If even only a few kilograms of a thermoplastic material catch fire, the spreading flames can easily cause tremendous damage. Flame retardants (FR) containing halogens were therefore frequently used in the past – but if a fire breaks out, these can have serious negative effects on people, furniture and equipment, and the building involved. The effects are primarily due to thick billows of smoke that make people lose orientation on the escape routes, as well as toxic fumes and corrosive conflagration gases, which are detrimental to health and can be dangerous to the fabric of a building. The halogens’ corrosiveness is also considered to be a problem for maintaining a material’s properties during recycling of waste materials such as old vehicles.

Germany's Kraiburg TPE is therefore continually working on consistently expanding its range of self-extinguishing thermoplastic elastomers (TPEs) that provide halogen-free flame-retardant properties (HFFR). The materials meet the requirements of the UL94 V0 standard, i.e. they extinguish themselves in case of fire and don’t form burning droplets. The certification applies to all degrees of hardness available and all color variations produced at Kraiburg TPE.

Being free of halogen in accordance with IEC 61249-2-21 also means that the material contributes to a significant reduction of harmful fire gases. Kraiburg TPE’s flame-retardant compounds thus meet the highest fire protection requirements, including those of the European Construction Products Regulation (EU-CPR) and the EN 45545 standard regulation for fire protection on rail vehicles.

Included in the company’s Thermolast K HFFR offerings are:

FR1 compound series: injection molding and extrusion compounds providing good adhesion to polypropylene and with UL94 V0 classification, starting from wall thicknesses of 3 mm;

FR2 compound series: specially developed for thin-walled components providing UL94 V0 classification, starting from wall thicknesses of 1.5 mm, and with good adhesion to polypropylene;

In addition, Kraiburg TPE offers a series of special HFFR compounds that is targeted towards direct adhesion to polar thermoplastics such as ABS, PC and selected types of polyamides.

“Our halogen-free flame-retardant TPEs provide plenty of possible applications for flame-retardant multi-component parts with attractive tactile properties such as soft touch and a good grip,” emphasizes Dirk Butschkau, Product Marketing Manager EMEA at Kraiburg TPE.

Typical applications are in the fields of electrical engineering and electronics, such as connectors, switch boxes and flush-mounted sockets. The materials are also ideal for use in manufacturing cable coatings, cable bushings and cable clips, as well as for furniture components and door and window gaskets.

The natural-colored compounds can easily be colored and provide excellent color stability. All products are manufactured at all Kraiburg TPE sites in the USA, Germany and Malaysia and are available worldwide.

“The diversified portfolio of our halogen-free flame-retardant TPEs demonstrates our market-driven and customer-oriented competence in developing materials, which is targeted to implementing innovative product ideas of the highest quality,” says Franz Hinterecker, CEO of Kraiburg TPE. “One excellent example of these is the trendsetting cable bushing system from our customer Conta-Clip.”