Labeling Cartons Consistently
A label printer-applicator improves bar code quality, reduces rejects, and cuts labor time.
In 1986, Dade Behring Chemistry Systems (Newark, DE) launched its Dimension clinical chemistry system, which enables laboratory technicians to conduct a wide range of in vit- ro diagnostic tests at one workstation. The firm manufactures and markets reagent combinations for 65 different test methods for the system.
Dade Behring began using bar codes with the system's commercial release. The cartons are preprinted on top with a Code 39 bar code, and pressure-sensitive labels with a lot number, expiration date, and an additional bar code, in Code 128 format, are applied after the reagent cartridges are placed inside. The Code 128 bar code contains a specially encoded character that links to the preprinted primary bar code to ensure that the proper test has been packaged in its designated carton.
Measuring 1.75 in. wide and 3.25 in. long, the pressure-sensitive label is wrapped across both the top and side of the carton. "We label our cartons on two sides so hospital technicians have two opportunities to identify the tests when they're piled up in their laboratory refrigerators," explains Jim Feeley, assistant engineer for Dade Behring. The lot number and expiration date are repeated in both locations, while the bar code only appears on the label portion applied to the carton's top.
Dade Behring had been using a print-and-apply system that was anchored to a stand and then wheeled to the conveyor when necessary. Located in a busy production area, the freestanding system was often jarred by operators, causing inconsistent label placement and poor label registration. "Placement of the label is critical," says Feeley. "We have limited real estate to get that bar code on without encroaching on the quiet zone of the primary bar code."
Also, the print-and-apply system was printing poorly, but with multiple vendors involved in the application, Dade Behring could not determine the source of the problems. "We had different vendors for the printer-applicator, for the software, for the ribbons, and for the labels," explains Curtis Yates, production manager for Dade Behring's chemistry group. "When problems arose, there was a lot of finger pointing and we had trouble getting service."
So Dade Behring began searching for a system that could provide consistent label application with improved print quality and for a vendor that could take responsibility for the entire operation.
Weber Marking Systems Inc. (Arlington Heights, IL) worked with Dade Behring to install a fully integrated print-and-apply system that upgraded the firm's labeling and production capabilities. The system includes a 10-ft custom conveyor with Weber's Label-Aire Model 2138 printer-applicator, a wipedown station, an automatic rejection area, and Windows labeling software. The high-speed printer-applicator incorporates a thermal-transfer print engine with a tamp-blow applicator that prints and applies labels at a rate of 5 in./sec.
After the reagent cartridges are filled, labeled, and individually wrapped, an operator places them into cartons and manually places each carton onto the conveyor. An electronic eye signals the printer-applicator and triggers the applicator pad, already staged with a printed label, toward the product. The pad extends to within 0.25 in. of the carton and blows the label onto it without contact, with a placement accuracy to ±0.03 in. The applicator applies only half the label to the carton's top, leaving the other half hanging off the end until it reaches the wipedown station, where a brush affixes it to the carton's side.
The new system, which Feeley says paid for itself within a year, meets Dade Behringï¿½s other goals, too. It applies labels consistently and has improved print quality, reducing the number of rejected cartons.