specialized in R＆D, production and marketing of
exterior wall thermal insulation board
How to determine whether the qualified polyurethane insulation material
In today's insulation market, counterfeit and flame retardant B1 grade polyurethane products are flying all over the sky. How to judge whether the qualified polyurethane insulation material is the urgent need of enterprises, management departments, design units and law enforcement departments at all levels.
Now the law enforcement department has a blind spot, only the oxygen index, and does not ask whether the other data of the insulation material reaches the new national standard. Check the oxygen index before the start of construction, and only check the oxygen index after completion. This kind of “hanging a leak” type inspection makes it easy for unqualified insulation materials to be legally mixed into the market. Once serious fire hazards are exposed, there will be no accountability. Responsible for the embarrassing situation. Oxygen index is only an additional condition for the new national standard to test the combustion performance of insulation materials. The oxygen index of the new national standard flame retardant B1 must be OI ≥ 30%, but more importantly, 9 inspection items, so it cannot be equivalent to a new oxygen index. National standard.
Many enterprises have already identified the blind spot where the law enforcement department only checks the oxygen index. As long as an oxygen index can pass the detection, it can hide the flammable or combustible problem of the insulation material. This method of inverting the original makes the original energy-saving material's energy-saving advantages disappear, resulting in the insulation of the upper wall becoming like a brick without much insulation function.
Discriminating and testing is a highly professional work. According to the new national standard inspection content and project requirements provided by the National Fireproof Building Materials Quality Supervision and Inspection Center, the methods for discriminating detection are as follows:
(1) Whether there is a qualified national test report. For example, the test report produced by the National Fireproof Building Materials Quality Supervision and Inspection Center has a total of 9 major inspection items, with conclusion reports and test instructions for sample products. An irregular test report without the contents of the above test items shall be rejected;
(2) Refer to the “General Test Form for National Test Report”. The B1 grade material combustion performance test index focuses on the “burn growth rate index” in the table. Whether it can reach ≤250 W/S is the key. The “combustion growth rate index” is an international standard project for testing and testing established by the European Union. It is a mandatory standard for the actual performance of thermal insulation materials. Its scientific and technical requirements are very high. According to the information we have, the “burning growth rate index” of domestic products sent by inspection samples is generally only in the short plate between 300-900 W/S, which is less than ≤250 W/S. It is an unqualified insulation material;
(3) Review the conclusions of the inspection report, whether it is written to reach the conclusion of the flame retardant B1 level;
(4) Check the product description in the remarks column of the inspection report, whether there is a description of “the sample is on either side of the fire surface”. If there is a text in this paragraph, it indicates that the material is homogeneous according to the new national standard issued by the state. Core material testing. If there is no such text, but the words "the use of calcium silicate board (or inorganic material such as sand) as the back sheet of the sample to be sent", the material is a composite of organic and inorganic materials. material. If it passes the test report of the flame retardant B1 grade, it cannot be easily recognized as a qualified insulation material because the core material of the composite material has not been detected. The newly introduced "Code for Fire Protection of Building Design" is designed to use composite materials. It is also necessary to increase the compliance of the core material in the composite panel according to international practice. It is known that the core material of this kind of so-called flame-retardant B1 grade composite material in China is flammable B3 grade and combustible B2 grade material. It is still a banned or strictly controlled elimination product if it is produced, designed, supervised and constructed. The unit allows such unqualified insulation materials to enter the construction project and will bear all legal liabilities for the consequences.
(5) Check the bulk density of the insulation materials submitted for inspection. Testing the bulk density of insulation materials is one of the important ways to verify the material's pass or fail. The bulk density of insulation materials is an important indicator to determine the thermal conductivity, strength and dimensional stability of the sheet. The weight of general qualified insulation materials is between 48 and 60 kilograms per cubic meter, but some enterprises increase the oxygen index, add a large amount of inorganic materials, and greatly increase the bulk density of the materials, reaching more than 100 kilograms per cubic meter, causing serious damage. The physical structure and thermal insulation properties of the thermal insulation material not only lose the thermal insulation function, but also increase the quality problems such as water absorption, shelling and shedding. If the bulk density is too low, it will deform and mold.
The new national standard test content and project publicized by the National Fireproof Building Materials Quality Supervision and Inspection Center has been very clear. The reality is that many testing organizations often have the same insulation materials. The testing contents and projects issued by different testing units will be in the north, and a few testing agencies will also issue fake reports, which are said to be qualified materials, so that management departments, design units and law enforcement. The department is difficult to choose. In any case, the testing requirements and content items of the National Testing Center shall prevail. To this end, the Ministry of Public Security and the Ministry of Housing and Urban-Rural Development have clearly stated that they must strictly follow the requirements of technical norms for law enforcement testing, and must not arbitrarily interpret the normative provisions, and must not selectively implement the norms, and must not adopt any alternative means to evade the implementation of applicable norms, and must not violate the norms. If the testing unit does not test according to the new national standard, it will bear legal responsibility and lifetime responsibility.
Key technical elements of the new national standard flame retardant B1 grade polyurethane insulation material
The new national standard flame-retardant B1 insulation material is specifically referred to as “wall insulation material foam”, that is, the homogeneous core material must reach the flame retardant B1 grade, not the inorganic doping composite material on both sides. If it is an inorganic-organic composite material, its core material must also be tested by the new national standard to be qualified material. Nowadays, many inorganic-organic composite materials are precisely the flammable B2 grades that conceal the flammable B3 grade of the core material or strictly limit the use. If such materials with serious fire hazards allow legal application, the construction of our country will never be better.
The following are the key technical elements of the technical data of polyurethane bare board insulation foam technology:
The new national standard Chapter 4 "Combustion Performance Rating", Chapter 5 "Combustion Performance Grade Criterion", Chapter 6.1 "Combustion Performance Rating" is the enforcement standard, and the core of the building material "wall insulation foam" The technical elements are based on the “flame growth rate index (F/GRA) W/S), total heat release in 600s (THR600S), M)” and other 9 high-tech test items, and the combustion performance level and classification criteria. To meet the B1 level oxygen index value OI ≥ 30%; (B2 level oxygen index value OI ≥ 26%).
Why does the new national standard emphasize the need to test and identify with the "Fast Growth Rate Index (F/GRA) W/S), total heat release within 600s (THR600S), M)", etc., because the fire safety of insulation materials is only It is not enough to judge whether it can reach the flame retardant B1 level from the combustion performance. It is also necessary to further investigate the combustion performance of the thermal insulation material in a real fire. This is called "fire performance".
Taking polyurethane as an example, polyurethane is a thermosetting organic insulation material that has a carbonized layer protection in case of fire. However, the combustion performance of polyurethane insulation materials stays at the level of flammable B3 or flammable B2, and its carbonized layer function is still unable to withstand high temperature attacks and will still burn. Polyurethane can only meet the requirements of ≤250 W/S of the new national standard B1 combustion growth rate index (F/GRA) W/S), while domestic enterprises can only squat between 300-900 W/S. To the new national standard.
Nowadays, the nano-modified polyurethane insulation foam developed by the “hybrid bond” reaction can meet the requirements of ≤250 W/S in the new national standard “combustion growth rate index and other technical tests. Such products have thermal insulation and reflection. The triple function of heat and radiation protection, and at the same time, in the event of high temperature fire attack, the surface of the material instantly forms a high-strength carbonized protective layer, which protects the wall insulation material from being ablated and burned through, and suppresses the release of smoke gas.
At present, the security inspection is only a blind spot with the oxygen index as the standard. It will leave room for fraud. This is because the inorganic material is added to both sides of the flammable combustible material or a large amount of inorganic material is added, so that the oxygen index value can be pulled up easily. Through security inspections, it opens the door to enterprises that hide flammable and flammable problems. In fact, this material was banned by the Fire Department of the Ministry of Public Security in 2010. It pointed out that "the sandwich material of organic materials and inorganic materials (referred to as organic-inorganic composite materials) has become a new type of fire hazard and decided to ban it." Now it is revived, replaced with new packaging, and can pass the security check.
The organic-inorganic composite material can be measured as non-combustible grade A according to the abolished 1997 edition standard test. In the new national standard test, it can also be detected in the name of building materials, and can also obtain the B1 level report. However, the new “Code for Fire Protection of Building Design”, which was officially enforced on May 1, 2015, stipulates that the architectural design department must design the insulation performance level of the insulation material (core material) instead of the composite product, if the design department The composite material will still bear all legal responsibilities for the fire protection design, which is also the professional supervision knowledge necessary for the security inspection department. Now some enterprises have begun to come out of the misunderstanding, pay attention to the research of core material flame retardant B1 insulation materials, even if the double-sided is the color steel plate of the non-combustible A-grade steel plate, the thermal insulation core material should also use the flame retardant B1 grade material.