Handle With Care
Traditionally, bookbinding has been a relatively simple operation. But, as in many industries, competition has become fiercer than ever. For many book manufacturers, this competition launched a race to apply quality manufacturing methods and standards, such as Lean or Six Sigma, to the bookbinding operation in order to reduce waste and working capital, increase inventory turns, or improve productivity.
Ironically, while great progress has been made in decreasing turnaround time from publishing to book delivery, several book manufacturers report increased numbers of rejections due to poor quality, despite advanced manufacturing techniques. And as every book manufacturer knows, a 'good' book is one that doesn't come back.
Many quality gurus lack a proper understanding of what happens to cover board during a bookbinding operation. Since cover board is a natural fiber, it responds to natural elements—particularly moisture—in different ways. For example, "cover curl" occurs when the covered panel of a case-bound book does not remain flat, and it's a major issue in cover quality.
Cover curl typically increases during dry, winter months. Modifying your standard approaches to manufacturing during the winter months might help control cover curl and increase overall throughput.
CURING CURL
In cold, dry weather, manufacturers need to compensate for lower humidity, but often don't. Cover board typically loses some of its internal moisture as the air becomes drier. This is evident when the top board units of an opened pallet start to curl upward in a cross-grain direction. The curling effect is natural with cellulose fiber, but sometimes leads to feeding difficulties on the case-maker.
When board is delivered from a cold warehouse or off the back of a truck, it needs to be acclimated to the manufacturing environment. Here are some questions you may want to ask your binder:
1 Does your binder store board in an environment similar to the manufacturing area?