The development trend of PU rigid foam
After decades of development, polyurethane materials have covered all aspects of production and life, but there is still a broad space for development in the future.
Rigid foam is the largest single application form of polyurethane material.
In the field of building insulation materials for exterior walls, the proportion of polyurethane rigid foam in my country is 7%, while that in the United States is 65%, and there is still a lot of room for improvement. Secondly, the rapid development of my country's cold chain logistics will bring greater demand for rigid foam.
Refrigeration equipment for household appliances and food industries
PU rigid foam is the most ideal thermal insulation material for freezing and refrigerating equipment, and can achieve ideal thermal insulation efficiency.
Refrigerators and freezers that use PU rigid foam as the thermal insulation layer have a thin thermal insulation layer. Under the same external dimensions, the effective volume is much larger than when other materials are used as the thermal insulation layer, and the weight of the electrical appliance is reduced.
PU rigid foam is also used in the manufacture of portable incubators for transporting biological products, medicines and foods that need to be kept warm and fresh.
The freezers and large-scale cold storages of marine fishery, meat and other food processing industries also use polyurethane foam plastics as insulation materials, and are mostly assembled with rigid foam metal sandwich panels, which are convenient and fast.
Industrial Equipment and Pipeline Insulation
Many brewing, chemical, storage and transportation enterprises have different heat and cold insulation, etc. PU rigid foam is convenient for construction, hygienic, and has excellent thermal insulation effect.
Storage tanks and pipelines are commonly used equipment in industrial production, and are widely used in petroleum, natural gas, oil refining, chemical industry, light industry and other industries.
As a pipeline insulation material, PU rigid foam is widely used for thermal insulation of pipelines in crude oil transportation pipelines and petrochemical industries. It has replaced materials with high water absorption such as perlite.
The hot water pipes of central heating projects in cities and factories generally use PU rigid foam as the thermal insulation material, which requires long-term resistance to 100°C, and the main pipe requires resistance to 130°C or even higher temperatures. Some high-temperature resistant PU rigid foam products have been used. developed for such use.
Building Materials
Housing construction is one of the most important application fields of PU rigid foam.
In the United States and other countries, PU rigid foam for construction accounts for about half of the total consumption of rigid foam, which is more than double the consumption of rigid foam such as refrigerators and freezers.
In my country, rigid foam has been widely used in thermal insulation and waterproofing of roofs of residential and office buildings, thermal insulation of walls, thermal insulation materials of cold storages, grain depots, etc.
PU rigid foam board can be made into various foldable mobile houses, which can be used as temporary houses in the field. Water conservancy facilities such as concrete dams need to take thermal insulation measures during construction in cold winter, and PU hard foam can be sprayed on the new concrete surface as an thermal insulation layer.
Transportation and Aquatic Materials
PU rigid foam is currently widely used in automotive headliners and interior parts. It used to be a composite of fabric or polyvinyl chloride film and polyurethane soft foam. At present, PU rigid foam material is basically used.
Rigid polyurethane structural foam is used in a variety of automotive components such as door panels, trunk lids, engine covers, and more. The elastic polyurethane semi-rigid foam is used as a shock absorber part for automobiles. The train car adopts PU rigid foam for thermal insulation, and the effect is remarkable.
PU rigid foam is also used as thermal insulation material for refrigerated trucks, refrigerated containers, etc., which can ensure that the temperature of frozen food is within the required range during long-distance transportation. It can also be used as a thermal insulation material for air-conditioned cabins.
In the frozen soil areas of Qingkang Highway and Qinghai-Tibet Railway in my country, rigid polyurethane foams have been used as roadbed insulation materials. There are two construction methods for the application of rigid polyurethane foam on the roadbed: the laying and sticking of the board method and the on-site spraying method.
Military and Aerospace
Polyurethane foam can also be used as the matrix of absorbing materials in echo-free anechoic chambers, and is often used in national defense and related research fields.
Polyurethane foam absorbing materials can also be used on the fuselage and wings of stealth aircraft, and can be used to build echo-free boxes to cover reflective objects in the test environment, such as radar antenna bins, antenna brackets, turntables, test stands, etc.
Polyurethane foam is also used as a camouflage material for military facilities, which can simulate the natural surface state and achieve the camouflage purpose of "concealing the truth and showing the false".
PU rigid foam is also used as a thermal insulation material for aerospace aircraft and the like. PU rigid foam has excellent temperature resistance, cold resistance and thermal insulation performance in the temperature range of -45~100 °C, and is very suitable as a thermal insulation material in the aerospace industry.
