IMPROVING INK FORMULATIONS

[Anonymous]

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.
First Stage:
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.
Second Stage:
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
Third Stage:
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 &lt5 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 

[Author]

February 1, 2006 at 11:05 AM