Isku-dhafka Birta
Kala-goysyada birta waxaa lagu sameeyaa 2.5mm taarikada qaboojinta duuban ka dib markii la nadiifiyo, la damiyo, la dhejiyo ama la daweeyo qalliin.Kala-goysyada birta waxay ku qalabaysan yihiin matrix dhibcood oo la xoojiyay feeraha ka-hortagga barafka, kuwaas oo leh awood quful aad u fiican.Waxay si fudud isugu geyn karaan tuubada caatada ah ee tuubooyinka kala duwan & nidaamyada wadajirka ah ee la qabsanaya hababka wax soo saarka ee kala duwan iyo saldhigyo kala duwan.