Ready for PUR Perfect Binding? - Here’s Your Checklist

An email dropped into my Inbox titled “Blog” a few weeks ago. It turned out to be from Bob Hamilton of Premier Packaging Solutions in Chattanooga, Tenn. Premier is a supplier of adhesives and support supplies to the packaging and bookbinding industries.

It turns out Bob is also a blogger. So, I dialed him up a week ago and we had a nice, long conversation. Bob supplies adhesive technology for perfect binding to many printing and finishing firms. Bob also reported that he has discovered an amazing array of small- to mid-sized firms that are perfect binding books. And, with the variety of small- to mid-size perfect binders on the market, it would seem fairly easy to begin binding books. But firms like Bob’s have a depth of expertise in adhesive technology, and that information can help you produce high-quality books from the get-go. PUR (polyurethane reactive) adhesive has made tremendous inroads in bookbinding, and for good reason. It can be used for all kinds of digitally-printed substrates that might cause problems when using EVA hot-melts. It is almost impervious to high heat and humidity, the page pull strength is amazing and it’s got great lay-flat.

But PUR cures by reacting with moisture in the atmosphere, so once heated for use, there are all kinds of items to be paid attention to. PUR can be applied to the book block via an open glue pot, or with a nozzle extrusion system. Whichever application system you use, there are cleaners and lubricants that are necessary helpers. Here’s a short list provided by Bob:

#1: Use a great PUR: A no brainer, use the best PUR adhesive you can find.

#2: Don’t forget the cleaner: Areas of the glue pot or perfect binder will accrue a build-up of PUR. These must be cleaned regularly to keep your binder operating efficiently. An organic citrus cleaner does not have any solvents and it does a great job of getting PUR off of the equipment.

#3: Use a coating agent: Bob recommends a product called Frekote, which comes in spray bottles and creates a thin coating that looks and feels like Teflon. Using Frekote in the bottom of the glue pot when the pot is empty will extend its life by creating a thin film where there are scratches or nicks. When sprayed on the binder rails, it will also help the product move more easily.

#4: Use a PUR-specific cleaner for the application systems: A top-rate PUR cleaner should be used for application equipment, melting pots, nozzle systems and any equipment that is used for PUR adhesive applications. A good cleaner will convert the reactive components of the polyurethane hot melt adhesive and takes them from the tank to keep it clean, and to rule out further cross-linking processes.

#5: And, finally, lube it!  Use a high-quality synthetic lubricant that’s based on mineral oils and is free of any alkaline soap or fatty acids. A moisture-free grease is critical when interacting with PUR adhesives.

If you’d like to see the full range of PUR-specific products (and Bob’s blogs on adhesives and binding) go to www.premierpacks.com   My thanks for Bob’s email!