ADDITIVES | ANTIOXIDANTS AND STABILISERS
Right: Meeting Circular
Economy goals means using stabilisation to lift the
performance of recycled polymers
specifically for fibre applications; Ultranox LC PP701 provides “state-of-the-art” colour protection for BOPP applications that need to be stearate-free. “Besides providing excellent colour and melt protection, these solutions provide improved gas fading protection and a larger operating window for colour control,” says Foster. The Ultranox LC series products are available in a non-dusting easy-to-feed form, simplifying operations for polyolefin reprocessors. They are approved in various countries for food contact applications.
Polyolefin recycling The new area of recycling and compounding of recycled polyolefins is being targeted by Baerlocher with its Resin Stabilisation Technology (RST) platform, which acts synergistically with traditional antioxi- dants. In its pure form, it is aimed at polymer producers and virgin resin compounders who can use it to expand the performance window of existing stabilisers or to work around solubility or cost constraints of certain additive formulations. In polyolefin recycling applications, Baerlocher
has taken advantage of the physical form of 100%-active additive blends enabled by Baeropol RST – a dust free pastille. “Recyclers are not used to employing additives and powders are usually a no-go,” says Technical Product Manager Henrik Eriksson. Eriksson says there are “clear unmet” needs with
respect to recyclate performance at many convert- ers. “For example, MFI fluctuations can be a major issue for a converter, as they bring a constant need to adapt the settings to changes in raw material flowability. A raw material equipped with a process
stabiliser based on the Baeropol RST-technology will perform in a much more stable way in this sense.” The challenge Baerlocher has taken on is to
explain how Baeropol RST can help the recyclers capitalise on the unmet needs of converters, focusing on practical matters such as handling and processing issues rather than reaction mechanisms and performance diagrams, Eriksson says. “The typical recycler-to-converter value chain does not respond to the same extent to the ‘chemistry- intense’ product promotion that is commonplace in the additives industry,” he says. “Once tried, the performance of the Baeropol
RST-technology quickly proves itself and the recyclers find that their customers are willing to pay for the small added cost it brings along. The struggle is to get to that point, but as we have learned to speak the language of the recyclers the commercial implementations have continued to grow,” he says, adding that Baerlocher is now looking to expand its offering for compounders of recyclates beyond stabilisers. UV light stabilisers and antioxidants from Solvay have demonstrated the ability to slow the degrada- tion of the physical and mechanical properties of recycled resins to facilitate performance competi- tive with virgin resins, according to Andrea Lan- duzzi, Global Marketing Director, Polymer Additives at the company.
Figure 1: Graph showing MFI of recycled/virgin PP blends after extrusion at 250°C in a twin screw extruder demonstrates how Solvay’s stabilisers can provide protection Source: Solvay
44 COMPOUNDING WORLD | September 2020
Landuzzi says Solvay’s polymer additives minimise changes in the melt flow index (MFI) of polyolefins. This “substantially enhances second- life performance and enables an increased percentage of recycled resin to be used. Incorpo- rating stabilisers into blends mitigates strand breaks, reduces scrap rates, and increases overall throughput and strand quality. These improve- ments allow for up to triple the amount of recycled resin to be used while maintaining the MFI.” Some of these gains are shown in Figures 1 and 2.
�
www.compoundingworld.com
IMAGE: SHUTTERSTOCK
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
