What is Rheology?
Dynisco, with its diverse portfolio of sensing and polymer testing equipment, brings rheology to the masses.
Rheological Measurements and The Plastic Extrusion Process In the plastic extrusion process, the elevated temperatures associated with melting processes, combined with the time that polymers spend in the barrel, can affect the molecular weight of the extrudates. Performing rheological measurements of a compound before, during, and after the melt processing is an efficient way to detect if any thermomechanical degradation has taken place during the extrusion process.
Why It Is Important to Avoid Degradation and Keep Polymers in Specification?
- Short-term and long-term properties such as impact resistance, fatigue resistance, and enviornmental stress cracking resistance are all sensitive to the changes in molecular weight.
- As recycling mandates require corperations to use a certain percentage of recycled content, it is important to keep producers' reprocessed scrap or the purchased recycled materials as close to their virgin specifications as possible to maintain quality.
- Also, the polymer is a "blind item". Recyclers and manufacturers can not tell the polymers' specifications just by looking at them.
- Minimize degradation during the recycling process
- Ensure that the polymer does not degrade to affect the quality of the product
It can provide companies with accurate information that allows them to validate and if necessary adjust their process to ensure the products they make either meet or exceed their specifications. This is especially important as plants often process tens of thousands of pounds of material at a time. Without having real-time knowledge of the rheological properties of the materials, manufacturers risk spending hours producing bad products before realizing it, thereby wasting time and money, sacraficing process consistency.