European Regulation Driving Flame Retarded Plastics Development

TAGS:  High Heat Materials      Automotive    

The plastics world is certainly experiencing a technical marketing inflection point in terms of new European initiated sustainability regulation drivers for flame retarded (FR) plastics development. Flame retardants are an important safety benefit but are now focusing on new sustainable solutions in consumer plastics product development, for example, in the automotive, building and construction industries.

Halogen-free flame retardants (HFFRs) are definitely being seen as more sustainable alternatives compared to traditional brominated systems. The Phosphorus, Inorganic & Nitrogen Flame Retardants Association, or PINFA for short, sees the continuing emergence of HFFRs.

HFFRs are viewed as very compatible with the European Union’s Green Deal that centers on eventual zero pollution for flame retarded plastic products. Also expected near term is an ongoing RoHS (Restriction of Hazardous Substances) regulatory revision further restricting brominated FRs. Finally, European Union regulation is being influenced by a new EcoDesign Directive that will eliminate halogenated FRs.

Historically, flammability standards have always been and will continue to be central to plastics part development that is near to or in contact with an electric current. The plastics industry cornerstone Underwriters Lab UL 94 standard rates FR plastics flammability by flame ignition test from HB lowest, V-2, V-1, to V-0 the highest performance.

Similarly, the useful Limiting Oxygen Index (LOI) is very effective in measuring the minimum percent oxygen concentration needed to support vertical candle like test plaque combustion. Stated simply, compounded flame retardants in plastics efficiently work to delay flame ignition, retarding burning from starting, or suppressing smoke formation.

Let’s start with the recent developments of flame retarded (FR) plastics in detail...

Adeka’s Liquid Phosphate Ester FR for Automotive Interior Parts

Flame Retardant (FR) additives supplier Adeka focused on their recent automotive application developments. Up to now, FR additive compounded plastics have been used extensively in automotive interior parts. Looming on the near-term horizon are broader-based Electric Vehicle (EV) introductions where FR plastics will be required in:

• Battery housings
• Propulsion systems, and
• Charging stations with their related high voltage components.

Korea-based Adeka recently commercialized a liquid phosphate ester ADK Stab FP-900L FR additive that has been successfully compounded into PolyCarbonate (PC) and PC alloys. It represents a marked improvement over Adeka’s traditional bisphenol-A phosphate ADK Stab FP-600 FR additive.

• ADK Stab FP-900L enhances compound heat deflection temperature (HDT) and requires lower dosing levels at 15% (versus ADK Stab FP-600 at 20%).
• ADK Stab FP-900L attains a UL V-0 rating with 10% glass reinforced PC, whereas ADK Stab FP-600 comes in at UL V-2 rating with 30% glass filled PC.

Car makers are readily using Adeka ADK Stab FP-900L FR additive stabilized compounds, in facing flame retardant selection challenges, including compliance with new EV standards and regulations, which call for improved sustainability, and the need to avoid corrosion of electronic and electrical systems.

FRX Polymers’ Phosphate-based FR for Auto Interior Piano Black Finish

Continuing, US-based FRX Polymers has advanced phosphonate-based Flame Retardants (FRs) compoundable with PolyCarbonate (PC), as well as blends with PC/ABS (Acrylonitrile Butadiene Styrene) and PC/ASA (Acrylonitrile Styrene Acrylonitrile). The preceding PC blends are characterized by:

• Excellent processability
• Outstanding mechanical property profile, and
• UL V-0 rating in thin wall dimensions (0.75 millimeters)

Attaining UL V-0 in traditional PC blends requires a part wall thickness of 1.5 millimeters or greater.

Nofia FR enhanced PC/PBT (PolyButylene Terephthalate) blend compounds have successfully been used in automotive interior applications, where they can be colored, maintaining a high gloss piano black hue critical here.

The heat deflection temperature (HDT) of traditional brominated FR compound falls off to 80°C in PC/PBT blends whereas the HDT of Nofia FR PC/PBT HDT is 115°C, within 5°C to 120°C of non-FR filled PC/PBT.

Nabaltec’s Aluminum Hydroxide FR for Construction Cables

Next, let’s turn our attention to Germany’s Nabaltec, which has commercialized, its aluminum hydroxide, Apyral FR, for use in building and construction polyolefin wire and cable compounds. Apyral FR is certainly a good starting point but remains limited for emerging low fire hazard wire and cable standards.

To counter this shortcoming, an Actilox PA-B2 FR synergistic booster was developed, that when used in tandem allows, Apyral to maintain its Halogen Free FR (HFFR) capability in demanding low fire applications. Actilox PA-B2 has excellent compound processability during compound extrusion and maintains very good mechanical property and heat aging performance.

Russian Mining Chemical Company’s FR for Non-combustible Building Panels

Finally, let’s end with the Russia-based Russian Mining Chemical Company’s EcoPiren magnesium hydroxide-based FR additive compounded into a polyethylene interlayer to make it non-combustible to meet the EN13501-1 European flammability standard.

Aluminum-composite cladding building manufacturers are using the EcoPiren technology to move from lower flame rated B1/B2 to more incombustible A2 paneling. Combustibility upgrades in European building cladding have spawned an ongoing FR development interest since the 2017 British Grenfell Tower fire.

The Russian Mining Chemical Company has devoted considerable R&D effort to extruding the FR polyethylene interlayer for A2 qualification that requires a 1.75grams per cubic centimeter density that is met by a new EcoPiren 400-1000 compounded material.

FR B1/B2 Grade Exterior Composite Cladding Panel (L, Gray), A2 Housing Panel (R, Blue)

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