RECENT UPDATES

VISCOSITY FORUM: Ask the experts

How do you test construction materials for “flowability”?

Measuring Viscosity? Kinematic or Dynamic Method. How to Choose?

11/21/13 at 11am EST

An Interview With Pat Maggi

Capillary and rotational viscometers are used around the world to measure viscosity. Why are there two different methods? Does each have certain advantages that recommend its use for certain categories of materials? This interview will review various test methods that encompass one or the other technique and provide guidance on how best to proceed when in doubt on the choice. read more

How do you test construction materials for “flowability”?

How do you test construction materials for “flowability”?

11/6/13 at 11am EST

Dr. Guy Rosenthal Interview

How do you test construction materials for “flowability”? For example, when you open a tub of joint compound, does it have the right consistency? Do you know right away when you stick your trowel in? Or is the proof of the pudding in how it spreads? read more

Life Below the Yield

Viscometer vs. Texture Analyzer

10/23/12

An Interview with Ross Clark

When does a viscometer make sense and when does a texture analyzer make sense? read more

 

BROOKFIELD RESPONDS: Q+A

10/2014

CUSTOMER CHALLENGE: What is the proper way to test yogurt for viscosity? When we use an RV disc spindle, the viscosity value seems to vary quite a bit. Sometimes the reading will be stable, but at other times it will drop as the spindle continues to rotate. Does the spindle position in the yogurt container make a difference? Please help; this issue is affecting our QC Department because we are rejecting several batches of yogurt each week.

BROOKFIELD ANSWERS:

The “best” approach for measuring viscosity may relate to the “thickness” of the product. Yogurts that are smooth, creamy, and flow easily off of a spoon can be measured in the way that you described; use an RV disc spindle (maybe RV3 or RV4), run at 10rpm and take the measurement after 30 seconds.

Yogurts that are thicker or that contain fruit particles/chunks may require a different spindle. The T-bar spindle with Helipath Stand has been used to measure viscosity of “thick” yogurts that do not flow easily. The disc spindle will create a hole as it rotates and the viscosity reading will drop. The T-bar cuts through fresh yogurt with each revolution of the spindle and gives a steady viscosity reading.

If the yogurt contains fruit, the T-bar may show viscosity readings that jump up and down when the spindle makes contact with the particles. In this case it may be helpful to take an average of the viscosity reading. The new DV3T Rheometer and DV2T Viscometer offer this feature.

The vane spindle may offer a better alternative for yogurts that contain fruit. When the vane rotates, the fruit trapped between the vanes will rotate with the spindle. The yogurt outside the circumference of the vane spindle shears against the yogurt within the vane. The viscosity signal may be more stable compared to the T-bar reading.

One added advantage of the vane spindle is that you can measure “yield stress”, which is a measure of the “stiffness” of the yogurt. The DV3T Rheometer has this measurement method using the built-in “EZ-Yield” program.

10/2014

CUSTOMER CHALLENGE: The expression “spindle geometry” is used when talking about viscosity test methods. What does it mean?

BROOKFIELD ANSWERS:

The shape and size of the spindle are the points of information that describe spindle geometry.

The most popular spindle in use by Quality Control Departments is the disc spindle. The disc located near the bottom of the spindle is the reason for the name. The geometry consists of the spindle shaft which is a cylindrical rod and the disc. Different diameter and thickness values characterize the variety of disc spindles that are available. In general, the smaller discs are used to measure higher viscosity materials, while the larger discs are used to measure low viscosity materials.

Other spindle geometries include cylinders, cones, plates, T-bars, spiral spindles, vanes, and more.

The Brookfield publication “More Solutions To Sticky Problems” provides the detailed geometry information on each spindle type.

ADDITIONAL INFORMATION CAN BE FOUND IN OUR CATALOG Register to Download

Join the Viscosity Journal Community Today… IT’S FREE!

The Viscosity Journal is a trusted resource brought to you by Brookfield Engineering, the global leader in viscosity, offering news, events, and information from industry experts to its members.

WANT TO READ OR HEAR MORE? Sign Up to join the thousands of international members that use the Viscosity Journal – it takes less than 30 seconds!

Click Here

VISCOSITY OF WATER TABLE

View the viscosity of water at temperatures between 0 - 100° C.

See the Table
 

VISCOSITY OF MATERIALS TABLE

Instant view of some dynamic viscosities of Newtonian fluids.

See the Table
 

VISCOSITY CALCULATOR

The cup to viscosity conversion engine assumes fluid is Newtonian.

See the Table
 

YIELD STRESS VALUES

Examples of values for typical food and personal care products

See the Table
 
signup for viscosity journal by brookfield
 
signup for viscosity journal by brookfield

March 2014

» Brookfield Introduces More Touch Screen Technology in 2014!

March 2014

» Brookfield Introduces New Family of RST Touch Screen Rheometers!

November 2013

» TexturePro CT Software Now 21 CFR Compliant

August 2013

» New Rheocalc T Software for DV2T Viscometers and DV3T Rheometers

August 2013

» IQOQPQ on Brookfield Powder Flow Tester for Pharmaceutical Industry

August 2013

» New Material Choices for Shear Cell Kits with Brookfield Powder Flow Tester

July 2013

» Having the Right Lid Strength is Apeeling!

July 2013

» Get a Better Grip on Samples: New 10mm Dual Grip Assembly for Tensile Testing

June 2013

» Peel Away the Confusion of Adhesive Measurement

June 2013

» Keep Your Tortilla Production Rolling!

May 2013

» Viscosity Measurement and Precision Temperature Control... ...with Just a Touch!

March 2013

» 2013 Brookfield Catalog Loaded with New Products!

March 2013

» New DV2T Viscometer Features Touch Screen Technology and Much More!

March 2013

» Totally New User Experience with Top-of-the-Line DV3T Rheometer!

January 2013

» Brookfield Viscosity Standards Now Come With Expiration Date

September 2012

» Full Range of Product Testing at Brookfield UK Laboratory

September 2012

» No One Likes Broken Lipstick!

September 2012

» Consistent Actuation Pressure Leads to a More Accurate Dosage!

June 2012

» Get a Hold of Your Fruit!

June 2012

» Capsule Loop Tensile Test Fixture

June 2012

» Multi-layer Tablets Have Met Their Match!