In the production of flexible packaging lamination, both solvent-free and solvent-based polyurethane laminating adhesives have their own advantages and disadvantages. Simply comparing the unit prices cannot truly reflect the production costs. From the perspectives of comprehensive consumables, energy consumption, operation and maintenance, and environmental protection investment, the cost structures of the two types of adhesives are significantly different, directly affecting the overall profit level and production capacity layout of the factory.
The unit price of solvent-based adhesives is relatively low, but the solid content is mostly around 50%, with a low proportion of effective components, and the amount of dry adhesive coating materials required is larger. At the same time, a large amount of ethyl acetate is needed for dilution during production, and the costs of solvent procurement, storage, and waste liquid treatment are high. Moreover, the drying tunnel operates at high temperatures for a long time, resulting in high energy consumption, equipment depreciation, and waste gas treatment operation costs. The overall hidden costs are relatively high.
The initial purchase unit price of solvent-free polyurethane adhesives is higher, but with 100% solid content and no solvent addition, the coating effective utilization rate is extremely high, and the unit production adhesive consumption is significantly reduced. Production does not require a drying process, and the energy and waste treatment costs of the drying tunnel can be saved. The production line speed is faster, the production capacity is higher, the labor and equipment amortization costs are lower, and there is no residual solvent, with very little rework loss.
Overall, small-batch, low-grade packaging is more cost-effective when using solvent-based adhesives. For large-scale, large-scale, and high-end food packaging production, solvent-free adhesives have lower comprehensive costs and better compliance. Enterprises can flexibly select models based on product structure to achieve a balance between quality and cost.
