Developing sustainable flexible packaging barrier solutions to support the 2025 sustainability pledges of global brand owners, retailers & convertors

随着应对全球塑料垃圾的挑战越来越大，可持续发展和迈向更循环经济的愿望是任何企业的关键话题。在欧洲，约40%的塑料垃圾来自塑料包装，约20%的欧盟塑料包装是柔性消费包装。因此，许多参与包装材料价值链的公司，从原材料生产商、电影制片人和转换器到品牌所有者和零售商，都承诺到2025年使用100%可回收、可重复使用或可堆肥的包装材料。软包装材料目前要么是简单的单层、单材料(可回收利用)，要么是复杂的多层结构(通常不可回收)，以满足更苛刻的包装需求，每一层都赋予最终包装特定的设计功能。这些层可以是聚合物的，例如薄膜层和湿法涂层/粘合剂，或无机材料，如真空沉积的阻隔层或铝箔。然而，用更环保的替代品取代单独的层并不容易，因为对机械或屏障功能(控制保质期)至关重要的性能可能会受到影响。这项提议的目的是为食品/医疗包装应用开发可持续的柔性屏障材料解决方案以及相关工艺，以支持和实现2025年的可持续发展目标。因此，该提案巩固了在可持续发展总括主题下联合起来的项目组合。初始阶段将是开发一种新的高速二氧化硅(SiOx)沉积工艺。SiOx是一种透明真空沉积阻挡层，已被证明具有良好的回收性能，并且由于沉积过程的低热影响，它非常适合于针对可回收单材料(聚烯烃为基础)和生物基包装解决方案的更热敏感的基材。然而，由于当前工艺的低沉积速率，封装的应用受到限制。对于可回收的单一材料解决方案的开发，重点将不仅放在作为阻隔层的SiOx上，还将研究其他真空沉积涂层，如透明氧化铝和铝金属。使用聚烯烃聚合物基板时的主要挑战之一是其在机械刚性、热敏性和表面极性方面的限制性能，这对薄膜加工以及实现替代现有材料所需的阻隔性能的能力构成了挑战。另一个项目将侧重于额外的障碍增强和保护，从而实现环境友好和创新的一步法解决方案，减少碳足迹。这将是相对于目前的做法的一个进步，即在额外的工艺步骤中离线应用湿增强涂层。进一步的包装创新还将包括使用可生物降解/可堆肥的聚合物薄膜以及纸基基材，以生产可持续的屏障材料。最后，我们的目标是开发创新的可持续蒸馏解决方案，由于其单一材料的性质，可以回收利用，与目前的多材料解决方案不同。通过将学术和行业专家聚集在一起，在研究员的领导下就这一项目进行合作，这项工作的成果将使更可持续的软包装解决方案能够投放到市场上，消费者很容易注意到，从而更接近循环经济和更可持续的包装未来。

With the rising challenge of tackling global plastic waste, sustainability and the aspiration to move towards a more circular economy are key topics for any business. In Europe, around 40% of the plastic waste originates from plastic packaging and around 20% of the total EU plastic packaging is flexible consumer packaging. Hence, many companies involved in the value chain of packaging materials, ranging from raw material producers, film producers and convertors to brand owners and retailers, have committed to using 100% recyclable, reusable or compostable packaging materials by 2025. Flexible packaging materials currently are either simple mono-layer, mono-materials (which are 'recycling-ready') or complex multilayer structures (typically not recyclable) for more demanding packaging needs, with each layer conferring certain designed functionalities to the final package. These layers can be polymeric, e.g. film layers and wet-applied coatings/adhesives, or inorganic materials like vacuum deposited barrier layers or aluminium foil. However, replacing individual layers for more environmentally friendly alternatives is not easy, since properties critical to mechanical or barrier functionalities (which govern shelf life), may be compromised. The aim of this proposal is to develop sustainable flexible barrier material solutions for food/medical packaging applications as well as associated processes in order to support and achieve the 2025 sustainability ambitions. The proposal thereby consolidates a portfolio of projects united under the umbrella theme of sustainability. The initial stage will be the development of a novel high-rate silicon oxide (SiOx) deposition process. SiOx, a transparent vacuum deposited barrier layer, has been shown to have good recycling properties and, due to the low thermal impact of the deposition process, it is ideally suited for more heat sensitive substrates targeted in recyclable mono-material (polyolefin-based) and bio-based packaging solutions. Applications for packaging are limited, though, due to the low deposition rate of the current process. For the development of recyclable mono-material solutions, the focus will not only lie on SiOx as a barrier layer, but other vacuum deposited coatings such as transparent aluminium oxide and aluminium metal will also be investigated. One of the main challenges when using polyolefin-based polymer substrates are their limiting properties in terms of mechanical rigidity, heat-sensitivity and surface polarity, which challenge the film processing as well as the ability to achieve the barrier properties required to replace existing materials. Another project will focus on additional barrier enhancement and protection, thus enabling an environmentally friendly and innovative one-step process solution with a reduced carbon footprint. This will be an advancement from current practice, whereby wet enhancement coatings are applied offline during an additional process step. Further packaging innovations will also include the use of biodegradable/compostable polymer films as well as paper-based substrates in order to produce sustainable barrier materials. Again, the 'new' substrates themselves present the main challenge here in achieving the targeted barrier performance.Finally, the aim is to also develop innovative sustainable retort solutions, which can be recycled due to their mono-material nature, unlike the current multi-material solutions. By bringing academic and industry experts together to collaborate on this project under the lead of the Fellow, the outcome of this work will enable more sustainable flexible packaging solutions to be placed onto the market readily noticeable to the consumer, thus advancing closer to a circular economy and a more sustainable packaging future.