Modified plastics refer to plastic products with improved flame retardancy, strength, impact resistance and toughness by filling, mixing and strengthening on the basis of general plastics and engineering plastics.
Among them, flame retardant resins are mainly divided into flame retardant high impact polystyrene resin, flame retardant polypropylene resin and flame retardant ABS resin. The above products are classified into different flame retardant specifications such as UL94 V0, UL94 V 1, UL94 V2, UL94 HB, etc. Compared with ordinary plastics, flame-retardant plastic products can greatly reduce the fire risk in the case of short circuit, overload and immersion.
What are the common flame retardant materials in life?
Flame retardant material is a kind of protective material, which can inhibit or delay combustion but is not easy to burn. There are solid materials such as cement, steel and glass ~ liquid materials, also referred to as flame retardants. If flame retardant is coated on the surface of various materials such as firewall, it can be ensured that it will not burn when it is on fire, and it will not aggravate and expand the combustion range. Flame retardant materials are widely used in clothing, petroleum, chemical industry, metallurgy, shipbuilding, fire protection, national defense and other fields.
What are the flame retardant plastics? Is PBT a fireproof material? What is the difference? Please answer! ! ! ! !
LS two people are talking about modified plastics, which means that the material itself may not be flame retardant, but after adding flame retardant, the material can reach a certain flame retardant level. In other words, most materials have flame retardant properties after adding flame retardant, but this should not be the answer that the landlord wants.
Fundamentally speaking, the flame retardancy of the test material depends on the extinguishing time of the material after it leaves the fire, or the burning time of the material. According to the different materials and sizes, the detection methods are also different. Of course, there are many materials that are naturally flame retardant. For example, PVC (polyvinyl chloride) will go out without flame retardant. There are PTFE (polytetrafluoroethylene), PPO (modified polyphenylene ether), polyetheretherketone (PEEK), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), polyethersulfone (PES), polyvinylidene fluoride (PVDF) and liquid crystal polymer (LCP).
The flame retardancy of PBT itself is not very good, but it can be modified with halogen-free flame retardant. The so-called halogen-free flame retardant or halogen-containing flame retardant means using halogen-containing flame retardant. Halogen-containing flame retardants generally produce toxic gases when burning, but the flame retardant effect is good and the price is low.
As for the difference you said, I don't know what you want to distinguish. It feels like you want to ask how to distinguish whether plastic is flame retardant. Generally, it is a direct test. Fundamentally speaking, it has a lot to do with molecular structure. For example, PVC (polyvinyl chloride) contains Cl, which will produce HCl when burning, so the flame retardant effect is good, but HCl is toxic. Read the book on polymers, I hope it will help you.
What is a fuel blockage?
Flame retardant material
Flame retardant material is a kind of protective material, which can prevent combustion but is not easy to burn by itself. There are solid materials such as cement, steel and glass. Liquid, also known as flame retardant, if coated on the surface of various materials such as firewall body, can ensure that it will not burn when it catches fire, and will not aggravate and expand the combustion range.
Edit the type of smoldering material in this section.
At present, the main flame retardant materials are organic and inorganic, halogen and non-halogen. High flame retardant material
Organic flame retardants are represented by bromine series, nitrogen series, red phosphorus and compounds, and inorganic flame retardants mainly include antimony trioxide, magnesium hydroxide, aluminum hydroxide and silicon series. Generally speaking, organic flame retardants have good affinity. Bromine-based flame retardants added to plastics have absolute advantages in organic flame retardant systems. Although there are many criticisms in environmental protection, it is difficult to be replaced by other flame retardant systems.
References:
baike.baidu/view/2 12569 1? WTP = TT
What is the difference between the flame retardant grades of plastic parts?
Flammability UL94 grade is the most widely used flammability standard for plastic materials. Used to evaluate the ability of materials to extinguish after being ignited. According to the burning speed, burning time, anti-dripping ability and whether droplets burn or not, there are many evaluation methods. Many numerical values can be obtained according to the color or thickness of each test material. When selecting product materials, its UL grade should meet the thickness requirements of plastic parts. UL grade shall be reported together with thickness value. It is not enough to report only the UL grade and not the thickness.
The flame retardant grade of plastics is gradually increased from HB, V-2, V- 1 to V-0:
HB: The lowest flame retardant grade in UL94 standard. It is required that the burning rate of samples with a thickness of 3 ~ 13mm should be less than 40mm/min；; For samples with a thickness of less than 3 mm, the burning speed is less than 70 mm per minute; Or go out before the 100 mm sign.
V-2: After the sample is tested twice 10 second, the flame goes out within 60 seconds. There may be combustible materials falling.
V- 1: After the sample is tested twice 10 second, the flame goes out within 60 seconds. No combustible materials can fall.
V-0: The flame goes out within 30 seconds after the sample is tested twice 10 second. No combustible materials can fall.
UL certification is the general name of various certifications conducted by American insurance companies. There are two methods for UL to certify the flammability of plastics: one is the common UL-94v 0, V 1, V2, V5, which is a vertical combustion test method; The other is UL94HB, which we seldom see. This is the method of proficiency testing.
UL94 HB: horizontal combustion. This kind of plastic can burn slowly, but it can't extinguish itself. This type is the lowest level of UL, and this method is usually adopted when vertical V0, V 1 or V2 mode is not feasible.
UL94 V0, V 1, V2, V5: vertical combustion.
UL flame retardant classification system is as follows:
Evaluation method of UL94 V0: After the flame is removed after ignition, the sample can quickly extinguish itself until there is no burning melt dripping in a certain time gap (that is, the burning melt drips on a cotton pad located one foot below the test sample, which cannot ignite cotton).
The evaluation method of UL94 V 1 is similar to that of V0, but it requires a longer self-extinguishing time. This test allows the melt to drip on the cotton pad, but it can't ignite the cotton.
UL94 V2 is the same as V 1, except that it allows burning water droplets to ignite cotton less than one foot.
UL94 V5 is the most stringent test method, which is related to the actual life of plastic products in flame. The experiment requires that the flame length is 5 inches, and the specimen burns 5 times, during which no liquid drops are allowed to drop, and the specimen is not allowed to have obvious distortion and burn holes.
UL94*** 12 fire rating: HB, V-0, V- 1, V-2, 5VA, 5VB, VTM-0, VTM- 1, VTM-2, HBF, HF/kloc-0.
Among them, VTM-0, VTM- 1 and VTM-2 are suitable for plastic films.
HBF, HF 1 and HF2 are suitable for foaming materials.
The specific test method is as follows:
[UL94 HB combustion]
Sample size: 125mm× 13mm× original thickness (maximum not exceeding 13mm), with at least 6 pieces.
Sample environment adjustment: (23 2)℃, (50 5)% RH, 48h.
Test method:
Sample placement: horizontal
Flame height: 20mm
Flame application time: 30s.
Combustion rate V = combustion loss length L/ combustion time t
Evaluation conditions of UL 94 HB level:
The burning rate of the sample with a thickness of 3.0-13mm is not more than 40mm/min; or
The burning rate of samples with a thickness of less than 3.0 mm is not more than 75 mm/min, or
Extinguish before 100 mm mark.
UL 94 V-0, V- 1, V-2 vertical combustion test.
Specimen requirements: 125mmX 13mmX original thickness (maximum not exceeding 13mm), at least 20 pieces.
Sample environment adjustment:
One group (23 2)℃, (50 5)% RH, 48h.
The other group was at (70 65438 0)℃
Test method:
Sample placement: vertical
Flame height: 20mm
Flame application time: 2 times of 10s.
Record the flame burning time and flameless burning time and whether the absorbent cotton is ignited.
UL 94 V-0, V- 1, V-2 evaluation criteria:
V-O......& gt& gt
Flame retardant grade of plastics
The flame retardant grade of plastics is gradually increased from HB, V-2, V- 1 to V-0:
The flame retardant grade of plastics is gradually increased from HB, V-2, V- 1 to V-0:
1 and HB: UL94 have the lowest flame retardant grade. It is required that the burning rate of samples with a thickness of 3 ~ 13mm should be less than 40mm/min；; For samples with a thickness of less than 3 mm, the burning speed is less than 70 mm per minute; Or go out before the 100 mm sign.
2.V-2: After the sample is tested twice 10 second, the flame goes out within 60 seconds. There may be combustible materials falling.
3.V- 1: After the sample is tested twice 10 seconds, the flame goes out within 60 seconds. No combustible materials can fall.
4.V-0: After the sample is tested twice 10 second, the flame goes out within 30 seconds. No combustible materials can fall.
What are the flame retardants commonly used to modify plastic raw materials?
Yisheng/flame retardant nylon reminds you! Common flame retardants
Organic class:
1. Bromine flame retardants are the most widely used, aliphatic is the best, alicyclic is the second, and aromatic is the worst. The processing temperature of aliphatic flame retardant should not exceed 205℃, and the processing temperature of aromatic flame retardant can reach 305℃.
2. Chlorine flame retardant is more toxic than bromine flame retardant, and its flame retardant efficiency is worse than bromine flame retardant.
3. Nitrogen flame retardant melamine and its derivatives, melamine and cyanurate. Melamine and its derivatives produce nitric acid and nitrous acid when burning, which can dehydrate and carbonize the plastic surface. Melamine cyanurate is a new type of efficient and environmentally friendly flame retardant, which has the advantages of odorless and tasteless. It is very stable when heated at 300℃, and it begins to sublimate at 350℃ without decomposition.
4. Phosphorus flame retardants, such as phosphate, phosphazene, phosphide, phosphine oxide, etc. Thermal decomposition produces phosphoric acid, which is then polymerized into polyphosphoric acid with strong dehydration ability, which carbonizes the plastic surface.
5. Nitrogen and phosphorus flame retardant intumescent flame retardant can form a uniform foam layer when heated, which has a barrier effect on plastics and can drip indoors.
Inorganic class:
1. Hydrated aluminum hydroxide releases crystal water, absorbs heat and dilutes it. Low decomposition temperature, used for flame retardant of general plastics. The decomposition temperature of nanocrystallization or surface treatment can reach above 300℃, which can be used for flame retardant of engineering plastics.
2. Hydrated magnesium hydroxide and aluminum hydroxide with decomposition temperature of 320℃ are used in engineering plastics.
3. Boride releases water and glassy covering when heated, which plays the role of dilution, cooling and barrier.
4. The mechanism of burning red phosphorus to produce phosphoric acid is the same as that of organic phosphorus, and the flame retardant effect is 3-4 times that of the latter.
Excuse me, is fireproof plastic flame retardant? Fire resistance?
Correctly speaking, fireproof materials are not generally non-combustible, but are flame-retardant, generally expressed by UL94 standard, and some plastics are non-combustible. There is no definite relationship between softening temperature and combustibility.