STTR Phase II: Nanofiber Fabrication via Melt Coextrusion for Fuel Filter Membranes

这个小型企业技术转移二期项目的更广泛的影响/商业潜力是展示一种低成本、环保的共挤压制造方法，用于生产高表面积的微纤维和纳米纤维非织造燃料过滤片。微/纳米纤维非织造结构是由两种不同的亲水性和疏水性聚合物在熔体共挤出和随后的剥落加工步骤中制成的。由此产生的多孔过滤介质具有优越的强度，可定制的孔径和燃油过滤效率，与目前使用的商用燃油过滤产品相当。这些成就标志着生产低成本热塑性过滤产品的高度可扩展制造工艺的前进道路，以解决日益严格的EPA对ppm水平水污染物的监管。据估计，熔体共挤出降低了制造过程的复杂性，当规模达到商业生产数量时，可降低高达60%的生产成本。此外，通过采用这种新颖的生产技术而不是竞争过程，由于其“更环保”，将实现重大的环境影响。无溶剂制造方面，消除了每年数百万加仑有机溶剂的需求，并支持回收设备，目前过滤行业用于制造电纺丝和湿铺复合非织造过滤介质。第二阶段研究项目的目标是通过一种新型的熔融共挤出方法制造用于燃料过滤器的纳米/微米级非织造纤维过滤垫，具有高燃料/水过滤效率和卓越的机械性能，具有商业相关的生产规模，以满足严格的EPA 2010过滤法规及其即将在2015年进行的修订。在第一阶段STTR计划中制造的第一代过滤器原型显示，其表面积增加了10倍，孔隙率增加了2倍，变形强度增加了6倍。共挤微孔过滤纤维的尺寸分布与商业熔喷工艺样品相当，优于领先的湿法工艺样品。初步的过滤效率实验表明，在相同的测试条件下，与使用商用过滤器的80%的水分离率相比，共挤微纤维过滤介质原型的超低硫柴油的水分离率为60%至80%以上。新的多层共挤过滤介质处理技术的商业利益集中在鉴定新的过滤介质薄膜聚合物材料，实现纳米级孔隙分布以提高过滤效率，并通过改进的过滤膜处理技术实现规模化生产成本节约。

The broader impact/commercial potential of this Small Business Technology Transfer Phase II project is to demonstrate a low cost, environmentally friendly co-extrusion fabrication method for producing high surface area micro- and nanofiber based nonwoven fuel filter sheets. The micro-/nanofiber nonwoven structures are fabricated from two different hydrophilic and hydrophobic polymers in a melt co-extrusion and subsequent exfoliation processing step. The resulting porous filtration media sheets have been shown to possess superior strength, tailorable pore sizes, and fuel filtration efficiency on par with currently utilized commercial fuel filter products. These accomplishments signify a path forward to a highly scalable manufacturing process for producing low cost thermoplastic filter products in addressing the increasingly stringent EPA regulation of ppm level water contaminant. The reduced manufacturing process complexity in melt co-extrusion is estimated to provide up to 60% reduced production costs when scaled to commercial production quantities. Additionally, a significant environmental impact will be realized through adoption of this novel production technology over competitive processes owing to its ?greener? solvent-free manufacturing aspects that eliminates the annual need for millions of gallons of organic solvents and supporting reclamation equipment currently utilized by the filtration industry in creating elctrospun and wet-laid composite nonwoven filtration media.The objectives of this Phase II research project are to fabricate nano/micro scale nonwoven fibrous filter mats for fuel filters via a novel melt co-extrusion approach, with high fuel/water filtration efficiency and superior mechanical properties, in a commercially relevant production scale, towards addressing the stringent EPA 2010 filtration regulations and its upcoming revisions in 2015. The first generation filter prototypes fabricated in Phase I STTR program exhibited up to a ten-fold increase in surface area, up to a two-fold increase in porosity and up to a six-fold the deformation strength of the commercial filters. The coextruded microporous filter fiber size distribution was comparable to a commercial melt-blown process sample and superior to the leading wet-laid technology samples. Preliminary filtration efficiency experiments on the coextruded micro-fiber filtration media prototypes exhibited 60 to greater than 80 % separation of water from ultra-low sulfur diesel as compared to 80 % water separation using commercial filter under same testing conditions. The commercial interest for the new multilayered, coextruded filtration media processing technique is centered on identification of new filtration media film polymer materials, achieving nano-sized pore distributions for improved filtration efficiency and achieving scale-up production cost savings through the improved filter film processing technique.