Triplex boosts efficiency

Improving efficiency in lamination is clearly a message that converters consistently send to suppliers. So flexibility, time saving and consistent quality is the goal.

For example, when Schiavi first developed its triplex lamination technology it was for the larger customized coating and laminating lines. However, more recently it has been applied to its compact machines, in line with the latest market trends.

In engineering its latest generation CL 660 coater-laminator, the company has produced a compact machine that may be supplied either in a triplex tandem configuration or easily upgraded to a tandem configuration at a later stage.

The triplex tandem configuration allows converters to expand their converting operation substantially both in terms of production capacity and flexibility of process, claims Schiavi. Two CL 660 machines can be used as separate duplex lines producing either two duplex laminates or a duplex laminate and a finishing application in two passes. Alternatively, they can work together in-line in a triplex configuration to produce three-ply laminates or duplex laminates plus a finishing application, such as coldseal coating, in one single pass.

Producing triplex laminates in one pass gives improved efficiency. It obviously speeds up the production of the triplex end product, resulting in a dramatic increase of production capacity and profitability, boasts the company. Since launching the CL 660 at drupa 2004, in addition to a number of duplex lines, Schiavi has sold two CL 660 triplex tandem configuration machines to leading converters in Europe and the Middle East.

Competitive

When operating in duplex configuration both CL 660s are able to perform either solventless or solvent based, or wet bonding lamination at a speed of up to 450m/min. When operating as a triplex line, solvent based duplex laminates are further laminated in-line with either solvent based or solventless adhesives, or coated with coldseal adhesives at a maximum speed of 325m/min depending on the application.

Schiavi also offers a competitively priced CL 660 configuration for triplex lamination only, hence not requiring a rewinder in the first laminator and a primary unwinder in the second one.

A triplex laminator can feature different coating systems, such as direct gravure, semi flexo or flexo. It is particularly important that the chosen system proves the most suitable solution for the application and jobs to be run on the line, otherwise the productivity and profitability would be in jeopardy, says Rotomec - specialist in standard medium-sized equipment, as well as very large customized production lines.

One such solution was recently demonstrated at its Italian production plant. The laminator, mainly dedicated to the production of triplex laminates, including thin aluminium foil, featured specific technical solutions. A flexo trolley configuration was used, which is particularly suited for the coating of solvent based adhesives directly on thin foil substrates. The system works on a neutral, unprinted surface. This aspect, together with the possibility of coating a lower weight, enables the percentage of solvent retention on the web to be reduced dramatically. Although this is an advantage with any application, it is particularly crucial for lines dedicated to petfood packaging, adds the company.

It says that the eight metre long tunnel with two thermoregulators and a high efficiency drying system, combined with the lower quantity of adhesive, brings the residual solvent value very close to zero. And application of the adhesive directly onto the aluminium foil is also said to ensure the best quality of end product, as it prevents the formation of "orange peel" problems during lamination. These usually result from an oily residue on the surface of the foil.

For an increasing number of companies, particularly those engaged in brand protection or anti counterfeiting, an off-the-peg coating machine is not an option. These companies, many of which are multinationals with a global presence, require a purpose-built, state-of-the-art system manufactured to tight tolerances with the ability to control with precision thinner coatings on ever-thinner substrates.

To meet the requirements of this type of customer, RK Print Coat Instruments unveiled the new VCM or Versatile Coating Machine concept during drupa. Each machine is custom designed and purpose built to suit the requirements of the customer and the industry sector. Since its launch several machines have been supplied, reports RK including a production machine dedicated to hologram conversion. This particular equipment incorporates several coating options.

Flexible

Dedicated gravure users are amongst converters who have expressed interest in the VCM. However, with its potential for hotmelt, gravure-offset (printing and coating), reverse gravure coating, knife-over-roll, extrusion, meter bar, flexo and wet/dry lamination capability, it will also be of interest to security organizations, substrate suppliers, research organizations and major packaging groups, says the company. Managing director Tom Kerchiss points out: "Although the basic concept of coating has changed little over the years, each element has been improved to match the advances in coating formulae and by the needs of the customer and the marketplace. Environmental concerns are being addressed through the use of solventless and high solids formulation, and better control of VOCs. Increasingly exotic applications, the laminating of high barrier films for flexible packaging food items and measures to combat counterfeiting provide opportunities for manufactures such as ourselves."

With converters seeking higher speeds and the ability to coat precisely on ever thinner and diverse substrates, the Mistral coating/laminating machine from Uteco claims an output of 350m/min coupled with short change-over times and multi process coating performance. Suitable for PE, PP, OPP, BOPP/MET, PET, PVC, nylon, aluminium foil and paper, it can be used for solvent based coating, water based coating, solventless, dry coating, wet bonding, primer/lacquering, im-register coating, hotmelt, heatseal, and coldseal on register.

The machine is available in several printing widths: 1,200mm and 1,400mm, and in coating widths of 1,100mm and 1,300mm, respectively. It is designed for high output, ease of use (touchscreen control), ease of cleaning, ease of maintenance, and offers fast product change-overs. Mistral also incorporates SmartPack, Uteco's state of the art software, which optimizes the multi process coating performance in flexible packaging applications. SmartPack provides supervisory control including monitoring and diagnostics for the entire production cycle - automatically and completely. The equipment is also available with a high efficiency six metre drying tunnel said to ensure high speed production and low solvent retention when processing a laminate.

A coating formulation that's proving to be a success in segments as diverse as flexible packaging, security (hologram) packaging, and digital printing (inkjet) applications is Curecoat and variant Curecoat HV, says Starna Industries.

Curecoat is claimed to be a versatile, quick drying, water based coating formula that can be used as a primer on coated and non coated papers, foils and fabrics. According to the UK and European supplier Starna, Curecoat offers users the possibility as a primer for metallized films and papers. Application can be by flexo, rollercoat and gravure, and drying and curing is by hot air or infra red. Its companion Curecoat HV is configured for screen and litho applications.

The products are said to impart a satin-like finish to treated substrates and can be supplied press ready. They dry quickly once applied due to the low film weight and the company recommends them where converters are experiencing problems associated with requirements for high gloss, or when processing problematic substrates or using low dyne synthetics. They are free from phthalates and do not contain VOCs or HAPs.