It should be noted that many of the constructions detailed in this article are protected by patents and have been the subject of much litigation over the years.
PROMOTIONAL ON-PACK COUPONING
A coupon label can be defined as a label or part of a label, which can be used to supply information, or have a redeemable value. Coupons may be pressure-sensitive, non pressure-sensitive, dry-peel or adhesive blocked.
Twin-web constructions are comprised of two separate web materials – usually a self-adhesive substrate and a non self-adhesive bond substrate – that are joined together to create a single web that performs two distinct functions. The base layer could, for example, perform the role of a standard product label whilst the top ply could be peeled away as a promotional coupon or even a receipt. It is possible to print on all the plies (see Figures 13.1 and 13.2).
Figure 13.1 - Illustration of typical multi-layer coupon constructions
Figure 13.2 - Typical multi-layer booklet label
The types of promotion which have been communicated by this method can be summarized as follows:
Fragrance (scratch and sniff) promotions
For self-adhesive coupon manufacturing the printing press requires a minimum of two web unwinds, each equipped with web guides. The self-adhesive web overlaps the bond substrate, so that registration is critically important. Good unwind tension control is required to ensure there are no ‘wrinkled’ glue joints.
The webs are printed front and back in the usual way and various combinations of adhesive and silicone are applied to the webs immediately before the lamination nip.
The choice of material can be critical, with both the bond substrate and pressure-sensitive face material being printable using the inks on the press, as well as by any subsequent variable print method chosen. The substrates should have good lay-flat, and sufficient strength to withstand die-cutting, matrix stripping, perforation, hole punching, fan folding, etc.
In use, the top layer of the construction should be easily removed by the consumer as a ‘tack-free’ coupon (Figure 13.3).
Figure 13.3 - Two ply peelable coupon
It is possible to add hinges and re-seal strips using hot melt adhesive to form simple re-sealable booklets. Also, by using a clear filmic base layer, peelable coupons can be created that leave no trace when applied to packaging (i.e. the packaging graphics show through the clear carrier).
Some coupons can be manufactured in-line on presses fitted with what is called a ‘web-shift’ mechanism. This allows the printed web to be slit lengthways down the web. The two narrower webs are then placed one above the other using the ‘web- shift’ mechanism to create the multi-layer structure.
In some cases more than two webs can be brought together to enable multiple coupons to be produced (see Figure 13.4). Clearly more printing heads and unwinds/rewinds will be required to facilitate the manufacture of these type of constructions.
Figure 13.4 - Typical 3 ply coupon construction with 5 printable panels
SANDWICH CONSTRUCTIONS (‘PIGGY-BACK LABELS’)
‘Sandwich’ labels consist of a double-layer label material whereby the top layer of the label can be removed and used as a ‘peel and apply’ sticker.
Whilst normal self-adhesive label laminates are produced from two plies, the so-called sandwich (or ‘piggy-back’) construction has been developed, most commonly of three plies.
They have two label layers and one liner. The top layer has an adhesive on the back whilst the second layer has a release coating on the face and an adhesive coating on the reverse (see Figure 13.5).
Figure 13.5 - Diagram of piggyback self-adhesive construction
The construction is die-cut down to the third ply.
When applied, the second ply, which can be self-contained carbonless paper, translucent glassine or clear film, has an adhesive coating which adheres the piggy-back label to the labeling surface, leaving the top ply as a peel-off label for subsequent use by the end user.
Booklet labels combine a self-adhesive label and a pre-printed leaflet in a single construction. These extended text leaflets have been developed to provide a means of adding information to a pack.
There are now a wide range of booklet labels, leaflet labels, fold-out labels, fold-in labels, concertina labels and other extended text multi-page label formats (see Figure 13.6).
Figure 13.6 - Extended text leaflets solve the problem of overcrowded labels
They are widely used in the agrochemical, DIY, pharmaceutical, chemical and promotional labeling sectors for information, instruction and marketing applications.
The demand for label-leaflets and booklets is being driven by a number of factors;
The rise in self-medication products
Tighter legislation relating to packaging information
Increasing demand for clearer labeling of products, particularly ingredients and safety information
Packaging minimization – the desire to reduce loose leaflet-carton combinations and other bulky packaging
Typical uses for multiple page booklet labels include:
Assembly and handling instructions
Copyright, patent and trade mark information
Diagrams to aid understanding
Directions for use (including dilution or mixing tables)
Environmental, Health and Safety statements
Security is the essential product identity need of the pharmaceutical industry and the self-adhesive booklet label satisfies the need for all-important information to stay with the product.
Using a self-adhesive booklet-label ensures that;
The correct information leaflet is issued with the product
The content of the information leaflet is legible and correct
The patient receives the information and is able to use the product as specified
The life and death standards, vital for both the health of the patient and the consequent commercial health of the industry, have powered many technical innovations in the labeling and leafleting businesses.
MANUFACTURING EXTENDED TEXT BOOKLETS
Extended text and multi-page booklet/leaflet labels can be produced in a wide variety of formats and designs, to suit virtually any container type.
They can be produced in any number of colors, with glossy or matt varnishing or transparent lamination to protect the information. Extended text booklets are often permanently fixed to the container or pack, but perforated or peel-off removable options are available. A re-seal capability can be specified if required to allow the booklet to be sealed after opening (see Figure 13.7).
Figure 13.7 - Typical resealable booklet construction on a self-adhesive carrier (produced in-line)
There are three main methods of producing a booklet label
With this method booklet labels are produced in-line on a narrow-web label press that is capable of accommodating a second web. The self-adhesive base web in printed as a normal label. At the same time the second non-adhesive web is printed on both sides (the web is turned over using a turner bar) before being folded using a plough folder. The folded web and base carrier web are brought together in register and secured in place, typically, with a filmic over-laminate. The booklet labels are then die-cut and wound into a reel ready for automatic application (see Figures 13.7 and 13.8).
Figure 13.8 - Diagram of typical booklet label construction. The booklet is folded in-line before being glued or laminated to a self-adhesive base layer
A wide variety of permanent and removable pressure-sensitive adhesives are available.
Using a two stage manufacturing method the leaflet element of the booklet is printed and folded off-line.
The leaflets are then stacked into a dispenser (or ‘on-serter’) which is mounted onto a narrow web label press.
The leaflets are then applied in register to a self-adhesive carrier web. To ensure consistent application the ‘on-sert’ unit is electronically linked to the press drive shaft.
The leaflet is held in place on the carrier web by static electricity or an adhesive before it is over-laminated and die-cut.
Other manufacturing variations use silicone or adhesive application in patches, stripes or patterns, with a wide variety of folding and finishing solutions.
The finished booklets are wound onto reels ready for automatic dispensing.
With this manufacturing method concertina and multipage leaflets and booklets are pre-printed - usually by sheet-fed offset
The booklet is folded in-line before being glued or laminated to a self-adhesive base layer.
The leaflets are then folded before being combined with a self-adhesive label on specialist equipment.
They are die-cut and supplied on reel for use with standard label application equipment.
The number of pages for booklet labels can vary, with the maximum usually 96 pages.
Apart from providing additional space for descriptive information, warning symbols and diagrams, multi-page solutions can incorporate bar codes, holograms and tamper-evident options, or can be overprinted with batch numbers, sequential numbers, date or use-by information, manufacturer codes or machine-readable data.
REVERSE SIDE PRINTING (BACK PRINTING)
Reverse printing involves printing on to the underside of a transparent film, with the printed image then read from the front side of the film. The printing plate(s) need to have the image areas reversed so that the image can be viewed correctly through the pack (Figure 13.9).
Figure 13.9 - Printing on the underside of a transparent film with the printed image then read from the front
This is achieved by de-laminating a self-adhesive laminate on a suitable label press, printing onto the adhesive and then re-laminating the roll before further printing and die-cutting.
If this technique utilizes a clear label material, reverse printing offers a completely protected print image that is scratchproof, with the finish of the label film providing a glossy or matt surface to match the container.
This effect is commonly used in the toiletries and cosmetics sector to create an innovative decorative effect where the pack graphics on the clear container are viewed through the product itself where the liquid is clear or transparent (Figure 13.10).
Figure 13.10 - Reverse printing on filmic materials – the image reverse printed on a clear back label is viewed through the pack and clear contents
A typical reverse printed label involves the following steps;
The image is printed in reverse on the underside of a transparent film
The image is overprinted with an opaque masking layer (high opacity inks applied by rotary screen or UV flexo printing are often used)
Additional graphics in the normal orientation are printed on top of the opaque mask layer.
This type of printing allows the reverse printed image to be visible through the pack whilst the label surface can be used as a standard back label.
Printing on both sides of the label (face and adhesive) saves using another label.