Best laser to cut DTF (PET) plastic film?

Community Laser Talk
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Hi,

I’m trying to build a custom DIY DTF roll-to-roll film-cutting machine. I was inspired by this lady who cut a single film sheet with her CO2 laser.

As you can see in the video, the CO2 laser cuts the film very fast and without charring.

I hoped to use Sculpfun’s S30 33w diode laser to achieve a similar result. Unfortunately, even with air assist, I’m getting a lot of charring.

I asked ChatGPT about the differences between diode lasers and CO2 lasers and received this response:

“CO2 lasers operate at a longer wavelength (typically 10.6 μm) compared to diode lasers (usually in the near-infrared range, around 0.8-1.0 μm). The longer wavelength of CO2 lasers is more readily absorbed by a wider range of materials, leading to cleaner cuts and less charring.”

The problem I face is that I would rather not work with a DYI CO2 laser. Between dealing with the CO2 tube, mirrors, cooling, limited lifespan, and being forced to use an enclosure with a CO2 laser, a diode laser would be much easier if I could get it to work without charring.

I’m thinking about trying Sculpfun’s new S70 70w diode laser. The gantry is much faster, and the laser is far more powerful.

I’m new to lasers. Do you think the extra power and speed of Scuplfun’s S70 laser will result in less charring? Or will I be forced to use a CO2 laser to get no charring?

Any advice is much appreciated.

Wyatt

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Visible-light diode lasers basically bounce off colored plastic film or pass completely through clear film, because the film reflects or transmits visible light. Because most of the laser energy bounces off or goes straight through, the beam must move slowly, giving any absorbed energy plenty of time to heat up the surrounding material.

Because the CO₂ energy is mostly absorbed, it will quickly vaporize a small patch of material as it moves along, with the surrounding material largely unaffected.

Although XTool is coy about the power, it looks like that’s a 55 W machine: nearly all that power goes into vaporizing the plastic.

A 70 W diode laser still deposits very little energy in the material, so doubling your S30’s power won’t make much difference. The description of the S70 talks only about “black acrylic”, for good reason.

As the Prophet Jagger put it: You can’t always get what you want.

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You will definitely want to use an enclosure for plastic. The fumes are toxic and unsafe to breathe.

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@ednisley @soniclab Thank you for your responses. I appreciate it.

Wyatt