How to Adjust Parameters for Curved Surfaces

This book addresses the problem of adjusting parameters for curved surfaces, and uses the example of mobile phone cases to provide a detailed explanation of the techniques involved in setting the parameters of laser marking equipment, including the methods for adjusting the core parameters of power, speed, and frequency. It also addresses common problems such as blurring and line breaks that occur when marking curved surfaces.

Why can't we get the parameters right for curved surfaces?

I often hear friends complain, "I can mark a flat piece of metal easily, but when I switch to a curved surface like a cell phone case, the marking just comes out a mess.In fact, this is directly related to the change in focal length caused by the change in curvature, just like how a magnifying glass used to focus sunlight will cause a distorted spot if the angle is slightly off.The problem of focus stability is precisely what curved surface marking is designed to solve.

Setting up a real battle plan is a four-step process.

First, choose the right equipment.

Don't rush to adjust the parameters. First check whether the clamping fixture is properly matched to the surface's curvature.The phone case was made with a silicone mold that used vacuum suction to hold the object in place, so it would be secure but not leave a mark.Remember to change the lens to a dynamic focus system, which automatically compensates for the height differential.

That's how the basic parameters were set.

A 20-watt laser is a common example.

- Adjust power to 60 % (about 12 W).

The speed was reduced to 800mm / s.

- Starting frequency: 20kHz.

At this point it's necessary to make a test run. If the lines are fuzzy, increase the power rather than decrease the speed. Too slow a speed can burn the plastic casing.

Advanced fine-tuning techniques.

If the problem is carbon buildup at the logo corner, try setting the parameters for each corner separately.

1. Maintain the original parameters of the main lines.

2. The position at the corner of a building reduces power by 5 % and increases speed by 10 %.

With the built-in regional parameters, it's just like switching driving modes for different road conditions.

These tests are mandatory.

We tested it on a used cell phone case.

5.

2. Arrange five groups of different defocuses in a vertical line.

After the paint has dried, the adhesion is tested by scraping it with a fingernail.

An actual case of a mobile phone case being damaged during engraving.

Last week one customer sent in a matte-finish curved cell phone case and asked that the label be applied in such a way as to preserve the matte finish.After finishing the routine, it was discovered that:

- Reflective markings are clearly visible at night.

- Burn marks on the edge.

The frequency was adjusted to 30 kHz, the power was reduced to 50 %, and auxiliary air was turned on.In the end, under the condition that the clarity of the image be maintained, the original frosted texture was perfectly preserved.

Three tips for avoiding pitfalls.

Don't put blind trust in the manufacturer's specifications--the reflectivity of materials can vary by 15 % in different batches.

2. For every 1 ° C above 28 ° C, reduce the power by 0.5 %.

3. Wait 30 seconds after drilling before touching the work piece, as the thermal expansion and contraction can cause minute deformations.