Research on the blending of post consumer HIPS yogurt cup mechanical recycling materials with raw materials for food contact packaging

Research Background and Object: A study published in Volume 58 of Food Packaging and Shelf Life (December 2026) focuses on the mechanical recycling of high impact polystyrene (HIPS) yogurt cups after consumption. Authors Javier Sep ú lveda Carter, Diego Lascano, Sim ó n Faba, Jos é L. Moreno de Castro, Laura Mar í n, Paula Ba ñ os, Alejandra Torres, Mar í a Jos é Galotto, Rafael Balart, Marcos S á nchez Rodr í guez, and Marina P. Arrieta blended post consumer HIPS recycled materials with native HIPS and evaluated their feasibility for food contact application scenarios. The core issue of this study is that the molecular structure and properties of mechanically recycled HIPS will change after use, collection, and reprocessing. If it is to be blended with native resin and reused in food packaging, a balance needs to be struck between processing stability, hygiene and safety, and mechanical properties. The study focuses on yogurt cups, a typical container for daily chemical and food packaging, which has strong practical relevance.

Research content and focus

From the perspective of research design, the work focuses on the blending of recycled materials and raw materials, examining the performance of the blending system in the reprocessing process, and evaluating it for food contact applications.

. For packaging materials, HIPS is commonly used for thermoformed products such as yogurt cups and dairy containers. Whether the recycled materials can be stably returned to similar or comparable applications depends on the thermal history and degree of material degradation during the processing. In this stage, stable processing is a key prerequisite for the application of recycled materials. Multiple hot processing can cause degradation of polymer chains, thereby affecting melt flow, color, and mechanical properties. The evaluation of blending and reprocessing involved in the research revolves around such issues. For formula designers, the role of antioxidants and other additives in the recycling system is worth paying attention to: on the one hand, it is necessary to suppress oxidative degradation during processing, and on the other hand, it is also necessary to consider the compliance and migration risk of the additives themselves under food contact conditions.

Significance for the polymer additive industry

This study suggests that the use of recycled materials in food packaging is not simply physical blending, but involves systematic engineering of material properties, processing windows, and regulatory compliance.. For additive suppliers, the stability requirements of the recycled material system may lead to differentiated formulation ideas: designing suitable antioxidant combinations based on the degradation characteristics of HIPS after consumption, to help maintain the processing stability of the blend during hot forming and extrusion processes, while meeting the requirements of food contact regulations on the types and amounts of additives. In addition, the study focuses on yogurt cups, indicating that the closed-loop recycling of packaging materials needs to consider the singularity of materials and the recyclability of auxiliary systems in the design stage. The blending ratio, stability of recycled material sources, and number of reprocessing times all affect the consistency of the final product’s performance. For packaging resin and additive companies, this means that they need to collaborate with the recycling and product ends to establish a technical path from material characterization to formula adjustment.

Issues that need further attention

This study is a journal paper with limited abstract information. Specific blending ratios, mechanical and barrier performance data, migration test results, and regulatory compliance conclusions need to be confirmed by reviewing the full text.

. Readers should refer to the original data when citing relevant conclusions, and should not directly equate research results with commercial formula recommendations.

Information source:Mechanical recycling of post-consumer HIPS yogurt cups blended with virgin HIPS for food contact applications， Organized by Herun Chemical.