Dab tsi ntawm cov yas tuaj yeem ua tiav los ntawm kev txhaj tshuaj molding tshuab?

Raws li cov khoom siv tseem ceeb ntawm kev ua cov yas, Txhaj tshuaj molding tshuab ua tiav qhov kev ua haujlwm siab thiab ua haujlwm tau zoo los ntawm cov cua sov thermoplastic lossis thermoset yas kom yaj lub xeev thiab txhaj tshuaj pwm kab noj hniav. Nws ua tiav ntau yam khoom, los ntawm cov khoom siv niaj hnub mus rau cov khoom lag luam, npog ntau tshaj 20 hom yas. Nyob rau hauv daim ntawv no, hom yas siv nyob rau hauv kev txhaj tshuaj molding tshuab yog soj ntsuam systematically los ntawm plaub yam: kev faib cov khoom, cov yam ntxwv ntawm kev ua tau zoo, ua adaptability thiab raug daim ntawv thov scenarios.

Cov khoom lag luam plastics suav txog ntau dua 70% ntawm cov khoom siv yas thoob ntiaj teb thiab muaj cov yam ntxwv ntawm kev tsim khoom siab, tus nqi qis thiab kev ua haujlwm ruaj khov. Lawv yog cov khoom siv tseem ceeb hauv kev txhaj tshuaj molding tshuab.
1.1 Polyethylene
Polyethylene (HDPE) thiab LDPE yog ob hom yas uas muaj txiaj ntsig zoo tshaj plaws. High density polyethylene (HDPE) cov saw hlau molecular yog nyob ze, muaj qhov zoo rigidity thiab tshuaj tiv thaiv, thiab feem ntau yog siv rau hauv kev tsim cov thawv loj xws li cov thawv xa khoom thiab cov thoob khib nyiab. Tsawg ntom ntom polyethylene (LDPE) muaj qhov ua tau zoo vim nws cov qauv ceg thiab tau siv dav hauv cov khoom siv tau yooj yim xws li cov yeeb yaj kiab thiab cov hnab ntim khoom. Thaum lub sij hawm txhaj tshuaj molding, HDPE yuav tsum ua kom qhov kub thiab txias hauv lub thoob ntawm 220 ° C thiab 260 ° C los tiv thaiv kev degradation, thaum LDPE tuaj yeem ua tiav ntawm qhov kub ntawm 180 ° C thiab 220 ° C.
1.2 Polypropylene (PP)
Polypropylene muaj qhov ntom ntom ntawm cov yas qis tshaj plaws (0.9-0.91 g / cm3), zoo heev qaug zog thiab kub tsis kam (melting point 160 -170 degree) ) thiab yog cov khoom nyiam rau cov khoom siv hauv tsev. Thaum lub sij hawm txhaj tshuaj molding, polypropylene warps yooj yim vim qhov sib txawv crystallization tus nqi, yog li nws yog tsim nyog los optimize pwm kub (pom zoo 80-100 degree) thiab tswj lub siab (pom zoo 60-80% txhaj tshuaj siab) los tswj shrinkage.
1.3 Polystyrene Cov
PS paub txog nws cov khoom kho qhov muag zoo heev (88-92% lub teeb xa tawm), tab sis nws cov brittleness thiab kub tsis kam (kub deflection kub 70-90 degree) txwv nws daim ntawv thov. Kev cuam tshuam loj polystyrene (HIPS) yog butadiene polymer uas yog peb mus rau 5 npaug zog dua PS thiab dav siv hauv cov khoom ua si vaj tsev thiab cov keyboards hauv computer. Exhaust txhaj molding tshuab tau zoo daws qhov teeb meem ntawm qhov tsis zoo ntawm PS kev ua haujlwm thiab txhim kho cov khoom zoo.
1.4 Acrylonitrile-Butadiene-Styrene Copolymer (ABS)
ABS ua ke cov tshuaj tiv thaiv ntawm acrylonitrile, lub toughness ntawm butadiene thiab cov txheej txheem ntawm styrene los ua cov khoom siv dav siv ntau tshaj plaws. Lub Vicat muaj qhov kub thiab txias ntawm 100-105℃thiab cuam tshuam lub zog ntawm 3 mus rau 4 npaug ntawm PS, thiab tshwj xeeb tshaj yog tsim rau kev tsim hluav taws xob vaj tsev thiab lub tsheb sab hauv qhov chaw uas yuav tsum muaj kev tiv thaiv sab nraud. Ob-xim txhaj tshuaj molding ua rau nws muaj peev xwm ua ke ABS nrog rau lwm yam ntaub ntawv, xws li PC, kom tau raws li ntau yam khoom tsim raws li kev cai.

Engineering plastics muaj cov khoom siv zoo heev, thermal stability thiab tshuaj lom neeg. kim raws li nws yog, nws plays lub luag hauj lwm irreplaceable nyob rau hauv siab - kawg manufacturing.
2.1 Polyamide (PA, nylon)
Ntawm PA tsev neeg, PA6 thiab PA66 yog cov siv dav tshaj plaws vim lawv cov khoom sib npaug thiab kev ua haujlwm. Lub melting point ntau yog 220-265 degree, cov dej nqus tus nqi siab li 2-3%, thiab qhov loj stability yog obviously cuam tshuam los ntawm cov av noo. Fiberglass Enhanced PA (GFPA) tsub kom lub zog tensile ntau tshaj 200 MPa thiab kub deflection kub mus rau ntau tshaj 200 degree, ua rau nws zoo tagnrho rau precision mechanical Cheebtsam xws li lub zog thiab bearings. Thaum lub sij hawm txhaj tshuaj molding, nruj tswj qhov kub ntawm lub thoob (PA6: 240-260 degree; PA66: 270-290 degree) thiab qhuav tej yam kev mob (120℃+ 4 teev ntawm qhuav) yog qhov tseem ceeb.
2.2 Polycarbonate (PC)
Lub npe hu ua "bulletproof kua nplaum," PC tau pom 300 npaug ntawm qhov cuam tshuam lub zog thiab 89 89% lub teeb xa hluav taws xob ntawm 89 iav, tab sis tsis zoo rau kev puas tsuaj (nto yog 2H xwb). PC / ABS alloys sib xyaw nrog ABS tau txhim kho tag nrho kev ua tau zoo ntawm cov khoom thiab tau dhau los ua cov khoom siv rau lub laptop vaj tse thiab lub tsheb ntsuas vaj huam sib luag. Thaum lub sij hawm txhaj tshuaj molding, kev txhaj tshuaj siab (80-120 MPa) thiab kev txhaj tshuaj sai (kev txhaj tshuaj ceev Ntau dua lossis sib npaug li 100 mm / s) yuav tsum tau tiv thaiv kom tsis txhob khov, thiab pwm kub ntawm 80-100℃yog pom zoo.
2.3 Polyoxymethylene (POM)
POM yog hu ua "super steel" nrog hardness (Rockwell hardness M85-105), abrasion kuj ze rau hlau, thiab zoo heev dimensional stability (linear expansion coefficient xwb 6 × 10-5 / degree). Los ntawm kev ntxiv polytetrafluoroethylene (PTFE) lubricant, kev sib txhuam coefficient yuav raug txo kom tsawg dua 0.1, yog ib qho khoom siv zoo tagnrho rau iav, slider thiab lwm yam kis tau tus mob. Thaum txhaj tshuaj molding, qhov kub hauv lub thoob yuav tsum tswj ntawm 190 thiab 210 degrees Celsius kom tsis txhob decomposition ntawm formaldehyde roj.

Thermoset plastics solidify los ntawm cov tshuaj tiv thaiv thaum lub sij hawm molding, tsim irreversible crosslinking qauv, haum rau tshwj xeeb tej yam kev mob uas yuav tsum tau kub kub thiab tshuaj tiv thaiv.
3.1 Phenolic Plastics (PF)
PF yog qhov ntxov tshaj plaws kev lag luam thermosetting yas nrog zoo hluav taws xob rwb thaiv tsev, kub tsis kam (nruam kub ntawm 150 degree) thiab nplaim hluav taws kub (oxygen Performance index ntau dua los yog sib npaug li 30%), tab sis nkig thiab tsis ua hauj lwm flowability. Los ntawm kev ntxiv cov tshuaj tiv thaiv toughening thiab kev txhim kho ntws, nws tuaj yeem tsim hluav taws xob hloov hluav taws xob thiab lub qhov (sockets). Thaum lub sij hawm txhaj tshuaj molding, chim kub yuav tsum tau tswj ntawm 70 thiab 90 degree, pwm kub ntawm 150 thiab 180 degree, thiab txhaj tshuaj ntawm 120-150 MPa kom kov yeej cov viscosity siab.
3.2 Epoxy cob (EP)
EP yog lub npe hu rau nws cov adhesion zoo heev (shear lub zog ntau dua los yog sib npaug rau 20 MPa) thiab tshuaj tiv thaiv thiab yog dav siv nyob rau hauv electronics ntim thiab composite matrix. Los ntawm kev ntxiv inorganic fillers (xws li silica hmoov), shrinkage tuaj yeem txo qis (los ntawm 2% mus rau qis dua 0.1%) thiab qhov tseeb qhov tseeb tuaj yeem txhim kho. Kev txhaj tshuaj molding yuav tsum muaj cov ntsia hlau tshwj xeeb (qhov sib piv Ntau dua lossis sib npaug ntawm 20: 1) thiab siab -siab txhaj tshuaj molding tshuab (siab tshaj lossis sib npaug rau 200 MPa), nrog pwm kub tswj ntawm 120 thiab 150℃.

Cov yas tshwj xeeb muab cov khoom tshwj xeeb los ntawm kev tsim qauv molecular kom tau raws li qhov siab -kawg xav tau hauv aerospace, kev kho mob thiab lwm yam.
4.1 Polytetrafluoroethylene 3
PTFE (PTFE) muaj qhov dav tshaj plaws ntawm kev ua haujlwm kub (-200 txog 260 degree), tshuaj lom neeg ruaj khov siab tshaj plaws (ua haujlwm rau huab tais dej corrosion) thiab qis tshaj kev sib txhuam coefficient (0.04). Txawm li cas los xij, nws cov viscosity siab heev (1010-1012 Pa. S) ua rau kev txhaj tshuaj molding nyuaj. Txias nias, sintering lossis hloov pauv ntawm polytetrafluoroethylene (xws li cov iav fiber ntau) yuav tsum tau txo cov viscosity yaj. Hloov kho PTFE cov khoom siv dav siv hauv cov ntsaws ruaj ruaj thiab cov tuav tuav.
4.2 Polyetheretherketone
PEEK muaj qhov ntev -lub sij hawm kub ntawm 240 degree, luv luv -lub sij hawm kub tsis kam ntawm 315 degree, thiab aa tensile zog 90-100 MPa. Cov pa roj carbon-fiber- txhawb nqa PEEK txhim kho cov qauv ntawm elasticity mus rau 140 GPa, ze rau qib ntawm aluminium alloy, thiab yog siv dav hauv cov qauv hauv dav hlau thiab kev cog qoob loo kho mob. Kev txhaj tshuaj molding yuav tsum tau tshwj xeeb siab - kub screws (chim kub 380-420 degree) thiab high-pressure systems (siab tshaj los yog sib npaug rau 250 MPa), nrog pwm kub tswj ntawm 180℃C thiab 200℃.
V. Kev lag luam hauv kev siv tshuab
Nrog rau kev txhim kho cov ntaub ntawv tshawb fawb thiab khoom siv thev naus laus zis, kev ua haujlwm muaj peev xwm ntawm kev txhaj tshuaj molding tshuab tau nthuav dav:
Multi-cov ntaub ntawv sib xyaw molding: Lub laminated bonding ntawm PC/ABS, PA/GF thiab lwm yam kev sib xyaw tuaj yeem ua tiav los ntawm co-txheej thev naus laus zis los txhim kho kev ua tau zoo ntawm cov khoom.
Microinjection molding: Kev txhim kho ntawm ultra- cov ntsia hlau precision (inch tsawg dua lossis sib npaug li 10 mm) thiab siab - teb cov tshuab ua haujlwm los tsim cov microcomponents xws li lub zog thiab cov khoom sib txuas uas hnyav dua 0.1 g.
Gas auxiliary txhaj molding: siab siab nitrogen gas auxiliary filling yog siv los txo cov cim dab dej los ntawm cov khoom phab ntsa thickness sib txawv. Nws yog haum rau lub tsheb qhov rooj vaj huam sib luag, cov khoom siv loj loj thiab lwm yam tuab -cov khoom siv phab ntsa.
Bioenergy qhov chaw plastics ua: hloov mus rau cov yam ntxwv ntawm polylactic acid, polyhydroxyapatite thiab lwm yam ntaub ntawv, tsim tshwj xeeb ntsia hlau qauv thiab kev tswj qhov kub thiab txias, txhawb kev lag luam ntawm cov ntaub ntawv tiv thaiv ib puag ncig.
Xaus:
Kev txhaj tshuaj molding tshuab tau nthuav dav los ntawm cov khoom lag luam ib txwm siv rau cov khoom siv plastics, thermosetting plastics thiab txawm tias cov yas tshwj xeeb, suav nrog cov kev xav tau ntau lawm los ntawm micrometer - nplai precision qhov chaw mus rau micron - nplai loj cov khoom siv. Nrog rau kev tsim kho cov khoom siv thev naus laus zis thiab cov cuab yeej txawj ntse, cov txheej txheem txhaj tshuaj molding yuav txuas ntxiv ua lub luag haujlwm tseem ceeb hauv kev tsim khoom siab - kawg, thawb kev lag luam plastics mus rau kev ua tau zoo, siab -kev ua tau zoo, kev ua haujlwm ntau, thiab kev txhim kho kom ruaj khov.