предговор
ИСО (Међународна организација за стандардизацију) је глобални савез националних тела за стандардизацију (Тела чланица ИСО). Развој међународних стандарда се обично спроводи преко ИСО техничких комитета. Свака институција чланица заинтересована за предмет за који је основан технички комитет има право да буде заступљена у тој комисији. Међународне владине и невладине организације које су у вези са ИСО такође су укључене у овај посао. ИСО блиско сарађује са Међународном електротехничком комисијом (ИЕЦ) о свим питањима електротехничке стандардизације.

Међународни стандарди се израђују у складу са правилима датим у ч 2 ИСО/ИЕЦ директиве.

The main task of the technical committee is to set international standards. The draft international standards adopted by the Technical Committee will be circulated to member bodies for voting. Објављивање као међународни стандард захтева одобрење најмање од стране 75% of member bodies.

Please note that certain contents of this document may be subject to patent rights. ИСО није одговоран за идентификацију било ког или свих таквих патената.

ИСО 2493-1 was prepared by Technical Committee ISO/TC 6, Папир, Board and Pulp, Subcommittee SC 2, Test methods and Quality Specifications for paper and board.

The first version, together with ISO 2493-2, cancelled and replaced the technically revised ISO 2493:1992. In the revised version, ИСО 2493:1992 is divided into two parts due to different measurement principles. Овај део ИСО-а 2493 describes a constant deflection rate, и ИСО 2493-2 describes the Taber type tester. The part can also use a smaller bend length and a lower bend Angle if desired. Added optional computations in index form. A precise note has been added to the informative annex A.

ИСО 2493 consists of the following parts under the general heading Paper and Board – Determination of Bending resistance:

— Парт 1: Константна стопа отклона

— Парт 2: Tabor tester

ИСО 2493-1-221 “Папир и картон – Одређивање савијања – Парт 1: Константна стопа отклона”

увести
In ISO 2493:1992, two principles for determining bending resistance are incorporated into the same standard, although the two principles are very different.

One principle involves deflecting the same number of specimens with relative surfaces in the direction of deflection; Овај део ИСО-а 2493 describes this principle.

Another principle uses a Taber-type tester, in which the specimen is inserted and deflected to the top, and then deflected in the opposite direction without altering the specimen. This principle is described in ISO 2493-2. This method is based on TAPPI test method T 489 om-04[4].

1 домет
Овај део ИСО-а 2493 specifies procedures based on the two-point loading principle for determining the flexural resistance of paper and board.

Белешка 1 See ISO 5628[1] for a detailed explanation of the two-point loading principle.

Овај део ИСО-а 2493 is suitable for measurement of bending resistance in the range 20 mN to 10 000 мН. It does not work with corrugated board, but it can work with components of such board.

The bending Angle is 15° and the bending length is 50 мм.

For samples where the bending resistance is too low to measure a bending length of 50 мм, a shorter bending length of 10 mm can be used.

Important note – Results obtained with different bending lengths will not be comparable.

For boards that tend to permanently deform when bent at 15°, a semi-bending Angle of 7,5 ° can be used.

Note 2Taber type tester and tester using the principle of constant deflection cannot give comparable results. Стога, ИСО 2493:1992 is divided into two parts.

2 Normative references
The following reference documents are not available or available for use in this document. За датиране референце, citation-only versions apply. For undated references, the new version of the reference (укључујући све ревизије) примењује.

ИСО 186, Папир и картон — Sampling to determine average quality

ИСО 187, Папир, board and pulp — Standard atmospheres for conditioning and testing and procedures for monitoring sample atmospheres and conditioning

ИСО 536, папир и картон – Determination of gram weight

3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.

3.1 Bending force

The force required to bend a rectangular specimen with one end clamped, measured under the conditions specified in this part of ISO 2493

3.2 Flexural resistance

The average of all valid readings of the measured bending force (3.1) calculated as specified in this part of ISO 2493

Белешка 1: Flexure is expressed in Newtons or millinewtons.

3.3 Bending Length

The radial distance between the fixture and the position of force applied on the sample under test is constant

Белешка 1: See l in Figure 1.

3.4 Bending Angle

The Angle of rotation of the fixture as it moves from its initial position to the position where bending resistance is measured

3.5 Free Length

The total length of the specimen protruding from the fixture

Белешка 1: See L in Figure 1.

3.6 flexural index

Bending resistance divided by gram weight to the third power

Јаван је само одељак са стандардним информацијама. Да бисте видели цео садржај, морате купити стандард преко званичних канала.