Printers signal benefits for bags

Whelen Eng., Chester, CT, designs and manufactures lights, beacons, sirens and other warning equipment for emergency vehicles such as police cars, ambulances and fire trucks. Dedicated to manufacturing in the U.S., Whelen stays competitive in the world market by leveraging automation in creative ways to minimize operating costs while maximizing product quality.

To eliminate the need to insert instruction manuals into each of its packages, Whelen searched for an in-line printer that could print the instructions directly on the packages during the bagging operation. To impart the needed information, they needed to achieve an 8-in.-W print area. The company found the NGT Series of large format thermal-transfer coding systems from Norwood Marking Systems/Allen Coding Systems (www.itw-norwood.com). Capable of producing the largest print area of any thermal transfer coder in the world, the NGT printers have allowed Whelen to reduce manufacturing costs and improve production flexibility while also increasing its throughput.

Large-format a must

“We went looking for a thermal-transfer printer that could do large-format printing,” notes Jon Hardy, supervisor of manufacturing engineering at Whelen. “We found several systems that produced two- and four-inch widths and a couple that produced five-inch widths. But we wanted a printer that could achieve an eight-inch width. We came to Norwood/Allen just as they were introducing their NGT printers in the U.S.”

The NGT 8 C that Whelen selected can produce a print area up to 8.4 in. wide and 19.68 in. long.

Whelen manufacturers several thousand different products at its Charlestown, NH plant. Each product requires instructions that provide users with the information needed to assemble and mount the part. Prior to installing the Norwood/Allen printers, operators at the bagging operation inserted preprinted instruction sheets into each bag, sometimes folding the 8½311-in, sheets in half or in quarters to fit inside the package.

Says Hardy, “We were motivated to print the instructions on the bags in an effort to reallocate labor to more productive tasks. With three in-line printers installed so far, we've managed to move three people handling the printing, storing and folding of the instruction manuals to more productive tasks.”

Whelen's initial decision to install the new printers was economic in nature, he adds. “We didn't fully anticipate the many benefits that would come from this shift to printing on-demand.”

Boosts operator throughput

Eliminating the need to fold and insert preprinted instruction sheets into each bag enables the operators at the bagging station to increase their throughput. “It only takes two seconds to bag and seal a product, but it could take four seconds to fold the paper,” says Hardy. “Our move to automated printing potentially increases the bagging rate by three times.”

The change also eliminates the repetitive task of folding and inserting the papers, which makes the operators' job easier.

“We were printing several million instruction sheets per year,” adds Bob Dubois, manufacturing engineer at the Charlestown, NH plant. “Eliminating as many of these sheets as possible helps save valuable resources and this new approach is better for the environment. It also gives us more production flexibility.”

Printing on-demand allows Whelen to ensure that the instructions are absolutely current. It eliminates the possibility that out-of-date instruction sheets or an incorrect sheet is inserted into the package. Whelen is also now able to easily customize the print on the package for a particular customer, which is especially valuable in today's environment where bagging to-order is increasingly preferred in an effort to reduce finished goods inventory, says Hardy.

In addition to printing the lengthy instruction manual onto the polyethylene bags, Whelen prints the product description, a bar code and the date. These elements are automatically formatted by Teklynx® (www.teklynx.com) Sentinel™ Software, which also allows the Norwood/Allen printers to be integrated with Whelen's plant-wide network via the NGT's integrated Ethernet card.

As of presstime, Whelen says that it has developed and formatted more than 100 instruction images, which replace almost 800 unique printed pages by consolidating various connector and lens color variations. With batch manufacturing that typically includes 500 to 1,000 units per run, Whelen often changes the printer over 30 times a day.

When an operator prepares for a new product run, they enter a job number into Whelen's software running on a local PC. This triggers the network to access the instruction sheet for that product, which is saved as a jpg file on one of Whelen's network servers.

The network sends a jpg file to the software, which integrates the image in real-time with the product's text description, bar code and the date of manufacture, appending the file and sending it to the appropriate printer.

The polyethylene bags are supplied to Whelen preformed on rolls. They are transparent on the back so that the product is visible through the package. They have a white front panel to produce crisp black-on-white printing. The bags, which range in size from 537 in. to as large as 10½315 in., are printed in-line with a resolution of 300 dots/in., both horizontally and vertically. An unlimited choice of TrueType font styles and a wide range of font sizes are available with the NGT. Six fonts come standard and there is space for 44 more.

The NGT Series of thermal-transfer printers are available in several different models—both intermittent and continuous-motion—for a variety of applications and to achieve different maximum print areas and print speeds. Whelen's continuous-motion NGT 8 C can produce the largest print area of the series—up to 8.4319.68 in. at speeds up to 9.8 in./sec.

Manufactured by Norwood/Allen's distributor, AC Codiergeräte GmbH (www.ac-coding.com), in Germany, with robust mechanics and superior components, the durable NGT Series of coders improves reliability to maximize production throughput. A pivoting frame provides operators with easy access for maintenance and adjustments.

Whelen installed its first NGT printer in January 2007 and a second in March 2007, followed by a third in November 2007. “We measure the success of the printers based on print quality, reliability and ease of use, notes Dubois. “We're very satisfied with the NGT printers.”

Adds Hardy, “The bottom line is that the printers have allowed us to move three people to more productive tasks. So the project was a home-run hit. The rest is icing on the cake.”