Optimal Options
A wide array of quality unwinds, rewinds, and splicers provides converters with endless choices.
HENRY FORD'S MODEL T made the automobile a permanent fixture in American society. It was mass produced and the working man could afford it.
For all its virtues, however, the Model T had one downfall: there were no color options. "The customer can have any color he wants, so long as it's black," Ford said.
Up until about two decades ago, converters dealt with a similar situation, though not as simple as color, when looking to invest in winding and splicing equipment. At the time, manufacturers mostly supplied shafted unwinds and rewinds, and splicers were very basic. Often, converters used the unwinds, rewinds, and splicers that came with the purchase of a new press, not because that was the easiest way to do business, but because their options were otherwise limited.
"There weren't so many options years ago," said John Powell Jr., vice president of Powell Engineering, Inc. (Pinson, Ala.). "In the past, there were only shafted unwinds. If you had a big roll of paper, weighing something like 3,000 pounds, the operator putting the shaft in the roll would often get hurt. Now, there are lots of options for converters, as well as manufacturers, really. Now you have the option to buy what exactly matches your operation."
Unwinds, rewinds: A varied selection
Options are necessary in an ever-changing industry like converting, where quality standards are constantly on the rise. "You need a precise way to hold the roll and that takes good core chucks, a good unwind stand, and a good braking system that is properly sized for the application," Powell said. "That takes three vendors, most of the time."
Nowadays, that's not a problem. Converters have numerous equipment manufacturers and products to choose from, depending on their needs and market demands. And that's particularly evident with winding technology. Machine manufacturers, in fact, do their best to offer converters the best of the latest trends.
At the moment, converters are looking for narrow-web equipment to serve a high demand for flexible packaging applications, and the unwind/ rewind market reflects that. With an eye on the market, Keene Technology Inc. (KTI, South Beloit, Ill.) offers its Narrow Web Unwinds/Rewinds. The KTI system is designed for roll-to-roll or roll-to-cut applications, and includes such automated functions as automatic process stops for web breaks or at predetermined roll diameters, and bi-directional unwind/rewind capability. Both unwind and rewind units are built with identical plate frameworks to minimize maintenance costs. The units can handle web widths from 13 to 18˝, and splice at speeds up to 800 feet per minute.
KTI also offers the MR Series Multiple Spindle Turret Rewinder for web widths of 16, 20, and 24˝. The MR cuts and transfers at zero speed via its integrated festoon, which allows for transfer at full line speeds up to 1,000 feet per minute. The MR comes equipped with three to five spindles.
CTC International (West Caldwell, N.J.) offers narrow-web converters a glueless start turret rewinder for automatic high-speed winding of tags and labels. The turret automatically tucks the web around the cores without the use of any adhesive. CTC International's turret can run a large number of relatively narrow-web strips, and can operate as a coreless winder in some circumstances. Additionally, an optional tail label roll closure system is available that permits complete glueless operation.
Also specifically designed for narrow-web applications is Web Techniques' (Fenton, Mo.) tabletop Model WT-25 Rewind and Inspection Machine. The WT-25 is economical and easy-to-use, and has a very short web path. It rewinds large master rolls 7 to 10˝ wide into rolls of predetermined length. The WT-25 can be run at variable speeds, winding labels in or out with dynamic braking and solid state reversing without damaging the motor or control. And "roll changes are fast since the web always runs against the stainless steel table surface and there are few idler rolls to thread material around," said Web Techniques President Ken Barstow.
The Elsner Model US-760 Unwind Stand, by Elsner Engineering Works, Inc. (Hanover, Pa.), is also for use on narrow webs. The US-760 makes handling rolls up to 30˝ wide and 40˝ in diameter easy. The unwind has a pneumatic, off-the-floor roll lift that can hoist up to 2,000 pounds. It features air-cooled and air-operated multi-pad disc brakes with changeable sizes to suit specific applications. The US-760 uses automatic edge guiding with ±2˝ of corrections, as well as the Elsner EPT-1 sonic web tension control system. It can also handle web speeds up to 600 feet per minute. Other models of the US-760 are available that can run 72˝ wide webs at a 1,000 feet per minute.
Martin Automatic's (Rockford, Ill.) Model LR Automatic Transfer Rewind is for web widths up to 46˝. The LR is designed to allow high-speed production of a wide range of roll diameters up to 50˝, using two spindles. It automatically transfers, winds, and delivers full rolls, leaving the operator's only task to loading cores. The automatic transfer rewind is rated for speeds up to 1,000 feet per minute.
Wide-web converters needing new winding technology have not been forgotten. For wider webs, Martin Automatic has the Martin RMAP, a two-spindle rewind that combines splicing, web-handling, and tension control technology in an automatic rewind suitable for a wide range of applications and materials. The RMAP can rewind a running web and hold a new empty core at the same time. When the rewinding roll is full, it is unloaded automatically. The RMAP can splice up to speeds of 1,725 feet per minute on webs as wide as 85˝.
Safety, as well as quality, are important factors in unwinds/rewinds. Powell Engineering manufactures roll-lifting, shaftless unwinds and rewinds for the paper, film, and foil converting industries. Powell's Model EP (Eccentric Pivot™) Junior Shaftless Unwind minimizes downtime between roll changes and increases worker safety. Its stand configuration includes a hydraulic lateral adjustment that can be used in conjunction with an edge guide, and can lift rolls up to 3,000 pounds. Other Powell models can lift rolls up to 10,000 pounds.
Powell also has a Mid-Process Rewind that is designed with the same framework as its unwinds, giving it similar flexibility in roll width, diameter, and core size. The bolt-on flange for core chucks can accommodate traditional shaftless core chucks or a special adapter that allows the use of a rewind shaft. The Mid-Process Rewind permits converters to store or move the product to another area of the plant before going to final production.
An abundance of splicing technology
Chris Plude, KTI's manager of product application and development, has seen a recent surge of activity for unwind splicers in packaging applications. That surge is adding to the resourcefulness of KTI's LS Series zero-speed web splicer, a company standard since the beginning. Suitable for a wide range of substrates—including tag and label, thin film, paper, light board, foil, and food packaging—the LS Series features digital autosplice and a safe electric dual-chain hoist for direct access to upper and lower roll positions, which eases the operator work load. The LS Series is available with many automated features such as automatic web and core acceleration, automatic web drive for fast press start-up, and an automatic low riding festoon.
Martin Automatic offers splicers for a variety of web widths. "What's been a good market for Martin is the narrow- to mid-web processes, webs up to 30˝ wide or so," said Craig Thomson, marketing manager at Martin Automatic. However, he added, "Many printers are serving multiple markets like label, film, and folding carton. That requires that the splicer and rewind be capable of handling the same variety of substrates and all tensions to rewind them."
Martin Automatic's wide-web CHW (cantilevered hot-wire) zero-speed splicer can reach splicing speeds up to 2,500 feet per minute, and can run webs up to 75˝ wide and wider with cores up to 6˝ in diameter. The CHW lap splicer features a pivoting split splice unit and in-aisle splice preparation, as well as a lift-and-load mechanism designed to keep rolls close to the ground. The splicer is also available with tape lap, heatseal lap, or heatseal butt splice capabilities.
One of Martin Automatic's options for narrow-web converters is the Martin Model STS Automatic Splicer. The STS offers non-stop production capabilities for form, fill, and seal; sleeving; laminating; label applicators; pressure sensitive labels; and in-register splicing. The STS has a compact footprint that allows it to be placed on the floor, above a process line, or even stacked in units. The STS is suited for web widths up to 13˝ and roll diameters up to 31.5˝.
By: Kate Sharon
