Slow curing of polyurethane foam (gel reaction lag) is usually caused by imbalance in raw material formulation, improper process conditions or external environmental interference, which needs to be analyzed from the perspective of chemical reaction kinetics and thermodynamics. The following are the specific reasons and corresponding solutions:
Precisely control the proportion of various raw materials according to different refrigerator models and thermal insulation requirements to ensure the optimal performance of the polyurethane rigid foam. Generally, the optimal formula is determined through experiments and experience. For example, the molar ratio of polyol to isocyanate is usually between 1:1 and 1:1.5, the amount of blowing agent is generally about 10%-20% of the polyol amount, and the amount of catalyst is adjusted according to the reaction rate and foam performance requirements.
The polyurethane rigid foam refrigerator process mainly refers to the use of polyurethane rigid foam as a filling material during refrigerator manufacturing to enhance the refrigerator's thermal insulation performance and energy-saving effect. Here is a detailed introduction:
In recent years, there has been a black technology on the market that is known as the strongest black technology in the coating industry - polyurea waterproof coating, many people are curious, what is polyurea? What is the power of polyurea, and what are the advantages compared with other waterproof materials?
Polyurethane rigid foam is a kind of foam plastic formed through a rapid chemical reaction between blended polyol and isocyanate mixed in a specific proportion. How to control the quality of rigid PU foam ? Let’s take a look from three aspects.
Water-based foaming materials play an important role in improving the performance of the whole vehicle such as heat preservation, vibration reduction, environmental protection, sealing, anti-corrosion, and fuel saving, and will have epoch-making significance for the improvement of the technical level of the entire Chinese bus industry.
With the polyurethane high resilience foam process, the foaming technology is becoming more and more perfect, and more and more people pay attention to the reboundrate of foam.
In mine and tunnel operations, a wide variety of problems are often encountered, with water leakage being the most common. With the R&D and development of polymer materials, polyurethane two-component organic water-blocking materials have attracted more and more attention.
Rigid polyurethane (PU) insulation is a polymer made by reacting isocyanates with polyols. Due to its good thermal insulation performance and excellent waterproof performance, it is widely used in external wall insulation, roof insulation, and thermal insulation of special parts such as cold storage, grain depot, archives, pipelines, doors and windows.
Polyurethane flexible foam has gained widespread application for its exceptional rebound performance, whether in furniture cushioning, car seats, or sports equipment. So, what factors influence its rebound performance? Let's have a look.