In-mould labelling
In-mould labelling is the use of paper or plastic
Principles
In-mould labelling (IML) was initially designed for blow molding, though developments using injection molding or thermoforming with reel-fed systems have increased the efficiency of the labelling process. The original concept involves coating the reverse side of the label with a heat seal layer, followed by a substrate material which heat resistant ink is applied to. A heat resistant coating of lacquer is then applied.[1] This process eliminates the need to flame treat the bottles prior to labelling in order to achieve adequate adhesion.[3] Initially, paper was used as the label substrate to which the heat reactive adhesive was applied. In more recent times polyolefin substrates have been employed, such as Polyart[4] from Arjobex Synthetic Papers. This creates the advantage that scrap polyethylene and polypropylene bottles produced in the molding process can be recycled, without the need for label removal prior to recycling.[5]
Labelling
There are several techniques for conducting the in-mould labelling process. Vacuum and compressed air can be used to handle the labels, also static electricity can be used. Electrostatic charging electrodes charge a label while it is being transferred to the moulding machine, so that when the label is placed on the tool and released by the labelling robot, it will wrap itself onto the tool. Most robot systems for placement of labels are not required for specific moulding machines and can be used with up to date presses with fast clamping systems.[6]
Labels may be
Use
In-mould labelling is a popular method of decorating injection molded parts for consumer electronics and for plastic bottles. Notebook computer and cellphone manufacturers are adopting IML technology for greater wear resistance than spray painting or pad-printing. IML can provide greater decorating options than other methods. Multi-color screen printed and offset lithography printed graphics are used to produce products with higher quality graphics than available with other decorating methods. Most applications in this area use second surface graphics. The decoration is printed on the back side of a clear substrate, typically polycarbonate or acrylic 0.125 to 0.375 mm (0.005 to 0.015 in) thick.[7] The injection plastic is on the ink side of the film. This encapsulates the decoration between the film layer and the injected plastic resulting in a decoration that cannot be abraded during use. Vision systems can check for accurate label positioning, and can validate label correctness.
See also
- In-mould decoration
- Plastic injection molding
References
- ^ ISBN 978-0-8493-0506-1.
- ISBN 075140151X.
- ISBN 978-1-85957-329-7.
- ^ "IML Labels (in-mold labelling)". Polyart. Retrieved December 15, 2017.
- ^ Polischuk, Tom (February 1, 2007). "Be Bold". packagePRINTING. Retrieved June 5, 2017.
- ISBN 978-0-8493-0508-5.
- ^ "In Mould Labelling can achieve cost reductions together with outstanding quality of decoration". IC-labels Ltd. Archived from the original on December 2, 2008. Retrieved December 28, 2012.