Rheological Identification of Thermal History in Recycled Polyolefin Compounds
Dynamic low-frequency rheometry identifies thermal degradation in recycled polyolefins that single-point melt flow tests miss entirely.
ISO 15528
Meaning
Standardized protocols define the methods used to obtain representative samples of liquid or paste-like chemical raw materials from bulk shipments. The international standard iso 15528 governs the manual and mechanical sampling of these fluid resins, dispersions, and liquid polymers prior to their compounding or conversion. Sourcing agents use this methodology to verify the batch consistency of incoming liquid components such as polyols, epoxy resins, and liquid colorants.
Sampling Procedure
Correct extraction of liquid samples requires specialized equipment that prevents contamination and moisture absorption. Under the rules of iso 15528, the technician must select sampling devices that match the viscosity and homogeneity of the material. This procedure is performed at the receiving dock or storage silo before the raw material is transferred to the primary production vessels.
Material Quality
Poor sampling practices lead to unrepresentative test results that do not match the true properties of the batch. Compliance with iso 15528 is necessary for detecting water contamination or polymer phase separation in liquid raw materials.
Processing Consequence
Inaccurate sample analysis allows off-specification material to enter the moulding or compounding process. For reaction injection moulding, inconsistent polyol blends cause density variations and surface defects in the finished polyurethane parts. Processors experience severe part reject rates when resin batches are accepted based on improper sampling of high-viscosity prepolymers.
Raw material testing must rely on certified sampling to maintain the integrity of the polymer supply chain.