Many substances, because of the nature of their yield values, have been considered unsuitable for viscosity or consistency measurements with rotational viscometers. Any rotating spindle, be it cylinder, disc, or paddle, will create a channel in such substances and after a very short time exert a negligible and meaningless torque on any sensing device. This effect also occurs with materials that have a gel structure.
Paint dyes, lithographic inks, and many other substances are thixotropic in that their structure is broken down and their viscosity is decreased when subjected to internal shearing. While no rotating spindle will ever spin freely in such materials, the torque required to produce this motion will become less as the period of internal shearing lengthens. The study of such data can lead to difficulties and require rigid testing procedures for QC.
Other materials, notably pastes and creams, show a combination of the two effects listed above. They will show a yield value as well as a change in relative viscosity/consistency with time.
The Brookfield Helipath™ Stand is designed to slowly lower or raise a Brookfield Viscometer/Rheometer so that its rotating T-bar spindle will describe a helical path through the test sample. By always cutting into fresh material, the problem of channeling or separating is eliminated and meaningful viscosity/consistency measurements can be made. The automatic reversing feature of the Helipath™ Stand allows measurements to be made over a variable period of time.
FEATURES & BENEFITS
- Designed for viscosity/consistency measurement of gels, pastes, creams, putty, gelatin and other non-flowing substances.
- A Brookfield Viscometer or Rheometer is mounted on the Helipath drive motor and a T-bar spindle is attached to the viscometer using a special coupling. The drive motor slowly lowers or raises the viscometer so that the T-bar spindle creates a helical path through the test sample thus eliminating the problem of “channeling”.
- Compatible with standard Brookfield Viscometers and DV3T Rheometers
- Simple to set up and clean
- Provides a solution for hard-to-measure materials
The Helipath Stand can be used with any standard Brookfield Viscometer and is supplied complete with a set of six T-bar spindles and a special coupling.
The Helipath Stand can also available to purchase with an EZ-Lock spindle couple system. This option allows spindles to be quickly attached and removed, and may also help prevent against damage that can occur from frequent spindle changes or multiple users. Please contact Brookfield or an authorized dealer for additional details and part numbers.
Existing Helipath Spindles can also be retrofitted with a special coupling adapter. Please contact Brookfield or an authorized dealer for details and part numbers.
**Note: The EZ-Lock option must be purchased for use with all “EXTRA” series Viscometers/Rheometers as well as all other instruments that have an EZ-Lock spindle coupling system.