How to choose the right polyurethane adhesive for flexible packaging

Soft packaging polyurethane adhesives are widely used in composite packaging in fields such as food, medicine, and daily chemicals due to their strong adhesion and wide adaptability. In the face of a wide variety of products in the market, scientific selection should revolve around core dimensions such as packaging requirements, composite structures, equipment compatibility, and environmental protection and safety.

 

The core demands of the packaged products should be considered first. Food packaging should give priority to odorless products that meet food hygiene standards. For meat products and beverage packaging that can withstand high-temperature cooking, models that can withstand temperatures above 121℃ should be selected. For the packaging of liquids containing acidic or alkaline components, emphasis should be placed on the chemical resistance of the adhesive. Pharmaceutical packaging needs to strictly control hygiene indicators to ensure that there are no residues of harmful substances.

 

The composite packaging structure is a key matching factor. The requirements for adhesives vary significantly among different membrane material combinations. For common structures such as NY//PE and PET//PE, two-component solvent-free adhesives with strong versatility can be selected. PE//NY//PE co-extruded films need to be matched with dedicated products with low viscosity and high peel force. At the same time, attention should be paid to the thickness and characteristics of the membrane material to avoid affecting the firmness of the composite due to improper adaptation.

 

Equipment compatibility and technical indicators cannot be ignored. The adhesive with the appropriate viscosity should be selected based on the tension control and operating speed of the dry lamination equipment. For two-component adhesives, attention should be paid to matching the operational time with the equipment efficiency. Technically, products with moderate solid content and stable curing should be given priority, taking into account both production efficiency and cost control.

 

Under the trend of environmental protection, solvent-free polyurethane adhesives have become the preferred choice due to their zero VOCs emissions and low energy consumption. At the same time, it is necessary to verify whether the products comply with industry standards to ensure quality compliance. Only by taking all the above factors into consideration can a flexible packaging Polyurethane Adhesive with strong adaptability, safety and reliability be selected.