Prevention and emergency measures of polyurethane foam fires

Polyurethane is called polyurethane. The foam made of this material has very good ‘s insulation, heat preservation and sound insulation properties. Polyurethane foam plastic, commonly known as sponge plastic（ hereinafter referred to as polyurethane foam）, is a best-selling product widely used in production and life. So how do we prevent polyurethane foam fire? Today the editor will bring you some relevant knowledge, let’s do it together Take a look!

1. Fire hazard

The finished polyurethane foam is porous It is a solid with poor thermal conductivity and can easily cause heat accumulation. The flash point of rigid foam is 310℃, and the auto-ignition temperature is 416℃. Every 1 kmol of foam burned can release 3073.53KJ of heat. Finished products without flame retardant treatment,The oxygen index is around 20;The flame retardant treatment is between 23～27, Individually it can reach around 30. Thermal degradation occurs at 200°C, releasing low-molecular substances such as CO and alcohols.

For flexible polyurethane foam, according to the measurement results of differential thermal analysis of fire hazard parameters, its initial decomposition temperature is above 260℃, its violent decomposition temperature is 280℃, and its auto-ignition temperature is 330℃ Above, it is easy to cause spontaneous combustion and decomposition combustion. After burning, it will decompose to produce highly toxic gases such as hydrogen cyanide and carbon monoxide, which can cause poisoning and death in a few seconds after inhalation. In addition, burning produces a large amount of smoke, reducing spatial visibility and making people lose their ability to escape.

II. Fire characteristics

Foam fires have different and unique characteristics compared with other combustible solid fires. Mainly manifested in:

1 , Easy to produce smoldering

Experiments have proven that some standard specifications of polyurethane foam can smolder even when stored alone. Soft polyurethane foam produces smoldering fire in still air The temperature does not exceed 400℃, and the smoldering time can last for several hours. Smoldering of rigid polyurethane foam only occurs on the surface, smoldering蕞The high temperature is aboutAround 500℃.

2 , Burning�, mixing time, polymerization temperature and other process conditions. In particular, it is necessary to grasp the ratio of toluene diisocyanate and water, as well as the amount of active catalyst added, and adjust the stirring mode or speed in a timely manner to ensure uniform mixing.

2 , Carry out flame retardant treatment to reduce fire risk.

Use inert gas to launch the cannon (Pour nitrogen, etc. into the reaction Inert gas), which can not only keep the reaction process under safe protection, but also achieve timely fire extinguishing and increase the flame retardant performance of the foam. Adding flame retardants is also a good way to improve the flame retardancy of polyurethane foam. There are mainly two types: reactive type and additive type: reactive type is made with polyurethane foam containing P, N, X >（halogen) and other polyols react with isocyanates, Directly prepare flame-retardant polyurethane foam;The additive type is a flame retardant（Halogen-containing phosphate esters, halogen-containing phosphite esters, halogen-containing compounds, halogen-containing ammonium phosphorus compounds, etc.）Direct Add it to the reaction system to make the flame retardant evenly dispersed in the foam. In addition, smoldering inhibitors of inorganic salts can also be added to the foam to prevent smoldering in storage.

3 , Reform technology and develop flame-retardant foam plastics.

We should overcome the imperfections in the current production technology and equipment and strengthen蕞Best matching ratio,蕞optimal aggregation conditions, 蕞Research on the best mixing method, reform the process and equipment, make it reliable in control, safe and easy to operate.

4 , Use reasonably to reduce fire hazard.

For equipment or buildings that use foam plastics for insulation and decoration, their appearance should be attached with a protective layer to increase fire resistance and flame retardancy. The author believes that polyurethane foam with smoldering and self-igniting characteristics is not suitable for use in the insulation of fire-hazardous production equipment and the interior decoration of aircraft, ships, vehicles and buildings.

Four. Summary

Polyurethane foam fires are frequent fires, causing great harm and losses, and are difficult to put out. In addition to the fire hazards of raw materials and finished products and the unique characteristics of fires, the causes of fires are also important factors such as insufficient understanding and poor supervision and management. Therefore, we should strengthen research on fire hazards, raise awareness, reform processes, develop new flame-retardant foam plastics, and formulate special fire supervision and management regulations and methods as soon as possible so that supervision can be followed and management is well-founded.

Well todayAuthor. I hope it will be helpful to everyone. If you like it, remember to share it with your friends.

The title of this article: Prevention and emergency measures of fires caused by polyurethane foam

The origin of this article: http: //www.wellgo.com.cn/newb/information_2406.shtml

There are rules to follow and management is based on evidence.

Well todayAuthor. I hope it will be helpful to everyone. If you like it, remember to share it with your friends.

The title of this article: Prevention and emergency measures of fires caused by polyurethane foam

The origin of this article: http: //www.wellgo.com.cn/newb/information_2406.shtml