Zaj chaw txhaj rwb, uas kuj zoo li qhia tias yog zaj chaw rwb lossis zaj chaw sau nrog rwb, yog ib qhov kev lag luam tsim los rwb cov nruab ntej ntev thiab yooj yim—xws li cov phuab plastic, cov phuab roj, cov roj rubber, lossis txhua yam nruab ntej polymer muaj zog—rwb nrog rau cov khoom cim lossis cov kab rwb kom me me, zoo siv, kom ua rau yooj yim khiav, tuav thiab siv. Cov khoom no yog tseem ceeb rau hauv qhov kev lag luam tom qab khiav thiab tsim kho, suav nrog cov ntaub ntawv khiav ntev los ntawm ib qhov khiav rhaum mus rau hauv cov khoom siv yooj yim uas tso cai rwb cov nruab ntej los ntawm kev plooj, kev plua pluaj lossis kev puas tsuaj. Lub tshuab feem ntau muaj qhov tshuab tawm lossis qhov tshuab sau nrog, qhov tshuab coob kom txhim kho kev sau nrog zoo, lub drum lossis lub mandrel rwb, thiab qhov tshuab tso tawm uas saib xyuas kev txhim kho thiab kev ntev. Kev saib xyuas kev txhim kho yog qhov tseem ceeb heev; kev txhim kho loj dhaws tuaj yeem tso cai rwb lossis plua cov nruab ntej, thaum li kev txhim kho me me tuaj yeem tshwm sim rwb ib qhov khoom rwb me me thiab tsis nyob. Lub tshuab tshiab feem ntau yog PLC (programmable logic controller) saib xyuas, tso cai rwb kev kho qhov loj ntawm lub coil, kev sau nrog (xws li sau nrog tsis paub lossis sau nrog zoo), thiab ntev. Rau cov nruab ntej muaj kev pom zoo lossis kev poob siab, xws li cov thermal plastic elastomers, cov dancing roller systems lossis cov pre-straightening units tuaj yeem siv. Tom qab ntawd lub coil feem ntau yog sau nrog hniav lossis sau nrog hlua, ready mus rau lwm lub teb chaws hauv qhov kev lag luam xws li kev tsim kho ywj, kev tsim kho tsev, thiab kev tsim kho khoom siv. Kev siv zaj chaw txhaj rwb tau pab tiv thaiv kev lag luam, rho qhov tshuab lag luam, tsainga qhov tshuab tshav thaum khiav lossis khiav puas, thiab tso cai rwb cov khoom mus rau qhov chaw pib lossis mus rau tus neeg siv raws li qhov xwm txheej zoo, yog li tiv thaiv qhov zoo thiab kev yooj yim hauv qhov kev lag luam.