September 9, 2026 Terrence Lewis

Jowat EVA vs PUR Adhesives Guide

1. Core Chemistry & Physical Characteristics

The primary distinction between EVA (Ethylene-Vinyl Acetate) and PUR (Polyurethane Reactive) lies in how they transition from a molten state to a permanent bond:

Performance Parameter	Jowat® EVA Hot Melts	Jowat® PUR Hot Melts
Bonding Mechanism	Thermoplastic (Physical): Solidifies upon cooling; completely remeltable when reheated.	Thermosetting (Chemical): Cross-links with ambient & substrate moisture to create an irreversible bond.
Application Temperature	190°C – 210°C (High thermal processing)	130°C – 150°C (Low thermal stress on delicate PVC/ABS tapes)
Glue Line Thickness	Standard visible glue line (~0.15mm – 0.25mm)	Micro-thin zero-joint line (~0.05mm – 0.10mm)
Moisture & Water Resistance	Moderate (Suitable for dry, interior climate-controlled environments)	100% Waterproof: Impervious to continuous steam, immersion, and humidity.
Heat Resistance (Finished Seam)	Up to ~70°C – 75°C (Can soften near ovens/dishwashers)	Exceeds 140°C: Will not remelt or creep under intense commercial heat.
Maintenance & Purging	Low maintenance; can remain in unheated pot across shifts.	Strict Purge Protocol: Must be flushed with Jowat Flushing Granules before shutdowns.

2. Application Matrix: When to Use EVA vs. PUR

Choose Jowat® EVA Hot Melts When:

Standard Commercial Casework: Producing residential closets, dry-area office furniture, retail display fixtures, and classroom storage.
High-Speed, Intermittent Runs: You need an adhesive that can sit molten in an open pot during machine pauses without skinning or curing.
Simplified Maintenance: You want a straightforward operation where operators can shut down machines at the end of the day without mandatory flushing cycles.

Choose Jowat® PUR Hot Melts When:

High-Moisture Environments: Building kitchen base cabinets (near sinks/dishwashers), bathroom vanities, healthcare lab casework, and outdoor-rated cabinetry.
Zero-Joint Aesthetic Requirements: Running high-gloss acrylic, textured melamine, or super-matte panels where visible glue lines are unacceptable to the architect or client.
High-Heat Exposure: Manufacturing components installed adjacent to commercial cooktops, radiant heaters, or unconditioned transport environments.

⚠️ Crucial PUR Purging Rule

Because PUR reacts permanently with moisture in shop air, you must never shut down an edgebander overnight or over the weekend with unpurged PUR in the pot or nozzle. Always run Jowat Flushing Granules through the dosing unit to displace reactive polymers.

3. Chemical Spray Protection for Both Adhesive Types

Regardless of whether you run EVA or PUR, preventing adhesive squeeze-out from contaminating panel faces is essential for high-speed production. An integrated Riepe® Chemical Spray System provides complete surface protection:

Infeed Protection: Riepe® LPZ II Release Agent forms an invisible barrier that stops molten EVA/PUR from sticking to the panel face.
Outfeed Cleaning: Riepe® LP163 Cleaning Agent removes residue and neutralizes static charge ahead of the buffing station.