lub raj mis ntshav zawv plaub hau- txhaj tshuaj thiab txhaj tshuaj stretch tshuab molding txheej txheem
Piv nrog rau kev txhaj tshuaj molding, extrusion thiab lwm yam thev naus laus zis, kev txhim kho ntawm tshuab moulding ua tshuab yog qhov lig.
Zoo li lub raj mis zawv plaub hau, nws cov txheej txheem txheej txheem los ntawm cov txheej txheem tshuab ntawm cov iav fwj lossis cov khoom iav. Xyoo 1930, thawj lub tshuab tshuab moulding tuaj tawm, tab sis vim muaj kev txwv ntawm cov khoom siv thiab cov khoom siv, nws tsis tau txais kev loj hlob sai thaum pib thiab tsuas yog siv los tsim cov fwj polyethylene tsawg. Hauv xyoo 1950, nrog cov chav kawm dav dav ntawm qhov siab {3}} ntom tshuab myethylene tau pib tsim ntau yam, thiab muaj cov ntawv sib txawv thiab cov qauv thiab ntau thiab tsawg tau nce dav siv nyob rau hauv ntau yam kab. Hauv kev lag luam.
