General Wire Insulations

When we talk of general laser wire stripping we mean extruded and tape wrapped insulations and not dipped enamel insulations or shield cutting.

For these types of applications carbon dioxide laser technology is used to vaporize or melt away the plastic insulation from the conductor or shield. Carbon dioxide lasers are powerful, low cost, reliable and maintenance-free – making them the perfect stripping source. More importantly, carbon dioxide light is in the far infra-red portion of the spectrum and is strongly absorbed by polymers but harmlessly reflects from metallic conductors and shields. This results in a very robust, self-limiting process.

There are a number of ways to remove the insulation from a wire or cable. The main methods are:

• Cross-cuts: A single line of insulation is removed from around the wire to create a 360 degree strip. The slug of insulation is then pulled off.
• Slits: A slit is where a single line of insulation is removed from along the wire. When joined with a cross cut, it aids the removal of the slug by peeling off the insulation.
• Window: When two cross cuts are joined by a slit, a portion of insulation can be removed mid-way along a cable. This could be used on a shielded cable to connect an earth bond.
• Area ablation: In this case the laser is passed back and forth over the wire multiple times to fully vaporize the insulation from the conductor leaving no slug.

The best method depends on the insulation materials and the cable construction and can be a complicated decision. We can help you decide and if required make samples to determine the best method. Contact us today to discuss your requirements and to have samples of your wire and cable laser stripped.

The general guidelines are as follows:

Cross-Cuts

Cross-cuts are the quickest and simplest stripping method, but can only be used if the slug can be pulled off easily. Many insulations are difficult to pull off and this is most commonly the case if the slug is much longer than 0.5″ (12 mm).

For wires <0.2″ (5 mm) diameter, cross-cuts are most easily created by passing a focused laser spot across the wire insulation from two sides. The two sided cuts join up to create a full 360 degree cut. The cut insulation can then be pulled off (the slug) to reveal the conductors. As the laser harmlessly reflects off the conductor, you are guaranteed a perfect strip every time.

Cross-cuts are made by moving the laser beam in one dimension across the wire insulation perpendicular to the wire.

Suitable laser wire strippers for this method are:

Mercury-2: can make cross cuts and slits.
Mercury-4: can make cross cuts, slits and ablate areas.

Cross-Cuts, Slits & Windows

Cross cut and slits are used to aid the removal of the slug. The slug can be peeled away easily provided it is not fully bonded to the conductor. Slits require the laser spot to be moved along the wire, so the optics must move in 2 axes. Windows are made by making two end cuts and joining them together with a slit
Suitable laser wire strippers for this method are:

Mercury-2: can make slits & windows.
Mercury-4: can make slits, windows and ablate areas.

Area Ablation

Area ablation is generally the last choice due to the higher cost of the equipment. In order to vaporize the area of insulation, it is necessary to use a very high speed stripping action to process the area in a reasonable time. Also, it requires the insulation to be fully vaporized. Some materials such as Kapton tape or TPU do not vaporize. Some materials may leave a small residue on the conductor which can interfere with soldering or crimping.

Suitable laser wire strippers for this method are: Mercury-4.