HFFR wire and cable

01 July 2024

Halogen-Free Flame-Retardant compounds in order to meet regulations in various industries from construction to the automotive.

HFFR (Halogen Free Flame Retardant)

The market demand for wired and cable components is very high has increased the challenges in various industries such as construction, automotive and electronics. Wire and cable components are looking for halogen-free flame-retardant compound solutions to meet the same stringent regulations. However, productivity of these products is still the main priority and the solution that allows the production process to be simplified. This is particularly evident in the growth of the halogen-free cross-linking flame-retardant compound industry.

Construction regulation and specifications for automotive cables are always required to use high-performance materials. This in turn will require high-performance compound technology or better usability. Many applications require crosslink materials, such as applications with high temperatures, wear or oil resistance. The main problem with most crosslinked polyolefin-based cables is their tendency to drip when burned. This is accompanied by the spread of fire and reduced use of crosslinked compounds in flammability tests.

Traditional HFFR compounds perform better in flammability tests but are classified into categories with low oil resistance and lower mechanical performance. This limitation could replace older cross-link HFFR cables. In the traditional process, crosslinked flame-retardant cables have two stages. In the first step, the polyolefin base polymer is grafted with reactive silanes, then in the second step, the grafted material is compounded with additives and flame-retardant fillers. Although this process seems practical, from BUSS’s point of view it is cost-effective with low efficiency. With the view that the material must be melted twice and two compounding devices are required or in some way a device with alternative products is used.

BUSS devices seem to have higher efficiencies for cross-linked HFFR compounds in one step and are currently being manufactured on an industrial scale in some parts of the world. This single-stage device requires high-speed mixing of grafted chemicals with process temperature control. The lowest temperature of the first part should reach 170 to 190 ° C to perform the graft process. Flame retardants, usually aluminum or magnesium hydroxide, are then added and mixed with the grafted compound. Precise temperature control in this process is essential to prevent thermal degradation of fire retardants around 200 ° C.