1. Siv kev faib tawm

Raws li cov yam ntxwv siv sib txawv ntawm ntau yam yas, cov yas feem ntau muab faib ua peb hom: cov yas dav dav, cov yas engineering thiab cov yas tshwj xeeb.

① Yas dav dav

Feem ntau hais txog cov yas uas muaj cov khoom loj, siv tau dav, yooj ywm thiab pheej yig. Muaj tsib hom yas dav dav, xws li polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) thiab acrylonitrile-butadiene-styrene copolymer (ABS). Tsib hom yas no yog feem ntau ntawm cov khoom siv yas, thiab lwm yam khoom siv feem ntau yog cov yas tshwj xeeb, xws li: PPS, PPO, PA, PC, POM, thiab lwm yam. Lawv siv tsawg heev hauv cov khoom siv niaj hnub, feem ntau yog siv hauv cov teb siab xws li kev lag luam engineering thiab kev tiv thaiv teb chaws, xws li tsheb, aerospace, kev tsim kho, thiab kev sib txuas lus. Raws li nws txoj kev faib tawm yas, cov yas tuaj yeem faib ua thermoplastics thiab thermosetting plastics. Hauv cov xwm txheej ib txwm muaj, cov khoom thermoplastic tuaj yeem rov ua dua tshiab, thaum thermosetting plastics tsis tuaj yeem. Raws li cov khoom siv kho qhov muag ntawm cov yas, lawv tuaj yeem muab faib ua cov khoom siv pob tshab, pob tshab thiab pob tshab, xws li PS, PMMA, AS, PC, thiab lwm yam uas yog cov yas pob tshab, Thiab feem ntau lwm cov yas yog cov yas pob tshab.

Cov khoom thiab kev siv ntawm cov yas siv feem ntau:

1. Polyethylene:

Cov polyethylene uas siv ntau feem ntau muaj peev xwm muab faib ua cov polyethylene qis qis (LDPE), polyethylene siab siab (HDPE) thiab polyethylene qis qis qis (LLDPE). Ntawm peb yam no, HDPE muaj cov khoom zoo dua thermal, hluav taws xob thiab mechanical, thaum LDPE thiab LLDPE muaj kev ywj pheej zoo dua, cov khoom cuam tshuam, cov khoom tsim zaj duab xis, thiab lwm yam. LDPE thiab LLDPE feem ntau yog siv rau hauv cov yeeb yaj kiab ntim khoom, cov yeeb yaj kiab ua liaj ua teb, kev hloov kho yas, thiab lwm yam, thaum HDPE muaj ntau yam kev siv, xws li cov yeeb yaj kiab, cov kav dej, thiab cov khoom siv txhaj tshuaj txhua hnub.

2. Polypropylene:

Hais txog qhov sib piv, polypropylene muaj ntau hom, siv ntau yam nyuaj dua, thiab ntau yam teb. Cov ntau yam feem ntau suav nrog homopolymer polypropylene (homopp), block copolymer polypropylene (copp) thiab random copolymer polypropylene (rapp). Raws li daim ntawv thov, Homopolymerization feem ntau yog siv rau hauv cov teb ntawm kev kos duab hlau, fiber, txhaj tshuaj, BOPP zaj duab xis, thiab lwm yam. Copolymer polypropylene feem ntau yog siv rau hauv cov khoom siv hauv tsev txhaj tshuaj, cov khoom siv hloov kho, cov khoom txhaj tshuaj txhua hnub, cov kav dej, thiab lwm yam, thiab random polypropylene feem ntau yog siv rau hauv cov khoom pob tshab, cov khoom ua tau zoo, cov kav dej ua tau zoo, thiab lwm yam.

3. Polyvinyl chloride:

Vim nws pheej yig thiab nws tus kheej tiv taus hluav taws, nws muaj ntau yam kev siv hauv kev tsim kho, tshwj xeeb tshaj yog rau cov kav dej phwj tuaj, cov qhov rooj yas hlau thiab qhov rai, cov phaj, tawv cuav, thiab lwm yam.

4. Polystyrene:

Ua ib hom khoom siv pob tshab, thaum muaj kev xav tau pob tshab, nws muaj ntau yam kev siv, xws li lub teeb tsheb, cov khoom siv pob tshab txhua hnub, khob pob tshab, cov kaus poom, thiab lwm yam.

5. ABS:

Nws yog ib hom yas engineering uas muaj ntau yam zoo, nws muaj cov yam ntxwv zoo xws li lub cev thiab lub zog thermal. Nws siv dav hauv cov khoom siv hauv tsev, vaj huam sib luag, lub ntsej muag, kev sib dhos, cov khoom siv, thiab lwm yam, tshwj xeeb tshaj yog cov khoom siv hauv tsev, xws li tshuab ntxhua khaub ncaws, cua txias, tub yees, kiv cua hluav taws xob, thiab lwm yam. Nws loj heev thiab siv tau ntau yam hauv kev hloov kho yas.

② Cov yas engineering

Feem ntau yog hais txog cov yas uas tuaj yeem tiv taus qee lub zog sab nraud, muaj cov khoom siv kho tshuab zoo, tiv taus kub siab thiab qis, thiab muaj kev ruaj khov zoo, thiab tuaj yeem siv ua cov qauv tsim kho, xws li polyamide thiab polysulfone. Hauv cov yas tsim kho, nws muab faib ua ob pawg: cov yas tsim kho dav dav thiab cov yas tsim kho tshwj xeeb. Cov yas tsim kho tuaj yeem ua tau raws li qhov xav tau siab dua hauv cov khoom siv kho tshuab, kev ruaj khov, kev tiv thaiv corrosion, thiab kev tiv thaiv kub, thiab lawv yooj yim dua rau kev ua thiab tuaj yeem hloov cov khoom siv hlau. Cov yas tsim kho tau siv dav hauv hluav taws xob thiab hluav taws xob, tsheb, kev tsim kho, cov khoom siv hauv chaw ua haujlwm, tshuab, aerospace thiab lwm yam lag luam. Kev hloov yas rau hlau thiab yas rau ntoo tau dhau los ua qhov sib txawv thoob ntiaj teb.

Cov yas engineering dav dav suav nrog: polyamide, polyoxymethylene, polycarbonate, hloov kho polyphenylene ether, thermoplastic polyester, ultra-high molecular weight polyethylene, methylpentene polymer, vinyl alcohol copolymer, thiab lwm yam.

Cov yas engineering tshwj xeeb muab faib ua hom sib txuas thiab hom tsis sib txuas. Hom sib txuas yog: polyamino bismaleamide, polytriazine, polyimide sib txuas, epoxy resin uas tiv taus cua sov thiab lwm yam. Hom tsis sib txuas yog: polysulfone, polyethersulfone, polyphenylene sulfide, polyimide, polyether ether ketone (PEEK) thiab lwm yam.

③Cov yas tshwj xeeb

Feem ntau yog hais txog cov yas uas muaj cov haujlwm tshwj xeeb thiab siv tau rau hauv kev siv tshwj xeeb xws li kev tsav dav hlau thiab aerospace. Piv txwv li, fluoroplastics thiab silicones muaj kev tiv taus kub siab, nws tus kheej lubricating thiab lwm yam haujlwm tshwj xeeb, thiab cov yas txhawb nqa thiab cov yas ua npuas dej muaj cov yam ntxwv tshwj xeeb xws li lub zog siab thiab lub cushioning siab. Cov yas no yog cov yas tshwj xeeb.

a. Yas txhawb zog:

Cov khoom siv yas uas muaj zog tuaj yeem muab faib ua cov granular (xws li calcium yas uas muaj zog yas), fiber (xws li iav fiber lossis iav ntaub yas uas muaj zog yas), thiab flake (xws li mica yas uas muaj zog yas) hauv qhov tsos. Raws li cov khoom siv, nws tuaj yeem muab faib ua cov yas uas muaj zog yas (xws li rag reinforced lossis asbestos reinforced plastics), cov yas uas muaj inorganic minerals (xws li quartz lossis mica yas uas muaj zog yas), thiab cov yas uas muaj zog fiber (xws li carbon fiber reinforced plastics).

b. Ua npuas ncauj:

Cov yas ua npuas ncauj muaj peb hom: cov ua npuas ncauj tawv, cov ua npuas ncauj ib nrab tawv thiab cov ua npuas ncauj yooj ywm. Cov ua npuas ncauj tawv tsis muaj kev ywj pheej, thiab nws qhov nyuaj ntawm kev nias yog loj heev. Nws yuav deform tsuas yog thaum nws mus txog qee qhov kev ntxhov siab thiab tsis tuaj yeem rov qab mus rau nws lub xeev qub tom qab kev ntxhov siab raug txo qis. Cov ua npuas ncauj yooj ywm yog yoog tau, nrog qhov nyuaj ntawm kev nias qis, thiab yooj yim rau deform. Rov qab kho lub xeev qub, qhov seem deformation yog me me; qhov yooj ywm thiab lwm yam khoom ntawm cov ua npuas ncauj ib nrab tawv yog nyob nruab nrab ntawm cov ua npuas ncauj tawv thiab mos.

Ob, kev faib tawm lub cev thiab tshuaj lom neeg

Raws li cov khoom sib txawv ntawm lub cev thiab tshuaj ntawm ntau yam yas, cov yas tuaj yeem muab faib ua ob hom: thermosetting plastics thiab thermoplastic plastics.

(1) Cov khoom siv thermoplastic

Cov Thermoplastics (Thermoplastics): hais txog cov yas uas yuav yaj tom qab cua sov, tuaj yeem ntws mus rau hauv pwm tom qab txias, thiab tom qab ntawd yaj tom qab cua sov; cua sov thiab txias tuaj yeem siv los tsim cov kev hloov pauv rov qab (kua ← → khoom), yog Qhov hu ua kev hloov pauv lub cev. Cov thermoplastics dav dav muaj qhov kub siv tas mus li hauv qab 100 ° C. Polyethylene, polyvinyl chloride, polypropylene, thiab polystyrene kuj tseem hu ua plaub hom yas dav dav. Cov thermoplastics raug faib ua hydrocarbons, vinyls nrog polar genes, engineering, cellulose thiab lwm yam. Nws ua mos thaum cua sov, thiab ua tawv thaum txias. Nws tuaj yeem ua kom mos thiab tawv dua thiab tswj tau qee yam duab. Nws yaj tau hauv qee cov kuab tshuaj thiab muaj cov khoom ntawm kev yaj thiab yaj tau. Cov Thermoplastics muaj kev rwb thaiv hluav taws xob zoo heev, tshwj xeeb tshaj yog polytetrafluoroethylene (PTFE), polystyrene (PS), polyethylene (PE), polypropylene (PP) muaj qhov tsis tu ncua dielectric qis heev thiab dielectric poob. Rau cov ntaub ntawv rwb thaiv tsev zaus siab thiab siab voltage. Cov Thermoplastics yooj yim pwm thiab ua tiav, tab sis muaj kev tiv thaiv cua sov qis thiab yooj yim nkag mus. Qhov degree ntawm creep txawv nrog load, qhov kub thiab txias ib puag ncig, cov kuab tshuaj, thiab cov av noo. Yuav kom kov yeej cov qhov tsis muaj zog ntawm cov thermoplastics thiab ua tau raws li qhov xav tau ntawm cov ntawv thov hauv thaj chaw ntawm kev siv tshuab chaw thiab kev tsim kho lub zog tshiab, txhua lub tebchaws tab tom tsim cov resins uas tiv taus cua sov uas tuaj yeem yaj, xws li polyether ether ketone (PEEK) thiab polyether sulfone (PES), Polyarylsulfone (PASU), polyphenylene sulfide (PPS), thiab lwm yam. Cov ntaub ntawv sib xyaw ua ke siv lawv ua matrix resins muaj cov khoom siv kho tshuab siab dua thiab tiv taus tshuaj lom neeg, tuaj yeem thermoformed thiab welded, thiab muaj interlaminar shear zog zoo dua li epoxy resins. Piv txwv li, siv polyether ether ketone ua matrix resin thiab carbon fiber los ua cov khoom sib xyaw, qhov kev tiv taus qaug zog ntau dua li epoxy / carbon fiber. Nws muaj kev tiv taus kev cuam tshuam zoo, kev tiv taus creep zoo ntawm chav tsev kub, thiab kev ua haujlwm zoo. Nws tuaj yeem siv tas li ntawm 240-270 ° C. Nws yog cov khoom siv rwb thaiv tsev kub zoo tagnrho. Cov khoom sib xyaw ua ke ua los ntawm polyethersulfone ua cov matrix resin thiab carbon fiber muaj lub zog siab thiab tawv ntawm 200 ° C, thiab tuaj yeem tswj tau qhov cuam tshuam zoo ntawm -100 ° C; nws tsis muaj tshuaj lom, tsis kub hnyiab, tsis muaj pa luam yeeb tsawg, thiab tsis muaj hluav taws xob. Zoo, nws yuav siv tau ua ib feem tseem ceeb ntawm lub dav hlau, thiab nws kuj tuaj yeem ua pwm rau hauv radome, thiab lwm yam.

Cov yas sib txuas ua ke formaldehyde suav nrog cov yas phenolic, cov yas amino (xws li urea-formaldehyde-melamine-formaldehyde, thiab lwm yam). Lwm cov yas sib txuas ua ke suav nrog cov polyesters tsis muaj roj, epoxy resins, thiab phthalic diallyl resins.

(2) Cov yas thermosetting

Cov yas thermosetting yog hais txog cov yas uas tuaj yeem kho tau hauv qab cua sov lossis lwm yam mob lossis muaj cov yam ntxwv tsis yaj (yaj), xws li cov yas phenolic, cov yas epoxy, thiab lwm yam. Cov yas thermosetting raug muab faib ua hom formaldehyde cross-linked thiab lwm hom cross-linked. Tom qab ua tiav thermal thiab molding, cov khoom kho tsis yaj thiab tsis yaj tau tsim, thiab cov resin molecules raug txuas mus rau hauv cov qauv network los ntawm cov qauv linear. Cov cua sov ntau ntxiv yuav lwj thiab puas tsuaj. Cov yas thermosetting ib txwm muaj xws li phenolic, epoxy, amino, unsaturated polyester, furan, polysiloxane thiab lwm yam khoom siv, nrog rau cov yas polydipropylene phthalate tshiab. Lawv muaj qhov zoo ntawm kev tiv taus cua sov siab thiab tiv taus kev hloov pauv thaum cua sov. Qhov tsis zoo yog tias lub zog kho tshuab feem ntau tsis siab, tab sis lub zog kho tshuab tuaj yeem txhim kho los ntawm kev ntxiv cov khoom sau los ua cov ntaub ntawv laminated lossis cov ntaub ntawv molded.

Cov yas thermosetting ua los ntawm phenolic resin ua cov khoom siv tseem ceeb, xws li phenolic molded plastic (feem ntau hu ua Bakelite), yog cov khoom siv ruaj khov, ruaj khov, thiab tiv taus lwm yam tshuaj lom neeg tshwj tsis yog cov alkalis muaj zog. Ntau yam khoom sau thiab cov khoom ntxiv tuaj yeem ntxiv raws li kev siv sib txawv thiab cov kev xav tau. Rau ntau yam uas xav tau kev ua haujlwm rwb thaiv tsev siab, mica lossis iav fiber tuaj yeem siv ua cov khoom sau; rau ntau yam uas xav tau kev tiv thaiv cua sov, asbestos lossis lwm yam khoom sau uas tiv taus cua sov tuaj yeem siv; rau ntau yam uas xav tau kev tiv thaiv av qeeg, ntau yam fibers lossis roj hmab tsim nyog tuaj yeem siv ua cov khoom sau Thiab qee cov neeg sawv cev tawv kom ua cov ntaub ntawv tawv siab. Tsis tas li ntawd, cov phenolic resins hloov kho xws li aniline, epoxy, polyvinyl chloride, polyamide, thiab polyvinyl acetal kuj tuaj yeem siv los ua kom tau raws li cov kev xav tau ntawm ntau daim ntawv thov. Phenolic resins kuj tseem tuaj yeem siv los ua phenolic laminates, uas yog tus yam ntxwv los ntawm lub zog siab, cov khoom siv hluav taws xob zoo, kev tiv thaiv corrosion, thiab kev ua haujlwm yooj yim. Lawv siv dav hauv cov khoom siv hluav taws xob qis-voltage.

Cov aminoplasts muaj xws li urea formaldehyde, melamine formaldehyde, urea melamine formaldehyde thiab lwm yam. Lawv muaj qhov zoo ntawm cov qauv tawv, tiv taus khawb, tsis muaj xim, pob tshab, thiab lwm yam. Ntxiv cov xim tuaj yeem ua rau cov khoom muaj yeeb yuj, feem ntau hu ua hluav taws xob jade. Vim tias nws tiv taus roj thiab tsis cuam tshuam los ntawm cov alkalis tsis muaj zog thiab cov kuab tshuaj organic (tab sis tsis tiv taus kua qaub), nws tuaj yeem siv ntawm 70 ° C ntev, thiab tuaj yeem tiv taus 110 txog 120 ° C hauv lub sijhawm luv luv, thiab tuaj yeem siv rau hauv cov khoom siv hluav taws xob. Melamine-formaldehyde yas muaj qhov nyuaj dua li urea-formaldehyde yas, thiab muaj kev tiv thaiv dej zoo dua, tiv taus cua sov, thiab tiv taus arc. Nws tuaj yeem siv ua cov khoom siv rwb thaiv tsev arc.

Muaj ntau hom thermosetting plastics ua los ntawm epoxy resin ua cov khoom siv tseem ceeb, ntawm cov uas kwv yees li 90% yog ua los ntawm bisphenol A epoxy resin. Nws muaj kev nplaum zoo heev, rwb thaiv hluav taws xob, tiv taus kub thiab tshuaj lom neeg ruaj khov, tsis tshua muaj shrinkage thiab nqus dej, thiab muaj zog kho tshuab zoo.

Ob qho tib si unsaturated polyester thiab epoxy resin tuaj yeem ua rau FRP, uas muaj lub zog zoo heev. Piv txwv li, iav fiber reinforced yas ua los ntawm unsaturated polyester muaj cov khoom siv zoo thiab qis qis (tsuas yog 1/5 txog 1/4 ntawm hlau, 1/2 ntawm txhuas), thiab yooj yim rau kev ua rau ntau yam khoom siv hluav taws xob. Cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob ntawm cov yas ua los ntawm dipropylene phthalate resin zoo dua li cov phenolic thiab amino thermosetting plastics. Nws muaj hygroscopicity qis, qhov loj me ntawm cov khoom ruaj khov, kev ua haujlwm molding zoo, acid thiab alkali tsis kam, dej npau thiab qee cov organic solvents. Cov tshuaj molding yog qhov tsim nyog rau kev tsim cov khoom nrog cov qauv nyuaj, kub tsis kam thiab rwb thaiv tsev siab. Feem ntau, nws tuaj yeem siv tau ntev hauv qhov kub ntawm -60 ～ 180 ℃, thiab qib tiv taus kub tuaj yeem ncav cuag F txog H qib, uas siab dua li qhov tiv taus kub ntawm phenolic thiab amino plastics.

Cov yas silicone hauv daim ntawv ntawm cov qauv polysiloxane yog siv dav hauv cov khoom siv hluav taws xob thiab cov thev naus laus zis hluav taws xob. Cov yas silicone laminated feem ntau yog txhawb nrog daim ntaub iav; cov yas silicone molded feem ntau yog puv nrog iav fiber thiab asbestos, uas yog siv los tsim cov khoom uas tiv taus kub siab, zaus siab lossis submersible motors, cov khoom siv hluav taws xob, thiab cov khoom siv hluav taws xob. Hom yas no yog tus cwj pwm los ntawm nws qhov dielectric tsis tu ncua thiab tgδ tus nqi qis, thiab tsis cuam tshuam los ntawm zaus. Nws yog siv hauv kev lag luam hluav taws xob thiab hluav taws xob los tiv taus corona thiab arcs. Txawm tias qhov kev tso tawm ua rau decomposition, cov khoom yog silicon dioxide es tsis yog conductive carbon dub. . Hom khoom siv no muaj kev tiv thaiv kub zoo heev thiab tuaj yeem siv tas li ntawm 250 ° C. Qhov tsis zoo tseem ceeb ntawm polysilicone yog lub zog kho tshuab qis, kev nplaum qis thiab kev tiv thaiv roj tsis zoo. Ntau cov polymers silicone hloov kho tau tsim, xws li polyester hloov kho silicone plastics thiab tau siv rau hauv cov thev naus laus zis hluav taws xob. Qee cov yas yog ob qho tib si thermoplastic thiab thermosetting plastics. Piv txwv li, polyvinyl chloride feem ntau yog thermoplastic. Nyiv Pooj tau tsim ib hom kua polyvinyl chloride tshiab uas yog thermoset thiab muaj qhov kub molding ntawm 60 txog 140 ° C. Ib lub yas hu ua Lundex hauv Tebchaws Meskas muaj ob qho tib si thermoplastic processing Features, thiab cov khoom siv lub cev ntawm thermosetting plastics.

① Cov yas hydrocarbon.

Nws yog ib hom yas uas tsis yog polar, uas muab faib ua cov yas crystalline thiab cov yas uas tsis yog crystalline. Cov yas crystalline hydrocarbon suav nrog polyethylene, polypropylene, thiab lwm yam, thiab cov yas uas tsis yog crystalline hydrocarbon suav nrog polystyrene, thiab lwm yam.

②Vinyl plastics uas muaj cov noob polar.

Tsuas yog cov fluoroplastics xwb, feem ntau ntawm lawv yog cov khoom tsis yog crystalline pob tshab, suav nrog polyvinyl chloride, polytetrafluoroethylene, polyvinyl acetate, thiab lwm yam. Feem ntau cov vinyl monomers tuaj yeem polymerized nrog cov radical catalysts.

③Cov yas ua los ntawm cov khoom siv thermoplastic.

Feem ntau suav nrog polyoxymethylene, polyamide, polycarbonate, ABS, polyphenylene ether, polyethylene terephthalate, polysulfone, polyethersulfone, polyimide, polyphenylene sulfide, thiab lwm yam. Polytetrafluoroethylene. Cov polypropylene hloov kho, thiab lwm yam kuj suav nrog hauv cov khoom no.

④ Cov yas thermoplastic cellulose.

Nws feem ntau suav nrog cellulose acetate, cellulose acetate butyrate, cellophane, cellophane thiab lwm yam.

Peb siv tau tag nrho cov khoom siv yas saum toj no.
Nyob rau hauv ib txwm muaj xwm txheej, PP-qib zaub mov thiab PP-qib kho mob yog siv rau cov khoom zoo sib xwsdiav. Lub raj xa dejyog ua los ntawm cov khoom siv HDPE, thiablub raj kuajfeem ntau yog ua los ntawm cov khoom siv kho mob PP lossis PS. Peb tseem muaj ntau yam khoom, siv cov ntaub ntawv sib txawv, vim peb yog ib tugpwmtus tsim khoom, yuav luag txhua yam khoom yas tuaj yeem tsim tau