Taber Stiffness Testers
Article No. 15496
Taber 150-T Stiffness Tester
- Model 150-T (115/230V, 50/60Hz)
- LCD operator touch screen with user-friendly interfaces to set-up and monitor testing
- Selectable display options minimize user error
- Includes a graphic display of stiffness values and test range set-up
- Test readings are automatically converted to the appropriate user-selected stiffness range and can be displayed graphically on the user interface
- Results can be displayed as Taber Stiffness Units or Millinewton Meters, and data can be easily stored or transferred to a computer.
- Calculates average, standard deviation, and high/low readings, plus technicians have the ability to operate in manual mode and select the direction, deflection and number of deflection cycles.
Features
- Used to evaluate stiffness and resiliency properties of materials up to 10,000 Taber Stiffness Units
- Precision instrument provides accurate test measurement to ±1.0% for specimens 0.004" to 0.297" thickness
- Materials include paper, paperboard, plastics, metals, textiles, rubber, wire, tubing, felts and other sheet materials.
- Bi-directional pendulum weighing system provides an accurate and responsive method for measuring small load increments, this system is a critical component for determining material stiffness or resiliency.
- Nine (9) distinct ranges permit testing of materials that are extremely lightweight and flexible (such as cellophane or thin metallic foils) to items that are very rigid (such as plastics).
Technical Attributes
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- Data
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Range Stiffness Units Sample Length Roller Position Sample Size Range Weight Angle of Deflection Scaling Multiplier 1 0 - 1 2cm SR Attachment 1.5" x 1.5" 10 Unit Compensator 15° 0.01 2 0 - 10 1cm Up 1.5" x 1.5" 10 Unit Compensator 15° 0.1 3 10 - 100 5cm Down 1.5" x 2.75" --- 15° 1 4 50 - 500 5cm Down 1.5" x 2.75" 500 Unit 15° 5 5 100 - 1,000 5cm Down 1.5" x 2.75" 1,000 Unit 15° 10 6 200 - 2,000 5cm Down 1.5" x 2.75" 2,000 Unit 15° 20 7 300 - 3,000 5cm Down 1.5" x 2.75" 3,000 Unit * 15° 30 8 500 - 5,000 5cm Down 1.5" x 2.75" 5,000 Unit * 15° 50 9 1,000 - 10,000 5cm Down 1.5" x 2.75" 5,000 Unit * 7 1/2° 100 * Auxiliary Range Weight Set (range 3,000 - 5,000 Taber Units) is sold separately and required for ranges 7 - 9.
More Information
Evaluation
After the test material has been deflected 15° (or 7 1/2°) to the left and right, the average reading is determined. This is then multiplied using the number assigned in the Set-Up Chart for the particular range. The product is the stiffness value of the material measured in Taber Stiffness Units.
Taber Stiffness Units are defined as the bending moment of 1/5 of a gram applied to a 1 1/2" wide specimen at a 5 centimeter test length, flexing it to an angle of 15°. A Stiffness Unit is the equivalent of one gram centimeter.
E = 0.006832 • (1/(w • d3 • θ)) • ST
Where E = Stiffness in flexure in pounds per square inch
w = specimen width in inches
D = specimen thickness in inches
θ = deflection of specimen converted to radians (15° = 0.2618 radians, 7.5° = 0.1309 radians)
ST = Taber Stiffness Units
Resilience is the elastic quality of a material expressed as the ratio of basic stiffness to initial stiffness, as determined with the following formula:
% of Resilience = (Basic Stiffness • 100) / Initial Stiffness
Initial Stiffness is the first reading obtained immediately when flexing the specimen to the end point of deflection (typically 15°), and is generally used for comparing relative stiffness qualities.
Basic Stiffness is the loss of stiffness caused by "elastic fatigue", or the realignment of the molecules experienced by the material when a specimen is held at the end point of deflection.
As reported in TAPPI Test Method T543, Taber Stiffness Units can be converted to Genuine Gurley™ Stiffness Units with the below equation. The range of correlation test studies between Taber and Gurley stiffness values were from 20 - 150 g cm on Taber.
ST = 0.01419SG - 0.935
Where ST = Taber Stiffness Units
SG = Gurley Stiffness Units
To convert Taber Stiffness Units to Millinewton-Meters, use the following equation:
"X" mN-m = ST • 0.098067
Where ST = Taber Stiffness Units
To convert Taber Stiffness Units to Pound-Inch, use the following equation:
"X" lb-in = ST • 0.000868
Where ST = Taber Stiffness Units
The extreme sensitivity of the Taber V-5 Stiffness Tester magnifies variations in the material. Therefore, it is recommended that 5 or more samples be tested and the average result taken as the stiffness rating. Variations in testing may also result from the way in which the specimen is clamped or how clearances are adjusted between the rollers and specimen. It is important to note:
- Do not flex a sample prior to testing
- Be careful not to crush the sample by over tightening the clamps
- Excessive compression of the sample will reduce the material's thickness thereby resulting in stiffness readings that are both inconsistent and inaccurate due to a reduced cross-sectional area at the clamp
Some materials have an inherent grain derived from their manufacturing process. This will typically affect the stiffness and must be accounted for during the test procedures by testing those samples in both directions. It is advisable to prepare and test 5 to 10 specimens in each grain direction for testing.
The following chart is used as a guide when setting up the instrument to determine which test range to use for the type of material being tested.
Standards
AS/NZS 1301.431rp, ASTM D3301, BS 3748, Canadian Pulp & Paper D.28P, ISO 2493, JIS P 8125, JIS P 8223, Tappi T 489, Tappi T 566, UNE 57 075
Procedure
- The Taber V-5 Stiffness Tester is used to determine the bending moment required to deflect the free end of a vertically clamped specimen 15° to the left and to the right when a load is applied at a constant bending length.
- For test ranges 2 - 9, specimens are mounted on the Taber V-5 Stiffness Tester using a clamping system. Located on the pendulum, the lower faces of the specimen clamp jaws are exactly on the center of rotation. This ensures a constant test length and deflection angle for accurate and repeatable results. Both jaws of the specimen clamp are adjustable, so the test specimen can be positioned precisely in the center regardless of material thickness.
- Force is applied to the lower end of the specimen by a pair of rollers. The rollers, which are attached to a driving disc located directly behind the pendulum, push against the test specimen and deflect it from its vertical position.
- The pendulum applies increasing torque to the specimen as it deflects further from the vertical. The test point reading occurs when the pendulum mark aligns with the appropriate driving disc mark (7.5° or 15°) which points to the stiffness reading on the fixed annular disc/dial point.
- Readings taken in the two directions are averaged to give the stiffness of the test piece. The final reading will depend on the range in which the test is being conducted and what scaling factor to use. The resistance to bending is calculated from the bending moment. Tappi T489 or ISO 2493 is intended for most paper or paperboard. Tappi T566 is intended for papers of low grammage or are highly flexible and exhibit bending stiffness in the range of 0 to 10 Taber Stiffness Units. The instrument outputs the moment load applied to the test specimen in TABER Stiffness Units (g · cm).
Note: The right-hand roller includes a ratchet stop mechanism that greatly reduces the potential for inter-operator error caused by over or under-tightening. The travel on the right-hand assembly automatically stops when the roller contacts the specimen.
Delivery Content
- Compensator Range Weight
- Taber Unit Range Weights 500, 1000, 2000
- Calibration Specimen
Accessories
10106
Stepdown Transformer (220/110v)
$263.00
Other Variations