A Practical Guide to Laser Marking Medical Stainless Steel under ISO 10993

The article explains the key points of laser marking of medical-grade stainless steel, including material selection, parameter settings, and compliance verification.The guidelines provide practical steps and precautions to help medical device companies efficiently respond to changes in the law, ensuring that their marks are clear and comply with the standards for biocompatibility.

Why does the new ISO 10993 standard affect medical marking?

Recently, many of his peers have been complaining about the new ISO 10993 standard, which imposes even stricter requirements on the surface treatment of medical-grade stainless steel.In particular, with laser marking, it is necessary to ensure that the mark is clear and will not fade, and that the surface of the material has not been damaged and that the residue is biologically safe.Those of us who actually do the work know that if the parameters are not set correctly, at best it means reworking the product, and at worst it means scrapping the whole batch.How do you balance these two?

Preparing for the tattoo.

Choosing the right stainless steel.

Not all stainless steel passes muster The new regulations clearly require that materials must pass a biocompatibility test (such as a cytotoxicity test).In terms of personal experience, the best choice would be medical-grade 316L stainless steel, with a surface smoothness of at least Ra ≤ 0.8μm. Under no circumstances should one use industrial-grade materials for the sake of saving money.

The most important points of equipment adjustment.

Start with 20 watts and adjust according to the depth of the marking.Last year, when we were using a 30-watt fiber laser, we found that the power was too high, causing carbonization at the edges. Later, we dropped the power to 24 watts, and the results were immediately stable.

Pitfalls to avoid.

The problem of clarity.

Don't rush to increase power if the characters are blurry. First check if the focal distance is correct, especially for curved objects.Last week, an engineer fixed a part 2 millimeters off, and as a result, the marking was blurred. Three hours were wasted.

Waste disposal techniques.

After marking you must rinse with ultra-pure water! The new rules include a new test for residual particles.Once we were lazy and used ordinary distilled water, and when we looked at the surface under the electron microscope, we found that it was covered in nanometer-scale iron oxide particles. We almost got returned by the customer.

The verification stage cannot be skipped.

After branding, two things must be done.

1. Use a 10-power magnifying glass to check whether the edges of the markings are sharp.

2. Send samples to a third party to perform ISO 10993-5 cytotoxicity testing.

Last year one factory was in a rush to get a shipment out and didn't do a verification test. As a result, allergic reactions appeared in clinical use and they had to pay out over NT $ 3 million.That will teach them a lesson they won't forget in ten years!

Tips for everyday maintenance.

Clean the laser head lens every week, don't wait until it gets dusty.A customer once complained that the color of the markings on her contact lenses had faded, but after cleaning them the color returned.Also remember to adjust the light path regularly, especially after moving the equipment.