https://blog.jwell-group.com/polypropylene-shrinkage-difficult-to-control-what-are-the-influencing-factors/

Polypropylene yana ɗaya daga cikin robobi da aka fi amfani da su a aikace, tare da fa'idodin ƙarancin yawa, kyakkyawan tauri, juriya ga lanƙwasawa, juriya ga sinadarai da kuma kyakkyawan kariya. Rashinsa sune rashin tasirin tasirin zafi mai ƙarancin zafi, tsufa mai sauƙi da kuma raguwar girman ƙera.

Gyara zai iya inganta halayen tasirin zafi mai ƙarancin zafi, raguwar ƙira da kuma tsufar zafi na polypropylene. Ragewa, idan an sarrafa shi sosai, yana da mahimmanci don haɓaka masu gyaran polypropylene kuma yana da mahimmanci wajen tabbatar da ingancin samfur. Musamman ma, raguwa yana da matukar muhimmanci lokacin amfani da polypropylene da aka gyara don maye gurbin robobi na injiniya na gargajiya.
Gyaran polypropylene yana da fasahar zamani a China, amma nazarin matsalolin raguwar ruwa ya fi warwatse. Haɗin hanyar sadarwa ta filastik sarkar bayanai na yanzu, don wannan batu ya samar da ɗan bayani, ina fatan ba ku a masana'antar don samar da ra'ayoyi.

Sanadin

Yawan raguwar polypropylene babban rashin amfani ne ga polypropylene kanta, galibi saboda yawan kristal ɗinsa. Bayan lu'ulu'u, takamaiman nauyin polypropylene yana ƙaruwa kuma ƙararsa yana raguwa. Takamaiman nauyi shine 0.851 da 0.936 a 0% da 100% lu'ulu'u bi da bi, don haka raguwar samuwar PP mai tsarki gabaɗaya yana tsakanin 1.7 da 2.2.

Babban abin da ke hana raguwar polypropylene shine yawan lu'ulu'u na kayan da aka yi amfani da su: ƙaramar lu'ulu'u, ƙaramar raguwa; akasin haka, mafi girman lu'ulu'u, mafi girman raguwa.

Inrobobi da aka gyara da polypropylene, ƙara nau'ikan gyare-gyare daban-daban, zuwa matakai daban-daban, ya lalata ainihin lu'ulu'u na polypropylene, don haka ya canza asalin raguwar polypropylene don ƙera shi.

I. Tasirin roba akan raguwar polypropylene

Yayin da yawan roba ke ƙaruwa, raguwar ƙera shi yana raguwa. Wannan ya faru ne saboda ƙara roba yana lalata lu'ulu'u na polypropylene da kansa, wanda ke haifar da raguwar raguwar ƙera shi, kuma elastomers guda uku POE, EPDM da SBS suna da tasiri daban-daban akan raguwar ƙera shi.

Idan abun cikin elastomer ya ƙasa da kashi 5%, tasirin kowane nau'in elastomer akan raguwar PP abu ɗaya ne. Sai bayan abun cikin elastomer ya wuce kashi 5%, matakin tasirin nau'ikan elastomer daban-daban zai bambanta, kuma tsarin tasirin akan raguwa shine POE>EPDM>SBS, wanda yayi daidai da tasirin tauri na elastomers akan PP.

Rage raguwar ƙanƙantawa ya fi kyau idan aka ƙara abubuwan cikawa marasa tsari zuwa PP a cikin cakuda tare da elastomers.

II. Tasirin cika ma'adinai akan raguwar polypropylene masu gyara a cikin ƙera

Manyan abubuwan da ake ƙarawa a cikin ma'adanai don polypropylene sune calcium carbonate, talc, mica powder, da sauransu. Akwai manyan dalilai guda uku da ke haifar da tasirin ƙarin ma'adanai akan raguwar polypropylene masu gyara don ƙera su.

Da farko, ƙarin ma'adinai da kansa ba ya raguwa, kuma ƙarinsa yana rage raguwar polypropylene mai gyara daga jimlar rabo; na biyu, ƙarin ƙarin ma'adinai ba makawa yana shafar lu'ulu'u na polypropylene, wanda ke shafar raguwar; na uku, ƙarawar microfine ma'adinai yana taka rawar wani abu mai hana nucleating, wanda ke canza yanayin tsarin polypropylene kuma yana hana samuwar manyan lu'ulu'u masu siffar ƙwallo, wanda kuma yana shafar raguwar samuwar polypropylene.

1) Siffar filler
Siffar cikawar da ba ta da tsari tana da tasiri daban-daban akan ƙimar raguwa, takamaiman girman tasirin yana cikin tsari na flakes > allurai > granules > spheres.

2) Girman barbashi na abin cikawa
Girman barbashi daban-daban na cika ɗaya suna da tasiri daban-daban akan ƙimar raguwa, ƙaramin girman barbashi, mafi girman raguwar ƙimar raguwa. Idan aka ɗauki PP cike da talc (20% talc + 8% POE) a matsayin misali, tasirin girman barbashi daban-daban na talc akan raguwa kamar haka.

3) Maganin saman abubuwan cikawa
Tasirin raguwar ya bambanta dangane da ko an yi wa saman cika ɗaya magani lokacin da aka yi masa laminate da resin. Cikakken da aka yi wa saman yana da tasiri sosai akan raguwar.

4) Adadin abin cikawa
Adadin abin cikawa iri ɗaya da aka ƙara yana da tasiri daban-daban akan ƙimar raguwa, gwargwadon yawan da aka ƙara, mafi girman raguwar ƙimar raguwa.

III. Tasirin zare akan raguwar polypropylene masu gyara a cikin ƙira
Zaruruwan da aka ambata a nan sun haɗa da dukkan nau'ikan zaruruwan da ba na halitta ba da na halitta. Misali, idan aka yi la'akari da gajerun ƙarfafa zaruruwan gilashi, ƙara zaruruwan gilashi masu bambancin abun ciki zuwa resin PP na iya rage raguwar ƙirar sa sosai.

Dogayen polymers da aka ƙarfafa da zare na gilashi suna da fa'idar ƙarancin raguwa idan aka kwatanta da gajerun zare na gilashi da kuma raguwar daidaituwa a duka hanyoyi na tsayi da na juye. Polymers da aka ƙarfafa da zare na gilashi suna da ƙarancin raguwa fiye da polymers da aka ƙarfafa da zare na gilashi.

Zaren gilashi suna da tasiri mafi girma akan raguwar ƙirar polypropylene masu gyaran gilashi. Lokacin da abun ciki na zaren gilashi ya kai kashi 30% ko fiye, raguwar ƙirar polypropylene mai gyaran gilashi yana raguwa daga 1.8 zuwa 0.5 kuma zaren gilashin da aka yi wa magani yana da tasiri mafi girma akan raguwar ƙirar fiye da zaren gilashin da ba a yi wa magani ba.

Da farko ƙara zare na gilashi yana lalata ƙarfin polypropylene kuma yana shafar raguwar, kuma mafi mahimmanci zare na gilashi yana iyakance raguwar polypropylene.

IV. Tasirin haɗakar polyethylene akan raguwar ƙera polypropylene
Ƙarin polyethylene kuma yana shafar raguwar ƙirar polypropylene mai gyarawa. Duk da cewa polyethylene shima filastik ne mai yawan lu'ulu'u tare da babban raguwar ƙirar, ƙara polyethylene zuwa polypropylene yana kawo cikas ga lu'ulu'u na juna zuwa matakai daban-daban, wanda ke haifar da raguwar raguwar ƙirar gaba ɗaya.

Ana iya amfani da haɗin sinadarai da sauran resins, ko kuma gyare-gyaren haɗin gwiwa da dasawa.

V. Tasirin canje-canje a cikin MFI na polypropylene akan raguwar ƙira
Ragewar polypropylene yana tasiri ne ta hanyar lu'ulu'u, wanda hakan ke shafar girman nauyin kwayoyin halittarsa. Lokacin da MFI ya ƙaru, nauyin kwayoyin halittar yana raguwa, lu'ulu'u yana ƙaruwa kuma raguwar tsarin halittar yana ƙaruwa.

Kwatanta tasirin masu gyara akan raguwar ƙarfi a cikin ƙirar polypropylene

An nuna tasirin masu gyara daban-daban akan raguwar masu gyara polypropylene a cikin tebur, wanda ke nuna cewa tasirin masu gyara daban-daban akan raguwar masu gyara polypropylene ya bambanta, tare da zaren gilashi yana da mafi girman tasiri, a cikin tsari mai zuwa: zaren gilashi > ma'adinai > elastomer > polyethylene.

Idan aka yi amfani da wasu gyare-gyare da dama, tasirin raguwar polypropylene ba iri ɗaya bane, tasirin abubuwa da yawa. Misali, matakin yaɗuwar mai gyara a cikin polypropylene, girman barbashi na mai gyaran ma'adinai da kansa, maganin saman abubuwan cika ma'adinai daban-daban, da sauransu, duk suna da tasiri kan raguwar ƙirar.

Bugu da ƙari, tsarin ƙera injin ƙera allura yana da tasiri sosai kan yawan raguwar aiki yayin aikin ƙera. Misali, canje-canje a zafin allura da matsin lamba na allura suna da tasiri kan ƙimar raguwar aiki.