Ndi zinthu ziti zomwe zimatsimikizira mtundu wa chikwama cha EVA?

Ndi zinthu ziti zomwe zimatsimikizira mtundu wa chikwama cha EVA?

Monga wamba ma CD zakuthupi, khalidwe laEVA matumbaimakhudzidwa ndi zinthu zambiri. Nazi zina mwazinthu zazikulu zomwe zimatsimikizira mgwirizano ndi magwiridwe antchito a matumba a EVA:

1. Kapangidwe kazinthu
Ubwino wa matumba a EVA umadalira poyamba pazomwe zili, makamaka zomwe zili mu ethylene-vinyl acetate (VA). EVA ndi zinthu zopangidwa ndi copolymerization ya ethylene ndi vinyl acetate, ndipo zomwe zili mu VA nthawi zambiri zimakhala pakati pa 5% ndi 40%. Kuchuluka kwa VA kumakhudza mwachindunji magwiridwe antchito a matumba a EVA, monga kusinthasintha, kukana mphamvu, kuwonekera, ndi zina zambiri.

2. Mapangidwe a mamolekyu
Mapangidwe a mamolekyu a EVA alinso ndi chikoka chofunikira paubwino. Pambuyo pa kukhazikitsidwa kwa vinyl acetate monomer mu unyolo wa ma molekyulu a EVA, crystallinity yapamwamba imachepetsedwa ndipo kulimba ndi kukana kwake kumatheka. Chifukwa chake, mapangidwe a maselo a matumba a EVA ndi ofunikira pakuchita kwawo.

3. Njira yopangira
Kapangidwe ka matumba a EVA nakonso ndikofunikira. Makampani ambiri amagwiritsa ntchito njira zopititsira patsogolo zochulukirapo, kuphatikiza njira ya ketulo ndi njira ya tubular. Kusiyanasiyana kwa njirazi kumabweretsa kusiyana kwa magwiridwe antchito a zinthu za EVA, monga kukana kugwedezeka komanso kukana kukalamba.

4. Kukonza ndi kuumba
EVA ndi polima ya thermoplastic yomwe ingagwiritsidwe ntchito pokonza ndi kuumba njira zosiyanasiyana monga jekeseni, kuumba kwa extrusion, ndikuwomba. EVA akamaumba ali otsika processing kutentha (160-200 ℃), osiyanasiyana, ndi otsika nkhungu kutentha (20-45 ℃). Izi zogwirira ntchito zidzakhudza mtundu womaliza wa thumba la EVA.

5. Kachulukidwe ndi kuuma
Kuchulukana kwa thumba la EVA nthawi zambiri kumakhala pakati pa 0.9-0.95 g/cm³, ndipo kuuma kwake kumayesedwa pogwiritsa ntchito kulimba kwa Shore A, komwe kumakhala kuuma kofanana kwa 30-70. Zochita zolimbitsa thupi izi zimagwirizana mwachindunji ndi mphamvu ndi kukhazikika kwa thumba la EVA.

6. Kuchita kwa chilengedwe
Matumba a EVA ayenera kukwaniritsa zofunikira zachitetezo cha chilengedwe, alibe zinthu zovulaza, komanso azitsatira miyezo ndi malamulo oyendetsera chilengedwe. Kuchita kwa chilengedwe ndi chinthu chomwe ogula amakono amadera nkhawa kwambiri posankha zinthu.

7. Kupanga
Mapangidwe a thumba la EVA adzakhudzanso khalidwe lake. Kupanga kumaphatikizapo kusankha kwa nsalu, makulidwe ndi kuuma kwa EVA, ndi kapangidwe kake kazinthu. Mapangidwe abwino amatha kusintha magwiridwe antchito komanso kukongola kwa matumba a EVA.

8. Kulimbana ndi kuponderezana ndi kugwedezeka
Matumba a EVA amayenera kukhala ndi kukana kukanika komanso kukana kugwedezeka kuti ateteze zinthu zomwe zapakidwa kuzinthu zakunja ndi kutulutsa

9. Kukana madzi ndi kukana dzimbiri
Matumba apamwamba a EVA ayenera kukhala ndi madzi abwino okana madzi komanso kukana dzimbiri, ndikutha kukana dzimbiri kuchokera kumadzi am'nyanja, mafuta, asidi, alkali ndi mankhwala ena.

Mwachidule, mtundu wa matumba a EVA umatsimikiziridwa ndi zinthu zingapo monga kapangidwe kazinthu, kapangidwe ka maselo, kupanga, kukonza ndi kuumba, katundu wakuthupi, magwiridwe antchito achitetezo cha chilengedwe, kapangidwe, kukana kupsinjika ndi kugwedezeka, komanso kukana madzi ndi dzimbiri. kukaniza. Opanga ayenera kuganizira izi mokwanira kuti apange matumba apamwamba a EVA.