hot melt adhesives often look similar in a tank or a glue stick, but the base polymer makes a measurable difference in how the glue runs on equipment, how clean the application stays, and how stable the bond remains over time. Two of the most common chemistries are EVA and PO hot melt glue. HUACHUN manufactures both families in multiple formats, so you can match adhesive behavior to your line speed, substrate mix, and end-use expectations.
EVA stands for ethylene vinyl acetate. EVA hot melt is widely used because it is forgiving on different substrates and is typically cost-effective for general production. In many packaging and assembly processes, EVA is selected when you need fast grab, broad compatibility, and an adhesive that is easy to tune by adjusting tackifiers and wax systems.
Typical processing data you will frequently see for EVA hot melt includes:
Application or melt temperature around 350°F
Viscosity commonly in the 900 to 3,000 cP range at 350°F
Open time often ranging from 5 to 60 seconds depending on formulation
These ranges are not universal for every grade, but they are useful benchmarks when comparing EVA to PO on the same equipment.
PO hot melt glue refers to polyolefin-based hot melts, commonly including polyolefin elastomer systems and related polyolefin families used for hot melt adhesive formulation. PO hot melts are often chosen for cleaner running behavior and better thermal stability in the tank, which helps reduce issues like char, gel formation, and odor on continuous lines.
A practical processing reference often cited for polyolefin hot melt is:
Typical temperature window around 160 to 200°C, depending on grade and application method
| Comparison point | EVA hot melt glue | PO hot melt glue |
|---|---|---|
| Substrate versatility | Often bonds well to many common materials and paper-based packaging | Often performs strongly where cleaner application and stability are priorities |
| Thermal stability in tank | Can be stable, but long high-heat dwell time may increase degradation risk | Typically designed for stable viscosity and lower gel or char formation on running lines |
| Odor and appearance | Can be more noticeable in odor and may show more color shift depending on formulation | Frequently positioned as reduced odor and cleaner-running for production environments |
| Process window | Commonly applied around 350°F, with wide viscosity options | Commonly applied in the 160 to 200°C range, tuned for steady output |
| Value logic | Often selected for cost control and broad use | Often selected for uptime, cleanliness, and stability benefits |
If you are deciding purely by chemistry, the best answer is the one that reduces your total production loss, not the one that looks cheapest per kilogram.
EVA is usually a strong choice when:
Your substrates change frequently and you want a versatile baseline adhesive.
You need a wide range of viscosities to suit different nozzles, bead patterns, or glue stick usage.
You want a cost-controlled option for steady daily output.
PO is usually a strong choice when:
You run long shifts and want fewer issues tied to tank dwell time, char, or gel.
You want reduced odor and more stable processing behavior for cleaner operation.
Your process requires stable viscosity and consistent bead control at speed.
Many “adhesive failures” are actually temperature control or application control issues.
Control pot temperature and hose temperature as a system. Hot melt needs enough heat to flow, but excessive heat and long dwell time can accelerate breakdown and create deposits.
Match open time to line speed. If the adhesive skins too fast, you lose wetting and bond area. If it stays open too long, you risk creep and misalignment. EVA open time can vary widely by grade, so select using your real takt time rather than guesswork.
Measure viscosity behavior at your true running temperature. Comparing datasheets at different test temperatures leads to wrong conclusions. Use your actual setpoints and confirm bead shape and wetting.
From a manufacturing perspective, adhesive performance depends on consistency. HUACHUN was founded in 1998, focuses on environmentally friendly hot melt adhesives, and emphasizes strict testing procedures for stable quality.
Capabilities that matter when you are qualifying EVA vs PO:
30,000 square meters facility scale supporting stable production planning
Monthly capacity around 2,000 tons to support wholesale supply and ongoing replenishment
Product formats including glue sticks, blocks, and pellets, with EVA and PO categories available for different process needs
If you are building an OEM/ODM adhesive plan, the most efficient approach is to define your substrate list, line speed, application method, and temperature limits first, then shortlist EVA and PO grades by open time, viscosity at your running temperature, and tank stability targets.
Not always. EVA often bonds extremely well across common packaging and assembly materials, while PO is often selected for stability and cleaner running. Final bond quality depends on grade selection and process control.
Often yes, but you should re-check temperature setpoints, bead pattern, and open time fit. Polyolefin ranges are commonly referenced around 160 to 200°C, while EVA benchmarks are often referenced around 350°F, so your setpoints may shift.
Run a controlled trial measuring stringing, wetting, set time, deposit formation, and bond retention after heat exposure. Tank stability and cleanliness over a full shift is where the EVA vs PO difference often becomes visible.
