Adhesives play an invisible but vital role in pack production and correct specification is essential to achieve the desired results. Steve Thomas-Emberson reports

The development of a range of adhesives has always been critical in the packaging industry, both from what the pack producers can offer and also end user requirements. From cartons, bags and sacks, through to bottle labelling adhesives, they have always been part of the finished pack.

Often there is a perception that adhesives are over engineered to ensure that the connecting items stick. Anyone that has bought LPs and books will have encountered the stuck fast label, which does not so much peel off as take the cover surface off!

Even with plastic packed computer software the security label can be removed quite easily but the adhesive remains stuck fast to the pack. What is doubly annoying is that these types of packs are not disposable. The pack needs to perform after opening and a semi-permanent sticky mess is not what a home or office environment needs.

Is this the fault of adhesive makers or an inherent desire to over secure the pack?

Jim Watson of manufacturer Pafra has a poignant and cohesive answer. “It is important that adhesive users continue to be educated in the use and specification of the products available to them. Adhesive is more and more being used as a ‘commodity’ item, whereas the truth is that it is more essential to the finished product than say the ink or board quality. Adhesive also represents a tiny fraction of the overall cost of the product.”

Board manufacturers and ink producers may disagree, but it appears the education element is critical.

What adhesives are there actually on the market and do adhesives have any competition? One of the main competitive elements is the non-use of adhesives altogether as Graeme Nutting, UK sales director of Beardow Adams explains: “As a wholly hot melt adhesive company we have found – and I’m sure other companies have also encountered this -that the major competition is from designing out the need for adhesives by the use of flaps. This is particularly relevant to cartons.

“It is a black art to customers so, if they can avoid using hot-melt adhesive they will, rather than understating the benefits from adhesives.”

Once again the need for adequate and proactive client education arises.

Hot melt top for cartons

Hot melt adhesive, whether applied automatically or via a hand-held applicator, is quite literally hot property in the packaging adhesive marketplace, with cartons top of the list. Alongside this very extensive market, the bottle labelling, bag and sack sectors are the other major areas.

Hot melt does not have everything its own way though as low temperature technology offers a competitive alternative. Traditional packaging hot melts are applied at between 160 deg C and 180 deg C and, with this high temperature, comes obvious risks – safety being one of them.

Low temperature technology can offer melts applicable at a temperature as low as 90 deg C, thereby greatly reducing the potential for serious burns. Dependent on application and product, there is also a potential for quite large energy saving throughout the production cycle. National Starch and Chemical quote two of their own products saving between 30% and 70% of energy used.

Hot melts also potentially require more maintenance and cleaning than low melts, which can be costly in downtime and spare parts on automatic lines. What is therefore vital is the development of free-flow adhesives that either minimise this negative factor or eliminate it altogether.

Adhesives are a very large global marketplace and one where there are many other large client bases, for example the automotive industry.

The key question is: How significant is the packaging industry and what are its quirks and foibles?

Pafra’s Jim Watson sums up the adhesive industry’s view of the packaging potential within its marketplace. “The packaging industry is very demanding, particularly in requiring very forgiving, versatile products that work in all kinds of adverse conditions, at a minimum cost.

“It is also demanding in that new designs are sometimes planned without sufficient thought on how they will be bonded before they are put into production. This leaves little time for good, new adhesive development.

“Carton manufacture is one of the most demanding markets within the industry due to the very wide and constantly changing range of surfaces, designs and use of cartons. It is also demanding in response time.”

&#8220Adhesive is more and more being used as a commodity item, whereas the truth is that it is more essential to the finished product than say the ink or board quality

UK has top suppliers

So packaging is important but can be problematical for adhesive manufacturers. We are therefore fortunate in the UK in having world leaders on our doorstep, both for supply purposes and the advice they can offer.

Privately owned Beardow Adams is the UK’s largest producer of hot melt adhesives and continued investment at its site in Milton Keynes has made it the biggest single hot melt plant in Europe. Its five manufacturing units and their production lines include two very large lines totally dedicated to the manufacture of packaging adhesives.

This futuristic plant has an overall capacity of more than 32 000t/pa, 4% of world hot melt production.

While the sheer size of its production capability is astounding so is its sales and financial performance, as Graeme Nutting of Beardow Adams comments. “We have an excellent range of adhesive products and, as a result, we now have 2% of the worldwide market in hot melts. This naturally means that there is still 98% out there for us to go at.

“Our company is very export orientated with Europe our largest opportunity, as well as USA and Scandinavia. We only employ 65 people plus distributors abroad and our current turnover is £18M. We still need to grow!”

Where does this volume come from? One of the company’s main products and one that is applicable to the packaging industry is the BAMfutura range which accounts for over a third of its sales.

The range comprises six hot melts all of which are odour and fume free and “prevent nozzle blockages and enable continuous trouble free production.” The BAMfutura adhesives can operate down to -40 deg C as well as in the very high temperature range.

This product’s success cannot be overstated. It has resulted in an exclusive five-year contract with Kellogg to supply the cereal giant with one adhesive, BAMfutura 1, that glues the top and bottom flaps of all its cases and cartons in both its UK and European factories. Some contract!

The range is supplied to other global brands, too, such as Coca-Cola, and Unilever and, because the product is odourless, it has been able to enter the chocolate, butter and other dry foods markets where adhesive odour has been a problem.

Another UK-based company, Power Adhesives, has the largest specialist range of industrial adhesive guns and high performance adhesives in the world today, sold under the Tec and Tecbond brand names. These offer specialist packaging grades which include very fast setting adhesives formulated to flow easily but set instantly when the carton flap is closed.

The company’s largest pneumatic driven spray gun has the highest output available and is becoming increasingly popular for use on heat-sensitive materials such as expanded PS, PE and PU foams, as well as positioning barrier films, foils and liners.

Waterborne adhesives, as manufactured by National Starch and Chemical, have made significant advances over the past few years. There has been considerable improvement in performance in order to be closer to hot melt alternative technology.

Indeed, improved adhesion, especially on plastic based substrates, together with faster setting times, have made waterborne adhesives a very real alternative as Thierry Pasquier, marketing project leader – Europe for National Starch and Chemical explains: “We have both Syntacol and Clear-Lok as our brand names.

“Clear-Lok is for labelling bottles in a most cost-effective way in comparison to pressure sensitive labels that are more expensive with reference to cost per unit and machining equipment.

“Other market areas for us are in the converting business – carton making, case making and tube winding. Water-borne technology can be used on quite a wide scale of applications and we are constantly developing such markets.”

Europe has a plethora of very good adhesive manu-facturers, including Henkel and Bostik-Findley to name just another two.

Further demands from the packaging industry in order to satisfy client demands will mean that machines will have to run even faster, while surfaces become even more difficult to handle as marketing needs continue to influence substrate choice. Costs must also continue to decrease.

Education and technical backup will or should also feature highly as customers rely more on suppliers to provide information on topics such as safety environmental and legislation.