Photopolymer resin's stamp cutting

Hi every one .. Recently i started cutting photopolymer resin stamps that I make using laser cutting machine. After the cut they turn yellow. Im unable to understand why. Is there some other technique to cut photopolymer stamps to shape ?

Looking forward to some positive suggestions.

Thank you in advance.

Vidushi

Hi Vidushi,

what wavelength has your laser?

Colour changing shows some "post-curing" with chemical reactions caused by heat or light energy (mostly with UV or blue) - or by fumes, if not vented properly or cut with too much energy in a CO2-lasercutter.

Cutting without embedding any heat or chemical energy can be done by milling, waterjet-cutting or with an oszillating needle ...

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Viktor
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Im not really sure of the wave length of the laser as im outsourcing it .. After curing it is perfect and almost clear .. But when i cut them in shape using laser machine they turn yellow. Could you suggest what wavelength should I be using ? Or any other method that would help me with precision cutting around my deisgn ?

... is the laser beam visible or invisible?

If the beam is invisible (only the burning spot shines yellow-white), then it should be a CO2-laser with 10640nm (or a NdYAG-laser with 1064nm ... or a fiberlaser with 1070nm -- both not so common with lasercutters).

The cheap CO2-lasers are made with a long glass-tube and needs water-cooling, better ones are sealed in a aluminium box and cooled by forced air.

The other common types uses blue laserdiodes with 445nm with powers of up to 3.5Watts ... or UV-laserdiodes with 405nm, but powers below 1 Watt ...

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Viktor
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The laser beam is visible ..

I do not have water jet cutting in my city .. Is there any way I can cut these photo polymer sheets exactly where i want them to cut .. Because the have designs on them .. And i want it to be cut around the design.

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Koolvidz
The laser beam is visible ..

... is it blue or red?

If blue - is it a "strong blue" (then should be 445nm), or a "pale blueish" (then 405nm)?

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.. Is there any way I can cut these photo polymer sheets exactly where i want them to cut .. Because the have designs on them .. And i want it to be cut around the design.

... you can try with milling -- or, if the sheets are thin enough, then with a knife cutter ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]