Avoiding Bubbles and Creases in Self Adhesive Labeling

Testing for Complex Contours

The first step is to identify the area of the product where the label is expected to be placed. Then, using a business card, hold the edge of your business card vertically against the product. Move the edge over the entire area where the label is expected to be applied. If a gap appears between the edge of the business card and the bottle surface then you have at least one curve, in this case in the vertical direction, on the area to be labelled.

Note: A curve in the vertical direction is usually a problem for self-adhesive as it is a curve that is difficult for a label to follow as it is usually dispensed in a direction horizontal to the product; matching the way the bottle product/bottle travels on a product conveyor.

While a flat label can “wrap” in the direction of one curve on a product’s surface, it cannot wrap in more than one direction. Taking the business card used before, and holding it horizontally against the surface you now look for gaps between the card’s edge and the product surface in the same area you found gaps when the card was vertically orientated.

Note: Curves in a Horizontal direction alone are quote common – round bottles being an obvious case but also oval cross section bottles such as shampoo bottles or detergent bottles.

If you do find a business card can show gaps in both a Horizontal and vertical orientation then that area of the bottle cannot be labelled with a self-adhesive label without bubbles or creases.

Learning from the Mistakes of Others

Now rotate the bottles while they still touch and see if you see gaps appear and disappear. Gaps suggest complex contours and the likelihood of creasing in these areas if labelled. In this case the complex contours are not designed but more a result of the bottle quality and variations.

Other sources of complex contours for label applicators can be with very thin walled flat sided bottles. Here the thin walls of the bottles can lead to surface irregularities before and after filling. Depending on where the label applicator is placed it can be a good idea to label thin wall bottles while they are empty; especially if they are hot filled.