Welcome to the Dove Direct Print and Marketing Blog. Today's post, "The Advantages of PUR Binding" clarifies the best type of binding, why it matters, and most importantly how perfect bound books can stand the test of time. PUR is the strongest most flexible binding adhesive available and offers several advantages over other binding methods.
There are two major types of binding. First, there's the punch and bind where you create uniform holes and bind the document with either a plastic or metal coil that feeds through the holes. The second type is sort and bind which uses heat where the spine of the document is set inside of an adhesive spine that is warmed until the binding occurs.
EVA Print Binding Process Evolution
The Ethylene Vinyl Acetate binding process was the abiding standard through the mid-1990s. This traditional method dubbed "perfect binding" employed a hot melt adhesive which came to be known as EVA. The EVA glue application is performed with a glue pot via a wheel applicator. EVA glue properties provide an allowance for the glue to be re-melted several times and consequently reduces the amount of waste throughout production.
EVA also provides quick set points that reduce cure time prior to trimming. While EVA is acceptable for most offset production requirements, issues can arise in the event more complicated stocks are selected.
The EVA glue process gave way to the development of the Polyurethane Reactive or PUR as it is commonly known today. This adhesive which began in 1989 was deemed the perfect binding solution and the clear winner according to industry players. As a result, PUR adhesive has become the overwhelming preference within the binding industry. As with EVA, the PUR adhesive requires the backbone of the book preparation in similar fashion employing the use of milling knives, notching heads, roughing and equalizing heads to create fiber.
The resulting fiber is the point where PUR molecularly bonds to a surface during the curing process. In PURs early inceptions, the glue setup time in many cases was over 24 hours. PUR technology has improved over the past decade to greatly shorten that set up time to just a few hours, with current formulations attaining 80% of their green strength during that period.
PUR's glue process binds to the book via a chemical reaction. Due to the properties designed within the adhesive, moisture is drawn out of the air, thus technically producing PUR as a moisture-curing product. That is why the application technique is so critical. Top bindery vendors employ a state-of-the-art extrusion head system that applies glue directly to the spine of the book, typically with a slot applicator that sprays the adhesive evenly.
PURs Benefits
When books make their way into the hands of customers, the business, organization or author relinquishes control over how the books are handled. Pages could be tugged forcefully, or ripped in some areas, or the spine could be flexed unreasonably, or the books may be subject to extreme temperature variances, from cold-to-hot. These extreme conditions perform better with PUR binding.
Therefore, book binding comes down to choosing between Polyurethane Reactive adhesive (PUR) or Ethylene Vinyl Acetate (EVA). EVA continues to be a good general purpose adhesive, however, it is unable to bond properly to certain paper types and ink applications. Further, EVA has the reputation of failing if roughly handled or exposed to extreme temperatures. Conversely, PUR uses a molecular bond to secure both the cover and pages, which in turn produces a stronger and more flexible spine.
Demographics for Perfect Bound Materials
Perfect bound books, directories, and catalogs are in demand among a range of demographic groups. Millennials tend to prefer books and catalogs over reading book content on computer devices. Another market that reaches for perfect bound books are the high-end, luxury demographics who prefer beautiful catalogs, coffee table books, and other visual and tactile product catalogs. Lastly, the 18-to-24 age group, in general, prefers reading real books versus reading content on a Kimble or other tablet device.
That said, it makes good sense to create a solid book, catalog, or directory that can better withstand harsh treatment, which is why using PUR is the obvious choice. PUR is considered the most durable binding adhesive on the market today. When quality and durability come to mind, along with how various paper types and ink selections can be accommodated, PUR is highly recommended.
PUR can ensure the book is protected against the following challenges:
- Extreme Temperature Issues – PUR adhesive bound books can be transported virtually anywhere practically eliminating any concern. With Temperature variances from as low as -40° F or as high as 200° F, the PUR binding remains hard, flexible and intact. With PUR, fractured spines resulting from bitter cold or pages becoming loose due to intense heat are a thing of the past.
- Loose Pages – Regardless of pulling, tugging or intense handling, PUR bound book pages will prevail by being securely fastened to the spine. Moreover, it is more or less far-fetched to pull a page out of a PUR bound book. In addition, and as opposed to EVA, PUR can also adhere exceptionally well to smooth, glossy finish pages. Further, the pages of a book can be finished in a variety of gloss coatings, such as UV, varnish, or aqueous coating. Moreover, pages that contain a protective film such as laminate or mylar are also protected with the PUR adhesive.
- Spines Cracking – That intensively strong bond that PUR adhesive creates remains very pliable. PUR bound books can withstand the severity of continuous opening and closing. Finally, the flexibility of PURs adhesive averts spine cracking, particularly in the event a book is opened wide or is pressed flat when open.
If you have ever experienced a book with binding issues, such as pages falling out, or spines cracking, or unexpected results due to weather conditions, it may be time to contact a printer that has the capability to offer PUR adhesive for your next book, yearbook, catalog, program, or other document that requires perfect binding.
The Net-Net
EVA continues to be a choice for a decent general purpose adhesive, however, EVA fails to compare to PUR for better bonding of paper stocks, finishes, glossy, ink types and varnishes. After all, it's not about growing a spine, but better yet, how to protect that spine for your next valuable best seller! Thanks for reading "The Advantages of PUR Binding."
Let's have a conversation about PUR binding, direct mail marketing strategies, printing, transactional documents, variable digital printing, brand equity and unified marketing collateral during our next Open House. We invite you to join us on Thursday, April 25, 2019, for an hour or two, anytime between 9:30 am to 4:30 pm. Let us show you how to improve your document processes to optimize your workflow, reduce your costs, and maximize your organization's printing, letter shop, and mailing capabilities. Dove Direct has an official USPS certified bureau located within our offices that will save you time and money. Moreover, if you bring us your files, we will create a demo file for you. For more information, call Carla Eubanks at 404-629-0122 or email Carla at This email address is being protected from spambots. You need JavaScript enabled to view it..
Dove Direct, your Atlanta based print and mail solutions provider offers organizations end-to-end data, printing, and mailing solutions: Data Management, Variable Digital Printing, LetterShop and Fulfillment, Fully Automated MLOCR Presort Bureau, Marketing and Production Management Support and Secure Data Life Cycle Management.
If you don't want to wait for the Open House, you can reach Dove Direct today by calling 404-629-0122 or use the contact form for Dove Direct.