INTRODUCTION

Tear testing measures the force required to continue the tearing of an initial cut in sheet materials. Models and weights are available to test material with a variety of strengths. This is also useful to evaluate strength of perforated materials.

Also known as the Elmendorf test, the tearing test has been performed in the paper industry for more than half century in order to measure the mean internal resistance of cellulose or papers to the propagation of a deliberately initiated tear. It enables rapid determination of the dynamic resistance of materials designed to be subjected to strong shearing loads (e.g. newspaper) or liable to be damaged by sharp or heavy objects (e.g. paper bags, seat belts, protective clothing).

Subsequently, the test was naturally adopted for all materials in the form of sheet or films, cardboards, cloth, knitted fabrics, plastic films, aluminum foil, non-woven fabrics, complex flexible packaging etc. for which the service requirements are similar to those for paper.

OPERATION

The test is carried out on a specimen composed of one or more samples of standard dimensions,
usually with a distance of 1.7 in (43mm) remaining to be torn after initiating the tear. The energy of a pendulum of suitable weight is used to completely tear the specimen. The difference in the angle from the vertical of the center of gravity of the pendulum between the downswing and the upswing is a measure of the energy absorbed in tearing the sample. This angular movement is measured with a digital encoder and is immediately converted to the mean tearing force for a single sheet by the microprocessor incorporated in the apparatus.

APPLICATIONS

Paper, Foil, Film.

SPECIFICATIONS

• Paper Standards
  • TAPPI 414, APPITA P 400, ASTM D 689, NEN 1760, BS 4468, SCAN P 11, UNI 6444, CSA D9, ISO 1974- 1974
• Plastic Film Standards
  • NF T.54.141, ISO 6383/2, ASTM D 1922
• Textile Standards
  • NF G.07.149, ASTM D 1424, M&S P-29, ISO 13937-1

FEATURES

• Automatic specimen notching
• Mechanical-pneumatic clamping avoids sample slippage to ensure repeatable results
• Automatic pendulum reset with lifting device
• Tearing force displayed digitally
• RS-232 data output
• Small, table-top instrument
• Maintaining a uniform quality level
• Safety Hood protects operator from injury while pendulum is in motion.

TECHNICAL CHARACTERISTICS

Specifications	83-20	83-21
Capacity	0-6400 grams	0-10,000 grams
Pendulum Range	400, 800, 1600, 3200, 6400	5000, 10,000
Accuracy	1.0% of pendulum range	1.0% of pendulum range
Calibration Weights	20%, 50% and 90%	20%, 50% and 90%
Measuring Principle	Hi-resolution digital encoder	Hi-resolution digital encoder
Measuring Range	0-100 N for Textiles	0-100 N for Textiles
Languages	German, French, English, Dutch, Italian, Spanish and Finnish
Statistics	Average, Maximum, Minimum, SD, COV and Tear Index

PRINCIPAL STANDARDS

Papers	Plastic Films	Textiles
NF Q 03.011	NF T 54.141	NF G 07.149
ISO 1974-1974	ISO 6383/2	ISO 13937-1
CSA D9
UNI 6444
SCAN P 11
		M&S P-29
TAPPI 414
APPITA P 400
ASTM D 689	ASTM D 1922	ASTM D1424
NEN 1760
BS 4468

INSTRUMENT SIZE

	Width:		21.3 in. (54cm)
	Depth:		19.7 in. (50cm)
	Height:		19.7 in. (50cm)
	Weight		115 lbs (52 kg)

CONNECTIONS

Electrical: 110V/60Hz or 220V/50Hz
Air Requirements: 600-700 kPa

ORDERING INFORMATION

The models 83-20 and 83-21 offer a combination of technological integration and user comfort unique to this type of instrument.

• Model 83-20-00 is designed for tests on paper, aluminum, plastic films, complex flexible packaging, non-woven fabrics and others low strength materials
• Model 83-21-00 is designed for testing cardboard, natural or synthetic fabrics, coated fabrics and other medium strength materials.

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