrave. Position the cast polyimide on the bed of the laser cutter and begin the laser cutting and engraving procedure. The laser cutter cuts or engrave the cast polyimide according to the design file and the required pattern.
Remove the material. Carefully lift the cast polyimide from the laser cutter’s bed after the cutting and engraving processes are complete.
Clean the material. Remove any dirt or residue from the laser cutting and engraving process by cleaning the cast polyimide with a soft cloth or brush.

What are the differences between General Part and Presentation Part Cutting for Polyimide?

Laser-cut PI components are able to be either presentation or general-purpose. General components don’t need to meet any specifications other than accuracy. Hence, they are capable of being swiftly and effectively cut by lasers. It allows for incredibly fast production. Keep in mind that polyimide is able to be sliced effectively with little airflow. An Nd: YAG, CO₂, or fiber laser are able to be used for the cutting or engraving.

On the other hand, presentation components have clean edges that look polished. High power and low speed should be used when operating the laser cutter. A CO₂ laser is an ideal option when PI presentation parts are required. It is due to the smooth and precise cuts produced by a CO₂ laser’s long wavelength, which is about 10.6 µm. The shorter wavelength fiber lasers are not as useful for presentation parts as a CO₂ laser.

What speed is better for Polyimide with Presentation Parts?

The speed is highly dependent on the thickness of the polyimide sheet. Generally, 12.5 mm/s for standard Kapton sheets is suitable. The greater the speed at a given laser power, the greater the depth of cutting or engraving. It doesn’t change depending on the type of laser (e.g., Nd: YAG, CO₂, or fiber optic) use laser power instead. Generally, the thickness of the PI plays a role due to the depth of the laser beam cut. Thinner sheets are cut much faster than thicker sheets.

What power is better for Polyimide with General Parts?

The laser power must be selected as high as possible, which applies to the cutting speed. It ensures fast workpiece processing and short production times. High power vaporizes polyimide quickly. Generally, 30-40 watts of laser power must be sufficient for good results.

How does Polyimide Sheet Thickness affect laser cutter watt need?

Laser power determines the distance the laser beam is able to penetrate the material. Therefore, the thicker the insert, the more power is needed for cutting or engraving. However, it is recommended to try the power setting before cutting the PI sheet to make sure the power is not too high. The polyimide is going to be badly burned if too much power is used. It releases irritating or even toxic fumes and damages the cutting edges. It is especially true of the black PI, as it absorbs the laser beam much better. It contains pigments that are very sensitive to heat.

What is the best setting for Laser Cutting Polyimide?

The laser power must be around 30-40W for cutting and 4-6W for engraving. The exact laser speed is about 12.5 mm/s for cutting. These settings are able to give good cutting results at a reasonable speed. Use sufficient airflow to avoid PI ignition.

What are the common mistakes for Laser Cutting Polyimide?

Listed below are the common mistakes for Laser Cutting Polyimide.

Overheating: Polyimide is a material that may be sensitive to high temperatures, and if the laser power is too high or the cutting speed is too slow, the material is going to overheat and deform or warp.
Incomplete cutting: The laser does not completely cut through the polyimide if the power is too low or the cutting speed is too fast, leaving partial cuts and necessitating extra passes.
Burning or charring: Polyimide is susceptible to burning and charring as well, mainly when the laser power is too high, or the cutting speed is too slow. The material is able even to get damaged or discolored as a result.
Melted edges: Edge melting occurs when the laser’s intense heat melts polyimide during cutting, leading to potentially unusable rough or irregular edges.
Incorrect settings: Uneven cuts, burnt edges, or incomplete cuts occur if the laser settings are not correctly adjusted for the particular polyimide material.

What are the beginner tips for Laser Engraving Polyimide?

Listed are the beginner tips for Laser Engraving Polyimide.

Choose the appropriate laser: Not all lasers are able to engrave polyimide. Ensure that the wavelength of the CO2 laser is appropriate for the material.
Prepare the surface: Clean the polyimide surface well before engraving to get rid of any dirt or debris that is able to get in the way of the engraving process.
Test settings: Begin by experimenting with various power and speed settings to identify the best parameters for etching polyimide. Be careful to begin with low power levels and raise the power gradually until getting the desired outcome.
Choose the proper focal length: Accurate and precise engraving depends on the laser’s length. Choose the appropriate focal length depending on the polyimide’s thickness.
Utilize a vector file: Employ vector files instead of raster pictures to produce sharp, precise lines. Vector files are able to be resized without losing quality because they don’t depend on the resolution.
Try out several designs: Polyimide is able to be intricately etched, so play with different patterns, typefaces, and pictures to discover the design that best meets the requirements.
Examine the depth: Make sure the depth is constant throughout the design by checking the depth of the engraving once it has been done. Set the laser settings to the desired depth.
Protect the edges: Consider protecting the edges of the material from harm during engraving since polyimide is able to be delicate. Masking tape or other protective materials are able to keep the edges from chipping or breaking.

Which Laser Cutter is best for Polyimide?

The two most common types of Kapton laser cutting machines are Nd: YAG, CO_2, and fiber lasers. These laser cutter types are a great choice as they are reliable, fast, and powerful. Therefore, polyimide is able to be easily cut. The BOSS Laser LS series is able to be used as a standard for cutting PI.

What are the Polyimide Projects for Laser Cutting?

Here are some awesome projects regarding PI laser cutting with different laser types:

Cutting Kapton with a 355 nm laser: https://www.youtube.com/watch?v=HA4cvwn1U_A
High precision laser cutting of Kapton: https://www.youtube.com/watch?v=jnVrNgi-wAg
Laser processing of PI: https://www.youtube.com/watch?v=MOJ2bkFhqY8
Laser Cutting of adhesive Kapton sheets: https://www.youtube.com/watch?v=HV5-ZNe13NM
PCB fabrication from PI with a laser: https://www.youtube.com/watch?v=MnsDlLu6uw8
Producing Kapton stencils with a laser cutter: https://www.youtube.com/watch?v=S8tOGcQKxbA
Laser cutting a polyimide solder mask: https://www.youtube.com/shorts/wLfL8fCyiec
Cutting PI for the electronics industry with a laser: https://www.youtube.com/watch?v=CCWTQ8FC54U

What are the alternatives of Polyimide for Laser Cutting?

Listed below are the alternatives of Polyimide for Laser Cutting.

Kapton: Kapton is a polyimide film that has the same high-temperature resistance and dimensional stability as polyimide. Kapton is often utilized as a substrate for flexible printed circuits and in aerospace and automotive applications. Kapton engraving is possible by using laser engraving techniques.
Polyester film: Polyester films, such as Mylar, provide still another choice for laser cutting. They have strong mechanical qualities, are translucent, and absorb little moisture. They’re often seen in electrical and electronic applications. Polyester film engraving is famous due to its durability, transparency, and low moisture absorption.
Acrylic: Acrylic is a thermoplastic substance that is able to be laser-cut with great success. It is often used in signs, displays, and building construction because it is straightforward and easy to make. Acrylic engraving is popular due to its affordability, versatility, and ease of use.
Polycarbonate: Another thermoplastic material that is able to be laser cut is polycarbonate. It possesses high impact resistance and is often utilized in applications requiring long-term durabilities, such as safety glasses and automobile components. Polycarbonate engraving is able to create a wide range of designs and patterns.
Foam material: Foam materials are able to be laser cut, including polyurethane foam and polystyrene foam. They are often used in packaging and insulation because they are lightweight and keep things warm. Foam material engraving is able to create a wide range of designs and patterns.

Is Nylon the same as Polyimide?

No, those materials are not exactly the same. They are both consisting of monomers, but they have entirely different physical properties. For example, nylon is able to be used up to 75 °C, while PI endures temperatures up to 400 °C. The relative density is 1.14 for nylon and 1.43 for polyimide.

What is the difference between Delrin and Polymide in laser cutting?

The main difference between those two materials lies in the maximum temperature they are able to endure. Delrin melts at about 120 °C while PI stays solid up to 400 °C. This means that Delrin needs a bit less laser power to melt or evaporate. The laser cutter is able to be run at a bit higher speed for Delrin than for polyimide. Of course, the sheet has to have the same thickness for direct comparison. A 355 nm Nd: YAG laser is able to use Delrin Cutting instead of the more common fiber or CO2 laser. The latter one has a shorter wavelength. CO₂ or fiber laser emit light in the infrared region (some micrometer wavelength).