A high-resolution dataset on the plastic material flows in Switzerland.

A material flow analysis of the main plastic types used and arising as waste in Switzerland in 2017 is conducted, including consideration of stock change. Seven main plastic application segments are distinguished (packaging; building and construction; automotive; electrical and electronic equipment; agriculture; household items, furniture, leisure and others; and textiles), further divided into 54 product subsegments. For each segment, the most commonly used plastic types are considered, in total including eleven plastic types (HDPE, LDPE, PP, PET, PS, PVC, ABS, HIPS, PA, PC, and PUR). All product life cycle stages are regarded, including the determination of the product subsegments in which the individual post-consumer secondary materials obtained from mechanical recycling are applied. The underlying data are gathered from official statistics and administrative databases, scientific literature, reports by industry organizations and research institutions, websites, and personal communication with stakeholders. The compiled data are then reconciled. All flow data are provided and depicted in two Sankey diagrams: one diagram shows the material flows on a product-subsegment level and the second one on a plastic-type level. Users may retrieve the data with a script and transfer them into a relational database. The present material flow analysis data are used as a basis for the scenario analysis in Klotz et al. [1]. Besides scenario modelling, the data can be used in conducting life cycle assessments. Both utilizations can serve as a support for designing future plastic flow systems.

Limited utilization options for secondary plastics may restrict their circularity.

Plastic recycling can provide environmental benefits by avoiding the detrimental impacts of alternative disposal pathways and enabling the substitution of primary materials. However, most studies aiming at increasing recycling rates have not investigated how the resulting secondary materials can be utilized in product manufacturing. This study assesses the future substitution potential of primary with secondary plastics, building on a material flow system of 11 plastic types in 54 product subsegments in Switzerland in 2017 with a recycling rate of 9%. In a prospective material flow analysis of a scenario for 2025, the collection rate of the plastic fractions collected in 2017 is increased to 80%. The secondary material flows are allocated to suitable uptaking product subsegments using a linear optimization. The maximum share of secondary materials utilizable in each product subsegment is estimated, whereby three sub-scenarios involving high, moderate and low allowed secondary material shares are modelled. Depending on plastic type and scenario, 21% to 100% of the secondary material gained can substitute for primary material, covering 11% to 17% of the total material demand. While the overall recycling rate could reach 23%, taking into account only the uptaken secondary materials a true recycling rate of only 17% results in the moderate applicability sub-scenario. Based on these results, the secondary material uptake can be said to constitute a limiting factor for increased future recycling. Therefore, thorough consideration of the possible secondary material application is a prerequisite for designing and assessing future recycling systems or for setting recycling rate targets.

Recycling process for carbon fiber reinforced plastics with polyamide 6, polyurethane and epoxy matrix by gentle solvent treatment.

Due to the complex composition of carbon fiber reinforced plastics (CFRPs), a complete and useful recovery of such composite material is a real challenge. This paper presents studies on potential solvent-based recycling processes for three CFRP samples comprising polyamide 6 (PA6), polyurethane resin (PUR) and epoxy resin (EP) matrix. Different proprietary CreaSolv® Formulations were applied in laboratory scale and under thermodynamically subcritical conditions in order to dissolve the polymeric matrix and separate the inert carbon fibers. By variation of decisive process parameters, the influence of the temperature-time-load during solvent treatment and solvent recovery was observed carefully. A complete removal of the polymer matrix of all samples was achieved by means of multi-stage solvent extraction without reducing both the length and tensile strength of the recovered carbon fibers. The recovered PA6 matrix polymer revealed no significant decline of its initial average molecular weight. For the dissolved and extracted resin matrices, feedstock recycling was identified as suitable reprocessing. All of the solvent formulations tested were recycled successfully, keeping the initial dissolution properties and, thus, being applicable in a closed loop process design.