Flame Retardants
MAGNESIUM HYDROXIDES

– for your safety –

 

Flame retardancy in our everyday lives

Aluminium hydroxide (ATH) and magnesium hydroxide Mg(OH)₂ work effectively as flame retardants by releasing around a third of their mass in the form of water at certain temperatures.

Fillers treated with aluminium hydroxide-based flame retardants release the crystal-bound water even at processing temperatures above 200 °C and are therefore unsuitable for use as flame retardants at higher processing temperatures > 200 °C. For applications with processing temperatures above 200 °C, magnesium hydroxide-based products, such as those from our ALFRIMAL® MG product range, are ideal, as they only release their water above this temperature and are therefore easier to process in many production processes. In the event of a fire, ALFRIMAL® MG acts as an effective smoke gas scavenger for acidic smoke gases in both halogen-containing and halogen-free systems.

Water release only begins at around 300 °C, which is why magnesium hydroxide can be used without any problems at high processing temperatures, such as those commonly found today in PP processing, for example.

 

Frequently Asked Questions – FAQs

 

 

 

In which materials are flame retardants used?

  • Plastics and rubber (e.g. tyres, power plugs, light switches)
  • Paints and varnishes (e.g. fire-retardant paint, car paints)
  • Cable sheathing (e.g. wall boxes, power cables, charging cables)
  • Textile floor coverings (e.g. bath mats, sisal mats, carpet backing)
  • Elastomers (e.g. linoleum flooring) – construction chemicals (grout/adhesives/plasters)
  • Insulation materials (e.g. insulating foam/ceiling panels)
  • PVC/polyester/thermosets (e.g. casting compounds/fillers, films/coated fabrics)

 

 

In which areas of everyday life are flame retardants used?

  • Public buildings (hospitals/schools/administrative buildings/sports halls)
  • All types of transport (cars/trains/buses/aircraft)
  • Workwear (e.g. fire service/chemical industry)
  • Textile home furnishings (carpets/wallpaper/floor coverings/building materials)
  • Electrical appliances (for the garden, kitchen, home and office) and much more

 

 

Why are flame retardants used?

Products on the market must be safe in the event of a fire, so that people can evacuate the area before the fire spreads. Flame retardants, which act immediately as ‘fire extinguishers’ in the event of a fire, must not impair the mixing and processing of the material, nor the colour, surface or texture of the end product. To this end, a whole range of ALFRIMAL® products has been developed, which are available to meet all market requirements and for a wide variety of materials.

 

 

How do flame retardants work in plastics?

The advantageous properties of plastics during processing and use stem from their flexible hydrocarbon backbone. A serious disadvantage of plastics for many applications is their high flammability; the addition of flame retardants significantly reduces this.

Halogen-containing plastics, on the other hand, are relatively flame-retardant. However, once halogen-containing plastics do catch fire, the resulting smoke is toxic and hazardous; it contains corrosive hydrogen halide acids as well as black particles, which drastically increase the density of the smoke. The flammability of plastics is significantly reduced by the addition of flame retardants. Flame retardants for plastics are either based on a single active component or consist of a flame retardant system comprising several active components, with the aim of preventing, or at least effectively delaying, the plastic product’s contribution to an incipient fire.

Plastic products with optimum flame retardancy do not contribute significantly to the development of a fire or to its spread, whilst at the same time minimising both the amount of heat released from the combustion of the plastic in the event of a fire and the density of the flue gases, ensuring, for example, that escape routes remain passable for longer.

The addition of ALFRIMAL® effectively reduces smoke density, particularly in halogen-containing systems. At the same time, the acidic fire gases are neutralised by the alkaline

component, which reduces corrosiveness. ALFRIMAL® MG works optimally to minimise smoke density due to its high pH value of 10.

 

 

 

ALFRIMAL® MG product range

ALFRIMAL® MG, a natural magnesium hydroxide, exhibits high activity as a scavenger of acidic combustion gases in halogen-containing flame retardant systems and PVC. ALFRIMAL® MG is used as a flame retardant at processing temperatures > 300°C. A hydrophobic surface coating improves dispersibility when used in all plastic systems. Thanks to ALFRIMAL® MG’s good compatibility with polymers, high loading levels can be achieved. ALFRIMAL® MG is a particularly good choice for end products that are laminated with water-impermeable layers.