ASTM D689 p\u00ebrcakton nj\u00eb metod\u00eb t\u00eb standardizuar p\u00ebr t\u00eb matur forc\u00ebn e nevojshme p\u00ebr t\u00eb grisur letr\u00ebn n\u00eb nj\u00eb drejtim t\u00eb p\u00ebrpjet\u00eb me planin e flet\u00ebs pasi \u00ebsht\u00eb inicuar nj\u00eb grisje. Testi bazohet n\u00eb nj\u00eb mekaniz\u00ebm pendulumi Elmendorf, i cili kthen humbjen e energjis\u00eb potenciale n\u00eb nj\u00eb forc\u00eb grisjeje t\u00eb matshme.<\/p>\n\n\n\n
Ndryshe nga testet e t\u00ebrheqjes ose t\u00eb shp\u00ebrthimit, ASTM D689 fokusohet n\u00eb rezistenc\u00ebn ndaj grisjes s\u00eb brendshme. Kjo pron\u00eb tregon se si sillet letra kur i n\u00ebnshtrohet forcave t\u00eb papritura gjat\u00eb p\u00ebrpunimit, palosjes, prerjes ose trajtimit. P\u00ebr k\u00ebt\u00eb arsye, ASTM D689 shpesh plot\u00ebson testet e tjera t\u00eb fort\u00ebsis\u00eb p\u00ebr t\u00eb ofruar nj\u00eb profil m\u00eb t\u00eb plot\u00eb t\u00eb performanc\u00ebs.<\/p>\n\n\n\n
Standardi zbatohet p\u00ebr shum\u00eb klasa letre dhe kartoni, megjithat\u00eb nuk i p\u00ebrshtatet letrave me drejtim t\u00eb lart\u00eb kur duhet t\u00eb vler\u00ebsohet grisja n\u00eb drejtim t\u00eb kryq\u00ebzuar.<\/p>\n\n\n\n
T\u00eb Test i forc\u00ebs s\u00eb grisjes s\u00eb letr\u00ebs<\/strong> p\u00ebrshkruar n\u00eb ASTM D689 p\u00ebrdor nj\u00eb Testuesi i grisjes Elmendorf<\/strong> p\u00ebr t\u00eb k\u00ebputur nj\u00eb ose m\u00eb shum\u00eb shtresa letre p\u00ebrmes nj\u00eb distance t\u00eb fikse. Instrumenti mat pun\u00ebn e kryer nga penduli gjat\u00eb k\u00ebputjes dhe tregon forc\u00ebn mesatare t\u00eb k\u00ebputjes.<\/p>\n\n\n\n Kur testohen disa flet\u00eb s\u00eb bashku, rezultati p\u00ebrfaq\u00ebson nj\u00eb vler\u00eb mesatare. Kjo vler\u00eb i lejon laborator\u00ebt t\u00eb llogarisin rezistenc\u00ebn e p\u00ebraf\u00ebrt ndaj grisjes s\u00eb nj\u00eb flete t\u00eb vetme. P\u00ebr letrat e holla, ku testi me nj\u00eb flet\u00eb t\u00eb vetme \u00ebsht\u00eb i mundur, rezistenca ndaj grisjes mund t\u00eb matet drejtp\u00ebrdrejt.<\/p>\n\n\n\n T\u00eb forca e t\u00ebrheqjes s\u00eb letr\u00ebs<\/strong> e fituar p\u00ebrmes ASTM D689 sh\u00ebrben si nj\u00eb tregues kryesor i lidhjes s\u00eb fibrave, gjat\u00ebsis\u00eb s\u00eb fibrave, kushteve t\u00eb rafinimit dhe integritetit t\u00eb p\u00ebrgjithsh\u00ebm t\u00eb flet\u00ebs.<\/p>\n\n\n\n Metoda Elmendorf funksionon mbi nj\u00eb parim mekanik t\u00eb thjesht\u00eb, por t\u00eb besuesh\u00ebm. Nj\u00eb pendulum me mas\u00eb dhe gjeometri t\u00eb njohura lirohet nga nj\u00eb lart\u00ebsi fikse. Nd\u00ebrsa l\u00ebkundet, ai k\u00ebput mostr\u00ebn e testit t\u00eb ngjeshur n\u00eb tester. Energjia e konsumuar gjat\u00eb k\u00ebputjes zvog\u00eblon lart\u00ebsin\u00eb p\u00ebrfundimtare t\u00eb pendulumit.<\/p>\n\n\n\n Shkalla e instrumentit konverton k\u00ebt\u00eb humbje energjie n\u00eb forc\u00eb k\u00ebput\u00ebse. Duke qen\u00eb se distanca e k\u00ebputjes mbetet konstante, ASTM D689 siguron q\u00eb rezultatet t\u00eb mbeten t\u00eb krahasueshme midis laborator\u00ebve kur procedurat dhe pajisjet mbeten t\u00eb nj\u00ebjta.<\/p>\n\n\n\n Ky parim e b\u00ebn metod\u00ebn Elmendorf t\u00eb shpejt\u00eb, t\u00eb p\u00ebrs\u00ebritshme dhe t\u00eb p\u00ebrshtatshme p\u00ebr testimin rutin\u00eb t\u00eb kontrollit t\u00eb cil\u00ebsis\u00eb n\u00eb fabrikat e letr\u00ebs dhe laborator\u00ebt e testimit.<\/p>\n\n\n\n P\u00ebr t\u00eb arritur rezultate t\u00eb sakta dhe t\u00eb p\u00ebrs\u00ebritshme, laborator\u00ebt duhet t\u00eb ndjekin nj\u00eb procedur\u00eb t\u00eb strukturuar n\u00eb p\u00ebrputhje me ASTM D689:<\/p>\n\n\n\n P\u00ebrgatitja e mostr\u00ebs<\/strong> Zgjedhja e shtresave<\/strong> Caktimi i instrumentit<\/strong> Nisja dhe testimi i lotit<\/strong> Regjistrimi i rezultatit<\/strong> Kontrolli i kujdessh\u00ebm i numrit t\u00eb shtresave dhe i orientimit t\u00eb mostrave luan nj\u00eb rol kritik n\u00eb minimizimin e ndryshueshm\u00ebris\u00eb.<\/p>\n\n\n\n ASTM D689 mbetet gjer\u00ebsisht e p\u00ebrdorur si parashikues i performanc\u00ebs n\u00eb p\u00ebrdorimin p\u00ebrfundimtar n\u00eb shum\u00eb lloje letre. Letrat e paketimit mb\u00ebshteten n\u00eb rezistenc\u00eb t\u00eb mjaftueshme ndaj grisjes p\u00ebr t\u00eb parandaluar d\u00ebshtimin gjat\u00eb mbushjes dhe transportit. Letrat e printimit p\u00ebrfitojn\u00eb nga nj\u00eb forc\u00eb e balancuar ndaj grisjes p\u00ebr t\u00eb shmangur d\u00ebmtimet n\u00eb skajet gjat\u00eb p\u00ebrpunimit me shpejt\u00ebsi t\u00eb lart\u00eb.<\/p>\n\n\n\n Duke monitoruar forca e t\u00ebrheqjes s\u00eb letr\u00ebs<\/strong>, prodhuesit mund t\u00eb rregullojn\u00eb l\u00ebnd\u00ebt e para, nivelet e p\u00ebrpunimit dhe parametrat e procesit p\u00ebr t\u00eb arritur cil\u00ebsi t\u00eb q\u00ebndrueshme.<\/p>\n\n\n\n Rezultatet e besueshme varen nga instrumentacioni i q\u00ebndruesh\u00ebm dhe i sakt\u00eb. Nj\u00eb modern Testuesi i grisjes Elmendorf<\/strong>, t\u00eb tilla si Cell Instruments Testuesi i lotit SLD-01<\/a><\/b>, ofron matje t\u00eb sakt\u00eb t\u00eb energjis\u00eb, l\u00ebvizje t\u00eb but\u00eb t\u00eb pendulit dhe lexim t\u00eb qart\u00eb dixhital ose analog. K\u00ebto ve\u00e7ori ndihmojn\u00eb laborator\u00ebt t\u00eb p\u00ebrmbushin k\u00ebrkesat e ASTM D689, duke p\u00ebrmir\u00ebsuar efikasitetin dhe p\u00ebrs\u00ebritshm\u00ebrin\u00eb.<\/p>\n\n\n\nParimi i testit bazuar n\u00eb metod\u00ebn Elmendorf<\/h2>\n\n\n\n
P\u00ebrmbledhje e procedur\u00ebs s\u00eb testimit sipas ASTM D689<\/h2>\n\n\n\n
P\u00ebrgatitni mostra letre n\u00eb madh\u00ebsin\u00eb dhe orientimin e k\u00ebrkuar. Testet zakonisht kryhen si n\u00eb drejtimin e makin\u00ebs ashtu edhe n\u00eb drejtimin transversal.<\/p>\n\n\n\n
Zgjidhni nj\u00eb num\u00ebr t\u00eb p\u00ebrshtatsh\u00ebm shtresash n\u00eb m\u00ebnyr\u00eb q\u00eb leximet t\u00eb bien brenda intervalit t\u00eb kalibruar t\u00eb provuesit t\u00eb grisjes Elmendorf.<\/p>\n\n\n\n
Verifikoni kalibrimin, sigurohuni q\u00eb pendulumi t\u00eb l\u00ebviz\u00eb lirsh\u00ebm dhe konfirmoni se asnj\u00eb f\u00ebrkim apo penges\u00eb nuk ndikon n\u00eb l\u00ebvizjen e tij.<\/p>\n\n\n\n
Ngjeshni mostr\u00ebn fort dhe lironi pendulumin p\u00ebr t\u00eb grisur letr\u00ebn n\u00eb distanc\u00ebn e p\u00ebrcaktuar.<\/p>\n\n\n\n
Regjistroni matjet individuale dhe llogaritni vlerat mesatare, maksimale dhe minimale p\u00ebr \u00e7do drejtim testi.<\/p>\n\n\n\nZbatimet e ASTM D689 n\u00eb industrin\u00eb e letr\u00ebs<\/h2>\n\n\n\n