Testing machines for paper materials - Zwick

Catalogue Testing machines for paper materials

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Zw/ck I Roell

Addition, this method takes a lot of time and requires much skill in making the specimen. For these reasons, Zwick-fluters are delivered which include a „third hand". With its help, a specimen can be easily and quickly prepared.

Empirical tests can be performed on a industrial testing machine. Tensile grips or the LPET penetration test rig may be used for such tests. Test results from LPET and Elmendorf showed a strong linear correlation (Fig. 29). The correlation should be crosschecked for individual paper grades.

Crush tests on corrugated board and corrugated board raw paper

It is important for these tests (Figures 30 to 33), that the forces are applied exactly vertically to the specimen during the test. Precision guided compression plates provide an extremely high transverse stiffness. They insure the reproducible results of the crush characteristics in corrugated board raw paper and corrugated board.

The Corrugating medium test

The Corrugating medium test provides information about the behavior of a corrugated paper after it has been formed in a fluter. A section of corrugated paper is glued one-sided, to a carrier paper and then loaded in compression. The maximum load characterizes the behavior of the paper during the converting processing steps (punching, printing) after board production. A disadvantage of this method is that only the A-corrugat-ion is tested. For other types of corrugations, the behavior in compression mode must be mathematically calculated.


	Standard	ISO 7263
		TAPPI T 809
	Material	corrugated
		medium paper
	Zwick-Item-No
	compression	070457.00.00*
	plates
	test program	069002.67.ff
	fluter	XW90000-016
	for specimens
	length	150 mm
	width	12,7 mm
	to machines	from zwicki


	Standard	ISO 1974
		TAPPIT 414
	Material	paper
	Zwick-Item-No
	Elmendorf-	on request
	pendulum tester
	for specimens
	length	62 mm (ISO)
		63 mm (TAPPI)
	width	50 mm (ISO)
		53 mm (TAPPI)

The Flat Crush Test

In the flat crush test, a single-flute corrugated board specimen is loaded perpendicular to its surface. The resistance this corrugated board presents to the force, gives an indication of its behavior in further processing and use. Characteristic curve: according to the height of the individual flutes, the highest flutes break first, then the middle ones and then finally, the rest of the flutes. If the corrugated board has leaning or crushed flutes, it has been predamaged, and the curve is fundamentally different. The crush

The advantages:

• easy PC connection via RS 232 interface

• established robust instrument

Tear force in N




	Tear resistance = 3,286 * LPET - 1,503 R² = 0,9978

0,0 0,5 1,0 1,5 2,0 2,5 LPET in J

Fig. 29: Correlation between the LPET and the Elmendorf test

Fig. 30: Specimens for: flat crush test, ring crush test and corrugating medium test

Fig. 31: Flat crush test: test curves showing correct and pre-damaged material