Research
SHT for PP recyclates
Developement of a method for an easy determination of the stress cracking resistance of polypropylene recyclates based on the strain hardening test
Project number: 01IF24200N
Project duration
From: 01.08.2025 To: 31.07.2027Description
Polypropylene (PP) is a widely used commodity. If, in the context of a circular economy, PP should be used more and more in technical applications, this requires a fast and reliable quality quantification. Regarding long-term properties, the stress crack resistance limiting the service life, is of high interest. Therefore, the research project aims at a method development based on the strain hardening test (SHT), which is so far only standardized for virgin high density polyethylene pipe materials. Thus, new application fields for PP recyclates should be exploited and optimization potentials should be revealed. Compared to other tests, the SHT offers several benefits like easy implementation with standard testing technology (tensile test) and short testing times. To tap this potential, the necessitated basic knowledge should be elaborated. For this, defined blends will be compounded and characterized regarding to their stress crack resistance. Besides a suitable technical implementation for PP blends, the focus is on an improved understanding of the component and proportion influences, including the development of a model for stress crack resistance estimation. Additionally, the optimization potential by blending PP recyclates with virgin material will be examined. The targeted research results are relevant to several industries like recycling enterprises, compounders, manufacturers and engineering service providers. They can provide information on PP collection and recycling, support quality assurance, liability risk reduction and product optimizations as well as contribute in general to the exploitation of applications for PP recyclates.Contact person:
