Should I bind with PUR or EVA?
It depends on the book. Choose PUR when page pull, lay-flat, coated or UV-coated stock, ink migration, or hot and cold storage matter more than glue cost. Stay on EVA or APAO for standard perfect-bind speed, jobs that ship right off the binder, and stock and inks already proven on that chemistry. Small tabletop or single-clamp binder? Cattie PUR comes in 100 g foil packs. Call 800-249-0337 for a sample matched to your binder.
Both are hot melts and both go on the spine molten. EVA (ethylene vinyl acetate) is a thermoplastic: it sets as it cools and can be re-melted again and again. PUR (polyurethane reactive) sets the same way at first, then cross-links with moisture in the air and paper into a tough, flexible film that won't melt back down. Almost every difference below comes from that cure.
PUR contains reactive isocyanate. Read the SDS before use; use ventilation and protective gear; hot melt can cause burns. Call us for data sheets
PUR vs EVA at a glance
| What matters | PUR hot melt | EVA hot melt |
|---|---|---|
| Page pull and flex | Stronger page pulls and flex than standard EVA | Good on standard uncoated stock |
| Lay-flat | Stays flexible after cure, so books open flatter and resist crack-back | Firmer spine; thicker books can crack when opened flat |
| Coated, UV, foil and film stocks | Bonds stocks that EVA struggles with; low-temp grades and primers for high gloss | Can struggle on coated and UV stock |
| Inks and solvents | Resistant to most inks and solvents that can migrate into an EVA glue line | Ink oils can migrate into the glue line |
| Heat and cold | About −40°F to +300°F (typical, grade-specific) | Can soften in heat and turn brittle in cold |
| Cure time | Handle once set; full cure typically 1 to 7 days depending on moisture, temperature and glue line | Typically ready as soon as it cools |
| Glue line | Typically a thinner film for the same bond | Typically a heavier film |
| Equipment | PUR-capable binder; sealed melter or small loads; purge at shutdown | Open glue pot; re-melt any time |
| Glue price | Higher per pound | Lower per pound |
Typical behavior, not specifications. Test on your stock and binder.
Page pull and lay-flat
PUR gives stronger page pulls and flex than standard EVA, and that counts most on heavy page counts and coated pages. Because the cured film stays flexible, photobooks, manuals and cookbooks open flatter and don't crack at the spine. Spine prep matters with both: a clean, well-roughed spine gives the glue fibers to grab.
Coated stock, digital print and inks
Coated, UV-coated, foil and film stocks are where EVA most often lets go and where binderies usually move to PUR. Digital and toner-heavy work benefits too, since PUR is resistant to most inks and solvents that can migrate into an EVA glue line. Low-temperature grades and primers are available for high-gloss stock.
Heat and cold in the real world
A manual in a hot glove box or a catalog in a cold container is a hard test for a thermoplastic. PUR resists about −40°F to +300°F (typical, grade-specific), so spines hold up in a hot car or a cold warehouse.
Cure time and open time
EVA is typically ready to trim and ship as soon as it cools. PUR sets fast enough to handle, then keeps curing with moisture, typically 1 to 7 days to full cure depending on moisture, temperature and glue line, with handling strength much sooner. Plan page-pull checks and stress tests after cure. We can formulate viscosity and open time for your binder.
Equipment and handling
EVA can sit in an open pot and be re-melted any time, which makes it simple to run. PUR reacts with moisture, so it is usually run from a sealed melter or premelter, or loaded only as needed, and the system is purged before PUR can cure in the tank. Purge with PUR-Purge-8530 (250–350°F) or 9006 PUR purge flake. Many small binders run both chemistries; purge PUR fully, then follow your binder maker’s changeover steps.
Cost per book
PUR costs more per pound than EVA. Because PUR typically runs a thinner glue line, the gap per book is often smaller than the price per pound suggests, and fewer returns from failed spines count too. For small shops, waste is the other cost: an opened 1 kg bag or 2 kg bar keeps reacting. Cattie PUR comes in 100 g foil packs so you open only what the run needs. Request a quote and we’ll reply with numbers.
PUR in 100 g foil packs How PUR runs on a small binder
Recycling
Hot melt spines are generally removed as a solid layer in paper recycling. PUR’s cured film holds together well and is generally considered easy to separate from paper fiber. EVA spines also screen out well when the glue line and softening point are high enough. Ask us if your customer has a recycling requirement.
What to send for a sample match
Stock (coated, UV, foil), binder make and model, speed, spine thickness, how many books you run in a typical week, and the failure mode (page pull, crack-back or heat). Cattie Adhesives makes industrial adhesives in Quakertown, Pennsylvania, and has served industrial adhesive buyers since 2001. Our chemical engineers and adhesive specialists match the glue to your binder.
Request a sample Call 800-249-0337 Request a quote
Related
PUR hot melt · Hot melt (EVA, metallocene, APAO) · Bookbinding adhesives · How to solve bookbinding problems · How to handle reactive hot melt
PUR vs EVA bookbinding FAQ
What is the difference between PUR and EVA hot melt for bookbinding?
EVA is a thermoplastic hot melt. It sets as it cools and can be re-melted. PUR (polyurethane reactive) goes on molten like EVA, then cross-links with moisture in the air and paper into a tough, flexible film that won't melt back down. That cure is what gives PUR its stronger page pull, flex, and heat and cold resistance.
Is PUR stronger than EVA for perfect binding?
Yes, typically. Cattie PUR gives stronger page pulls and flex than standard EVA, which counts most on heavy, coated, or high page-count books. Test on your own stock and binder.
How long does a PUR-bound book take to cure?
Books can be handled once the glue sets. PUR is moisture-curing, typically 1 to 7 days to full cure depending on moisture, temperature and glue line, with handling strength much sooner. Hold page-pull checks and stress tests until it has cured. EVA is typically ready as soon as it cools.
Will PUR bind coated and UV-coated stock?
PUR bonds coated, UV-coated, foil, and film stocks that EVA struggles with. Low-temperature grades and primers are available for high-gloss stock. It is also resistant to most inks and solvents that can migrate into an EVA glue line.
What temperatures can a PUR binding handle?
PUR resists about −40°F to +300°F (typical, grade-specific). That is why PUR spines hold up in a hot car or a cold warehouse where an EVA spine can soften or crack.
When should I stay on EVA?
Stay on EVA or APAO for standard perfect-bind speed, when the job ships right off the binder, and when the stock and ink system are already proven on that chemistry. EVA can be left in an open pot and re-melted, so it is simpler to run.
Do I need a different binder to run PUR?
You need a PUR-capable binder. Because PUR reacts with moisture, it is usually run from a sealed melter or premelter, or loaded in small amounts, and purged at shutdown. A binder that only runs EVA in an open glue pot is not a match. Call 800-249-0337 to confirm fit.
Does Cattie have PUR for small binders?
Yes. Cattie PUR comes in 100 g foil packs for tabletop and single-clamp desktop binders that are set up for PUR, so you open only what the run needs. Larger lines can use cartridges, foil slugs, pails, and drums.
How do I get a PUR or EVA bookbinding sample?
Call 800-249-0337 or email sales@cattieadhesives.com for an adhesive or a sample. Tell us your stock, binder make and model, speed, spine thickness, and the failure mode. Cattie Adhesives is based in Quakertown, PA 18951.
