Gluing--Sticking With Direct MailMarch 1999
At Rickard Bindery, most of the remoist glue jobs are done in-line with other binding processes. For example, operators may apply remoist glue, stop-perforate the sheet, apply seam glue to form a pocket, fold it (barrel folds, accordions and gatefolds), apply wafer seals, slit it and keep the job in mail-sort order—all in-line.
Needless to say, in-line production greatly reduces turnaround times and cost, making non-heatset web and sheetfed companies competitive on many jobs. Regardless if the piece is a self-mailer, or will be bound into another product, in-line production is a good value.
Rickard Bindery, for example, frequently does remoist jobs ranging in quantity from 5,000 to 200,000 pieces, or even more.
Extrusion remoist glue jobs can be fed from cut sheets, fan packs or rolls. Occasionally, a call comes in from a frantic web printer whose remoist glue doesn't work for some reason. Recently, Rickard saved a 1-million-piece job for a company that ran the job without noticing that the glue strip was missing.
The Key Factors
The five key factors of successful remoist glue application are: paper, glue, ink, coatings and atmospheric conditions. Let's take these one at a time:
- Paper. Knowing the characteristics of the paper is important. Remoist glue rests on the surface of enamel stock, yet is able to create a good bond when moisture-activated. Uncoated stock also generally works fine, but will normally require a heavier line of glue, since it is more porous and some will seep into the sheet.
- Glue. Understanding the difference between water-soluble and hot melt glue is important. Ask the bindery which glue it intends on using for the project and why.
- Ink. Generally, remoist glue can be applied over ink with fine results, but problems may occur when activated glue needs to adhere to paper with 100 percent ink coverage. Be safe and plan the artwork so that remoist glue doesn't require adhesion to heavy ink solids.
- Coatings. Remoist glue doesn't adhere to paper coatings such as varnish. If flood varnishing is planned for a sheet, change the design to spot and knock out varnish from where the remoist strip is to be applied and adhered.
- Atmospheric conditions. In high humidity areas, it's essential to apply water-soluble remoist glue in a climate-controlled environment. Regardless of glue type, be safe and include a moisture-absorbing packet in each box. These packets draw moisture out of contained areas and prevent remoist glue from unintentionally bonding.
Even perfectly manufactured remoist glue products sometimes will unintentionally bond inside a hot truck, so all preventative measures should be taken.
If a form with side-by-side envelopes is being used, don't have the glue strips rest against each other as they're coming off the machines. Unintentional adhesion can occur when glue strips are directly in contact with each other face to face, especially during shipping. Staggering designs so that glue strips avoid contact with each other is a much better way to plan a job.
Avoid flatbed trimming after remoist glue application because it may cause a series of three problems.
First, productivity will decline because sheets will have to be cut in very small lifts in order to clamp properly and not tear, due to inadequate clamp pressure. Second, glue bulk will raise a bump in each lift, resulting in the top sheets being longer than the bottom ones after trimming. Third, cutting through remoist glue wreaks havoc on knives, especially those super-hardened for long life.
Remoist glue makes many direct mail programs better. Printed pieces, which incorporate easy response mechanisms, are more effective than those without.
The bottom line is that remoist glue makes these response mechanisms easy and quick to use.
About the Author
Jack Rickard is president of Rickard Bindery, president of the Printing Industries of Illinois and Indiana, and a former president of the Binding Industries of America. Rickard Bindery specializes in discovering solutions to challenging bindery jobs. He can be reached at (800) 747-1389.