Substances that prevent or retard the burning of other objects can be called flame retardants.
Different flame retardants work on the three combustion factors: oxygen, combustible material, and ignition point.
Flame retardants are generally added during the processing of an object to provide safety and protection against fire, delaying combustion and preventing the spread of flame.
PM series precipitated magnesium hydroxide are patent product developed recent years. Their performance could compete with high level magnesium hydroxide produced by Austria, Japan, Russia. It could be applied to produce low smoke zero halogen flame retardant cable and wire. Our customers includes world top level cable companies such as Prysmian, Nexans, LS Cable…
The production of natural Brucite is started in the year 2000. B series Brucite has both high purity and high whiteness characteristics. We can tailor-made products in different purity, whiteness, particle sizes, and surface treatment based on customer’s requirements. B series Brucite is widely used in PVC cable, HFFR cable compound, flame retardant panel, aluminum composite panel, flue gas desulfurization, wastewater treatment, magnesium fertilizer, etc.
Virtually all the aluminum hydroxide used commercially is manufactured by the Bayer process which involves dissolving bauxite in sodium hydroxide at temperatures up to 270 °C (518 °F). The waste solid, bauxite tailings, is removed and aluminum hydroxide is precipitated from the remaining solution of sodium aluminate. Aluminum Hydroxide can be used as a halogen-free flame retardant due to its well-distributed granularity, good stability, non-toxic and non-polluting.
Flame retardants are functional additives that give flame-retardant properties to flammable polymers and are designed primarily for the flame retardation of polymeric materials.
Organic flame retardants.
Phosphorus-based flame retardants: phosphate esters
Phosphorus + nitrogen-based flame retardants.
Phosphorus + halogen-based flame retardants: halogenated phosphate esters
Nitrogen-based flame retardants
Halogen-based flame retardants.
Other flame retardants
Inorganic flame retardants
Boron compounds: zinc borate
Metal oxidizer flame retardants: Antimony trioxide
Aluminium hydroxide
Magnesium hydroxide
Other
Additive type.
Halogenated flame retardants
Non-halogenated flame retardants: hydrated metal oxides: ATH,MDH
Phosphorus-based flame retardants
Metal oxides
Metal borides
Intumescent flame retardants
Reactive type.
Vinyl derivatives
Chlorine-containing compounds
Hydroxyl-containing compounds
Epoxy-containing compounds”
The elements that sustain combustion: combustible material, oxygen, heat.
The combustion process can be divided into 5 stages.
1, Heating stage.
Heat generated by an external heat source is given to the polymer, causing a gradual increase in the temperature of the polymer.
2, Degradation phase.
After the polymer has been heated to a certain stability, the weakest chains break and thermal degradation occurs.
Chain energies of the different chains.
O-O 146.7 KJ/MOL
C-N 305.9 KJ/MOL
C-Cl 339.4 KJ/MOL
C-C 347.8 KJ/MOL
C-H 414.8 KJ/MOL
C-F 431.6-515.4 KJ/MOL
3, Decomposition phase.
When the temperature of the polymer rises to a certain level, in addition to weak bond breakage, the main chain also
Breaks, i.e. cleavage occurs, producing low molecular weight.
Combustible gases: H2, CH4, C2H6, CH2O, CH3COCH3, CO, etc.
Non-flammable gases: CO2, HCL, HBr, etc.
Liquid products: partial decomposition of the polymer into liquid products
Solid products: partial coking to coke, or incomplete combustion to produce particles such as smoke, etc.
4. Ignition stage.
When the flammable gas reaches a certain concentration and the temperature reaches its ignition point or flash point, and
by the presence of sufficient oxygen or oxidising agent, a flame begins to appear, which is ignition, and combustion begins from there.
5, Combustion phase.
The energy released by combustion and the chain reaction caused by the active free radicals, constantly provide
combustible material, so that combustion automatically spreads or expands and the flame becomes larger and larger.
UL-94 Flammability Test: 133MM, 13.3MM wide specimen hung vertically, specimen
The upper end (6MM in place) is held by a clamp on the holder, the lower end of the specimen is 10+- 1MM from the lamp nozzle
10+-1MM and 300+-10MM from the dry medical skimmer ball, the specimen is first burned with the blue flame of the alcohol
The specimen is first burned with the blue flame of the alcohol lamp for 10S, the lamp is moved and timed at the same time, and the flaming time is recorded.
The flaming time was recorded. Immediately after the specimen has extinguished itself, burn it a second time for 10S, move the lamp and start timing, record the flaming and flameless burning time. Five specimens should be tested in the first test.
The US UL-94 standard test method observes the burning of plastics when in direct contact with an ignition source and is divided into three classes.
Class V-0
Extinguish 10S after leaving the fire without igniting the wool 30CM below.
Class V-1
Extinguished 10-30S after ignition and does not ignite the wool 30CM below it.
Class V-2
Extinguishes 30S after being removed from the fire and ignites the wool 30CM below it.
IEC60332-1/BS4066-1 Flame retardant grades
(Flame Test on Single Vertical Insulated Wire/Cable)
EC60332 is divided into classes A, B, C and D to assess flame resistance.
IEC6032-3 – BS4066-3 Flame retardant grades
(Flame Tast onBunched Wire/Cable)
The test provides for a 3.5m long bundle of cable specimens to be fixed by wire in a trapezoidal test frame, the number of specimens being determined by the amount of non-metallic material required for each classification. The specimens are hung vertically on the back wall of the combustion furnace and air is introduced into the furnace through an air inlet in the base plate. The specimen is exposed to a flame of 750°C on a propane plane. The specimen must burn vertically for 20 minutes without igniting and the cable must extinguish itself within 2.5m of the flame spread under forced air blowing (3.5m3 /min, wind speed 0.9m/s).
Requirements and labelling of flame retardant products and components in public places GB 20286-2006
Flame retardant products and components for public places: flame retardant building products; flame retardant fabrics; flame retardant plastics/rubber; flame retardant foam; flame retardant household and components; flame retardant wires and cables. In addition to building products In addition to construction products, each of its five categories is divided into two classes of combustion performance, flame retardant class I and flame retardant class II.
Classification of burning performance of building materials and products GB 8624-2006
Building materials are divided into flooring materials and building products other than flooring materials.
There are seven classes of floor coverings, from highest to lowest: A1FL, A2FL, BFL, CFL, DFL, EFL, FFL
There are seven combustion classes for building products other than floor coverings: A1, A2, B, C, D, E, F
Test items of GB31247
GB31247 is a classification standard for the combustion properties of cables and optical fibre cables, divided into four classes: A (non-combustible), B1 (flame-retardant class 1), B2 (flame-retardant class 2) and B3 (ordinary). Of these Both Class B1 and Class B2 require the GB31248 mass burn test, GB17651.2 smoke density test and GB18380.12 single burn test, as well as the additional GB17650.2 gas acidity test. The reason for the different levels is the difference in the specific data requirements obtained during the test.
Test items of EN 13501-6
EN13501-6 is a standard for the classification of fire resistance of electrical cables, with seven classes: Aca, B1ca, B2ca, Cca, Dca, Eca and Fca. Of these B2ca, Cca and Dca are subject to EN50399 Large-scale burning test and EN60332-1-2 Single burn test, as well as the additional EN61034-2 smoke density test and EN60754-2 gas The reason for the different levels is also due to the specific data requirements obtained during the test.
Inorganic flame retardants
Aluminium hydroxide
Magnesium hydroxide
Antimony trioxide
Boron compounds
Red phosphorus, phosphates, ammonium phosphate, phosphorus-nitrogen compounds, ammonium polyphosphate
Phosphorus-based flame retardants
Phosphoric acid esters
Phosphonates and their chlorine-containing derivatives
Phosphite
Organophosphates
phosphine oxide
Phosphorus-containing polyolipids
Phosphorus/nitrogen compounds
Several typical brominated flame retardants
1, Hexabromocyclododecane, HBCD for short
2, Tetrabromobisphenol A (TBA or TBBPA)
3, Polybrominated diphenyl ethers (PBDEs)
4, Tris(2,3-dibromo-1-propyl) cyanate
5, Melamine brominated derivatives
HFFR cable
PVC cable
LSZH Flame Retardant Cable Industries
Rubber compounds
Thermoplastic PVC- and polyolefin-based Compound
Engineering Plastics Compounds
Flame Retardant Coating
TPO roofing membranes
Agricultural
Water treatment
Aluminum-Composite Panel
LSZH Flame Retardant Cable Industries
Mineral Filler
Thermoplastic PVC- and polyolefin-based Compound
Engineering Plastics Compounds
Flame Retardant Coating
TPO roofing membranes
Agricultural
