Comparison of Advantages and Disadvantages of Single-component and Dual-component Polyurethane Adhesives

The single-component Polyurethane Adhesive is a wet-curing type. It undergoes a chemical reaction with moisture in the air or on the substrate surface to achieve curing, without the need for adding a curing agent. The construction process is simple. Its advantages are prominent: it can be used immediately after opening the container, without the need for mixing or proportioning. The operation threshold is low, making it suitable for on-site construction, manual coating, and large-scale applications. It has stable storage properties, a mature formula, and is less likely to have proportioning errors. After curing, the adhesive layer has excellent toughness, good seismic, impact, and fatigue resistance, and is suitable for scenarios with high requirements for deformation adaptability. However, its disadvantages are also obvious: the curing speed is slow and is significantly affected by environmental temperature and humidity. In low-temperature and low-humidity environments, the curing period is significantly prolonged; when thickly applied, the interior is difficult to fully cure, resulting in bubbles and voids; the final bonding strength, heat resistance, and resistance to media are limited, and it is mostly used for non-structural bonding. 

 

The two-component polyurethane adhesive is composed of the main agent and the curing agent. When mixed in proportion, it undergoes self-reaction and curing without being restricted by environmental humidity. Its advantages are significant: the curing process is fast and controllable, and the operation time can be adjusted through formula modification, making it suitable for industrial mass production; it can achieve complete curing of thick layers, with a dense and bubble-free adhesive layer; the bonding strength is high, and it can be used as structural adhesive, with superior heat resistance, water resistance, and chemical corrosion resistance compared to single-component; the formula has a wide range of adjustability, allowing the production of different products from flexible to rigid, and suitable for various materials and conditions. However, the disadvantages are: strict mixing ratio is required, and the mixing error will directly affect the performance; there is an applicable period after mixing, and it will lose effectiveness after expiration; tools and equipment need to be cleaned in time during construction; the construction process is relatively complex, and higher requirements are placed on equipment and operational standardization, and the cost is also relatively higher.