introduzione
ISO (Organizzazione internazionale per la standardizzazione) è un'alleanza globale di organismi nazionali di normazione (Organismi membri dell'ISO). Lo sviluppo di standard internazionali viene solitamente effettuato attraverso comitati tecnici ISO. Ogni istituzione aderente interessata ad un argomento su cui è stato costituito un comitato tecnico ha il diritto di farsi rappresentare in tale comitato. Anche le organizzazioni internazionali governative e non governative che collaborano con l'ISO sono coinvolte in questo lavoro. L'ISO lavora a stretto contatto con la Commissione elettrotecnica internazionale (standard di progettazione) su tutte le questioni di normalizzazione elettrica.
Le norme internazionali sono redatte in conformità alle regole riportate nella Part 3 della direttiva ISO/IEC.
La bozza di norma internazionale adottata dal Comitato Tecnico sarà distribuita agli organi membri per la votazione. La pubblicazione come standard internazionale richiede l'approvazione di almeno 75% delle istituzioni membri.
Lo standard internazionale ISO 15359 è stato sviluppato dal Comitato Tecnico ISO/TC 6, Carta, Board and Pulp, Sottocommissione SC 2, Test Methods and quality Specifications for paper and board.
Annexes A and A to this standard are for reference only.
Discussion of coating durability: natural climate exposure test method
introdurre
This standard describes procedures for the determination of static and dynamic friction coefficients of paper or board by horizontal method.
The condition of paper surfaces depends on their history. Their frictional properties are largely determined by the static and dynamic coefficients of friction, which in this international standard are determined by sliding one sheet of paper onto another or onto another surface on a horizontal plane, with a downward vertical force applied to the upper material. The frictional properties are related to the horizontal forces required to initiate and maintain motion between two surfaces.
The coefficient of friction is a property of two surfaces. The value obtained for the coefficient is affected by the test conditions. Under the conditions specified in this standard, the condition of the two surfaces may or may not be related to the condition of the surface in a particular end-use situation. Tuttavia, the test results are useful for determining the combined properties of the surface under test.
When measured in machine direction MD or transverse CD, the friction coefficient of machine-made paper may be different. Generalmente, there are differences between the two sides of a paper.
For some papers, such as copy paper, it may be of interest only to the static friction coefficient of the first sheet, questo è, the coefficient obtained without prior sliding of the surface between the lower surface of one sheet and the upper surface of another similar sheet.
For some other types of paper, such as transport bag paper, box board paper and solid fiberboard, the coefficient of friction after a certain degree of wear between surfaces may be important. In questa norma, one specimen is slid three times with respect to another in order to determine the coefficient of friction of a worn surface. Measure the force required to start and hold the slide on the third rail.
The intended use of the paper grade determines the sides of the paper to be contacted, the orientation of the paper specimen with respect to the direction of slide, and the number and type of friction coefficient to be evaluated.
Annex A provides a list of recommended symbols to indicate the orientation and position of the surface under test.
Appendix A summarizes the test conditions for some common standard methods for paper products and plastics.
A bibliography is attached.
Discussion of coating durability: natural climate exposure test method
1 Gamma
This standard specifies
— Friction test method based on horizontal plane principle, e
A procedure for determining static and dynamic friction coefficients before and after a specified amount of wear between surfaces.
It is suitable for paper and cardboard.
2 referenze normative
I seguenti documenti normativi contengono disposizioni che, per riferimento qui, costituiscono le disposizioni della presente norma internazionale. Per riferimenti datati, any subsequent revisions or amendments to these publications will not apply. Tuttavia, Parties to an agreement based on this International Standard are encouraged to investigate the possibility of applying new versions of the following normative instruments. Per riferimenti non datati, a new version of the standard-setting document referred to applies. ISO and IEC members maintain a register of currently valid international standards.
ISO 186:1994, Carta e cartone – sampling to determine average quality.
ISO 187:1990, Carta, tavola e polpa. Standard atmosphere for conditioning and testing and sample atmosphere and conditioning monitoring procedures.
ISO 4046:1978, carta, board, pulp and related terms – Glossary.
Discussion of coating durability: natural climate exposure test method
3 Termini e definizioni
For the purposes of this International Standard, si applicano i seguenti termini e definizioni.
3.1 Friction
Resistance that occurs when the surface of one material tends to slide or slide over another surface of the same or other material
3.2 Static Friction
The force that resists the initiation of motion by sliding one surface over another
Nota 1: The force required to initiate motion is equal to the force required to resist motion initiation.
3.3 Static friction coefficient μS
The ratio of static friction to the vertical force applied to two surfaces in a friction test
3.4 Dynamic Friction
Resistance to the constant sliding of one surface over another
Discussion of coating durability: natural climate exposure test method
Nota 1: The force required to keep sliding is equal to the force to resist sliding maintenance.
3.5 Dynamic friction coefficient m·
In a friction test, the ratio of dynamic friction to the force applied perpendicular to two surfaces
3.6 Slope Time
The time required to increase the horizontal applied force from zero to the static friction value
Solo la sezione informativa standard è pubblica. Per vedere il contenuto completo, è necessario acquistare lo standard attraverso i canali ufficiali.