Self-adhesive Labels

Self-adhesive labels (and decals) are pieces of paper, plastic film or metal foil coated with pressure sensitive adhesives which adhere to any solid surfaces after removal from a release liner. They are typically used to convey various kinds of information -for example, product or package contents, barcodes, price stickers, insfructions, and technical data. 

The most important adhesive raw material compositions for adhesive labels are polyacrylate dispersions, styrene-butadiene rabber solutions, and styrene-butadiene-styrene (SBS) and styrene-isoprene-styrene (SIS) hot-melt adhesives. Permanent and removable UV-cross-linkable acrylic hot-melt adhesives have recently also been introduced [19-22]. 

In the 1970s, Japanese paper label manufacturers started converting from rubber solutions to water-borne systems because of very strict environmental protection regulations, resulting in acrylic dispersions becoming the most important group of PSA raw materials in Japan. In North America, 85 % of the PSA label market was solvent born in 1975 [23] but in 1991 approximately two-thirds of the market was waterborne [24]. 

In Europe, the conversion was carried out in the 1980s and now the use of acryhc dispersions in self-adhesive products is widespread and well advanced. The importance of acryhc dispersions continues to increase for reasons of environmental protection (nonflammable, no hazardous solvents), high soHds contents, good aging resistance, and excellent coating and processing properties. 

About 2.9 billion m of self-adhesive labels were produced in Europe in 1996, corresponding to 35 % of world production. At average appHcation rates of 24 g m, this corresponds to a demand for adhesives of 70 000 dry tons year in Europe. 

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Coiling up station for heat seal, wet glue, and self-adhesive labels... 

There are many decoration options for bottles but the most common is the wet-glue labeller, which is described here, although self-adhesive labellers, sleeving and even a form of bottle printing using heat to transfer the print from a backing paper to the bottle are all available, together with machinery of application. 

Because of their conductivity, reflecting effect, and light barrier properties, metallized films are increasingly used as functional coatings in technical applications. Examples include battery cell cases, prepaid telephone cards, self-adhesive labels, insulation foil in the building industry, decorative foil for design elements, security features for bank notes, and tear tapes, etc. 

Over the years letterpress printing has declined into niche markets, two of which are the printing of plastic self-adhesive labels on narrow-web rotary-offset letterpress machines that are fitted with UV drying and the common-impression rotary-offset letterpress and UV-curing on mandrel of plastic containers such as yoghurt tubs and toothpaste tubes. In uses such as these the most common self-adhesive plastic is PVC and the most usual for tubs and tubes are polystyrene, PVC, ABS, and polypropylene. 

Self-adhesive labels. This method is sort of cheating because you are... 

The adhesive may be solvent or water-based, hot-melt, coldseal or heatseal and pressure sensitive or chemically reactive. So the solidification process may occur via drying of water or solvent-based adhesives, by cooling of hot-melt and heat-seal adhesives, or by curing of chemically-reactive systems. With two notable exceptions - self-adhesive labels used on items of fruit or vegetables, and heat-sealable layers on packaging films - adhesives are in general not intended to touch the packaged food directly. 

Filler-free formulations of two-component silicone rubbers crosslinkable by condensation or addition are utilized, with or without added solvent, for the coating of papers and plastic foil, optionally as an aqueous emulsion, e.g. for strippable paper for self-adhesive labels or packaging foil for bitumen. Vulcanization is carried out at high temperature (100 to 180°C), to attain as short hardening times as possible. 

Waste paper stock destined for recycling is normally segregated into grades according to whether the original pulp was produced by chemical or mechanical methods. The separate stocks are then repulped (dispersed) in a hot dilute solution of sodium hydroxide, sodium phosphate, or sodium silicate in water, and cleaned via a series of raggers, cyclones, and screens. Self adhesive labels and tapes pose a perennial problem in recycle pulps that a recently developed test method may help to solve [70]. Standard printer s inks... 

Self-adhesive labels normally have the following type of structure (layers) ... 

Self-adhesive labels can be applied to most materials wood, plastic, metal, glass, paper and board. As the adhesives are resin-based (plasticised thermoplastics), migration problems can occur when they are applied to certain plastics (PVC, LDPE, etc.). Adhesive systems for pressure sensitive labels include latex and acrylic bases and adhesives which may be applied as a hot melt, or via a solvent, emulsion or dispersion base. Water-based adhesives are currently increasing in use. 

Modem adhesives for self-adhesive labels include acrylic, polyethylene combinations. There is a distinct move away from solvent-based adhesives (for ecological reasons) to water-based dispersion/emulsion systems. 

Exchange between product and pack can occur in both directions, e.g. certain labelling materials such as heat sensitive and self-adhesive labels when in contact with plastic materials. Both the plastic and the adhesives may contain plasticisers or migratory constituents. Most cellulosics use phthalate, sebacate, phosphate-type plasticisers (e.g. methyl phthalate (DMP) may be used in cellulose acetate). Plasticisers may also be found in poly vinyl chloride/acetate copolymers, polyvinyl acetate and polyvinyl alcohol formulations, polymethyl methacrylate, nylon and certain thermosetting resins. 

The pharmacist normally purchases the blisters in reels, and has a special sealing machine for the lidding operation. The pockets can usually be individually labelled (on the lidding) using a computer-based system involving self-adhesive labels. 

Although 10 years ago the US pharmaceutical industry predominantly used heat seal labels, the UK was rapidly moving to the more expensive self-adhesive labelling systems. Since Europe is now predominantly using self-adhesive, there appears to be an international trend even though it is a more expensive label process. It has the advantage, with the correct choice of materials, that it will adhere to most substrates. 

Roll-fed labels are recommended. In this case, it is desirable to have a procedure adapted to the type of label (self adhesive labels or those to be glued) and thus avoid confusion, in the case of roll-fed labels, it is desirable not to have a joint but if one exists, the joint should be shown in order that the text may be verified by the supplier and the user. 

A yellow Quarantine self adhesive label shall be affixed in a prominent position on the container or composite storage facilities of the container (e.g. pallets, etc.). 

Starting materials that are approved and accepted, shall be properly labelled as such, by means of a Green Released self adhesive label, which is to be affixed over the Yellow Quarantine label, in such a way that a small section of the Yellow Quarantine label may still be seen. This is to be carried out by the Quality Control operator. 

LABELS AND LABELLING DATA 60 High Street, Potters Bas Herts ENG SAB UK, -1-44 (0)1707-645322. Self-Adhesive Label Markets in Western Europe. 

Use of self-adhesive labels is another option, but this approach poses similar problems. Labeling operations can have high scrap rates (up to 30% in some operations) due to off-center placement of labels, which may slip before the adhesive is fully set, or which may tear or be scuffed during handling. 

No self-adhesive labels (post-its) are used in the laboratory, even for private information. 

The label is an important part of the pharmaceutical product. The most common label used within the European pharmacy is the self-adhesive label. This consists of a laminate of two special types of paper the carrier material and the label paper. The carrier material consists of paper on which a silicon layer is fixed. The label paper can be printed on the printing side and on the carrier side it has an adhesive layer. The adhesive is usually of the permanent type, rendering the label non-removable once applied [25]. Label adhesives on plastic containers such as infusion bags require additional attention, see Sect. 24.4.13. 

Adhesive Coating of Paper and Board. Pressure-sensitive coatings, for example, for self-adhesive labels and envelopes include natural rubber-resin combinations in solvents, polyacrylate emulsions, and hot-melt adhesives. Polyacrylate emulsions and hot-melt adhesives are becoming increasingly significant because they are solvent-free. 

Products based on PSAs are protective films, self-adhesive labels and tapes. Protective films are made from flexible plastic material (PP, PE, PVC) coated with PSAs (5-15 g dry m ) and they are used to protect painted or polished metal surfaces, lacquered furniture surfaces, acrylic sheets from scratching and soiling during manufacture, shipping... 

In North America 3.5 biUion m of self adhesive labels were produced in 1999. Assuming the same coating weight, the adhesive demand in North America was 84 000 dry tons year . ... 

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