Fire hazards and firefighting countermeasures of polyurethane foam

Polyurethane foamYes YesIsocyanateandHydroxy compound is made by polymerization and foaming. Its thermal conductivity is only about 40% of that of cork or polystyrene foam. It has sufficient strength, oil resistance and bonding ability. It is an excellent thermal insulation material and is widely used in medical dressings and industrial environment experiments. It is used as thermal insulation material in rooms, building ventilation and air-conditioning ducts, as well as refrigeration and cold storage (rooms) in the food industry. font face=”宋体”>Polyurethane foam can also be used in buildings Insulated construction. However, if care is not taken during use, fire accidents may easily occur.

On April 22, 2000, a fire broke out in the chicken processing workshop of Fengxu Industrial Co., Ltd. in Qingzhou City, Shandong Province, causing 38 deaths and 20 injuries. The public security fire department found out that the cause of the fire was fluorescent lamp ballast. The device overheats and ignitespolyurethane foamdue to thermal insulation materials.

1, Polyurethane foam‘s fire characteristics

Polyurethane Foam is made of polyether or polyester resin as the main raw material, and isocyanate A kind of foam plastic made by quantitative mixing and foaming. Polyurethane foamparameters in thermodynamics are not mentioned in many literature materials.

1.1Test data

The Sichuan Fire Protection Research Institute of the Ministry of Public Security extracted the fire scenePolyurethane foamThe test analysis will help us fully understand Fire hazard of polyurethane foam.

The horizontal burning method is used to test the burning speed of the sample. The size of the sample is 125mm*12mm*12mm. A large amount of smoke is generated during the burning process, and There is curling, the burning length of the specimen exceeds 100mm, and the burning speed of the specimen is 256mm/min (according to GB2 408-08).

Oxygen index value of test specimen, specimen size150mm*6mm*6mm,The test result is23.4.

The specimen was subjected to thermogravimetric analysis, and the temperature rise rate was 40 ℃/min, air flow 40mdeograph”>“Regulations on the Supervision, Audit and Management of Fire Protection in Construction Projects” of the Ministry of Public Security pointed out: “Building Fire Protection Facilities and fireproof materials must use products that have passed the national product quality certification, the national nuclear production license or the national fire product quality inspection center”.

“Cold Storage Design Specifications”（GBJ72-84 span>）Article 3.3.1 stipulates: “Selection of thermal insulation materials,yi It is a refractory or non-combustible material“. Article 3.3.25 stipulates: “When both the exterior wall and the attic floor are made of loose combustible insulation materials, fire breaks should be set up at their intersections;Non-combustible insulation materials should be used as horizontal fireproof strips on each floor of the exterior wall. ”

“Code for Fire Protection Design of Buildings”(GBJ16-87) Article 7.2.10 stipulates: “Cold storage uses foam plastics and other combustible materials as walls When installing the inner heat insulation layer, non-combustible heat insulation materials should be used as fireproof strips. The fireproof belt should be set at the level of each floor board. The combustible insulation layer of the cold storage attic layer and wall should be made of non-combustible materials Separated by walls. “

“Fire Protection Code for Internal Decoration Design of Buildings”(GB50222-95) Regulations:Important public places, waiting rooms of railway stations and bus stations, theaters, auditoriums, concert halls, gymnasiums and large The interior decoration of shopping malls is prohibited from using materials that do not meet the standards of B1class flame retardant requirementsPolyurethane foam.

“Regulations on Fire Protection Design for High-Rise Civil Buildings”(GB50045-950) stipulates: “Insulation materials for pipes and equipment, Sound-absorbing materials and adhesives should be non-combustible or refractory to combustion materials”.
4, Conclusion

ForPolyurethane foamExisting fire hazards, construction units and design units , technical personnel of the construction unit and project supervision unit, as well as building fire protection design reviewers and fire extinguisher personnel of the public security fire protection agency >Polyurethane foamPotential hazards There should be a correct understanding.