Apparatus and process for cutting adhesive labels
A method and apparatus are provided for die cutting label stock comprising a facestock, an adhesive and optionally a liner to form labels where a liner of the linered pressure sensitive adhesive label stock may be a thin or ultrathin liner.
1. A method of forming a cut adhesive backed label on a liner, comprising:
providing a web of label stock comprising a facestock having a first side and a second side, an adhesive layer adhered to a first side of the facestock and, optionally, a release liner adhered an exposed surface of the adhesive layer, wherein the release liner has a thickness less that 0.0254 mm;
when a liner is present, feeding the web of label stock to a separator station, wherein the separator separates the liner from the facestock and adhesive layer;
when a liner is not present or following separation of the liner from the facestock when present, feeding the facestock and adhesive layer to a cutting station to form a plurality of cut adhesive backed labels and a surrounding matrix, wherein the cutting station comprises a flexible rotary die and an anvil roller wherein the flexible rotary die comprises a die plate that is fastened to a mounting cylinder,
wherein a solid material fills an air gap formed between the die plate and the mounting cylinder wherein the solid material has a greater thermal conductivity than air; and
wherein the adhesive is cooled prior to entering the cutting station or the flexible rotary die is chilled, or a combination of both, wherein the cooling is to such a degree so as to reduce the tack of the adhesive to the die;
when a release liner is present, relaminating the previously removed release liner to the cut adhesive backed labels and matrix or, optionally, laminating a new release liner to the cut adhesive backed labels.
2. The method of claim 1 wherein the surrounding matrix is stripped from the cut labels after a liner is laminated to the cut labels and matrix.
3. The method of claim 1 wherein the cut labels and liner are wound onto a roll.
4. The method of claim 1 wherein the mounting cylinder is a magnetic mounting cylinder.
5. The method of claim 1 wherein the die plate is mechanically fastened to the mounting cylinder.
6. The method of claim 1 wherein the flexible rotary die comprises an engineered interior that allows sufficient heat exchange at the surface of the rotary die.
7. The method of claim 1 wherein the flexible rotary die comprises a cooling system and a coolant.
8. The method of claim 1 wherein the flexible rotary die is cooled to the dew point to allow condensation to build up on the die.
9. The method of claim 1 wherein the adhesive layer is cooled by passing the facestock and the adhesive layer through a chilling zone after the liner, if present, has been separated from the web of label stock and prior to feeding the facestock and the adhesive layer to the cutting station.
10. The method of claim 1 wherein the die is lubricated with a lubricant.
11. The method of claim 1 wherein web tension of the facestock and adhesive layer is controlled with an electrostatic charge after the liner, if present, has been separated from the web of label stock and prior to relaminating the removed release liner, or laminating a new release liner, to the cut adhesive backed labels and matrix.