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SPF films conference showcases materials and technology premieres, debates sustainability issues

The agenda of the conference, organized by Maack Business Services, also featured discussions on some highly innovative barrier technologies, new additives, new film extrusion technologies, market and application developments in oriented films, biopolymers and brand owner perspectives. Without exception, presentations were the subject of lively debate in extensive Q&A sessions.
ExxonMobil continues to champion metallocene-catalyzed polyethylenes, mPE, which it markets under the Exceed and the more recently introduced Enable banners. Enable resins, copolymers of ethylene and hexene, have long chain branching that gives them processing characteristics similar to low density polyethylene (LDPE), yet they retain the high performance – toughness and strength – of linear-low density resins. François Chambon, the company’s PE market development manager for Europe, Middle East and Africa, said Enable can replace blends of low and linear low density resins, enabling film makers to down-gauge or increase output, depending on whether they are using LD- or LLD-rich blends.
Chambon also highlighted the suitability of Enable grades for pallet- and collation shrink applications. Collation shrink accounts for over 1.6 million tonnes of polyethylene globally, and the market is growing at over 5%/yr, he said. Film structures that have Enable-rich blends in the core and Exceed-rich blends in the skin can be made around 25% thinner than more traditional combinations of LLDPE and LDPE, meeting the increasing demand for more sustainable packaging.
Metallocene polyethylenes also featured in a presentation from Ineos Olefins & Polymers. Jacques D’heur, technical service leader for film and advanced packaging applications, introduced the company’s new Eltex PF mLLDPE (also using hexene comonomer). He said a key feature is its “reverse comonomer distribution” - more comonomer on long polymer chains and less on short polymer chains, the opposite of what happens with Ziegler-Natta catalysts – which yields high impact strength as well as very good sealing properties and optics. Again, long chain branching is present, providing high melt strength.
Exploring a similar theme of higher alfa olefins, but this time in the context of terpolymers, Borealis application marketing manager for PO blown films, Paulo Cavacas, introduced Borshape. He described this as a new generation of the company’s Borstar technology that makes possible the production of films that are both tough and stiff, as well as easy to process.
Cavacas said Borshape makes it possible to produce very thin films that retain the ‘feel’ of thicker films. It is particularly suitable for frozen food film grades, as core layers between skins of LDPE and mLLDPE/LDPE blends. He too emphasized processing characteristics, saying output levels achievable, as well as extruder energy consumption levels, can be similar to those of LDPE, depending on the grade used. Furthermore, films run very well on converting equipment, not only because of their stiffness but also because they have high hot tack strength.
Hiroshi Takayasu, a Senior Researcher at Mitsui Chemicals, talked about polypropylene films made using the company’s Notio propylene-based elastomer. Notio has a crystalline structure controlled at nano scale, Takayasu said. It has well-balanced physical properties and is completely miscible with PP, bringing softness and clarity to the films.
Equistar Chemicals, part of LyondellBasell, includes Plexar tie-layer resins for multilayer barrier films in its portfolio, the first ever tie-layer resins made in North America. R&D manager Maged Botros introduced a new technology for making resins that enables high inter-layer adhesion without the normal compromise in total film clarity. New resins, which are not yet commercial, are based on LLDPE.
Tie-layer resins normally reduce transparency because the interface between them and the neighboring barrier layer is uneven, “possibly because of covalent bonding that amplifies interfacial stresses, which lead to nanometer-scale distortions,” Botros said. The new resins have a graft architecture that enables them to absorb and dissipate these stresses. As a result, the interface between the tie layer and the barrier resin is virtually seamless.
Nippon Gohsei Europe R&D Manager Kaoru Inoue said the company has introduced Nichigo G-Polymer vinyl alcohol polymer, which combines advantages of conventional PVOH and EVOH resins: it exhibits gas-barrier, water-solubility, biodegradability and extrudability. In fact, oxygen barrier in dry conditions is 200 times higher than with EVOH, and in conditions up to 60% relative humidity it has the higher barrier of any extrudable resin.
A new collection of special ionomer resins from DuPont was discussed by Karlheinz Hausmann, R&D Fellow at the company. He discussed new sealing resins with higher melting points that withstand pasteurization, and also grades with high comonomer content that, unlike non-ionomeric sealant materials, have increased stiffness despite their reduced seal initiation temperature.
In the modifier area, the company has developed a product line of antistatic ionomer based polymeric additives under the trade name of Entira AS allowing for the production of transparent PE or PP based mono or multilayer films having a permanent antistatic effect due the non-migrating character of the additive polymer.
In a session on oriented films, Harrold Goertz, Global Technical Product Manager for Akulon polyamides at DSM Engineering Plastics, said caprolactam evaporation during film processing of PA6 is an issue that causes pollution of buildings and equipment. The average BOPA film producing company can have 15 to 50 tons/year lactam pollution, Goertz said. A new Low Oligomer PA from DSM offers a step up in quality, he said. Residual caprolactam in the polymer has been cut from 0.16-0.18% to 0.10%, but because caprolactam is also produced during the extrusion process itself, any further reduction would have limited value. “Stabilization is most effective,” he said. DSM is currently carrying out full scale trials on stabilized polymer.
Copolyamide 6/66 has been well known by barrier film producers around the world for many years, said Christopher Passe, in polyamide and copolyamide R&D at Ube Engineering Plastics. Copolymerisation produces a polymer with lower crystallinity than nylon homopolymer. It has better properties than nylon 6 and is more stable in extrusion. Ube also recently introduced a 6/66/12 terpolymer, Terpalex. This demonstrates especially high shrinkage with high puncture resistance, and cast films show improved thermoforming behaviour.
Topas Advanced Polymers’ market development specialist Oliver Schuck introduced new applications for cyclic olefin copolymers (COCs)in multilayer film packaging, where use can be made of their shrink properties, formability, barrier, stiffness, chemical resistance and clarity. They often exceed other polyolefins in these properties, while remaining compatible in blends and coextrusions.
“This property profile is the basis for a growing number of specialty applications in pharmaceutical and flexible packaging, said Schuck. He also introduced a concept called Topal, a metallized three-layer coextrusion with Topas skins, which has high moisture and oxygen barrier, and is suitable for packaging of dry foods.
In an additives session, advances in PP and PE nucleation and its effect on performance enhancement in blown film were discussed by Wim Van de Velde, Global Market Manager at Milliken Europe. His presentation focused on the company’s latest nucleation andclarification technologies – particularly Hyperform HPN-20E and Millad NX8000 - and the two major performance effects in blown film: the first being the productivity and optical improvement in PP and PE blown film; and the second the significant enhancements in barrier improvement in HDPE film.
In the first of two talks from equipment suppliers, Jim Stobie, Sales Vice President at Brampton Engineering, introduced the company’s new flexSTACK  multi-layer Co-Extrusion Die and flexWind Center/Surface Winding Technology for increased profitability in processing of co-extruded films. FlexSTACK uses a reconfiguration of the proven BE stacked die to decrease the residence time of co-extruded structures to ensure maximum flexibility and fast purging for various structures.  The purge time between structures has been shortened by 50%, while providing unparalleled layer and material flexibility.
David Atkinson, Vice President for Global Sales at NDC Infrared Engineering, discussed latest developments in near-infrared gauges used for high-speed in-line measurement and control of cast and blown films. Infrared gauges can discriminate between many different types of polymers, so the film processor can when necessary measure the amount of barrier material in the film or coating in addition to the total product thickness or weight. Use of special algorithms even makes it possible to measure the thickness of voided films and of blown film after it has been collapsed into a two-layer lay-flat.
In a session on bioplastics and environmental issues, Markus Schmid, Project Manager at the Fraunhofer Institute for Process Engineering and Packaging (IVV), discussed how biopolymers can functionalize existing packaging materials in terms of barrier improvement. He described the Wheylayer project, sponsored by the European Union, and aimed at developing whey protein coated plastics films using waste whey from the dairy industry in place of more expensive barrier polymers. The BioPaperCoating project concerns development of a coating system based on renewable materials that can be extrusion-coated onto paper and board for production of cartons for solid and liquid packaging. Base materials are PLA and PHA (polyhydroxyalkanoates), which are compounded with various additives. So far, over 150 blends have been produced.
Tuomas Mustonen, Business Development Manager at the VTT Technical Research Centre of Finland, introduced Atomic Layer Deposition (ALD) technology for putting ultra-thin film coatings of barrier resins onto substrates. ALD produces high quality thin layer metal oxide coatings with excellent barrier to water vapour and oxygen. Originally developed as a batch process, recent developments, including a “continuous operation” mode, have made it possible to extend the use of ALD for new higher volume applications, including high barrier coatings on biopolymer films.
A new ʺcrade to cradleʺ approach for PLA recycling was described by Steve Dejonghe, Project Manager at Galactic, a major lactic acid producer. LOOPLA is a new process based on chemical recycling of PLA back into lactic acid. Starting from used PLA (post-industrial or post-consumer), the process includes a pretreatment to prepare the PLA before entering into a reactor where the product is converted back into a crude lactic acid. After purification, lactic acid is obtained and can be recycled to make a virgin PLA with a yield close to 100%. The properties of this PLA are exactly the same as the original PLA.
PLA is of course a biodegradable polymer, but Dejonghe pointed out that if the polymer is allowed to degrade in the general environment, its value is lost. Chemical recycling on the other hand retains its value. The LOOPLA process is said to be low-cost, consumes little energy, and requires use of few additional chemicals. It is also robust, and can tolerate high levels of contamination. The company is already operating a 2000 t/yr unit in Belgium.
In a session on “Processor and Brand Owner Perspectives,” Achim Grefenstein, head of research at major film producer RKW, discussed “New developments in polyolefin films as sustainable products” and described the main environmental drivers from the perspective of a film manufacturer. RKW does produce degradable film for agricultural applications, but using the example of sacks for cement, Grefenstein concluded that in many cases, PE bags are more environment-friendly than alternatives such as biodegradable polyester and paper with PE liner. His conclusion was based on a full life cycle analysis. Grefenstein also discussed such other applications as diaper backsheet, shrink sleeves for bottles, and flow wrappers to demonstrate how well-tuned conventional thermoplastics and process technologies can provide sustainable solutions to numerous packaging problems.
Andy Sweetman is Business Development and Sustainability Manager at Innovia Films, which makes bioplastic films (cellulosic types made from wood pulp sourced from managed plantations) as well as BOPP films. He talked about the company’s NaturFlex films and how Innovia is working towards meeting brand owner sustainability objectives. He said sustainability requires focus on four key elements of a product life cycle: the raw materials, the process to make the product, its functionality and its end-of-life treatment. He said functionality is the most important of these, since wastage of package contents is a major factor. Compostable materials are typically permeable, so they perform well for ‘short shelf-life’ perishable foods, but need to prove their suitability for dry food applications, he noted. Innovia has developed NatureFlex NK, which he described as the first “off the shelf” biofilm to offer BOPP-like moisture vapour barrier properties.
Michael Remus, a Senior Scientist in Package Development at Procter & Gamble, said P&G has set the development focus in the flexible packaging sector on “delivering outstanding packages on shelf, at best possible cost, highest development speed and lowest environmental footprint, in partnership with film, resin and equipment manufacturers.” Remus said that with so many consumer buying decisions now being made at the time of purchase, it is more important than ever that technology is translated into “consumer meaningful” applications. He emphasized that P&G’s package development requires partners that can meet the scale, global needs and technology range of its businesses.