*NEWS*IMPROVING INK FORMULATIONS
*NEWS*IMPROVING INK FORMULATIONS
2006-02-01 at 11:04:00 am #14308
Improving Ink Formulations One Stage at a Time
Robotic Viscometer Aids in the Effort
The expansion of the ink jet and other specialty print markets has driven demand for improved inks. One leading ink producer found itself facing the combined challenge of producing new and innovative products while lowering material and production costs.
This ink maker was interested in improving formulations in both dye and solvent-based inks up to 50 cP in viscosity. They needed to be able to evaluate hundreds of small samples a day with an appropriate accuracy and repeatability to support their efforts in screening and developing new ink formulations.
Multi-Stage Formulation Approach
New product development is more and more a numbers game. Winning products will be developed by those that sort through the alternatives most efficiently and effectively. Many users are gravitating to a multi-phase approach, which places different demands on instrumentation.
High throughput screening is used as a first cut to identify significant differences in the desired product parameters. Detailed analysis on all possible formulations is impractical. Screenings use a minimum number of tests enhanced by sophisticated statistical tools to speed the process. At this stage, the accuracy of the instrument used is typically not as critical as appropriate evidence of the targeted characteristic, the sample usage, and throughput time.
Once the number of potential formulations-from thousands to a few hundred-is identified, a next level of analysis is necessary. Candidate formulations undergo more detailed tests in this stage, which require larger sample sizes and more precise performance analysis. Despite the improved performance characterization, 80% to 90% of the formulations will not make it out of this stage. Controlling the time spent examining each of these leads is essential. In this stage, a test accuracy of 2% to 3% provides enough sensitivity to identify the best formulations, and often tests are performed in replicate to estimate repeatability to guard against errors.
Liquid handler with 60-sample rack
The third level of high throughput screening frequently involves the final 10 to 15 formulations. These finalists are scrutinized in detailed evaluations for the desired performance characteristics. The goal of this testing is to determine if any one of the samples should be recommended for further development or pilot production. Primary analysis concerns for measurements at this stage are accuracy and repeatability, while test time and sample size are less significant.
Ink Maker’s Choice of Robotic Viscometers
“Cambridge Applied’s VISCObot proved to be the best option for us out of three tested systems. We were pleased not only with the general performance but also the robustness of the instrument and its user-friendly interface,” concluded the evaluating engineer.
VISCObot with 40-mL to 15-mL Vials
Important characteristics of the VISCObot include:
•Unattended operation with high throughput of <5 minutes (including sampling, measuring and cleaning)
•The freeing up of lab technician hours, saving money in each step of a viscosity test
•The elimination of operator dependence, making the results systematically repeatable, statistically verified and therefore more robust for meeting continuous improvement objectives
•Acceptable accuracy of ۬% of reading for inks with viscosities of up to 15 cP and ۭ.5% for fluid viscosities ranging from 15 cP to 50 cP, including UV curable inks
•A sample size of only 5 mL is required for fluids of 2 cP to 50 cP
•Works effectively with water as well as various solvents including MEK
•The sampler accepts trays of up to 100 samples and can be adjusted to different sampling bottles or tray layouts