Safeguarding the environment through responsible selection and use of materials, technology and working methods is one of the stated aims of my company which, in common with other label printers is faced with the challenge of a more environmentally-conscious approach to the manufacture of self adhesive labels. This applies particularly to the selection of materials and adhesives where we need to balance the new environmental concerns against the commercial and technical of self adhesive label production and application.

Types of adhesives

Adhesives are made up of the following components:

• Polymer – The backbone of adhesive.
• Tackifier – Part of the formulation giving its sticky properties where required.
• Carrier Agent – Allows the polymer and tackifier to flow during coating and application.
• Additives – specific additives may be used, depending on the particular properties the adhesive requires.

Given the best composition above, adhesives can be grouped into:

• Emulsion systems – These are usually based on an acrylate (polymer) and tackifier using water as the carrier agent. They are most widely used, and are solvent free.

• Solvent systems – The polymer used may be either acrylic or rubber, with a solvent-based carrier agent.
• Hot melt systems – Usually rubber-based systems: the manufacturing process involves melting rubber or acrylic to form a thermoplastic compound.

Adhesive systems are usually inerted in the final laminate state and under normal conditions of use are not hazardous to health.

Considering these adhesives families, the ‘easy’ answer to the most environmentally- friendly adhesive question may appear to be emulsion or hot melt systems (which account for more than 80% of all label adhesives produced). However, the label printer must also be concerned with the performance and end use of the label, and sometimes a solvent system may be required to meet application conditions. There has been considerable development of emulsion systems to meet a wider range of conditions but there may always be some conditions where solvent systems will offer the best, or indeed the only, adequate performance characteristics.

Next time – more on Label Printing…

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands.

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued) – 11th March 2010
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued)

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

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Letterhead Printing: We now have a new selection of Letterhead Templates Available. Choose from Traditional Letterheads, Modern Letterheads and Professional letterheads

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Many companies worldwide are investing and will be investing significant amounts in the recycling issue; some of the adhesive manufacturers’ approaches having been highlighted here.

It is strongly apparent that if significant progress is to be made then all interested parties must work together in order to reach mutually acceptable goals and standards. These programmes must therefore demand the commitment of industry research organisations, adhesive manufacturers, recycling mills and a host of other co-suppliers and users in the industry if they are to succeed.

One must never lose sight of the end product, i.e. a book or magazine and its user’s expectations of that product.

Whilst the driving forces for recycling of books and adhesives is becoming stronger, customer’s expectations of adhesive performance have not diminished and key parameters such as page retention, flexibility, heat and cold resistance must be retained. We are, however, coming close to releasing quality and adhesive performance.

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands.

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued) – 11th March 2010
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives – part 3

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

NEW Product Alert – we now sell Exhibition Stands, Pop Up display stands and A Boards

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books, Online printing, Printers in Oxford

See Our Latest Press Release about our Web to Print Solution.  See us on the RED TIE Web to Print site

Other areas of interest to the industry where considerable investments are being made are those of composting and biodegradability. Work on composting hot melt adhesives has indicated that formulations can be engineered so that their degradability in soil is maximised. The rate and mode of degradation can be altered by careful selection of the appropriate raw materials. The quality of the final compost in tests conducted has not been negatively influenced by the addition of hot melt adhesive.

To accelerate the degradation process, a significant amount of work has been done and will be done on biodegradable polymers and adhesives which are not based on traditional raw materials.

Starch-based hot melts have proven, most recently, to be effective in this area and patented technology now exists for these materials, indicating that traditional problems have thermal stability and formulating compatibility have been overcome. It is anticipated that use of this technology will expand across the industry shortly. A key aspect here is that the starch is derived from freely available renewable sources, thus improving its ‘friendliness’ in environmental terms.

To be continued…

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands.

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of Adhesives (continued) – 11th March 2010
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives – part 3
• Environmentally Aware Printing – Types of adhesives – part 2

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

NEW Product Alert – we now sell Exhibition Stands, Pop Up display stands and A Boards

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books, Online printing, Printers in Oxford

See Our Latest Press Release about our Web to Print Solution.  See us on the RED TIE Web to Print site

This, of course, does not give us a truly recyclable adhesive but it allows the finished product to be recycled in a ‘safer’ fashion and at the moment this is regarded as a step forward.

Research into the area of dispersible products will continue but this work needs to take a somewhat new direction with the increasing popularity of closed loop systems and restrictive disposal legislation. A water-dispersible product must be 100% dispersed in the pulping system and be carried through to the finished paper with 100% retention on the fibres, without any detrimental effect on paper properties. In fact, the ultimate goal would be to incorporate the adhesive into the paper to give some positive benefit. The adhesive may then be considered totally recyclable. Looking at the alternative definition of recyclable given at the start if this paper, re-use of the adhesive should be investigated; not necessarily as the same adhesive as a binder or filler.

To be continued…

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of Adhesives (continued) – 11th March 2010
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives – part 3
• Environmentally Aware Printing – Types of adhesives – part 2

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

NEW Product Alert – we now sell Exhibition Stands, Pop Up display stands and A Boards

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books, Online printing, Printers in Oxford

See Our Latest Press Release about our Web to Print Solution. See us on the RED TIE Web to Print site

Undoubtedly one of the most likely technologies to have an impact in the replacement of solvent-based products and recyclability in general is that of reactive hot melt adhesives.

Conventional hot melts are made of relatively low molecular weight thermoplastic materials, to ensure melting and application at moderate temperatures. This leads to obvious limitations with heat resistance and strength which can be exploited in the high temperature, high shear repulping process giving rise to small average particle size.

To overcome this, moisture-curing polyurethane hot melts have been developed utilising a cross-linking reaction which raises heat resistance and strength to previously unattainable levels whilst maintaining flexibility and low temperature adhesion. This unusual blend of properties makes this type of product ideal for recycling purposes since the high cohesive strength and excellent flexibility allows the product to remain intact rather than deforming/ breaking down under heat and shear to be forced through screens or shattering as a hard, highly cohesive conventional hot melt might.

Laboratory work on these products suggests that the adhesive does indeed remain as a discrete film and is filtered out completely in the process. These laboratory results have been borne out in typical recycling mills where complete spines of directories/ books have been removed at the first coarse screening stage, with no trace of the adhesive further down the line.

This approach is gaining in mills from a safety viewpoint since there is little or no chance of adhesive contamination in the papermaking process. The technique obviously still involves disposal of the rejected adhesive, probably in landfill, but the amount compared with conventional hot melts is halved.

To be continued…

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives – part 3
• Environmentally Aware Printing – Types of adhesives – part 2
• Environmentally Aware Printing – Types of adhesives – part 1

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

NEW Product Alert – we now sell Exhibition Stands, Pop Up display stands and A Boards

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books, Online printing, Printers in Oxford

See Our Latest Press Release about our Web to Print Solution. See us on the RED TIE Web to Print site

The vinyl monomers used in the vinyl/ graft copolymers may be acrylates or vinyl acetate and the grafted component (s) are hydrophilic in nature. Adjustment of copolymer or graft component type or concentration leads, to a range of compositions with varying glass transition temperature, molecular weight and water sensitivity.

These types of copolymers do not suffer from the inherent oxidative and thermal stability problems of other dispersible systems. Water sensitivity and dispersibility are key factors in the performance of such a product and, using Tappi UM 666, it can be seen that the graft copolymer is significantly more dispersible than standard polyethylene-based hot melt. It is also seen that increasing the processing temperature or the hydrophilic component concentration increases the water sensitivity of the polymers.

Products based on this vinyl graft technology have been developed for a variety of applications including bag making, roll wrap, bookbinding and case/ carton sealing. Laboratory scale tests and trials at recycling mills around the world have revealed excellent results with regards to dispersibility and recyclability. Under the right conditions the product has been proven to be totally dispersible with a large percentage of adhesive by weight (more than 20%) being incorporated into the paper with no adverse effects or stickie problems.

A question of backwater saturation still remains in closed loop systems but calculations indicate that saturation cycle at typical addition levels is several months. This is probably comparable with the usual cleaning cycle in a mill and would therefore not cause significant problems.

To be continued…

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of Adhesives (continued)
• Environmentally Aware Printing – Types of Adhesives – part 3
• Environmentally Aware Printing – Types of adhesives – part 2
• Environmentally Aware Printing – Types of adhesives – part 1
• Environmentally Aware Printing – Dealing with the stickies problem Part 4

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books, Online printing, Printers in Oxford

See Our Latest Press Release about our Web to Print Solution. See us on the RED TIE Web to Print site

A wealth of literature exists describing supposedly water-dispersible or soluble polymers which can be used as adhesive bases for a range of market applications. Polymers such as functionalised polyesters, acrylic acid homopolymers/ copolymers, vinyl methyl ethers, maleic anhydride/ acids, polyvinyl alcohols and vinyl-pyrolidone copolymers are among those investigated, but such polymers from inherent problems which are usually related to the thermal and oxidative stability of the product during manufacture/ application and/ or the water sensitivity/ humidity resistance of the glue film when applied. Obviously, poor humidity resistance could give rise to a rapidly degradable spine if used in a bookbinding application.

To overcome these problems, patented technology has emerged where hot melt adhesives are based on a unique class of graft copolymers of various vinyl monomers. These products can be considered as dispersible in the mill system under shear; pH and temperature but remain stable to moisture at ambient temperatures.

Rather than forming tacky agglomerates and therefore stickies, the finely divided particles of the vinyl graft copolymer-based hot melt may then become incorporated into the reclaimed paper without any adverse effects.

To be continued…

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of Adhesives – part 3
• Environmentally Aware Printing – Types of adhesives – part 2
• Environmentally Aware Printing – Types of adhesives – part 1
• Environmentally Aware Printing – Dealing with the stickies problem Part 4
• Environmentally Aware Printing – Dealing with the stickies problem Part 3

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books

See Our Latest Press Release about our Web to Print Solution.

3. Hot melts

a)    EVA-based hot melts.

Hot melt adhesives based on conventional synthetic polymers such as ethylene vinyl acetate (EVA) represent a potentially significant source of contamination in the recycling process. Such adhesives generally soften and partially disintegrate but do not disperse under the influence of temperature and shear. Contamination can originate from anywhere in the adhesive composition, i.e. polymer, wax, pigment, plasticiser or resin.

These EVA-based hot melts are removed reasonably efficiently by modern mill systems, indeed in some cases relatively soft, low melting point adhesives can be used without problems due to the effectiveness of the screening, cleaning and dispersing systems.

Unfortunately, in many mills which have limited cleaning capacity and/or a high attrition pulping phase, small particles of adhesives can find their way into the high finished product already described. An interesting and somewhat disturbing thought is that less than 1kg of adhesives can totally ruin over 100 tonnes of stock unless adequate precautions are taken.

Acceptability standards for conventional hot melts vary widely in different countries and within different mills.  This is related to be varying mill systems and wide range of difficult test employed. Requirements and standards also differ depending on whether paper recycling or board recycling is the issue.

Higher cohesive strength EVA-based hot melts are available which optimise the strength/ flexibility balance in order to maximise filterability and minimise risk of stickie contamination but these will only really be effective in low attrition systems.

b)    Acrylic/ pressure sensitive adhesive systems

As previously stated, the term ‘stickies’ was originally used to refer to pressure sensitive adhesives in the papermaking process. In one sense these types of materials have the potential to cause significant problems in that they are likely to be permanently tacky (if they remain intact) and do not need heat reactivation. Having said this, most of the methods described for removal of conventional EVA hot melts can also be applied to pressure sensitive adhesives (PSA), i.e. chemical and/ or mechanical treatment.

Work has shown that if the PSA product has the right balance of cohesive strength and flexibility, then screening is relatively simple, as with EVA based products. Both high-cohesive, cross-linked (by radiation curing) and water-dispersible PSA products have been developed which are potentially beneficial to the recycling process.

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of adhesives – part 2
• Environmentally Aware Printing – Types of adhesives – part 1
• Environmentally Aware Printing – Dealing with the stickies problem Part 4
• Environmentally Aware Printing – Dealing with the stickies problem Part 3
• Environmentally Aware Printing – Dealing with the stickies problem Part 2

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books

See Our Latest Press Release about our Web to Print Solution.

2. Animal glue

Animal based adhesives have been used reasonably successfully for some time in the bookbinding industry and in recent times have been favoured on the grounds of water solubility. This type of adhesive suffers from inherent problems which are of significance to both the converter and the mill.

Relatively slow production speeds, limited moisture and heat stability capital outlay for specialised equipment are not attractive to the binders. Problems for the mill are related to the fact that the adhesive is effectively a protein which will have a high biological oxygen demand (BOD). This will have an adverse affect on bacteria in effluent disposal systems.

Another factory worth mentioning, which is sometimes overlooked, is that of ethnic minority and animal rights groups who abhor the use of animal by products.

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Types of adhesives – part 1
• Environmentally Aware Printing – Dealing with the stickies problem Part 4
• Environmentally Aware Printing – Dealing with the stickies problem Part 3
• Environmentally Aware Printing – Dealing with the stickies problem Part 2
• Environmentally Aware Printing – Dealing with the stickies problem – Part 1

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for graphic design, short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

See our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books

See Our Latest Press Release about our Web to Print Solution.

1. Aqueous/ emulsions e.g. PVA, dextrine, starch, latex, PVOH etc.
2. Animal glue – water soluble
3. Hot melts

1. a)    EVA based.
2. b)    Acrylic/ pressure sensitive’s.
3. c)    Water-disperible hot melts polymers.
4. d)    Reactive systems.

1.    Aqueous systems

The need for recyclability centres mostly around polyvinyl acetate (PVA) emulsions, the other categories generally being considered as repulpable.  Currently, PVA is treated using one or several of the techniques already described to inhibit the formation of stickies.

Patented technology is, however, available which allows vinyl acetate homopolymers and copolymer-based emulsion adhesives to become almost totally water-dispersible. This is achieved by the addition of specific water soluble ionic salts, such as magnesium chloride.

To be continued…

Peter Harrison is Joint Managing Director of The Printing House Ltd, and Print Buying Direct of Crewe, Cheshire, UK.

NEW: We now sell Large Poster Printing and Banner printing online (A1 Posters, A0 Posters etc) and Banner Stands

Also – checkout our new online print prices Print Buying Direct are UK market Leaders in Leaflet Printing | Brochure Printing. For more free articles on Printing and Graphic Design see our Online Printing | Print Buying Direct Website. For more information on printing and graphic design please see some of our recent blog articles;

• Environmentally Aware Printing – Dealing with the stickies problem Part 4
• Environmentally Aware Printing – Dealing with the stickies problem Part 3
• Environmentally Aware Printing – Dealing with the stickies problem Part 2
• Environmentally Aware Printing – Dealing with the stickies problem – Part 1
• Environmentally Aware Printing – Definition of recyclability of Adhesives

Print Buying Direct is the online division and a Trading Name of The Printing House Ltd. One of the UK’s leading quality printing companies for short run, long run and large format colour printing. Based in Crewe, Cheshire (Cheshire Printers), in the North West of England – delivering to customers across the UK and Ireland.

Also see our other websites The Printing House, Print Buying Direct, Prospectus printing, Golf Club Centenary Books

See Our Latest Press Release about our Web to Print Solution