The Binding Edge
Perfect binding is an economical, attractive way to present information in a bound book format with both short and long runs. Once looked at as a binding method for thick books or publications only, perfect binding equipment can now work with minimum page counts as low as 24 and thicknesses as small as 1/16 of an inch. This, coupled with advancements in equipment, has caused perfect binding to become a popular option. However, it doesn’t come without challenges.
Knowing where the potential problems lie can help operators allow extra time for set-up or run-time difficulties; and can help customer service staff and sales teams guide the customers in creating appropriate expectations.
The Binding Edge contacted three companies for insights on the challenges in perfect binding. Contributors include Jody Harrison, product manager of book and publication binding, Muller Martini; Jim Kaeli, division manager of book and publication binding, Muller Martini; David Young, Technical Sales, Deluxe Stitcher; and Don Dubuque, Marketing Manager, Standard Finishing Systems.
Question: What challenges are there when doing layouts for perfect binding jobs? How are they overcome?
There are some things that are just understood when it comes to layout for perfect binding jobs. Page counts must be divisible by four. Binding on the landscape side can cause problems with certain machines. Glue adhesion is generally best if the product doesn’t have a spine of more than three inches.
One of the most common challenges with layout comes when there is a read-across section (where the image must align across two consecutive pages), particularly if they are in two different signatures. It is recommended to try to avoid this if possible by working with the layout and moving pages so the read-across falls in the same signature.
Also, when you are working with gate folded pages and the image on the gate is the same as underneath (or similar), very accurate folding is required.?If this takes place, it is best to try to ensure that the margin area where the match must be made does not have very precise tolerances, since there would be detailed images or print that would clearly show off-fold register. Paper grain is another key to successful perfect binding. Cross-grain pages can cause waves or cracking at the spine, or reduced spine strength. Less paper fiber also is exposed during milling, leading to less-than-optimal glue adhesion. Again, working with this during the layout stage can help decrease a lot of problems during the perfect binding process.
Question: What difficulties arise when a binder needs to accommodate a customer’s request for inserts? (CDs, pull-outs, etc)
From the point of view of layout, the location of the insert in the book can create issues, and the type of carrier can create a “hard to bind” situation. It is suggested to avoid the placement of multiple inserts in a book in the same relative location since that creates significant localized buildup of thickness.
In addition, when running inserts or “gimmicks” (as they are sometimes called), much more time and effort is required to get a machine ready to run. There is usually a pre-determined slow down percentage allowed for the production run, including more time to ramp up to an acceptable running speed. This makes production numbers much harder to reach. Each machine has certain limits of what type of paper, cards, CDs, etc., that it will run, and more and more printers are accepting difficult work. Every printer wants to make the customer’s advertisement look unique, and the customer continues to push the envelope so its advertisement stands out in a book or magazine, making more modification and adjustments to the perfect binding process necessary.
Question: How does stock thickness / spine thickness affect the way a perfect bound job is done?
Stock thickness can greatly affect the run speeds of the machine used to produce it, with thicker books requiring slower speeds and greater accuracy in setting up the trimmer. Thicker paper stocks usually run a bit easier, but the machine requires more workers to keep it full as it can run out of stock much faster. This may not be an issue for shorter runs, but thicker paper can certainly add time and cost to larger runs.
Generally, the spongier the stock, the more of a challenge it can be to perfect bind as it does not compress well unless under pressure (in a clamp for example). For thicker products, this can be an issue and cause multiple passes on the perfect binder. It is recommended to consider this when selecting the paper stock and avoid the more spongy stocks for thicker books or publications.
Question: When are glue adhesion issues most likely to occur?
Referring back to the previous question, stock thickness also affects adhesive selection. Heavyweight coated stocks will make using a PUR adhesive more attractive. PUR adhesives are many times more costly, but may be necessary for certain applications. In addition, cross grain signatures can cause adhesion issues, and other issues can be caused when printers/designers do not allow for the proper masking off of the spine area on covers when varnishes and heavy ink coverage is being used. This refers back to the first question where these issues can be avoided if the layout is properly done.
Stock or covers with slick coated surfaces make surface adhesion of the adhesive more difficult as well. Often, running a quick binding test will determine if the paper will need extra attention.
Question: What benefits does automation bring to perfect bound jobs?
Automation in perfect binding equipment is driven by a decline in run lengths, quicker turnaround requirements, and the need to easily train workers. As run lengths get shorter, set-up time becomes a bigger percentage of total job time, driving up labor cost per unit produced.
In addition, short production runs leave little margin for error or on-the-fly equipment adjustments. That’s where new software makes a difference. Touchscreen technology guides equipment operators through each step of the setup procedure, reducing the likelihood of waste due to errors. Advanced automated systems deliver shorter set-ups, less set-up waste, and faster turnaround, which translates into higher profits.
With today’s run lengths becoming shorter and shorter, binderies and printers must look at newer, more automated equipment to decrease downtime and set-up time from job to job.