The One-Two Punch

Facing off in the laminating ring are in-line vs. off-line laminators; and while each has their own punches to throw and to receive, it is the converter who decides the champion.

by Joy English, Assistant Editor

JUNE 19, 1936 MARKED the day that heavyweight champion Joe Louis and Max Schmeling squared off in what would be a boxing match to remember. Schmeling entered the ring as the underdog, but claimed the titled when he handed Louis his first ring defeat. It wasn't until two years later that Louis would reclaim his heavyweight title from Schmeling.

Today, squaring off in the laminating ring are in-line vs. off-line machines. Both systems have their own strengths and weaknesses, making this a close match. Yet, it is the converters who will be the judges in deciding the winner for their own package printing needs.

Let the match begin

First to enter the ring is the in-line laminator. As the term describes, in-line lamination occurs in-line with the printing press. "In-line laminating incorporates the laminator with another process (typically flexo or gravure printing) all in one process or 'pass'," explained Rick Runzel, area manager for Comexi America, Inc.

In the opposite corner is off-line lamination. The off-line laminator stands alone, incorporating the basic elements—primary unwind, secondary unwind, coating section, and laminating nip and rewind—in a single machine dedicated to lamination. Bill Moreland, president of Moreland Machinery Co., Inc., authorized agent for Nordmeccanica, NA, said, "Off-line lamination has proven to be the preferred method of choice, as it can be done at the fastest possible speeds. It also allows the most control over production variables, giving the highest possible quality."

The victor of the laminating face off, though, is ultimately decided by individual converters. John Metolik, area sales manager, North American Cerutti Corp., said, "Choosing between in- or off-line lamination is strictly an individual decision. A case can be made for either, depending on the level of risk/reward one is comfortable with." In this match, the strengths and weaknesses of the machines—along with the overall work process—are the keys to a converters' laminating success.

Round 1

As Round One begins, the off-line laminator is already the projected winner, garnishing the support of many converters as the laminator. But the in-line laminator has its own punches to throw.

"The advantages of the in-line process are many," says Phil Faria, Lamart Corp.'s manager of process engineering. "Cost is a primary consideration since the materials are only being handled once. The product that comes off the laminator is ready for final conversion without requiring additional processing steps."

Peter Medlicott, VP of sales, North America, Valmet Converting, said, "The main reason that converters in the industry use lamination in-line is due to the run lengths and also to have a complete product on one machine. This can save both time and material as only one setup is necessary."

"Waste is another area I would consider to be important to in-line lamination. The reduction in the number of machines used to convert a given product will reduce splicing waste and handling waste. This in turn will increase the efficiency of the slitting or finishing department," said Metolik.

Industry experts cited other benefits of in-line lamination as higher volumes and higher yields, reduction in utility costs, and familiarity for maintenance personnel.

In addition to the general considerations for tension control and drying, Runzel commented that run size is another extremely influential factor. "Typically, if this is a dedicated product—or range of products—adaptable for consistently long production runs, the more justifiable the in-line process becomes, since there is less downtime involved and an efficiency of materials, material handling, and personnel is realized." But for converters with short to mid-size runs, in-line lamination will go down with a quick one-two.

Round 2

In today's printing industry where short runs and fast changeovers are increasingly popular, off-line laminators offer converters the flexibility they need. "In these cases, a stand-alone laminator will offer more flexibility since it can be used on an 'as needed' basis," said Runzel.

Moreland agreed. "In most cases, off-line lamination will achieve higher production and lower scrap rates in short and mid-sized run situations. Additionally, off-line lamination adds to the processors' versatility and quality in production, giving them more options during the production process."

Ernest Gregory, business development manager, web coating systems, Nordson Corp., expanded on this flexibility. "Off-line coating systems may be engineered to process at higher speeds and wider widths than standard press offerings. This coating option allows converters to run several products and run them based upon their schedule vs. when the press is available."

Most converters will agree that the flexibility for short runs is one key strength of off-line laminators. "An off-line laminator will also be able to run a wider range of jobs—different materials, tensions, adhesives, etc.—more efficiently, and normally, at greater speeds," said Runzel.

Reliable tension control is one other advantage of off-line lamination. Moreland said, "Tension controls are of utmost importance today to meet [the demands of today's structures], putting further strain on in-line processing. These types of structures (i.e., foils as thin as 6 microns and PE films less than 25 microns) along with versatility and the ability to move quickly and efficiently from job to job continue to add support for the decision to go off-line."

Round 3

A boxer, regardless of his competitor, would never enter the ring with 10-lb. weights tied to his arms. In-line laminators, though, have a potentially damaging added weight—the other in-line equipment. Runzel commented, "Whether it is people, materials, or equipment, no process is any better than its weakest link. This is important to consider with in-line and off-line laminating." The in-line process includes other steps before lamination, mainly printing and drying. "Any problem with one process—mechanical or electrical, inherent technical limitations of the equipment or application, etc.—will have a negative effect on the other." If the printing press goes down, so does the laminator, and vice versa.

Yet, though the off-line laminator seems to be the winner, it has its weaknesses, too. The largest disadvantage, according to Moreland, is that off-line laminators become one more step in the printing process, and this requires additional labor and manpower.

Another negative side to off-line laminators "is that printed stock may go unprocessed for an extended period of time, opening the door for problems such as transfer or blocking, and possibly stock that has become dry and brittle," said Metolik. "It is in these circumstances that the off-line process will cost more in waste, particularly if the job must be repeated."

Naming a champion

In the package-printing ring, the match between in-line laminators and off-line laminators is a close one. However, the champion is ultimately decided by the converters.

"For many years, off-line laminating was clearly associated with European converters and in-line was more of an American phenomenon. Although the delineation may still exist, it is beginning to disappear as more North American companies purchase off-line laminators to diversify their product range and develop a more vertically integrated approach to their means of production. … Off-line laminators are the most convenient and cost-effective way to accomplish this," explained Runzel. Each process has its strengths and weaknesses, and both are still widely used, though Runzel observed that off-line laminators are experiencing wide growth.

Regardless of the process, improvements in lamination are constantly being made, says Dave Scholmer, president of Dri-Tec, LLC. "We work on better control of adhesives, better temperature control, and better monitoring and web control. There has been a lot of research and advances and improving of machines."

With constant improvements and the benefits of each approach, Faria concludes, "There will always be a demand for both types of laminating processes. Each has a role to play within the printing and converting industries. The choice one needs to make ideally should be based on economics, performance requirements, and the markets being served."

Resources

Converting Machinery Tech. www.uvcoatings.com

Comexi America www.comexi.com

Dri-Tec LLC www.dri-tec.com

Faustel www.faustel.com

Inta-Roto www.inta-roto.com

Kroenert Corp. www.kroenert.com

Lamart Corp. www.lamartcorp.com

May Coating Technologies www.maycoating.com

Moreland Machinery www.moremach.com

Nordson Corp., www.nordson.com

North American Cerutti Corp. www.cerutti.com