pe yeeb nkab fittings yog ib hom ntawm high crystallinity, tsis-polar thermoplastic cob. Cov tsos ntawm tus thawj HDPE yog milky dawb, thiab daim ntu yog translucent rau qee yam. PE muaj kev tiv taus zoo rau cov tshuaj lom neeg feem ntau hauv tsev thiab kev lag luam. Qee hom tshuaj yuav tsim cov tshuaj lom neeg hauv lub cev, xws li corrosive oxidants (concentrated nitric acid), cov roj ntsha uas muaj ntxhiab (xylene) thiab halogenated hydrocarbons (carbon tetrachloride).
1. Ntim, ntim thiab tsheb thauj mus los: Txav deb ntawm hluav taws thiab kub rwb thaiv tsev thaum lub sijhawm cia khoom. Lub chaw rau khoom yuav tsum muab khaws cia kom qhuav thiab huv. Nws yog nruj me ntsis txwv tsis pub sib xyaw hauv txhua qhov tsis huv, lub hnub thiab nag. Kev thauj khoom yuav tsum muab khaws cia rau hauv qhov chaw huv, qhuav, tsheb vov lossis cab, thiab tsis muaj cov khoom ntse xws li cov ntsia hlau. Kev sib xyaw nrog kev thauj mus los nrog nplaim taws uas muaj ntxhiab hydrocarbons, halogenated hydrocarbons thiab lwm cov kuab tshuaj organic yog txwv tsis pub.
2. Kev rov ua dua tshiab: cov kav dej PE thiab fittings yog qhov loj hlob ceev tshaj plaws ntawm kev lag luam yas rov qab. Qhov no feem ntau yog vim nws txoj kev yooj yim hais rov qab, yam tsawg ntawm kev ua haujlwm thiab nws muaj ntau ntawm cov ntawv thov rau hom phiaj ntim. Lub ntsiab rov ua dua tshiab yog rov ua dua 25% cov khoom siv rov ua dua tshiab, xws li cov khoom siv tom qab siv dua, thiab HDPE ntshiab, thiab tom qab ntawd siv lawv los ua cov hwj uas tsis cuam tshuam rau cov khoom noj.
3. Cov yam ntxwv tseem ceeb: Cov yam ntxwv ntawm ntau qib ntawm HDPE yog qhov sib xyaw kom haum ntawm plaub qhov sib txawv: ntom, molecular phaus, molecular phaus faib thiab ntxiv rau. Cov catalysts sib txawv tau siv los tsim cov ntawv cog lus polymers nrog cov khoom tshwj xeeb. Kev sib xyaw ua ke ntawm cov hloov pauv no ua rau HDPE qib sib txawv; ua tiav qhov zoo tshaj plaws tshuav nyiaj ntawm kev ua haujlwm.
4. Khoom zoo: High-density polyethylene yog xim tsis muaj tshuaj lom, tsis muaj ntxhiab thiab ntxhiab tsw dawb nrog lub siab ntev txog 130 ° C thiab qhov txheeb ze ntawm 0.941 txog 0.960. Nws muaj zoo thaum tshav kub kub ua hauj thiab txias kuj, zoo tshuaj lom neeg ruaj khov, siab rigidity thiab toughness, thiab zoo txhua yam muaj zog. Dielectric zog thiab ib puag ncig kev nyuab siab cracking kuj tseem zoo.