I. Cov ntsiab lus ntawmplastics
Yas yog cov khoom siv polymer cov khoom siv nrog cob ua nws lub ntsiab, uas tuaj yeem ua pwm rau hauv cov duab ntawm qhov kub thiab lub siab, thiab tuaj yeem khaws qee cov duab ntawm qhov kub thiab txias.
Resin yog hais txog cov organic polymer uas feem ntau muaj kev hloov pauv los yog yaj thaum rhaub, muaj fluidity thaum hloov los ntawm sab nraud quab yuam, thiab yog cov khoom tawv lossis ib nrab lossis cov kua ntawm qhov kub. Nws yog cov feem ntau yooj yim thiab tseem ceeb tivthaiv ntawm plastics. Hais lus dav dav, txhua yam polymer uas yog cov khoom siv yooj yim ntawm cov khoom siv ntawm cov yas ua kev lag luam tuaj yeem hu ua cov khoom ntoo.
Thib ob, kev faib tawm ntawm cov yas
Nyob rau tam sim no, tsis muaj tseeb kev faib tawm ntawm plastics, thiab kev faib tawm dav dav yog raws li nram no:
1. Raws li cov yam ntxwv ntawm lub cev thiab tshuaj ntawm lub plastics, thermoplastic plastics: cov yas uas tuaj yeem kho tau, ua kom txias thiab txias thiab ua kom tawv dua ib zaug hauv qhov ntsuas kub. Xws li polyethylene yas thiab polyvinyl chloride yas. Thermosetting plastics: cov pa uas tuaj yeem ua rau cov khoom tawg yooj yim vim muaj cua sov lossis lwm yam mob. Xws li phenolic plastics, epoxy plastics, thiab lwm yam.
2. cais cov plastics dav dav raws li lawv siv: -ib feem ntau hais txog cov plastics nrog cov zis loj, kev siv dav, zoo qauv thiab tus nqi qis. Xws li polyethylene, polypropylene thiab polyvinyl chloride. Engineering plastics:-feem ntau yog hais txog cov plastics uas tuaj yeem thev tau cov quab yuam sab nraud, muaj cov yam ntxwv zoo thiab qhov chaw ruaj khov, tseem tuaj yeem tswj tau lawv cov khoom zoo nyob rau qhov kub thiab tsis kub, thiab tuaj yeem siv ua yam xws li tshuab kev teeb tsa. Xws li ABS, nylon, poly alum, thiab lwm yam.
Cov plastics tshwj xeeb: -Qhov feem ntau hais txog cov plastics uas muaj cov haujlwm tshwj xeeb (xws li kev tiv thaiv tshav kub, kev nqus tus kheej, thiab lwm yam) thiab siv rau qhov tshwj xeeb. Xws li fluoroplastics thiab organic silicon.
3. Kev txhaj tshuaj yas raws li kev txhaj tshuaj yas: kev ua kom sib xyaw moulding. Xws li cov thermosetting uas nyob nrog. Laminated plastics: yog hais txog fiber ntau cov ntaub impregnated nrog cov ntaub nplaum, uas tuaj yeem ua tau laminated thiab kev sib txuas los ntawm kub nias los ua ib qho khoom siv tag nrho. Kev txhaj tshuaj, extrusion thiab tshuab moulding plastics:-feem ntau yog hais txog kev cob qhia cov khoom sib xyaw roj uas tuaj yeem yaj thiab ntws ntawm lub thoob kub thiab ua kom tawv sai sai hauv cov pwm. Xws li thermoplastics feem ntau.
Nrum yas: cov kua roj ua kua sib xyaw uas tuaj yeem hliv rau hauv pwm thiab khov rau cov khoom lag luam nrog qee qhov tsis muaj zog lossis tsis tshua muaj siab. Piv txwv li MC nylon. Cov tshuaj tiv thaiv kev txhaj tshuaj molding sib xyaw: feem ntau hais txog cov khoom siv ua kua, uas tau txhaj rau hauv cov pwm kab noj hniav hauv qab qhov siab, thiab tom qab ntawd ua tiav thiab sib tw ua kom tau txais cov khoom tiav. Xws li polyurethane.
4. Moulding hmoov raws li yas ib nrab khoom thiab cov khoom lag luam: tseem hu ua cov hmoov yas, uas yog tau txais los ntawm kev sib xyaw tag nrho, nias thiab zom cov thermosetting cob (xws li phenolic resin) thiab muab tub lim. Xws li phenolic cov hmoov yas. Reinforced plastics: ib hom kab uas muaj cov khoom siv ntxiv thiab qee cov khoom siv kho tshuab tau zoo heev piv nrog thawj cov ntaub. Ua npuas yas: yas nrog ntau cov micropores hauv tus kheej. Nyias zaj duab xis: feem ntau hais txog cov khoom tiaj thiab mos yas siv nrog tuab hauv qab 0.25mm ..
Thib peb, cov cuab yeej yooj yim ntawm plastics
1. Lub teeb yuag thiab lub zog tshwj xeeb. Plastics yog lub teeb, thiab qhov ntom ntawm cov plastics feem ntau yog nruab nrab ntawm 0.9 ~ 2.3 g / cm3, uas tsuas yog li 1/8 ~ 1/4 ntawm cov hlau thiab 1/2 ntawm txhuas, thaum lub ntom ntawm ntau cov ua npuas plastics tseem qis dua, uas yog nruab nrab ntawm 0.01 ~ O.5 g / cm3.
Lub zog muab xam los ntawm cov pawg pawg hu ua lub zog tshwj xeeb, thiab lub zog tshwj xeeb ntawm qee qhov kev txhim kho plastics plahaum los yog txawm ntau tshaj qhov ntawm cov hlau. Piv txwv, lub zog tensile rau ib pawg loj ntawm cov hlau loj yog 160 MPa, thaum lub hnab yas txhawb nrog iav iav tuaj yeem ncav cuag 170 ~ 400 MPa.
2. Kev ua tau zoo hluav taws xob zoo ua tau zoo. Yuav luag txhua tus plastics muaj cov hluav taws xob zoo hluav taws xob tiv thaiv, xws li poob qis me me thiab qhov zoo tshaj plaws arc tsis kam, uas yog qhov sib piv ntawm cov xeb hluav taws xob.
3. Muaj tshuaj lom neeg zoo heev. Feem ntau, cov yas muaj cov tshuaj tiv thaiv zoo rau tshuaj xws li acid thiab alkali, tshwj xeeb tshaj yog polytetrafluoroethylene, uas muaj cov tshuaj tiv thaiv corrosion zoo dua li kub, thiab txawm tuaj yeem tiv thaiv qhov corrosion ntawm muaj zog corrosive electrolytes xws li aqua regia, yog li nws hu ua" yas huab tais" ;.
4. Cov tshuaj tiv thaiv zoo thiab hnav tsis kam. Feem ntau cov plastics muaj cov tshuaj tiv thaiv zoo, hnav tsis kam thiab tus kheej lubricating khoom. Ntau yam los tiv thaiv kev sib txhuam ua rau ntawm cov tshuab hluav taws xob ua rau siv cov yam ntxwv ntawm plastics. Thaum qee cov roj nplua nyeem thiab cov ntxig ntxiv tau ntxiv rau cov yeeb yaj kiab tiv thaiv kev sib txhuam, lawv cov kev sib txhuam coefficient tuaj yeem raug txo lossis lawv qhov kev hnav tsis kam tuaj yeem hloov kho ntxiv.
5. Lub teeb kis tau tus mob thiab tiv thaiv kev ua haujlwm. Cov plastics feem ntau tuaj yeem siv ua cov pob tshab lossis cov khoom lag luam, ntawm cov uas polystyrene thiab acrylate plastics yog cov pob tshab zoo li iav. Cov tshuaj lom neeg lub npe ntawm plexiglass yog polymethylmethacrylate, uas tuaj yeem raug siv los ua aviation iav khoom.
Polyvinyl chloride, polyethylene, polypropylene thiab lwm cov yeeb yaj kiab yas muaj lub teeb xa tau zoo thiab cov khoom cua sov rwb thaiv tsev, thiab tau siv dav ua cov yeeb yaj kiab ua liaj ua teb. Cov yas muaj ntau yam ntxwv tiv thaiv, yog li lawv feem ntau yog cov khoom siv tiv thaiv thiab tiv thaiv, xws li yas yeeb yaj kiab, cov thawv, cov thoob ntim, cov fwj, thiab lwm yam.
6. Kev nqus tau zoo heev thiab lub suab nrov txo kev ua tau zoo. Qee tus plastics yuav hloov tau thiab ywj. Thaum lawv raug rau kev kub ntxhov ntawm cov neeg sab nraud thiab kev co, ua rau muaj kev sib txhuam hauv sab hauv, thiab lub zog hluav taws xob tau hloov mus ua lub zog cua sov. Yog li no, lawv tau siv los ua cov ntaub ntub dej thiab cov ntaub ntawv tawm hauv tshuab. Piv txwv li, cov kabmob thiab cov hniav ua los ntawm cov yas ua tshuab ua hluav taws xob tuaj yeem txo suab nrov, thiab ntau yam ua npuas yas plastics tau siv dav ua cov ntaub so ntswg zoo thiab cov ntaub ntawv tawm.
Cov khoom zoo zoo ntawm cov plastics saum toj no ua rau nws siv dav hauv kev lag luam thiab kev ua liaj ua teb thiab neeg' s lub neej txhua hnub; Nws tau siv los hloov cov hlau, iav, ceramics, ntoo thiab fiber ntau yav dhau los, thiab tau los ua cov khoom siv tsis tseem ceeb rau lub neej niaj hnub thiab kev lag luam kev lag luam.
Txawm li cas los xij, plastics kuj muaj qhov tsis ntev. Piv txwv li, cov tshav kub tsis kam ua qhov phem dua li ntawm cov hlau thiab lwm yam khoom siv. Feem ntau, cov yas siv tsuas yog siv tau qhov kub qis dua 100 ℃, thiab qee qhov tuaj yeem siv ntawm ib ncig 200 ℃;
Lub tshav kub thermal coefficient ntawm cov yas yog 3 ~ 10 npaug loj dua li ntawm cov hlau, thiab nws yooj yim rau cuam tshuam los ntawm kev hloov kub thiab nws qhov kev ruaj ntseg seem yog cuam tshuam. Hauv kev thauj khoom, yas yuav maj mam tsim cov dej ntws khov los yog deformation, uas yog, nkag siab; Tsis tas li ntawd, plastics yuav muaj hnub nyoog nyob rau hauv qhov kev ua ntawm huab cua, hnub ci, ua kom ntev ntev lossis qee qhov ua tau zoo, uas yuav ua rau tsis zoo ntxiv mus thiab lwm yam.
Cov shortcomings ntawm plastics ntau los tsawg dua cuam tshuam los yog txwv nws daim ntawv thov. Txawm li cas los xij, nrog kev txhim kho kev lag luam yas thiab kev tshawb nrhiav tob dua ntawm cov ntaub ntawv yas, cov kev ua tsis tiav no tau maj mam dhau los, thiab cov yas tshiab nrog cov kev ua tau zoo thiab ntau yam khoom siv yas sib txuas yog qhov tawm tshiab tas li.
Thib plaub, kev siv cov plastics
Plastics tau siv dav hauv kev ua liaj ua teb, kev lag luam, kev tsim kho, ntim, kev tiv thaiv kev tiv thaiv kev lag luam thiab cov neeg' s lub neej niaj hnub thiab lwm cov teb. Kev Ua Liaj Ua Teb: Ntau lub hnab yas yog siv los tsim cov yeeb yaj kiab mulching, yub zaj duab xis, zaj duab xis tsev cog qoob loo, dej ntws thiab pov dej ntws, ntses nuv ntses, ntab ntab, thiab lwm yam. cov khoom siv;
Hauv kev siv tshuab hauv kev lag luam, kev xa cov kis, cov kabmob, cov kabmob plhaub thiab ntau qhov chaw ua los ntawm cov yas yog siv los hloov cov khoom siv hlau; Hauv kev lag luam chemical, yas yog siv los ua cov kav dej, ntau lub ntim thiab lwm yam khoom los tiv thaiv xeb; Hauv kev tsim kho kev lag luam, nws yog siv los ua qhov rooj thiab cov qhov rai, tus ntaiv tes ntaiv, cov pob zeb hauv pem teb, saum nthab, rwb thaiv tsev kub thiab suab rwb thaiv tsev, phab ntsa, dej ua yeeb nkab thiab cov kav xa dej, cov rooj tog zaum zoo nkauj thiab cov khoom lag luam huv, thiab lwm yam.
Hauv kev tiv thaiv kev lag luam hauv teb chaws thiab kev siv thev naus laus zis, plastics yog qhov tseem ceeb ntawm cov khoom siv, txawm nws yog cov khoom siv dav hlau, dav hlau, nkoj, foob pob hluav taws, foob pob hluav taws, khoom siv hluav taws xob cuav, chaw ua haujlwm thiab kev lag luam atomic energy. Hauv cov neeg' s lub neej txhua hnub, plas plas yog siv dav, xws li yas khau khiab, khau khiab, khaub ncaws hnav, hnab tawv me, hnab looj tes, menyuam' s cov khoom ua si, txhuam hniav, xab npum thawv, thermos plhaub thiab lwm yam.
Tam sim no, nws tau siv dav hauv ntau yam khoom siv hauv tsev, xws li TV, kab xev kaw suab, kiv cua fais fab, tshuab ntxhua khaub ncaws, tub yees thiab lwm yam. Raws li cov khoom ntim tshiab, cov yas tau siv dav hauv cov ntim ntim, xws li ntau yam hollow ntim, txhaj tshuaj moulded ntim (tig thawv, ntim, thoob, thiab lwm yam), ntim cov yeeb yaj kiab, hnab ntim ntawv, corrugated thawv, ua npuas plastics, khi cov hlua khi thiab pob khoom siv, thiab lwm yam.
V. Kev tsim keeb kwm thiab nthuav tawm cov xwm txheej ntawm kev lag luam plastics
Thaum pib ntawm lub xyoo pua puv 19, tib neeg twb tau siv cov khoom siv xws li cov asphalt, rosin, amber thiab shellac. Xyoo 1868, cov cellulose ntuj tsim tau nitrated, thiab camphor tau siv los ua cov yas ua kom lub ntiaj teb' s thawj cov khoom yas, hu ua celluloid. Txij ntawd los mus, keeb kwm ntawm tib neeg siv yas siv neeg pib.
Xyoo 1909, thawj cov hluavtaws yas-phenolic yas tau tshwm sim. Xyoo 1920, lwm cov khoom siv hluavtaws yas-aminoplast (aniline formaldehyde yas) tau yug los. Ob hom plastics no tau ua lub luag haujlwm zoo hauv kev txhawb nqa kev txhim kho kev lag luam hluav taws xob thiab kev siv twj paj nruag lub sijhawm ntawd.
Los ntawm xyoo 1920 thiab 1930s, alkyd resin, polyvinyl chloride, acrylate, polystyrene thiab polyamine tau tshwm sim ib qho dhau ib qho. Txij li xyoo 1940, nrog kev loj hlob ntawm kev tshawb fawb, thev naus laus zis thiab kev lag luam, thiab kev nthuav dav thiab kev siv cov khoom siv roj av, kev lag luam yas tau tsim kho sai heev. Polyethylene, polypropylene, unsaturated polyester, fluoroplastics, epoxy resin, polyoxymethylene, polycarbonate, polyimide thiab li ntawm tau tshwm sim hauv ntau hom.
