Performance of novel tinplate products: adhesion of polyester to new, REACH-compliant steel substrates

钢制食品和饮料罐头通常涂上一层漆，以改善食品保存性，并符合法律规定。直到最近，这些主要以双酚A(BPA)为基础的“环氧型”漆应用于马口铁已经非常成功地使用了很多年。然而，由于最近对双酚A漆的使用(食品)安全的担忧，欧洲已经出台了立法，禁止在罐头中使用双酚A漆。Protact(塔塔钢铁的聚合物涂层基板)被视为解决这些问题的完美候选者。在特罗斯特雷(威尔士)和IJmuiden(荷兰)正在实施大型投资项目，以增加产量并开发这一不断增长的市场。此外，欧洲立法要求工业在生产过程中远离六价铬。Protact目前的衬底是一种镀铬钢(ECCS)，通过铬(VI)工艺生产。虽然最终产品不含铬(VI)，但ECCS需要更换，以保护劳动力免受铬(VI)的影响。为了确保合适的基板的供应，塔塔钢铁开发了一种名为TCCT的替代基板，该基板本身就是EngDoc研究的活跃课题。然而，目前对Protact与基材粘附性的机理研究都是在ECCS上进行的，对影响TCCT粘附性的因素认识相对有限。聚酯层压板(如塔塔钢铁的Protact材料)非常适合解决当前和未来的所有食品安全问题，新的基材也将符合REACH法规。在IJmuiden，生产线上已经安装了一个新的TCCT单元，近期将对Trostre进行投资。随着这些大型新投资的实现，对材料性能的了解对于塔塔钢铁支持Protact在市场上的使用至关重要。本提案的主题是了解Protact在食品杀菌等恶劣条件下涂层附着力方面的特性，并确定实现足够的产品性能所需的材料。

Steel food and beverage cans are generally coated with a lacquer to provide improved food preservation and to fit with legislation. These "epoxy-type" lacquers, until recently mainly based on bisphenol A (BPA), applied to tinplate have been used very successfully for many years. However, due to recent (food) safety concerns about the use of BPA lacquers, legislation has been introduced in Europe banning its use in cans. Protact (Tata Steel's polymer-coated substrate) is seen as the perfect candidate to solve these issues. Large investment projects are being realised in Trostre (Wales) and IJmuiden (The Netherlands) to increase production volumes and develop this growing market. Furthermore, European legislation requires industry to step away from Cr(VI) during production processes. Current substrate for Protact is a chrome-coated steel (ECCS), produced via a Cr(VI) process. Although the final product is Cr(VI)-free, ECCS needs to be replaced to protect the workforce against exposure to Cr(VI). To ensure availability of the right substrate Tata Steel has developed an alternative substrate, called TCCT, itself an active subject of EngDoc research. However, all mechanistic studies on adhesion of Protact to substrate were done on ECCS, and relatively limited understanding of the factors influencing the adhesion on TCCT are clearly defined. Polyester laminates (like Tata Steel's Protact material) are uniquely suited to solve all current (BPA) and future food safety issues and with the new substrate will also comply to the REACH legislation. In IJmuiden, already a new TCCT cell has been installed in the production line, and investment in Trostre will be done in the near future. With these large new investments being realised, the understanding of the material performance is essential for Tata Steel to support the use of Protact in the market. The theme of this proposal is to understand the properties of Protact with respect to adhesion of the coating under severe conditions like food sterilisation and to determine requirements of the material to achieve sufficient product performance.