EVA films, which stand out for their excellent elasticity, are often produced by extrusion blow molding. The properties of this film are closely related to the content of vinyl acetate (VA). Raws li VA cov ntsiab lus nce, zaj duab xis txhim kho nyob rau hauv cov nqe lus ntawm elasticity, kev nyuaj siab nthuav tawm, tsawg kub tsis kam, thiab kub frealability, thiab kub ceev foob. When the VA content reaches 15%~20%, its performance is even comparable to that of flexible PVC film. Conversely, when the VA content is lower, the film performance is closer to that of LDPE film. Generally, the content of VA in EVA film is controlled in the range of 10%~20%.
EVA films are known for their transparency, softness, and self-adhesiveness to the comfortable feel. Its excellent stress crack resistance and high elasticity make the elongation as high as 59%~80%, making it an ideal spiral wound film. Hauv kev ntim khoom, nws yog dav siv nyob rau hauv kev sau thiab qhwv ntawm cov thawv thiab cov khoom ntim, ntxiv rau cov ncab qhwv ntawm pallets. Nyob rau tib lub sijhawm, Eva zaj duab xis tseem haum rau kev tsim cov hnab ntim rau cov khoom siv hnyav xws li chiv thiab tshuaj lom neeg raw. In addition, it has excellent low-temperature heat sealing and inclusion sealing, and is often used as a heat sealing layer for composite films.
Txoj kev tsim khoom ntawm PVA films muaj xws li kev daws teeb meem casting thiab extrusion tshuab moulding. Vim tias lub siab melting kub ntawm PVA thiab nws qhov sib thooj rau lub decomposition kub, ncaj qha melt extrusion yog qhov siv dej kom tau yooj yim yog feem ntau siv los txo qhov kub. In this way, the film needs to be dried and dehydrated after molding to obtain a practical PVA film. In the field of packaging, the industry prefers to use the cast method to produce PVA films.
PVA cov yeeb yaj kiab tuaj yeem muab faib ua cov yeeb yaj kiab dej-resistant thiab cov yeeb yaj kiab dej-soluble. Cov yeeb yaj kiab dej-resistant yog ua los ntawm PVA nrog cov polymerized qib ntau dua 1000 thiab so dej-solonified pva nrog tsawg kawg ntawm polymerization. Hauv kev siv cov ntawv thov, peb tsuas yog siv cov dej-resistant PVA zaj duab xis.
PVA Zaj duab xis, uas sawv rau nws cov lus qhia zoo heev thiab ci, tsis yog tsawg dua rau cov hluav taws xob muaj peev xwm thiab kev nqus plua plav, tab sis kuj tau ua haujlwm zoo. Nyob rau hauv lub xeev qhuav, nws ua kom pom zoo heev airtightness thiab cov tshuaj tsw qab mus cia siab, zoo li cov roj tsis kam zoo. Tsis tas li ntawd, PVA cov yeeb yaj kiab muaj qhov zoo mechanical zog, tawv, thiab tuaj yeem ua kom muaj kev ntxhov siab tawg, thiab tuaj yeem ua kom sov. Txawm li cas los xij, vim nws cov kev vam meej noo noo sib npaug thiab cov dej nqus dej muaj zog, qhov seem ruaj khov yuav tsum tau txhim kho. Txhawm rau kom daws tau cov teeb meem no, polyvinylidene chloride txheej, piv txwv li, ke txheej, tshuaj tsw qab zib tiv thaiv thiab noo noo tsis kam. Qhov tshwj xeeb no kho pva zaj duab xis yog qhov zoo tagnrho rau khoom noj ntim khoom.
PVA zaj duab xis feem ntau siv los ua cov txheej txheem thaiv rau cov yeeb yaj kiab sib xyaw, thiab yog siv dav hauv cov khoom noj ceev, cov nqaij cov khoom lag luam, cov khoom noj qab zib, cov khoom noj qab zib. At the same time, its single film is also widely used in the packaging of textiles and clothing. Tsis tas li ntawd, dej-soluble PVA zaj duab xis tseem muaj kev ua tau zoo heev hauv lub meterical thiab tshuaj ntxuav, thiab lwm yam, nrog rau lub hnab ntxuav ntawm cov neeg mob khaub ncaws.
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Lub sij hawm Post: Mar-18-2025