PUR glue

Perfect Binding: PUR Glue vs. EVA Glue

Ann O'Brien

May 19, 2022

One of the most popular ways that self-publishers, as well as publishing houses, choose to bind their books is with the perfect binding method. This type of binding can be used with softcover books, magazines, or booklets and is a popular style of binding because it creates a book spine as well. While the cover is made of a thicker construction and attached after the binding process, the interior pages of the book are bound together using strong adhesives. There are two types of adhesives used with perfect binding — PUR glue and EVA glue.

What’s in a Name: Perfect Binding

This type of book creation has an interesting name, but binding with this method is not called “perfect” because it is an ideal method. Instead, the name stems from the post-binding process. Once the book material has been sealed together with either PUR glue or EVA glue and the cover has been attached, the publisher must trim the pages of the book to create a perfectly aligned straight edge. This trimming is necessary for the printing process because a tiny amount of slippage is inevitable during the earlier stages of binding a book. And by trimming the edges after the binding, the publisher can be assured that the finished book will have a clean, straight page edge. Perfect bound books:

  • are lighter in weight than hardcover books which may cost less to ship or handle
  • have a strong binding that is very durable
  • cost less to produce than hardcover books, making them perfect for self-publishers

PUR Glue

The newest type of glue that is used to secure a perfect bound book is called PUR, short for polyurethane reactive. This adhesive has several qualities that make it stand out as a bookbinding material.

PUR does not require high heat to work. In the past, adhesives used in bookbinding needed a high heat to bond the materials together. But PUR glue does not need high heat and so the book pages will have less risk of damage when using this adhesive. Also, the bookmaking process is less challenging when large numbers of books are being created.

PUR won’t crack or melt over time. Polyurethane reactive adhesive is very stable so books made with it will stay together well. In addition, books that are made with PUR can lay flat easily without the glue cracking or breaking off with repeated use.

PUR doesn’t need a lot of glue to create a strong bond. This cost-effective glue adds less to the publishing cost making it a good choice for self-publishers.

PUR dries clear. While every effort is made during the publishing process to keep the glue off of the pages of the book, the clear drying nature of PUR makes it an ideal choice for bookbinding.

PUR glue creates a permanent bond. A supremely strong adhesive, once PUR has dried and cured the bond it creates is long-lasting.

EVA Glue

The first adhesive traditionally used with perfect bound books was ethylene-vinyl acetate or EVA for short. This hot-melt adhesive has been used for years but one of its biggest shortcomings is that it is able to be remelted when exposed to high heat because it only stays solid at room temperatures. This flaw means that books bound with EVA may potentially have bindings that loosen, shift, or even fail if exposed to high heat for long periods of time. But there are other excellent reasons for using EVA in bookmaking.

EVA is quick to set.  Unlike PUR, EVA has a fast set time because it does not require any additional chemicals or solvents to set and so it will reach the curing process earlier.

EVA does not emit any chemicals during the adhesive process. Since EVA does not emit MDI (diphenylmethane diisocyanate) as PUR does during the heating and setting process, it is safer.

EVA cures fast. For self-publishers that need a fast turnaround, using EVA adhesive will allow books to be ready sooner than those made with PUR.

EVA is inexpensive. Not only is the glue inexpensive, but bindings done with EVA also use less expensive machinery that is more common. The price difference may be passed along to the author in some cases.

Which Glue Is Best?

While both EVA glue and PUR glue are frequently used with perfect binding, many publishing companies use PUR adhesives more often now. Many reasons contribute to PUR’s rise in usage over the use of EVA in the perfect bound book process, but each type of glue is good for specific reasons.

PUR is best for

  • Durability – Once PUR adhesive is set and cured, it is unlikely to melt, fail, or break.
  • Flexibility – Bindings made with PUR adhesive are able to bend and flex without cracking or breaking. Books with PUR can also lay flat more easily than books made with EVA as a result.
  • Accommodating – Books that use PUR can bind a large variety of materials in addition to paper, including paper stocks that are varnished, UV-coated, recycled, and others.
  • Heat Resistance – PUR adhesive does not remelt at high temperatures or crack when very cold. This means that storing completed books is easier to do with PUR bindings without fear of slippage or damage to the binding in locations without temperature controls.
  • Volume of Adhesive – PUR uses less glue than EVA in the binding process.

EVA is best for

  • Cost – The adhesive used with EVA is less expensive than PUR bindings and so the overall binding cost is reduced for self-publishers.
  • Speed – Ethylene-vinyl acetate cures quickly so bookmakers or self-publishers that require a short timeline will use EVA glue.
  • Publisher’s Cost – The process for using EVA requires less expensive machinery. Some publishers like EVA because it keeps their in-house costs down with the machine cost as well as the lesser amount of maintenance that machines that run EVA need as well.

Why Is PUR Glue Popular?

For most publishers, PUR glue is the most popular adhesive choice for perfect binding. Not only is it extremely strong, it also provides a robust connection between the papers and the cover of a book. Bookmakers do not have to worry if the glue will melt, shift, or bleed out onto the book itself. Books made with PUR adhesive can be stored or shipped under virtually any conditions without having to make special provisions for extreme temperatures.

The publishing process uses less glue than with EVA and even though EVA cures faster than PUR does, books that have been set and cured with PUR are more reliably bound. Since PUR dries clear, bookmakers and self-publishers don’t have to worry about the glue being visible on a book if some of the glue does shift from the binding area. Books that use PUR are stronger and more long-lasting than EVA-made ones due to the composition of the adhesive.

Getting Your Perfect Bound Book Published

Authors who are considering self-publishing their book, booklet, magazine, or another project with a soft cover often begin by choosing a reliable publishing company to work with. Publishing Xpress has been helping authors bring their books to print and is an expert in using the perfect bound process and digital printing.

Most of the time, PUR glue will be used with perfect binding but a few exceptions may require the use of EVA. For example, if a finished book is smaller than 5 x 7 inches or the book has very few pages, the binding machine with EVA will have to be used to accommodate the book itself. Books that need to be shipped immediately also will use EVA glue, since it sets and cures quickly enough to ship finished books out right away.

If you are ready to get started with Perfect Binding your project, contact the expert bookmakers at Publishing Xpress to get started making your authorship dreams a reality with your own self-published book.

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