Sino-adhesive 
EN
What are you looking for?
In the packaging industry, the demand for high-performance, sustainable, and reliable bonding solutions is rapidly increasing. Reactive PUR (polyurethane) hot‑melt adhesives are emerging as a key technology for both flexible packaging and carton structures, offering unique advantages that meet modern packaging challenges.
High Strength and Durability
After application, PUR hot-melt adhesives cure through moisture reaction, forming a strong, cross-linked network. This network delivers excellent bond strength and long-term durability—ideal for packaging that needs to withstand stress during transport and storage.
Resistance to Temperature and Humidity
The cured PUR bond resists heat, cold, and moisture, maintaining integrity under fluctuating environmental conditions. This makes it especially valuable in carton sealing and high-barrier flexible packaging.
Environmentally Friendly, Solvent-Free Formulation
PUR hot-melt adhesives are often 100% solid and do not require solvents, minimizing volatile organic compound (VOC) emissions. This aligns with environmental regulations and the packaging industry’s push for green, safe materials.
Fast, Automated Application
PUR adhesives can be dispensed via automated hot-melt equipment, enabling high-speed production and efficient bonding processes without sacrificing initial tack or final strength.
Wide Substrate Compatibility
These adhesives can bond various materials such as metallized films, foils, and paperboard. This versatility supports flexible packaging laminates as well as structurally demanding carton designs.
Flexible Packaging (Laminated Films)
In flexible packaging, PUR adhesives laminate materials like PET, aluminum foil, or barrier films. Their strong bonding and resistance to environmental stress make them ideal for food, pharmaceutical, and industrial pouches.
Carton and Folding Box Packaging
For folding cartons and corrugated board, PUR provides high seal strength and structural stability. It ensures carton integrity under stacking, transport, and temperature changes.
Adhesive Selection
Choose a PUR grade appropriate for the specific packaging substrate. Key parameters include viscosity, open time, and cure speed.
Surface Preparation
Ensure substrate surfaces are clean and free of contamination. For low-surface-energy materials, pre‑treatment such as plasma or corona may improve adhesion.
Maintain optimal melt temperature for stable flow and application.
Design bead patterns (e.g., I‑bead or U‑bead) to balance coverage and prevent adhesive overflow.
Control ambient humidity for consistent moisture-driven curing.
Quality & Reliability Testing
Conduct accelerated aging tests (temperature cycling, humidity exposure, compression) to validate long-term bond performance.
Enhanced Package Strength and Reliability
PUR bonding improves structural integrity and shelf performance of both flexible and carton packaging.
Sustainability Advantage
Solvent-free PUR adhesives help reduce environmental impact, supporting sustainable manufacturing goals.
Cost Efficiency
Automated application and high bond strength reduce material waste and rework, lowering total production costs.
Competitive Differentiation
Packaging companies using advanced PUR technology can offer premium, high-performance, and eco-friendly products.
As packaging continues to evolve — driven by trends such as recyclable films, mono‑material pouches, and intelligent packaging — reactive PUR adhesives are well‑positioned to support these innovations. Sino‑adhesive is committed to ongoing R&D, developing next-generation PUR formulations with faster cure, enhanced flexibility, and greener profiles to meet the packaging industry's future needs.
