Polyethylene (PE)
1. Kuita kwePE
PE ndiyo plastiki inogadzirwa zvakanyanya pakati pemapurasitiki, ine density inosvika 0.94g/cm3. Iyo inoratidzirwa nekuve translucent, yakapfava, isiri-chepfu, yakachipa, uye iri nyore kugadzirisa. PE yakajairika crystalline polymer uye ine post-shrinkage phenomenon. Kune marudzi mazhinji ayo, anowanzo shandiswa iLDPE iyo yakapfava (inowanzozivikanwa seyakapfava rabha kana maruva zvinhu), HDPE iyo inowanzozivikanwa seyakaoma nyoro rubber, iyo yakaoma kupfuura LDPE, ine hurombo husina kufambiswa kwechiedza uye yakakwirira crystallinity. ; LLDPE ine mashandiro akanaka kwazvo, akafanana neeinjiniya mapurasitiki. PE ine makemikari akanaka ekupikisa, haisi nyore kukanganisa, uye yakaoma kudhinda. Iyo yepamusoro inoda kuve neoxidized isati yadhinda.
2. Kushandiswa kwePER
HDPE: kurongedza mabhegi epurasitiki, zvinodikanwa zvezuva nezuva, mabhakiti, waya, matoyi, zvekuvakisa, midziyo.
LDPE: kurongedza mabhegi epurasitiki, maruva epurasitiki, matoyi, yakakwirira-frequency waya, zvekunyora, nezvimwe.
3. PE maitiro maitiro
Chinhu chinonyanya kuzivikanwa chezvikamu zvePE ndechekuti ivo vane hombe yekuumba shrinkage rate uye inowanzoitika kune shrinkage uye deformation. PE zvinhu zvine mvura yakaderera kunyura uye hazvidi kuomeswa. PE ine tembiricha yekugadzira yakakura uye haisi nyore kuora (tembiricha yekuora ingangoita 300 ° C). Iyo tembiricha yekugadzira ndeye 180 kusvika 220 ° C. Kana kudzvanywa kwejekiseni kwakakwira, density yechigadzirwa ichave yakakwirira uye shrinkage rate ichava diki. PE ine fluidity yepakati, saka nguva yekubata inoda kuve yakareba uye tembiricha yeforoma inofanira kuramba iripo (40-70 ° C).
Iyo degree yecrystallization yePE inoenderana nemamiriro ekuumba maitiro. Iine yakakwirira solidification tembiricha. Iyo yakaderera tembiricha yekuumbwa, inodzika iyo crystallinity. . Munguva yekristalllization process, nekuda kweiyo anisotropy ye shrinkage, kushushikana kwemukati kwemukati kunokonzerwa, uye PE zvikamu zviri nyore kukanganisa uye kuputika. Kuisa chigadzirwa mumvura yekugezera mumvura mu80 ℃ mvura inopisa inogona kuzorodza kushushikana kwemukati kune imwe nhanho. Munguva yekugadzira, tembiricha yemidziyo inofanira kunge yakakwira kupfuura kupisa kwefodya. Kudzvanywa kwejekiseni kunofanirwa kuve kwakaderera sezvinobvira uku uchivimbisa kunaka kwechikamu. Iko kutonhora kwemuumbi kunonyanya kudiwa kuti kukurumidza uye kunyange, uye chigadzirwa chacho chinofanira kunge chichipisa kana chichigadzirwa.
Polypropylene (PP)
1. Kuita kwePP
PP icrystalline polymer ine density ye 0.91g/cm3 chete (pasi pemvura). PP ndiyo yakareruka pakati pemapurasitiki anowanzo shandiswa. Pakati pemapurasitiki akajairwa, PP ine yakanyanya kupisa kupisa, ine kupisa deformation tembiricha ye80 kusvika 100 ° C uye inogona kubikwa mumvura inopisa. PP ine yakanaka kushushikana yekupwanya kuramba uye yakakwira yekukotama hupenyu hwekuneta, uye inowanzozivikanwa se "100% plastiki". ".
Kuita kwakazara kwePP kuri nani pane kuya kwePE zvinhu. Zvigadzirwa zvePP zvakareruka, zvakaoma uye zvinodzivirira kemikari. Zvakaipa zvePP: kuderera kwechimiro, kusasimba, kusamira zvakanaka kwemamiriro ekunze, nyore kugadzira "mhangura kukuvadzwa", ine post-shrinkage chiitiko, uye zvigadzirwa zvinogara zvichichembera, kuita brittle uye kuremara.
2. Kushandiswa kwePP
Zvinhu zvakasiyana-siyana zvemumba, mavharo ehari akajeka, pombi dzekutakura makemikari, midziyo yemakemikari, zvekurapa, zvekushandisa, matoyi, filaments, makapu emvura, mabhokisi ekuchinja, mapaipi, hinges, nezvimwe.
3. Maitiro maitiro ePP:
PP ine mvura yakanaka pakunyungudika tembiricha uye kuita kwakanaka kwekuumba. PP ine maitiro maviri:
Kutanga: iyo viscosity yePP inonyunguduka inoderera zvakanyanya nekuwedzera kweshear rate (zvishoma zvakakanganiswa nekushisa);
Chechipiri: Dhigirii rema molecular orientation yakakwirira uye shrinkage rate yakakura.
Iyo tembiricha yekugadzirisa yePP iri nani kutenderedza 200 ~ 250 ℃. Iine kugadzikana kwakanaka kwekupisa (tembiricha yekuora i310 ℃), asi pakupisa kwepamusoro (280 ~ 300 ℃), inogona kudzikisira kana ikagara mudhiramu kwenguva yakareba. Nekuti viscosity yePP inodzikira zvakanyanya nekuwedzera kweshear rate, kuwedzera iyo jekiseni kudzvanywa uye jekiseni kumhanya kunovandudza fluidity; kuti uvandudze shrinkage deformation uye mazino, tembiricha yekuumbwa inofanirwa kudzorwa mukati meiyo 35 kusvika 65 ° C. Iyo tembiricha yecrystallization ndeye 120 ~ 125 ℃. PP inonyungudika inogona kupfuura nepaburi rakatetepa mold uye kugadzira mupendero wakapinza. Munguva yekunyunguduka, PP inoda kutora huwandu hukuru hwekunyungudika (yakakura chaiyo kupisa), uye chigadzirwa chichave chichipisa zvakanyanya mushure mekubuda mu mold. PP zvinhu hazvidi kuomeswa panguva yekugadzirisa, uye shrinkage uye crystallinity yePP yakaderera pane yePE.
Nguva yekutumira: Zvita-28-2023