AB Lorentzen & Wettre Kağıt Mukavemet ve Uzama Test Cihazı , Kırılma Mukavemeti ile Birlikte

AB Lorentzen & Wettre Kağıt Mukavemet ve Uzama Test Cihazı , Kırılma Mukavemeti ile Birlikte

Tensile tester and fracture toughness tester in one complete unit

In a single, easily manageable and ergonomic unit L&W Tensile Tester with Fracture Toughness combines measurement of both tensile strength and fracture toughness all in accordance with the STFI method.

Among the parameters that determine the strength properties of a paper material, optimum fracture toughness is essential for avoiding cracking and the consequent risk of expensive web breaks in paper machines and printing presses. Good fracture toughness is also important for reducing the risk of cracking, for example when punching corrugated fibreboard.

L&W Tensile Tester with Fracture Toughness offers a simple and accurate way of measuring the fracture toughness, in accordance with the STFI method, as well as tensile stiffness, tensile strength, elongation, tensile energy absorption, breaking length, etc. in a single, easily programmable unit.


Measurement results with a minimum of effort

L&W Tensile Tester with Fracture Toughness is designed with special emphasis on ergonomics and high performance.
The notch for measuring the fracture toughness is made automatically by a built-in knife. A special holder is also provided to hold the test piece flat during the test.

Simple to preset

Interactive software makes L&W Tensile Tester with Fracture Toughness very easy to configure. The dialogue language can be selected by pressing a button, and up to 30 measurement programs can easily be preset and stored in the built-in memory.

Automatic starting of measurement

A further example of the many practical features of L&W Tensile Tester with Fracture Toughness is that the measurement sequence is started automatically as soon as the test piece is in place in the clamps. The clamps do not need to be replaced if test pieces of different widths are tested.

The wide measurement range of 7–1500 N (1.57–330 lbf) enables accurate measurements to be made on all grades of paper.

The clamping force is adjustable between 1000 and 6000 N (225–1350 lbf), and even extremely strong materials can therefore be reliably clamped for testing.

The measurement results are presented on the built-in and easy-to-read graphic display in the form of curves or numerical measured values. The built-in printer can also print out the results.

Measurement procedure

A test piece is loaded to fracture at a constant elongation rate. The instrument automatically records the tensile force as a function of the elongation. The computer uses the recorded data to calculate the tensile strength, tensile energy absorbtion and tensile stiffness.
Calculations based on the tensile testing data produce a JI curve as shown above. JI is a parameter that can be said to describe the stress condition at the tip of the crack.

A 50 mm test piece is clamped in the tester. The notch is cut automatically in the tester before the test piece is loaded to fracture. The fracture toughness JIC is defined as the JI value at the critical elongation νc of the test piece.

The instrument carries out all calculations necessary for obtaining the fracture toughness value.

  • Measures fracture toughness, tensile strength, stretch, TEA, tensile stiffness, etc.
  • Built-in, easy-to-read graphic display and report printer
  • Editing facilities. Values can be replaced, erased etc.
  • Automatic compensation if the test piece is not stretched at the beginning of measurement
  • Automatic starting of measurement when the test piece is in the correct position
  • Excellent ergonomics
  • Measures in accordance with all established standards, including the SCAN standard for fracture toughness
  • Three load cells to choose from

L&W Tensile Tester with Fracture Toughness – Code 064
 Foot switch


Range (force)
3–750N (0.67–170 lbf)
(Strech at break)
32% max. at 100 mm (4 in) and fracture toughness, 64% max. at 100 mm without fracture toughness, 17% max at 180 mm (7.1 in)


Testing velocity
2–100 mm/min (0.08–4 in/min)
Clamping length
100 mm and 180 mm (4 in and 7.1 in)
Clamping force
1000–6000 N (225–1350 lbf)
Test piece width
15, 25 or 50 mm (0.6, 1.0 or 2.0 in) without the need for changing clamps


 Measurement values (in SI or FPS units)
- tensile strength
- max. force
- breaking length
- strain at break
- elongation
- elongation at 2/3 of max. force
- tensile energy absorption
- tensile stiffness
- Emodulus (Young’s modulus)
- arithmetic mean value
- median value
- standard deviation
- coefficient of variation
- MD/CD ratio of arithmetic mean value or median
- geometric mean value of the arithmetic mean value or median



- graphic raw data, individual measured values and statistics
- connectable to L&W Autoline Data Acquisition Workstation


Installation requirements

100 W
Instrument air
0.6–1 MPa (75–150 psi)


Measurement range 0.5–150 N or 7–1500 N
Calibration equipment



0.8 × 0.5 × 0.3 m
31 × 21 × 12 in


0.3 m³
11 ft³

Net weight

49 kg
106 lb

Gross weight

65 kg
143 lb


Applicable standards
APPITA/AS 1301.448, PAPTAC D.34, DIN 53112 Teil 1  
ISO 19242, SCAN P38, SCAN P67, TAPPI T494, EN ISO 1924-2, ISO 1924-3, JIS P8113  
Fracture toughness meausurement: SCAN P 77
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