Kev tsim kho tshuab ntxig tshuab yog qhov tseem ceeb, chav kawm nyob ib qho uas xa tshuab ntxig rau hauv tshuab sau tshiab, ua phau xis uas thawj meej yuav raug siv los tshuaj xyuas thiab tshuaj xyuas kom zoo rau nws daim duab. Nws tsis yog ib qhov khoom sib txig tsuas li; nws yog ib qhov chaw siv tshuab thiab kho tshuab tshuab. Kev tsim kho tshuab feem ntau muaj ntau yam khoom tseem ceeb: qhov sib txig, uas sib txig rau tshuab ntxig; qhov kho tshuab, ib daim ntawv hlwb hlwb muaj cov rooj hlwb uas sau cov khoom tsis zoo thiab tsim cov thawj meej sib npaug los tshem qhov kev ntxig ntawm qhov kho; thiab lub cev tshuab ntxig tshuab, uas nyob hauv cov tshuab ntxig. Rau co-extrusion, qhov tsim kho tshuab yuav tsum tau ntau dua, muaj ntau qhov ntxig los layer ntau yam khoom. Cov tshuab ntxig hauv qab ntawm tshuab ntxig tshuab tau tsim kom meej kom thawj meej tuaj yeem ntxig tshuab ntxig nrog ib qhov sib npaug thiab sib npaug hnyav hauv qab zib. Qhov twg muaj qhov tsis sib xws no yuav tshwm sim qhov sib txawv hauv qhov hnyav thiab qhov tshua hauv qab zib. Lub tshuab tsim kho tshuab tau muaj ntau qhov siv tshuab ntxig thiab thermocouples uas tsim kom muaj qhov sib npaug tshaj plaws, uas tseem ceeb heev rau kev kho tshuab viscosity. Txij thaum pib, lub tshuab tsim kho tshuab tsum muaj kev ruaj khov kom tso taub rau qhov siab siab, feem ntau tshaj 5,000 psi, thiab tsim los tso tshuab kom ua kev saib xyuas thiab kho. Yog li, qhov kev ua haujlwm ntawm tshuab ntxig tshuab ntxig tshuab yog qhov tseem ceeb rau kev pom qhov kev ua haujlwm zoo thiab tsim cov khoom zoo, sib npaug.