Idatha ye-PTFEishidi/ipuleti kwakhiwa ngokubumba nokufaka i-cylindrical blank, esikwa ibe yi-aishidi ngethuluzi lomshini bese ibhalwa ngekhalenda.Ngokwezindlela zokwelapha ezihlukene, ingahlukaniswa ngezinhlobo ezintathu: ulwelwesi oluqondile, ulwelwesi olungaqondile kanye nolwelwesi olungaqondile.Njengamanje, imikhiqizo ye-membrane ye-PTFE ihlanganisa ulwelwesi olunezimbotshana,ukuhlunga okuncane ulwelwesi, ulwelwesi lombala nokunye.