Label – graphic or text mark applied in the form of a sticker, tag or coupon on the product, exhibit, any other product of production, indicating the manufacturer’s brand, name, production date, expiration date. In this case, the label may be applied directly to the packaging of the product.
The label usually contains a description of the product inside the package. But along with this purely informative task the label is designed to perform a number of other functions. It should present the product favorably, that is, “dress” it up so attractive that the product could stand out in the face of fierce competition of similar products next to it on the counter. That is why the requirements to the printing properties of label papers are quite high.
The share of label papers within the huge paper market is relatively small. Nevertheless, this special segment requires a wide range of paper grades with different properties. The quality of label papers must not only guarantee a high level of printing, e.g. by offset or silkscreen, but also ensure their suitability for lacquering, bronzing or foil embossing. On the whole, this component is the most highly profitable of the label paper production.
The coating or lacquering process takes a print on the label and simultaneously turns it into a protective coating. The coating increases the adsorption, which reduces the chances of the paper losing its “charcoal effect” and thus increases the life of the printed image. A good quality coating also covers all printing areas more completely.
It should be understood that even the highest printing properties of paper do not yet make it a good label paper. The most important requirement for such paper – its efficiency – only shows up in the second process – the actual labeling. For example, a labeling speed of 80,000 bottles per hour indicates not only excellent equipment quality, but also the highest quality paper. At this speed, more than twenty labels per second are fed from the buffer to the line.
Here are some of the requirements that must be met during labeling
- The labels should not stick or hang and the adhesive applied to the labels should be absorbed to a certain extent.
- The paper must absorb the water in the adhesive. The label should adhere to the package in exactly the specified position.
- The label should not only retain the printability and natural gloss of the paper when wet, but also prevent wrinkling or peeling.
- According to the latest technical requirements, labels used for returnable containers must not disintegrate when washed (although in some countries technical regulations, on the contrary, require that they dissolve in an alkaline environment).
There are two paradoxes of label papers
- The label must remain flat during printing and before gluing (the so-called “flattening”), at the same time, it must curl in a certain direction when it is glued
- Label paper must be impermeable to water in order to meet the requirement of item 3. 3, and at the same time must be permeable to an aqueous caustic soda solution in order to allow the labels to be rinsed away quickly
Failure to meet one of the requirements described above leads to a disruption in the continuity of the production cycle. The wrong choice of label paper can lead to considerable additional costs, even though the label itself is usually only 12% of the cost of the labelled goods. So, the right choice of label paper is a guarantee of success.
Labels are applied to goods or packaging typographically or by other means. For example, food products packaged in production conditions have a label on the package, on which text, drawings and other information is typographically applied.
Each type of packaging (consumer, transport, internal, etc.) has its own label, which differs in appearance and functionality (Fig. 1). The geometric shape, graphic design, and text information of the labels are directly related to the product, the type of material, and the configuration of the packaging. The product determines the main semantic content of the label. Material and package configuration play a major role in choosing the design features and technology of the label.
The most important functions of labels include
- identification (of the product and manufacturer)
- product information (arbitrary and mandatory)
- advertising (pictorial and informational)
- product packaging (tobacco and confectionery products, sealing boxes)
In some areas of the food industry, labels perform the functions of product packaging at the same time. For example, the packaging of chocolate. Here, the labels act as outer packaging, and the inner packaging is metal foil or special types of thin, greaseproof paper.
The traditional material for these labels is paper, but recently synthetic polymer films have become increasingly common, including special types called “twist films”, characterized by increased resistance to unrolling the product packed in them.
Product packaging is also the main function of labels, which are used to seal boxes. Sealed boxes can serve the function of both external and transport packaging. Historically, packaging labels also include blanks for packs of tobacco products – cigarettes and cigarettes. Depending on the class of tobacco products, such labels (packs) can serve as both internal and external packaging. In the latter case, the role of the inner packaging is usually performed by metallized paper.
Types of labels
The following types of labels are distinguished by their purpose (Fig. 2):
- basic brand names
- packaging: tobacco, confectionery and box sealing
- information labels
- additional fonts
Types of label paper
According to the main structural elements that determine the types of materials used, properties, manufacturing technology and application on the packaging, labels are divided into:
- to dry – cellulose papers: calendered and coated
- with an adhesive layer (or self-adhesive) which consist of
- of a backing (paper, metallized, synthetic)
- adhesives (rubber solutions, aqueous dispersions, polymer melts)
- anti-adhesive paper
- printing – die-cutting
- shrinkable – oriented sleeve polymer films (surface preparation – printing – trimming)
The printing of labels is becoming more and more complex: a huge range of materials is used, multicolor printing with up to eight colors, printing in triad and complementary colors, a large range of special inks is used.
Different types of finishing are popular: the excellent appearance of labels gives a stamping foil, types of which are very diverse. Hot or cold (with a special polymerizing varnish) foil stamping, relief embossing, lamination, varnishing, full or selective, cutting out on a complex contour are used.