The latest developments in adhesives technology are aimed at meeting the needs of materials, machinery and regulatory requirements
Adhesives literally are the glue that holds many converted products together, from labels to laminates, to cartons and corrugated cases. The manufacturers have been working hard to formulate products that perform this prime function as efficiently and cost effectively as possible – while also complying with today’s environmental concerns.
Flexibility – “not only with regard to packaging, but also along the value chain” – is one of the key benefits offered by Liofol Fast One, Henkel’s new one-component laminating adhesive. It is said to feature an extremely fast cure, combined with high initial bond strength.
“Our goal was to develop an adhesive that would enable just-in-time manufacturing of flexible packages,” explains Georg Kinzelmann, Henkel’s corporate technical director and head of the R&D platform for polyurethanes. “With this unique one-component PUR laminating adhesive, curing is substantially reduced to just a few days, compared with a curing time of up to two weeks with a conventional adhesive.”
The extremely fast cure of Liofol Fast One, combined with a considerably higher initial tack, is said to enable packaging manufacturers to bundle printing, lamination and cutting in one single step. These technical benefits create significant competitive advantages by increasing flexibility across the whole processing chain, according to Henkel. In addition to time saving, the reduction of warehousing costs and lower capital employed are key benefits that will be immediately apparent to converters, the company claims.
Liofol Fast One is also said to be the first-ever laminating adhesive to contain no free isocyanates – avoiding any possibility of the formation of primary aromatic amines. In addition, the new product stays well within the specific migration limit (SML). It is toxicologically safe in terms of Risk Phrase R40 – no R40 labelling is necessary, offering maximum safety for both converters and consumers, states Henkel.
It is also claimed that the product shows “environmentally-sustainable” performance. The one-component laminating adhesive minimizes the risk of mixing-ratio errors that can occur with the use of a conventional two-component system. This results in less adhesive waste than with a two-component system.
Depending on the type of solvents used, another positive aspect is the possibility of re-using the solvents from the recovery system, which can be fed back directly into the production process without the need of purification. Henkel will be featuring Liofol Fast One among its exhibits at ICE Europe 2011, on stand 20 in Hall B6.
Planatol has introduced a crosslinker for its proven water-based adhesives for film lamination, that enables the user to reduce the necessary amount from the usual 5% to 2%, “while still delivering excellent lamination results”.
On the packaging front, the company offers a new hotmelt pressure-sensitive adhesive that combines aggressive tack with very short stringing at the nozzle. Econ-Fold 1 is a new water-based dispersion adhesive for gluing paper sacks which, it is claimed, “excels in adhesive strength and clean processability”. Planatol will introduce these products at ICE Europe 2011(Hall B6, stand 342).
Fullbor WB 6364 was specially developed by HB Fuller in response to legislative requirements for the handling of liquid borax products in the manufacture of corrugated board.
It is said to ensure dust-free handling within a closed or semi-closed corrugator starch dosage system, and can be used in a 1:1 replacement of borax decahydrate powder in starch adhesive formulas. Its use is also claimed to improve the final properties of finished starch adhesives in terms of film formation, water retention, reduced warp and improved mileage.
HB Fuller has also re-launched its Datac water-based envelope adhesives, which can be used for flap, side seam and window applications. The borate-free product promises clean machining to minimise adhesive-related downtime. The company also says it has high adhesion to a wide range of substrates.
Andrew Gibson, Fuller’s business development manager for paper converting, comments: “We are delighted with the response Fullbor WB 6364 and Datac adhesives have had from our customers – we have received some really positive feedback.”
Two dedicated proprietary adhesives for pharmaceutical labelling have been introduced by Avery Dennison for its Fasson S2000NP and Fasson S692NP paper and film facestocks. They are said to represent a new generation of technology in the critical areas where pharmaceutical manufacturers need the reassurance of high mandrel performance, low migration, long-term adhesion, and regulatory compliance.
Fasson S2000NP is said to be particularly versatile. Its high mandrel performance makes it suitable for the tight-diameter curves of glass, PE, and PP ampoules, vials, and test tubes. It is also suitable for sterilisation by autoclaving, ETO and gamma radiation. Fasson S2000NP partners Fasson LW supercalendered, double-machine coated lightweight paper, the facestock for labels where small print legibility is a prerequisite.
Fasson S692NP is a clear, permanent acrylic-based adhesive said to offer a particularly low migration risk, excellent UV resistance, and good adhesion to apolar substrates. It complies with European food directives, the US FDA 175.105, and the German BfR recommendations XIV for direct contact with dry and moist, non-fatty foodstuffs. The new product can partner Fasson LW paper facestock, or a choice of Fasson film facestocks – Fasson PE85 Top and Fasson PP Top White and Clear.
Collano played a pioneering role in the replacement of solvent-based adhesives with ecologically-friendly aqueous and 100% adhesive systems. The latest addition to its range is a pressure-sensitive hotmelt adhesive made from renewable raw materials.
Targeted at users who are looking for sustainable, high quality products, 70% of Collano T2 1465 is made from renewable raw materials, complementing the sustainability credentials of substrates made from renewable or recycled sources. The hotmelt has a service temperature of 0-55°C and offers a wide range of adhesive properties for label, adhesive tape and other self-adhesive applications.
Another Collano development is printable UV N4 pressure-sensitive adhesives which can be applied in virtually any form and to any substrate by flexo and screen printing, and then cured with UV-LED light. This method offers savings on energy and prevention of ozone formation, while affording a way of printing heat-sensitive substrates.
The company claims that its latest deep-freeze adhesive formulation, Collano L3 927, “raises the bar for low temperature adhesion”. It adheres at temperatures as low as -20°C – even to critical packaging materials, such as cartonboard. As low penetration is one of its features, it can also be used on unprimed base papers.
Collano’s deep-freeze adhesives are suitable for refrigerator and freezer applications, for indirect food contact, for specially treated packaging film and high speed blow-labelling.
UPM Raflatac recently launched a UV-hotmelt adhesive for use with transparent and opaque films in beverage and food labelling. The RC 7B adhesive is said to perform well on a range of substrates including glass and PET, and is suitable for applications requiring a no-label look.
The new hotmelt also “provides excellent performance in challenging conditions, showing good adhesion and lasting clarity even when labels are applied to moist bottles”. High temperature tolerance is claimed to make this adhesive “an optimal choice” for packing and bottling processes involving pasteurization.
Good resistance to water-whitening at any stage of its lifecycle, including prolonged immersion in water after labelling, is also claimed for RC 7B.
While environmentally friendly pressure-sensitive hotmelts have surpassed solvent and water-based adhesives in many self-adhesive sectors, the only disadvantage to date has been the lack of thermal resistance due to the thermoplastic reversible performance.
Novamelt has addressed this issue by developing Novamelt PS 5587, a hotmelt adhesive said to improve thermal resistance values greatly. Its shear temperature is almost 100ºC which, it is claimed, has been achieved without compromising the higher processing viscosity and limits in the melting performance and application speed.
Traditional coldseal adhesives for food packaging are applied by patterned gravure. This means for every change in impression length or configuration, a new gravure cylinder must be re-etched. To help eliminate the excess time and cost involved in this process, US-based group Ashland Performance Materials has developed a novel synthetic coldseal adhesive for the European food packaging industry.
The water-based Pureseal 23322E coldseal adhesive can be applied via the flexo printing process, avoiding the cost-intensive etching and re-etching of cylinders entirely by using a photopolymer plate. This is of particular importance for shorter, specialized runs such as in the confectionery bar market.
“A key benefit of this technology is that it provides manufacturers with the opportunity to produce coldseal flexible packaging on existing narrow web press equipment,” says Stuart May, Ashland’s director of sales, EMEA. “As with any water-based product, the coldseal adhesive must be dried before rewinding.”
Pureseal 23322E can be applied as an overall coat or pattern. It seals packages comprised of biaxially oriented polypropylene (BOPP), white OPP, metalized OPP, polyester and other substrates suitable for food packaging. It releases from release-treated films or release lacquer-coated substrates and complies with the relevant US Food and Drug Administration regulations for food packaging.
Ashland’s new adhesive is also a specially formulated synthetic-based cohesive with no natural rubber components, making the product suitable for medical and protective packaging.
“One of the greenest adhesive products on the market” is another US manufacturer’s claim for its new high performance packaging and paper converting hotmelt adhesive. Due to its special low density chemistry, GreenMelt, from Wisdom Adhesives, is said to provide a 10% saving in adhesive usage at the same volume of application as comparable conventional products, making it a more sustainable and cost-effective solution.
Excellent adhesion, runnability and mileage are other attributes of Greenmelt, a flat-rounded chip form adhesive with a novel component blend process that, the company says, makes it easy to handle and simple to dispense into melt equipment. The product is available in mini-chip and micro-chip sizes.
Paramelt has recently introduced products within its Aquaseal range of water-based heatseal and barrier coatings, produced using the new Bluewave technology platform developed in partnership with Dow Chemical. “Superb barrier characteristics” and tailored minimum sealing temperature are claimed for the company’s range of alternatives to the use of plasticised vinyl systems.
For aluminium lidding foils, a fully water-based combi-lacquer dispersion, based on chlorine-free, high molecular weight thermoplastics, has been developed by Paramelt, offering excellent sealability to both polypropylene and polystyrene substrates. Targeted particularly at the dairy sector, this product is said to combine excellent seal and peelability characteristics with the necessary resistance to water, fat and lactic acid.
For thinner heatseal foils intended for diverse applications such as soup cubes, processed cheese and chocolate wraps, Paramelt has developed a range of aqueous, ethylene copolymer emulsions which, it says, provide excellent adhesion to aluminium combined with good laydown, film formation, flexibility and crease resistance. The company will be exhibiting at ICE Europe (Hall B5, stand 946).
A new spray adhesive from Burnishine Products provides both temporary and permanent bonds, and is said to be suitable for many uses in packaging and labelling. A non-staining formula, it can be used to bond paper, cartonboard, acrylics, fabric, felt, metal and rubber. The product comes in a recyclable can and contains no ozone-depleting compounds.
On the equipment front, Norcross now offers a PLC-based viscosity control system that controls up to 10 stations (loops), provides three trend plots for each, and allows adjustment during operation. The VISC6000 is a PLC-based process control system that operates viscosity sensors through an intuitive touchscreen interface.
Its software displays trend data for each station in real-time, provides data logging for one hour up to seven days, and permits set-point and other viscosity parameter adjustments on-the-fly.
Planatol innovation offers savings Planatol HB Fuller has developed Fullbor WB 6364 HB Fuller New UV-hotmelt label adhesive from UPM Raflatac UPM Raflatac Henkelâ€™s fast curing adhesive Liofol Fast One Liofol External weblinksConverting Today is not responsible for the content of external internet sites.Ashland Burnishine Collano Fasson Avery Dennison Fasson Henkel Novamelt Paramelt Planatol UPM Raflatac Norcross Wisdom