Keeping a cool head

Sometimes lasers get very hot under the collar, especially when processing thick steel. CoolLine is for chilling with a water fog.

Although they look very robust, they can get quite touchy when a laser sets to work. Parts made of thick mild steel are full of surprises that can upset the cutting process. Uneven chemical composition and surface quality are the main culprits. In the past, mild steel that was not of a laser-cutting grade could not be processed at all or only with great difficulty.

And the results, even materials amenable to laser cutting, were not always convincing. The thicker the sheet metal component, the lower the cutting speed — and the more laser energy required to cut the metal. This becomes especially noticeable when thickness exceeds fifteen millimeters. The material around the cutting point gets hotter and hotter, causing a significant temperature difference compared to the rest of the metal, with an unpleasant out-come: the so-called self-burning effect.

The kerf in the hot sheet metal becomes irregular; the material in the kerf no longer flows away in a controlled fashion and starts to burn. This leads to an unsightly build-up of excess slag on the back of the workpiece.

A sure cut in spite of difficult conditions

To ensure that everything stays cool in the kerf, TRUMPF has developed a solution for localised workpiece cooling. The centerpiece of the CoolLine option is a separate cutting head with special nozzles that spray a fine fog of water. The cold fog is sprayed onto the material through holes in the nozzle, coaxial to the laser beam. It then settles on the workpiece and evaporates.

That’s a simple measure with great effect. Thirty milliliters of water evaporating each minute represent about one kilowatt of cooling power. That cools the metal by approximately twenty percent with a five kilowatt laser. Temperatures in the processing zone are thus reduced significantly. The laser beam hits material of a uniform temperature and can even process mild steel that is not laser-cutting grade at complete stability.

An efficiency bonus for high-grade material

The fine water fog is also beneficial when processing laser-grade sheet metal. With more precise cutting quality, thick components can be nested closer together, reducing waste. The same factor provides more latitude with complex contours. In pre-tempered material, the laser cuts thinner strips and diameters, quickly and reliably. It is possible to cut diameters less than half of the sheet metal gauge without sacrificing feed rate.

And there are very few changes for the operator, who programs and controls the work with TruTops Laser. All the necessary tubing for the water supply is integrated into the CoolLine cutting head. The job can get started immediately after the standard cutting head has been replaced by the CoolLine head — no matter what surprises the sheet metal might have in store.

14 enhancements for laser cutting

Highly productive, top quality, process reliability — these useful assistants simply make work easier.

1.BrightLine

This special cutting system produces the highest quality cuts in thick stainless and mild steel. The smoothness and squareness of the cut edge are far superior to a standard cut. No finishing work is required.

2.ContourLine

ContourLine makes it possible to accurately cut contoured holes with diameters much smaller than the material thickness. A pulsed beam system controls the introduction of heat into the material.

3.ControlLine

Sensors keep the distance between the cutting nozzle and the sheet metal constant – even if the sheet is uneven. ControlLine determines the position of the sheet and adjusts the cutting program, eliminating the need to correct the position manually.

4.CoolLine

The selective cooling of the workpiece during the cutting process allows new geometries and significantly increases process reliability in the processing of thick mild steel.

5. DetectLine

The intelligent camera system scans sheets in process very accurately and determines their precise position. The machine can also use this data to detect parts which have already been cut, in order to process them further and with absolute precision. In addition, DetectLine automatically adjusts the focus position.

6.Single cutting head strategy

Save time by using a single cutting head that does not require changing. This reduces non-productive time, especially when you are automatically processing a number of different materials.

7. FlyLine

The cutting head travels at high speed over the entire sheet line by line. The control system cuts all the contour sections in the respective beam path. This reduces the time spent on traversing and positioning, especially when cutting perforated grids.

8.FocusLine

An adaptive mirror in the beam guidance system makes it possible to automatically adjust the focus position to the material type and thickness. The result: Maximum processing speed and excellent edge quality across the entire range of surfaces and materials – without the need for manual adjustment.

9. High-speed cutting

A special cutting head selectively introduces metal vapor plasma to significantly increase cutting speed.

10.Laser output control

The laser power output is automatically adapted to the cutting speed. This ensures optimum cut quality even on sharp corners and small contours.

11. LensLine

LensLine immediately switches off the beam if the focusing lens accumulates a critical amount of debris. This prevents the lens from thermally decomposing and keeps the beam guidance system clean. The system automatically checks the condition of the lens in the mounted cutting head. So the lens is only cleaned when necessary – not just as a precaution.

12.NitroLine

This technique introduces nitrogen at very high pressure to produce oxide-free edges. As a result, you can cut thicker sheets and achieve very high cutting speeds in stainless steel and aluminum.

13. PierceLine

PierceLine monitors and controls the piercing process. This reduces stress on the material and machine and shortens pierce time by up to 80%.

14.PlasmaLine

If plasma forms when thick sheets are being cut, the control system reduces the feed speed or stops the axis motion. The beam is not interrupted, meaning PlasmaLine ensures high process reliability and part quality.