Sample for evaluation
Analysis Section manager
We provide a rheology lecture once a year. We receive more than 200 consultation and sample testing requests, and measure and analyze data of various samples from our clients. Most of the samples are non-Newtonian substances, and more than half of them show thixotropic behavior. Thixotropy refers to the characteristics that hold time-dependent rheology, reduces the apparent viscosity at certain shear rate over time, and gradually recovers after shear stress is removed.
Viscosity is an important characteristic as an evaluation parameter for workability (coating properties, coating film thickness, leveling/dripping/extrution/mixing characteristics, and so on) of paint, ink, adhesive, sealing materials, etc. Especially the evaluation of thixotropic characteristic widely vary depending on the shear load while working, and the recovery after work strongly affecting the result, thus making it a very important parameter. Before introduction, we used to pre-adjust the status using a rotation viscometer and then make the various measurements. If carrying our evaluations other than viscosity at the same time, we would need a device that enables imposing quantitative shear load on a required amount.
By carrying out viscosity measurement and various evaluations at the same time on the sample mixed by THINKY MIXER, workability evaluation parameters are easily obtained from the sample's rheological data. In other words, by measuring viscosity after different mixing and storage time length, evaluation can be easily made.
Viscosity is very important in evaluating solid state properties. However, because of the complicated characteristics of viscosity's non-Newtonian behavior (such as shear rate and time dependence and yield value), it is understood well by only some of the researchers, and solid state property evaluation of viscosity is often avoided. We have been able to easily obtain valid evaluation by using the samples pre-adjusted with several mixing conditions of THINKY MIXER and measuring them with various measuring devices.