Your packaging line doesn't care what polymer chemistry is in the tank - until the seams open in a heat wave, or the glue chars overnight, or the PUR unit cures in the hose and costs you a full system flush. Choosing between EVA, polyolefin (PO), and PUR hot melts is mostly about matching three things: the substrates you bond, the temperatures the finished product will survive, and the equipment you're willing to run.
This guide compares the three chemistries honestly - including where each one loses - and ends with recommendations for five of the most common applications we supply.
The One-Minute Overview
| EVA | Polyolefin (PO) | PUR | |
|---|---|---|---|
| Base polymer | Ethylene-vinyl acetate copolymer | Amorphous poly-alpha-olefin (APAO) | Polyurethane (moisture-curing reactive) |
| Bond type | Thermoplastic (re-meltable) | Thermoplastic (re-meltable) | Crosslinking (chemically cures, won't re-melt) |
| Substrate versatility | Good on paper, cardboard, wood; fair on plastics | Excellent on PP/PE and coated surfaces | Excellent on nearly everything, including metals |
| Heat resistance (bond) | ~60–80°C | ~90–110°C | Up to 120–150°C after cure |
| Cold flexibility | Moderate (can embrittle) | Good | Excellent |
| Cost | Lowest | Mid | Highest (glue + equipment) |
| Equipment | Standard hot melt unit | Standard hot melt unit | Sealed system - needs moisture-free tank, purge, and special nozzles |
| Pot life / stability | Good; tolerates some overheating | Very good; low odor, low char | Limited open life once melted; must purge |
| Typical uses | Carton sealing, paper packaging, crafts | Product assembly, PP/PE plastics, diapers/hygiene, label PSA | Structural lamination, automotive, electronics, high-spec furniture |
Read the table top to bottom and a pattern appears: EVA is the economical generalist, polyolefin is the problem-solver for difficult plastics and demanding service conditions, PUR is the structural specialist that trades equipment complexity for permanent, heat-proof bonds.
Where Each Chemistry Wins - and Where It Loses
EVA: the workhorse, within its limits
EVA hot melts dominate general carton and paper packaging for one reason: cost per bonded carton. Bonding kraft paper and cardboard at high line speeds is a solved problem for EVA, and there's a mature ecosystem of grades tuned for pot stability and low stringing.
Where EVA loses:
Heat. An EVA bond softens meaningfully above ~70–80°C. A carton glued with EVA and left in a hot trailer in summer can open. If your product sees heat - or hot-fill - move up the table.
Low-surface-energy plastics. PP and PE simply don't wet well with EVA. If you're bonding plastic to plastic, this is the wrong tool.
Cold service. Standard EVA grades stiffen in deep cold; deep-freezer applications need either a special EVA grade or (usually better) a polyolefin.
Choose EVA when you bond paper to paper, board to board, at moderate service temperatures, and cost is king. Most product assembly beyond that deserves a look at PO.
Polyolefin (PO/APAO): the difficult-substrate specialist
Amorphous polyolefin adhesives bring two things EVA can't: better adhesion to LSE plastics (PP, PE, coated and printed surfaces) and a wider service-temperature window in both directions - better heat resistance up top, better flexibility down low. They also run with low odor and low charring, which matters in hygiene and sanitary product plants.
Where PO loses:
Price per kilo. PO typically runs above EVA - though always calculate cost per bonded part, because PO often achieves the same bond at a lower coat weight. (Our guide to the real cost of cheap adhesive covers this calculation.)
Some very-high-heat structural bonds. A thermoplastic is still a thermoplastic: heat it past its softening point and it lets go. For permanent structural bonds that must survive real heat, that's PUR territory.
Choose PO when you bond plastics (especially PP/PE), need wider temperature tolerance, run hygiene/sanitary products, or want a cleaner-running, lower-odor adhesive.
PUR: the permanent bond - if your equipment is ready
Polyurethane-reactive hot melts are a different animal: applied hot like any hot melt, but then cured by ambient moisture into a crosslinked polymer that will never re-melt. The result is bond strength, heat resistance (120–150°C cured), and solvent resistance that thermoplastics can't touch.
Where PUR loses:
Equipment cost and discipline. PUR needs a sealed, moisture-protected application system, tank purging, and prompt nozzle hygiene. A crew that forgets to purge on Friday buys a Monday teardown. Budget for the learning curve.
Glue cost. The highest of the three per kilo - justified when the bond is structural, wasteful when a PO would do.
Cure time. Green strength is instant (it's a hot melt), but full crosslinking takes 24–72 hours depending on humidity. Your QC schedule must account for this.
Choose PUR when the bond is structural, must survive heat after cure, or joins dissimilar materials (plastic to metal, foam to wood) where thermoplastics peel over time.
Five Common Applications - and What We'd Spec
1. Standard RSC carton sealing, ambient warehouse.
EVA, mid-viscosity, standard open time. If seams ever open in summer transit, first check application temperature and compress, then step up to a higher-softening EVA before changing chemistry.
2. Courier bags / mailing bags (PE film to PE film).
Polyolefin, low viscosity for fine patterns, fast set. This is the classic "my EVA supplier can't make it stick" application - the substrate is LSE film, and PO is the chemistry built for it. Winter-run lines should verify the grade's low-temperature flexibility.
3. Diaper / sanitary napkin / medical fixation products.
Polyolefin-based PSA (or specialized PO hot melts): low odor, skin-contact-compliant formulations, and clean running for 24/7 lines. Ask for compliance documentation matching your market - this is a case where the certificate is part of the product.
4. PP or coated-surface product assembly (appliances, automotive interior trim, foam lamination).
Polyolefin for moderate demands; PUR when the part sees heat, vibration, or structural load after assembly. The deciding question: if this bond were to soften at 90°C, what happens? If the answer is "the part falls apart," spec PUR.
5. Woodworking / furniture edge-banding and flat lamination.
PUR for water-resistant, heat-resistant permanent bonds (kitchen and bathroom furniture especially); EVA remains the economical choice for standard interior furniture where humidity exposure is limited.
Two Selection Mistakes We See Repeatedly
Mistake 1: choosing by price-per-kilo. A cheaper adhesive that needs 25% more coat weight, causes two char-related line stops a month, or fails in the field is far more expensive than the "expensive" alternative. Always compare cost per thousand parts - we walk through that math in the real cost of cheap hot melt adhesive.
Mistake 2: upgrading chemistry before checking process. Roughly a third of "wrong adhesive" complaints we investigate turn out to be application temperature, open time vs. line speed mismatch, or compress problems - see our troubleshooting pieces on label edge lifting and winter adhesive failures before you re-spec.
Frequently Asked Questions
Can I switch from EVA to polyolefin on the same equipment?
Usually yes - both are standard hot melts. Flush the system when changing chemistry, and re-check application temperature and open time against the new TDS, since set speed differs.
Is PUR worth it for carton sealing?
Almost never. Carton sealing rarely demands cured-bond performance. PUR earns its cost in structural or high-heat assembly.
How do I compare two adhesives fairly?
Same substrate, same coat weight, same temperature, 24-hour dwell - then heat-age or cold-soak both samples to your worst-case service condition. Our sample testing protocol guide shows the full sequence.
Not Sure Which Chemistry Fits Your Line?
You don't have to guess from a table. Send us: (1) what you're bonding to what, (2) your line speed and application method, and (3) the minimum and maximum temperatures the finished product must survive. Our technical team will recommend a specific grade - and ship free samples so you can verify on your own line before committing. That's how we'd want to be treated as a buyer, too.
Banglin Technical Team - hot melt and pressure-sensitive adhesive manufacturing since 2006, Hangzhou, China. EVA, polyolefin, and PUR product lines, from a single custom formulation lab.