Research

In this project, a recycling strategy for polyvinyl chloride (PVC) coated polyethylene terephthalate (PET) mesh fabrics is developed while avoiding melting of the PET fibres. Thermal reprocessing of this polyester is usually associated with degradation of the polymer chains as a result of thermal damage, acting shear forces and hydrolytic chain scission. To avoid this polymer damage, which occurs in the course of re-granulation, the use of PET fibres as reinforcement in plastics which are distinguished by significantly lower melting temperatures is being tested. The requirements for achieving high strengths and thus for the success of this possible application are (i) the separation of the fabric into individual fibres while maintaining high fibre lengths, (ii) enabling continuous feeding into the production machine and (iii) homogeneous dispersion of the fibres in the plastic matrix. Due to the minimum fibre lengths necessary to achieve high mechanical strengths, the separation of the fibres by means of a heating-cooling mixer is tested with variation of the settings and different fabric concentrations between 10 and 40%. Profile extrusion of the three blends into strip profiles will be tested using the NCT 55 conical co-rotating production extruder. To evaluate this application possibility, the bending properties as well as the Charpy impact strength will be determined on the profiles.

Project objective: To develop the residual material from insect farming into a high-quality fertiliser with an integrated microbial system. In the next few years, the production of insects is expected to increase dramatically due to the growing demand for alternative protein sources. The advantage of insects is that they take up little space in the breeding process compared to other farm animals and cause far fewer climate-damaging emissions. Considering the zero-waste context and the need to contribute to the circular economy, it is necessary to recycle all components of insects, including their by-products. One by-product generated from insect breeding is the frass, which consists of the unreacted food source and the faeces produced by mealworms. This has a high potential to partially or completely replace conventional NPK fertilisers due to its rapid mineralisation and high content of readily available nutrients. Benefits for the company Threepoint GmbH: On the one hand, this alternative way of upgrading the insects' residues improves the value cycle of mealworm breeding and represents a possibility to provide a sustainable fertiliser in the near future, which not only serves as a nutrient supply, but also increases the diversity in the soil.

Within the framework of this project, insect components are examined with regard to their chitin and chitosan content. The skins consist mainly of chitin, which is currently separated with the contained wheat bran (food for mealworms) after production and offered as fertiliser in agriculture. While on the one hand an agricultural application of this product is to be assessed as positive in terms of the circular louse economy, this waste product of mealworm breeding could represent a possibility to obtain chitosan from it.