## 4 Conclusions  
This study adds value to a plentiful byproduct from the packaging industry, commonly referred to as CoP, which is massively generated during the manufacturing processes of stoppers in local factories which, in turn, are economically relevant in the area and have an extended impact throughout Spain and in other international wine producers. This finding allows companies to recirculate what used to be waste into a raw material with great production potential, which is in line with the global circular economy strategy.  
The novel material was blended with traditional thermoplastics like PP, yielding a new composite material categorized as CAG, owing to its agricultural origin. The compatibility between the residue and polymer spans the entire compositional spectrum, with the micrometric filler seamlessly integrated within the polymeric matrix without notable defects. As shown, an increase in the CoP concentration to 35% does not significantly modify the mechanical characteristics of the CAG in relation to the properties of the virgin polymer. Additionally, the calorimetric results show that the polymer structure is preserved and, most importantly, so is the crystallinity. However, due to the formation of conglomerates of CoP with a particle size of 0.5 mm, variations in the MFI could occur that represent trend changes in this rheological property, which have been described by other authors. On the other hand, the adhesion of the cork spike to the new CAG-injected stoppers with different CoP mixtures revealed a direct relationship between the thermoplastic content and adhesive consumption. This correlation is ascribed to the inclusion of CoP in the polymer, thereby eliminating the associated economic expenses. The research further demonstrates the viability of producing components and mechanical assemblies from industrial byproducts using various manufacturing methods, including both conventional (extrusion, injection, etc.) and emerging (3D printing) techniques. This approach helps mitigate the costs associated with raw materials. For the packaging company that manufactures cork stoppers, if firmly committed to this solution, it will lead to them achieving cost savings proportional to the percentage of cork used in the stopper. This new CAG encourages the use of sustainable packaging in an industrial sector that is a large consumer of thermoplastics.  
Figure 11: Prototypes manufactured through injection molding: (**a**) CAG adhesion tests in a 30:70 ratio, (**b**) wine bottle insertion tests.  
**Author Contributions:** Methodology, M.S., C.P.-M., G.A. and M.P.V.; Formal analysis, M.S., C.P.-M. and M.P.V.; Investigation, M.S., C.P.-M., G.A. and M.P.V.; Writing--original draft, M.S., C.P.-M. and G.A.; Writing--review & editing, C.P.-M. and M.P.V.; Supervision, M.P.V. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was funded by the Junta de Andalucia (Research group ref. TEP-181). Co-funding from the EU is also acknowledged. Furthermore, this work is part of the AGROCOM project, funded by the Call for Operational Groups 2020 (GOPC-CA-20-0004)--Junta de Andalucia, approved by Order of 30 July 2020. Grants aimed at supporting the operation of Operational Groups of the European Innovation Partnership (EIP) in the field of agricultural productivity and sustainability.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The raw data supporting the conclusions of this article will be made available by the authors on request.  
**Acknowledgments:** The authors would like to express their gratitude to the TORRENT group for providing the products. Special thanks are extended to the Peripheral Services of INMAR for conducting the FTIR analyses and to the Peripheral Services of IMEYMAT for conducting the SEM studies.  
**Conflicts of Interest:** The authors declare no conflicts of interest.