Applications PLA
Applications PLA solution for soil engineering By: Nopadol Suanprasert CEO and President Global Biopolymers Bangkok, Thailand Prefabricated Vertical Drains, commonly known as PVDs, are installed at construction sites as a ground treatment solution to consolidate the ground, hardening the soil to support civil construction. Construction in areas where the soil is unstable because of a high water content, as is the case for mud or clay, requires this to first undergo some sort of soil treatment in order to settle the ground. In general, the technology used involves driving PVDs into the water-saturated soil. The PVD is made up of two parts, an inner core made from plastic and wrapped in a non-woven outer filter. The outer filter absorbs the water in the soil. Water flows through the inner core to the surface and drains out. As a result, the soil dries and hardens enough for civil construction to take place. PVD technology is normally used for the construction of roads, runways, playgrounds and the like in muddy area or on reclaimed land. PVDs are widely used in the countries of southeast Asia due to the prevalence of soft tropical soils. The use of PVD technology is standard in the construction of roads and runway in this region, as it is both reliable and economical. Conventional PVDs are made from plastics. The inner core, produced from polypropylene (PP) or poly vinyl chloride (PVC), is enclosed in an outer filter that is generally made of a PP non-woven material (Fig.1). PVDs are driven into the ground by heavy equipment. Following their installation in the ground, the PVDs will start to absorb and drain the water in the soil (Fig.2), accelerating the soil consolidation process and making the construction of roads, runways or playgrounds in these areas possible. Once the soil has hardened, the PVDs have no further function but they cannot be removed. Made of plastic, which does not readily degrade, PVDs that remain in the soil are environmental hazards, potentially able to contaminate the soil, causing problems to the underground natural environment. Plastic PVDs underground also constitute obstacles to underground constructions, such as tunnels. Airport runways, for example, constructed with the help of PVD technology, must reckon with the obstacles formed by the PVDs left in the soil when planning and building baggage tunnels, service tunnels and/or other underground constructions. The idea of making PVDs from a bioplastics that will degrade in soil at the end of the PVD’s service life is one that has been under consideration for many years. To date, however, no one has yet designed a PVD made from bioplastic. Global Biopolymers Co., Ltd. (GBP, from Bangkok, Thailand), together with a group of strategic partners that includes a PVD manufacturer, a civil contractor and soil engineering company, have formed a business cooperation group to develop PVDs made from bioplastics. The business cooperation group has developed a bioplastic PVD prototype made entirely from biodegradable bioplastic. Instead of PP or PVC, the core is now made from a PLA compound. The non-woven PP filter has been replaced by non-woven PLA filter (Fig.3). The business cooperation group will field test the new PVDs at Bangkok International Airport. Bangkok International Airport is in the process of a Phase 2 expansion project in which new runways, aprons and road systems are being constructed. Over 40 million meters of PVDs are expected to be required. Other applications are in road and highway construction projects in Thailand and neighboring Cambodia, Laos, Vietnam and Myanmar. The fact that the new PVDs are biodegradable means that many government construction projects may be expected to be receptive to switching to the use of bioplastic PVDs. The benefits will be a better environment, a policy that the government has implemented for public construction projects. In addition to a better environment, a positive impact on local industrial growth will also be felt, since the bioplastic resins PLA, and PBS are now produced in Thailand. Other downstream converters can start up PVD manufacturing in South East Asian countries. The Free Trade Agreement among these countries will propagate new industries within the region. www.globalbiopolymers.com Fig.1 Plastic PVD with PP core and non-woven PP filter Fig.2 Bioplastics PVD with PLA core and filter Surcharge Final Road Level Drainage Sand Blanket Fig.3 Application of PVD with surcharge loading for ground improvement work of road embankment Pumping Well Soft Clay PVD 26 bioplastics MAGAZINE [01/19] Vol. 14
Applications In 2016 the International Hockey Federation (FIH) announced a partnership with SportGroup Holding and its leading brand, Polytan (both from Burgheim Germany), as World Cup and Olympic Partner and supplier of hockey fields for the 2018 and 2022 hockey World Cups as well as the 2020 Olympic games in Tokyo. Tokyo has set itself the goal of organizing the first ever carbon-neutral Olympic Games in 2020 by using green technologies. Polytan, a leading supplier of world class hockey fields and global partner of the FIH, is making an important contribution by developing the sustainable hockey turf Poligras Tokyo GT (Green Technology): 60 % of the filaments are based on Braskem’s renewable I’m greenTM polyethylene technology. Polytan is using biobased polyethylene to add a sustainable dimension to the outstanding playing properties of its tried-and-tested polyethylene monofilament fibres. An elastic base layer ensures optimum absorption and is an important part of the entire hockey turf system. The Polytan PolyBase GT elastic layer, which has also been newly developed, gives the hockey turf an even better environmental balance. A binder, supplied by Covestro, which can score highly thanks to its reduced CO 2 production is used for the permanent elastic binding of the granules. “FIH is delighted that this new turf technology will support Tokyo’s carbon-neutral vision and make a positive contribution to the Games. FIH has a strategic priority to improve hockey’s environmental footprint, which is why partnerships with progressive companies such as Polytan are crucial. We are pleased to note that the surface that will be used in Tokyo requires 2/3 less water than surfaces used at previous Olympic Games. FIH firmly believes that hockey can contribute to a more sustainable environment by making use of all the technological possibilities modern turf offers”, FIH CEO Thierry Weil stated. “With the development of the Poligras Tokyo GT, we have succeeded not only in making a hockey pitch more sustainable, but also in significantly improving its performance. Never before has a hockey turf been more environmentally friendly, never before has a turf allowed such a dynamic and precise hockey game. I am very proud of this,” said Polytan Director Product Management Friedemann Söll. “We are so proud that Polytan and the FIH have chosen Braskem’s I’m green polyethylene for the hockey fields for the games in Tokyo in 2020. Tokyo has set itself the goal of organizing the first carbon-neutral games, and we are happy that Braskem can make its contribution together Green turf technology for the 2020 Olympic Games with the FIH and Polytan,” added Marco Jansen, Commercial Director, Renewable Chemicals Europe & North America at Braskem. The reason why Polytan has chosen this raw material for its artificial turf production is that the carbon footprint of I’m green polyethylene has a positive impact compared to fossil polyethylene. For every kg of I’m green polyethylene used in Polytan’s hockey fields for the games in Tokyo in 2020, almost 5 kg of CO 2 will be saved. All this is being achieved without any compromise on the quality of the turf. MT www.braskem.com | www.polytan.com bioplastics MAGAZINE [01/19] Vol. 14 27
