ADDITIVES | FLAME RETARDANTS
from 20 to 15%. “We are exploring more and more opportunities,” he says. “We are now also looking at PBT. We are developing several solutions, including combinations with ammonium polyphos- phate (APP) for polyolefins.” Imerys also offers engineered minerals for use in
Above and below: Test set up and test plaque for a PP-compound containing 12.5 wt% glass fibre and 65 wt% Actilox HTB PP exposed for 20 minutes to a torch flame test (propane/butane-burner, 1650 W). The test specimen stayed intact (no burn-through) with a closed surface and high structural stability
flame retardant polyolefins. The company says it is possible to replace 10-15% of metal hydroxides such as ATH and MDH with its talcs and still get the same cone calorimeter results. Mechanical proper- ties of the compound can be improved, heat release rate can be reduced, or the peak heat release rate can be pushed back. Applications include EVA cable compounds. Another minerals major, Nabaltec, points to work it is carrying out to help improve fire safety in cars. The company points out that China already has a safety standard for EV batteries (GB 38031- 2020) that includes a thermal propagation test. A key requirement is to ensure a minimum of five minutes escape time for passengers before thermal propagation leads to battery fire or explosion. Automotive OEMs in Europe and North America,
Mineral moves In August of this year, Imerys introduced its ImerShield mineral-based synergists, which is says offer an engineered high aspect ratio morphology and chemistry, for use in intumescent FR systems. Michael Schmidt, Technical Service Manager, Plastics, says the company is on the way to devel- oping a full range of ImerShield synergists to cover various polymers.
Imerys says it has initially been exploring how the additives can be used, not only to reduce the required level of the principal flame retardant (with potential to make cost savings) but also to partially replace glass in reinforced flame retardant PA6 and 66 compounds while maintaining fire properties and mechanicals. It says the use of ImerShield can also help in efforts to improve flow length and weld line strength.
Schmidt cites the example of a 30% glass
reinforced PA6 in which one third of the glass was replaced by ImerShield and a V-0 rating at 3.6mm was obtained while reducing the phosphinate level
28 COMPOUNDING WORLD | December 2022
raw material suppliers and independent testing labs are working on their own fire propagation test procedures. “Industry has not yet agreed on a harmonised standard, but a high energy torch flame test will be the core part of it,” says a Nabal- tec spokesperson. “The test duration is expected to be in the range of 10 to 20 minutes. Nabaltec has developed Actilox HTB mineral-based filler blends which are designed to fulfil such increasingly severe fire propagation tests.” Three new FR products — one for PP, one for PA, and one for unsaturated polyester — will be launched shortly, Nabaltec says. The company will also develop customised formulations with partners. Flame retardant synergist manufacturer Pax-
ymer says its technology works in the condense phase, providing drip suppression for polyolefins and engineering plastics. Company CEO Amit Paul says its Paxymer synergist also increases the gas phase activity of the PN-based additives. “The value proposition includes cost savings and improved mechanical and processing performance in compounding and moulding,” he says. “A key focus during the year has been to expand the use of Paxymer in engineering resins as well as improve our toolkit for comparative evaluation. The toolkit offers us an exciting possibility to do comparative evaluation between formulations that address larger scale testing like for the building and construction industry. It significantly shortens the time to market and increases precision in
www.compoundingworld.com
IMAGE: NABALTEC
IMAGE: NABALTEC
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76
