Textiles such as clothing, household textiles, medical textiles, technical textiles and furniture are an important part of everyone’s daily life. Thereof results a worldwide textile demand of millions of tons each year which brings along tremendous environmental impacts. The textile industry is within the top five industries being responsible for the environmental impact, climate change, water consumption, land use as well as raw material usage. Polyethylene terephthalate (PET) made from fossil-based sources is the most widely used material for textiles and thus the material with the highest overall environmental impact. Implementing thermo-mechanical fiber-to-fiber recycling of PET fiber waste is one of the starting points to target a closed-loop textile industry. In this article, main opportunities as well as challenges of thermo-mechanical fiber-to-fiber recycling are discussed to identify relevant needs that recycling systems must fulfill. On this basis, BB Engineering’s VacuFil Visco+ recycling solution is discussed. Different advantages of this fully redesigned process are pointed out and verified with recent feasibility studies and process investigations. A more extensive comparison of this process with competing systems is carried out which underlines tremendous advantages regarding sustainability of recycling fibrous polyester materials by using VacuFil Visco+ fiber-to-fiber recycling lines. This article addresses both, post-industrial as well as post-consumer recycling of fibrous polyester materials.