I-unit ye-stretching-bending straightening (eyacelwa njengoba "umshini we-stretch straightening") ngumshini ophathelene okusha okwenzelwe ukuthatha izidingo eziningi zokuphakama kwesitripu, okwenza kube nomthelela wemshini we-straightening roller kanye nomshini we-straightening-stretching. Izimo zakhe zezokusebenza kuyinto ukuthi isitripu isenza ukunyakaza okuphazamiseka phakathi kwe-roll ye-tension stretching kanye ne-roll ye-bending continuous alternating kanye nokunyakaza okwenziwe ngokuphela. Kuyakwazi ukuthuthukisa izifo zezimoto ezintathu zesitripu, njengoba ukubhendula kwesibhakela, isitolo esikhulu kanye nokubhendula okukhulu, kanye nokwethula okwenzekayo kwesimo.