amafonti

Plastic Injection Molding Shrinkage

Ipulasitiki yomjovo wokubumba ukuncipha kungenye yezinto lapho izinga lokushisa lempahla liconsa. Izinga lomjovo wokubumba shrankage liyadingeka ekunqumeni ubukhulu bokugcina bokusebenza. Inani likhombisa inani lokusikwa okuvezwa wuhlaka lomsebenzi ngemuva kokuthi selususiwe kwisikhunta bese lupholiswa ngo-23C isikhathi esingamahora angama-48.

Ukunciphisa kunqunywa yi-equation elandelayo:

I-S = (Lm-Lf) / Lf * 100%

lapho i-S isilinganiso sokuncipha kwesikhunta, i-Lr ubukhulu bokugcina bokusebenza (ku. noma mm), no-Lm ubukhulu besikhunta (ngaphakathi noma mm). Uhlobo nokuhlukaniswa kwempahla yepulasitiki kunenani eliguquguqukayo lokuncipha. I-shrinkage ingathinteka ngokuhlukahluka okuningana njengokuqina kwamandla okupholisa okokusebenza, umjovo kanye nengcindezi yokuhlala. Ukwengezwa kokugcwaliswa nokuqiniswa, okufana nefayibha yengilazi noma ukugcwaliswa kwamaminerali, kunganciphisa ukuncipha.

Ukuncipha kwemikhiqizo yepulasitiki ngemuva kokuyicubungula kuvamile, kepha ama-polymer amakhemikhali kanye nama-amorphous ancipha ngokuhlukile. Zonke izinto zokusebenza zepulasitiki ziyancipha ngemuva kokucutshungulwa njengomphumela wokucindezelwa kwazo nokusikwa okushisayo njengoba zipholile kusukela ekushiseni kokushisa.

Izinto ze-amorphous zine-shrinkage ephansi. Lapho izinto ze-amorphous zipholile phakathi nesigaba sokupholisa senqubo yokubumba umjovo, baphindela ku-plymer eqinile. Amaketanga e-polymer akha i-amorphous material awanawo umumo othile. Izibonelo ze-pf amorphous materials yi-polycarbonate, i-ABS, ne-polystyrene.

Izinto ezinamakhristali zinendawo yokuncibilika kwekristallini Amaketanga e-polymer azibeka ngokwawo ekuhlelweni kwamangqamuzana. Lezi zindawo ezi-odiwe zingamakristalu akha lapho ipolymer ipholile kusuka esimweni sayo esincibilikile. Okwezinto ze-semicrystalline polymer, ukwakheka nokupakisha okwandisiwe kwamaketanga wamangqamuzana kulezi zindawo zamakristalu. i-injectio molding shrinkage yezinto zokwakha i-semicrystalline iphakeme kunezinto ze-amorphous. Izibonelo zezinto zekristalline ziyinyiloni, i-polypropylene, ne-polyethylene.Ibalula inani lezinto zepulasitiki, zombili i-amorphous ne-semicrystalline, kanye nokuncipha kwesikhunta.

Ukuncipha kwe-thermoplastics /%
impahla ukuncipha kwesikhunta impahla  ukuncipha kwesikhunta impahla ukuncipha kwesikhunta
ABS 0.4-0.7 i-polycarbonate 0.5-0.7 I-PPO 0.5-0.7
I-Acrylic 0.2-1.0 I-PC-ABS 0.5-0.7 i-polystyrene 0.4-0.8
I-ABS-inayiloni 1.0-1.2 I-PC-PBT 0.8-1.0 I-Polysulfone 0.1-0.3
I-Acetal 2.0-3.5 I-PC-PET 0.8-1.0 PBT 1.7-2.3
Inayiloni 6 0.7-1.5 I-Polyethylene 1.0-3.0 PET 1.7-2.3
Inayiloni 6,6 1.0-2.5 I-Polypropylene 0.8-3.0 TPO 1.2-1.6
PEI 0.5-0.7        

Umphumela we-shrinkage oguqukayo usho ukuthi ukucubungula ukubekezelela okutholakalela ama-polymorphic amorphous kungcono kakhulu kunalawo ama-polymer e-crystalline, ngoba amakristalu aqukethe ukupakisha oku-ode kakhulu nokuncono kwamaketanga e-polymer, ukuguqulwa kwesigaba kukhulisa ukuncipha kakhulu. Kepha ngama-plastiki amorphous, lokhu ukuphela kwesici futhi kubalwa kalula.

Kuma-polymorphic amorphous, amanani we-shrinkage awekho phansi kuphela, kepha ukuncipha uqobo kuyashesha ukwenzeka. Nge-polymer ejwayelekile efana ne-PMMA, ukuncipha kuzoba ngo-1-5mm / m. Lokhu kungenxa yokupholisa kusuka cishe ku-150 (izinga lokushisa lokuncibilika) kuye ku-23C (igumbi lokushisa) futhi kungahlotshaniswa no-coefficient of expando thermal.


Isikhathi Iposi: Sep-19-2020