Labels and labelling: the key points of the process

"Labelling comes last and is more complex than it seems"

In the chronology of the process for packaging glass bottles or jars, labelling comes last and is more complex than it seems. The idea is to attach one or two grams of paper or plastic — in a few tenths of a second — which becomes the main communication vector for the customer. General information on the content, numerous legal notices, communication of the brand’s image, practical information: everything must fit on these few square centimetres, which themselves will remain firmly attached to the glass container. In the field of glass packaging, where the majority of sales are made on standardised models, the label is often the only means of differentiating or personalising an item — a means that is almost free compared to the cost of a personalised bottle or screen-printing, for example.
But the story doesn't end there. Although the label is designed to be resistant to everything a product undergoes during its lifespan (being put in a cellar, being put in a bucket of ice for wines served chilled, and all abrasions or impacts linked to the packaging line, packaging in cardboard boxes, storage and use by the consumer), it must also be possible to take it off the glass after use. This should be possible either by washing when the bottle is going to be returned or by mechanical separation when the glass begins the recycling process which will take it back to the glass furnace.

A group at CETIE is committed to fulfilling the requirement of label separability

The “label and glass recycling” working group at CETIE is committed to fulfilling the requirement of label separability. This committee, which brings together drinks brands, label manufacturers, glass manufacturers and glass recyclers, as well as CITEO and ADELPHE, has just finished its work, publishing two documents at the start of July:

Guidelines No. 2.01: Pressure Sensitive Labelling on Glass Containers. This 45-page document starts by describing the various constituents of the system (firstly, the types of labels, the substrate and the adhesive, then the glass container, and of course the labelling equipment). It then shows how the labelling is actually done, how it is controlled, and where any malfunctions might come from. Finally, it explains what happens to the label at the packaging’s end-of-life.

Label separability on glass containers - recycling simulation (DT41.00). This document defines a method for determining whether a label is sufficiently easy to remove from the bottle or the jar such that the recycling process is efficient, i.e., without causing material loss or diminishing the quality of the glass coming out from the recycling process (the cullet).

These two documents supplement an already extensive collection of technical files and guides:

Guidelines No. 2 – Functional specification for labelling, defines the concrete questions that must be asked in order to draw up a complete specification of all of the elements that influence the quality of labelling (label, bottle, glue, labelling machine).

DT19.00 – Gives a very precise definition of the characteristics of the lateral labelling spotting bar for glass containers. This text, which is currently being revised, defines the most common spotting bars, also known as “Meyer-Dumore”. It will be completed by a document that describes the other types of lateral spotting bars used in Europe. These purely mechanical devices (the rotation of a bottle is stopped by a finger on the spotting bar) are still used very often, although the optical identification systems are less damaging to the glass, even if they are thought to have inferior angular precision.

FS20.00 – Appropriate specification, bottle quality control and application control of self-adhesive labelling. It is supplemented by FS22.00:

FS22.00 – Measurement of labelling surface flatness of glass bottles or jars.

Finally, DT35.00 defines the label area planarity tests for flaconnage.

In 2020, label manufacturers and their main association (FINAT) actively contributed to Cetie’s working groups, and this collaboration promises to continue, with ongoing considerations of new topics, and bottlers and brands focusing particularly on this topic.

PDF (FR)

L&C N°413 in French