Laser ablation marking system for and a method of providing an image to a web of packaging material

A method for providing an image to a web of packaging material, comprising:

• feeding the web of packing material continuously in a downstream direction;
• providing at least one marking device having at least one laser and a plurality of individually controlled light outputs connected to said at least one laser, wherein each light output is configured to emit light having a power output of at least 60 W in order to provide laser ablation, wherein the plurality of light outputs are arranged in a linear array,
• providing a controller being connected to the marking device and configured to control the light outputs based on the speed of the web of packaging material, and
• controlling at least one of the light outputs to emit light in order to ablate selected parts of a coating substance arranged on a coated area on said web of packaging material such that the emitted light will always hit the web of packaging material at the same angle,
• extending the linear array in a direction being perpendicular to the travel direction of the web of packaging material, and
• generating the image on the web of packaging material by controlling the marking device with the controller in a pulsed manner corresponding with the speed of the web, so that the cross-wise resolution of the image is determined by the number of light outputs in the linear array, while the lengthwise resolution of the image is determined by the number of consecutive laser pulses from each light output in the linear array as, when each light output is in use to generate the image, only a single laser pulse is emitted from each light output at each lengthwise position and each cross-wise position of the image as the web of packaging material continuously passes the marking device.

A laser ablation marking system for providing an image to a web of packaging material, comprising:

• at least one marking device having at least one laser comprising a plurality of individually controlled light outputs arranged in the cross-wise direction of the web of packaging material, each light output having a power output of at least 60 W and being configured to emit light to provide laser ablation, and
• a controller being connected to the marking device and configured to control the light outputs based on the speed of the web of packaging material such that the emitted light will always hit the web of packaging material at the same angle,
• wherein the plurality of light outputs are arranged in a linear array,
• wherein the linear array extends in a direction being perpendicular to the travel direction of the web of packaging material,
• wherein when generating the image, the controller is configured to activate the marking device in a pulsed manner, so that the cross-wise resolution of the image is determined by the number of laser outputs, while the lengthwise resolution of the image is determined by the number of consecutive laser pulses as, in use, the web of packaging material passes the marking device,
• wherein the marking system further comprises a sensor configured to detect a change in lateral position of a reference mark located on the web of packaging material, and
• wherein the controller is configured to control the light outputs based upon the detected change in the lateral position of the reference mark to account for shifting of the web of packaging material.

A laser ablation marking system for providing an image to a web of packaging material, comprising:

• at least one marking device having at least one laser comprising a plurality of individually controlled light outputs arranged in the cross-wise direction of the web of packaging material, each light output having a power output of at least 60 W and being configured to emit light to provide laser ablation, and
• a controller being connected to the marking device and configured to control the light outputs based on the speed of the web of packaging material such that the emitted light will always hit the web of packaging material at the same angle,
• wherein the plurality of light outputs are arranged in a linear array,
• wherein the linear array extends in a direction being perpendicular to the travel direction of the web of packaging material,
• wherein the controller is configured to activate the marking device in a pulsed manner, so that the cross-wise resolution is determined by the number of laser outputs, while the lengthwise resolution is determined by the number of consecutive laser pulses as, in use, the web of packaging material passes the marking device, and
• wherein the packaging material is also provided with one or more reference marks, and a sensor is included in the marking system configured to detect a position of the reference mark, especially the lateral or cross-wise position so that the position of the detected reference mark is transmitted to the controller which is configured to associate the position of the reference mark with a position of already applied coated areas.