BS ISO 9352:2012 pdf free download.Plastics一Determination of resistance to wear by abrasive wheels.
4 PrincIple
Twe abrasive wheels we apped to tie teat specimen with a specified load The wear obtained after rotation
of the lest specimen through a speciled number of revolutions is asasss.d by en eppropnate procedure (a g
mass loss. volume loss, change m optical properties)
5 Apparatus
5.1 Abrasion test machine
3.1.1 The lest specimen is placed on a mmor-dnven rotating disc A pew of abrasive wheels is stowed 10 turn freely on their aios and is appled to the test specenen — a specified poeieon under a specified load Figure 1 dlusb’ates the relative positions of these isifeicrit oomponents The apparatus shall comply With tie teqwrements given in 51.21051.7,
5.1.2 The test specimen si.çport disc shall be lat and fixed to its driving shaft. When the disc is rotated. no point on a 45 nwn radius cede traced on its horizontal surface shall oscilate vertically through more than 0.05 mm about its mean poslXn. The disc shal have a nonwial dIameter of tOO rrmi and its speed of rotation sh be 72 revlnsn at 60 Hz – 60 revhnin at 50 Hz.
5.1.3 The abrasive wheels shall be supported by two .ymrTie1ral arms that can oscillate freely about a honzontal axis The method of alladwig the wheels shall permit free rotation. e.g by means of bal bearings In the test position. the mounting bosses shall be coaxial and positioned in such a way that the vertical proec1ion of tier common axis on to the plane of the lest specimen support disc is 19,1 mm 0.1 mm from a paratel line passing through the ass of the disc (see Figure 1).
The distance between the wbside faces of the abrasive wheels shall be 52.4 mm ± 0.2mm
Each arm shall be constructed In such a way as 10 permIt the fitting of a counterweight 10 balance Its mass against that of the abrasive wheat and additional loads of known mass (see 5.4)
5.1.4 The abrasive wheels shall have a cytindflcal shape. They shall conlain an axial hole allowing them to be fitted wIthout play to the mounting bosses en the arms
They aliaS consist of one of the following two altematrves
a) An abrasive material (abrasive wheels) The thickness of the wheels shall be 12.7 mm ±0.1 mm and their external diameter 31.6mm ± 0,1 mm when new, but in no case less than 44,4 mm
b) A matal disc with its peqhery clad with a 6 mm layer at veicenized rubber of hardness 50 IRHD to 55 IRIID (International hardness in accordance with ISO 48) bonded without gaps or overlap with a strip of abrasive paper (ter example, secured with the sid of dotiile.slded adhesive tape). The abrasive wheel shall have a thickness of 12.7mm 50,2mm ends diameter 0151.6mm 0.2 mm. The width of the abrasive paper shall be as specified In the relevant material (or producti standard
The quality of the abrasive wheel or abrasive paper to be used sh be as stated In each relevant material (or product) ipecitication. Rater to Tebi. 1 for guidance in satecbng suitable abrasive wheat., The .brasiv.pcrasr properties of the wheels may be characterized. if requested. by the procedure give ii Annax A.
5.1.5 The vacuum device for removal of the wear debris abel lickate two exhaust nozzles above the test specimen wear zone. One nozzle shall be located between the abrasive wheels and the other shal be located diarrearicaty opposite (see Figure I). The bore of each nozzle shall have an heard isarneler citfi mm i 0.5 mm and it distance from the test specimen abel be maintained at 1,5 nan 0.5 nan. When the nozzles are blocked dosed. the pressure shall be 1.5 liPa 101,6 kPa.BS ISO 9352 pdf download.