PETpla.net Insider 10 / 2018

CAPS & CLOSURES 29 PET planet Insider Vol. 19 No. 10/18 www.petpla.net CAPS & CLOSURES 29 etary metallocene catalyst technology. Metallocene polymerisation produces PE with a much higher molecular weight than that made by the Ziegler- Natta recipe; indeed, some have claimed that PE made using metal- locene methods can be a better mate- rial than Kevlar for making bulletproof vests. However, that level of strength is not what LG Chem is focused on. “We have three Lucene ranges: SM100; SM250 and SM800,” said Joon. “The metallocene catalyst pro- cess enables us to produce HDPEs with excellent mechanical, process- ing and organoleptic qualities. They are very suitable for high performance caps and closures applications; they have very high ESCR (environmental stress-cracking resistance) character- istics and offer excellent ‘flowability’ in processing.” SM100 is very suitable for lightweight CSD closures, such as the PC 1881; it and SM250 are both suitable for aseptic fill water and tea; and SM800 is the grade for sports clo- sures, as well as CSD and edible oils. Lighter weight without black spotting “Lucene products offer custom- ers a number of features and advan- tages,” Joon continued. “They can be processed at lower temperatures, which means less energy consump- tion as well as less incidence of ‘black spot’ and flow marks. The improved ESCR characteristics offer poten- tial for light weighting, and they also present an excellent appearance, with high gloss and good whiteness.” Light weighting and lower energy consumption are two ‘hot button’ issues for manufacturers across the world. But it is one thing saying these characteristics can be delivered; it is another to see them confirmed in practice. In order to see first-hand what LG is doing in order to ensure it is meeting customer needs, we took a drive down to the R&D facility at Daejon. We travelled in the thick of the typhoon season, so the trip took rather longer than would nor- mally be the case – 2.5 hours by road, through wind and stream- ing rain. The rain had eased by the time we arrived at the plant but its effects were obvious, both inside and out. But LG’s staff weren’t about to let water ingress and other inconven- iences stop research, devel- opment and production. A key question is: how does Lucene retain strength while achieving weight reductions to below 2 g for CSD caps? The people with the answers were Yo Han Bae, Professional at the Tech Center, in the PO TS Team; and In-Gyu (“Joseph”) Park, General Man- ager and Team Leader. Designing the future “Our technicians amend and control the molecular structure of Lucene during the metal- locene process, in order to retain the required qualities of rigidity, ESCR and so on,” Bae explained. “It is a question of achieving balance. If the material is made very stiff, its ageing and processing performances may not be as strong.” “It was difficult to deter- mine the design,” Joseph said. “The minimum density and melt index are vital in determining the quality of the material. We worked with a leading closure system manufacturer, who took soundings from their custom- ers on their reaction to different formulations. It was that col- [email protected] Tel: +90 212 695 50 00 Fax: +90 212 694 97 24 100815dmyR .com In 2017, LG Chem spent a total of 841US$ on R&D.