Gabatarwa zuwa PBT

Polybutylene terephthalate (PBT a takaice) jerin polyesters ne, wanda aka yi da 1.4-pbt butylene glycol da terephthalic acid (PTA) ko terephthalic acid ester (DMT) ta hanyar polycondensation, kuma an yi shi da farin madara ta hanyar haɗuwa.Mai jujjuyawa zuwa opaque, crystalline thermoplastic polyester guduro.Tare da PET, an san shi tare da polyester thermoplastic, ko cikakken polyester.

Masanin kimiyyar Jamus P. Schlack ne ya fara haɓaka PBT a cikin 1942, sannan Celanese Corporation (yanzu Ticona) ya haɓaka masana'antu kuma ya yi kasuwa a ƙarƙashin sunan kasuwancin Celanex, wanda aka ƙaddamar a cikin 1970 a matsayin fiber na gilashin 30% ƙarfafa filastik ƙarƙashin sunan kasuwanci X- 917, daga baya ya canza zuwa CELANEX.Eastman ya ƙaddamar da samfurin tare da kuma ba tare da ƙarfafa fiber gilashi ba, a ƙarƙashin sunan kasuwanci Tenite (PTMT);A wannan shekarar, Ge shima ya haɓaka irin samfuri iri ɗaya tare da nau'ikan da ba a amince da su ba, ƙarfafa da rashin hisiya.Daga baya, mashahuran masana'antun duniya irin su BASF, Bayer, GE, Ticona, Toray, Mitsubishi Chemical, Taiwan Shin Kong Hefei, Changchun Synthetic Resins, da Nanya Plastics sun yi nasara shiga cikin samar da kayayyaki, kuma akwai masana'anta sama da 30 a duk duniya.

Kamar yadda PBT yana da juriya na zafi, juriya na yanayi, juriya na sinadarai, halayen lantarki mai kyau, ƙarancin ruwa mai laushi, mai kyau mai sheki, ana amfani da shi sosai a cikin kayan lantarki, sassan mota, kayan aiki, kayan gida, da dai sauransu, da samfurori na PBT da PPE, PC, POM, PA, da sauransu tare da aka sani da manyan manyan robobin injiniya na gaba guda biyar.PBT crystallization gudun, mafi dace aiki Hanyar ne allura gyare-gyaren, sauran hanyoyin ne extrusion, busa gyare-gyaren, shafi, da dai sauransu.

Iyakar aikace-aikace na yau da kullun

Kayayyakin gida (masu sarrafa abinci, abubuwan tsabtace injin, masu sha'awar lantarki, bawo mai bushewa, kayan kofi, da sauransu), abubuwan lantarki (masu sauya, mahalli na mota, akwatunan fis, maɓallan madannai na kwamfuta, da sauransu), masana'antar kera motoci (firam ɗin datsa fitilu. , tagogi grille na radiator, sassan jiki, murfin dabaran, kofa da abubuwan taga, da sauransu).

Chemical da kayan jiki

PBT yana ɗaya daga cikin mafi girman injin thermoplastics, abu ne na Semi-crystalline tare da ingantaccen kwanciyar hankali na sinadarai, ƙarfin injina, kaddarorin wutar lantarki da kwanciyar hankali na thermal.pbt yana da kyakkyawan kwanciyar hankali a ƙarƙashin yanayin muhalli.pbt yana da rauni sosai abubuwan sha.Ƙarfin da ba a ƙarfafa PBT ba shine 50 MPa, kuma ƙarfin ƙarfin ƙarfin gilashin fiber additive type PBT shine 170 MPa.Ƙarar fiber na gilashi da yawa zai sa kayan ya zama tsinke.crystallization na PBT yana da sauri sosai, kuma rashin daidaituwa zai haifar da nakasar lankwasa.Don kayan da ke da nau'in ƙari na fiber gilashi, za a iya rage yawan raguwa a cikin jagorancin tsari, kuma ƙimar raguwa a cikin madaidaiciyar hanya ba ta bambanta da kayan al'ada ba.Matsakaicin raguwar kayan PBT na gabaɗaya tsakanin 1.5% da 2.8%.Rushewar kayan da ke ɗauke da abubuwan ƙara 30% na fiber gilashi yana tsakanin 0.3% da 1.6%.

Halayen tsarin gyaran allura na PBT

Tsarin polymerization na PBT ya balaga, ƙananan farashi da sauƙi don ƙirƙira da tsari.Ayyukan PBT da ba a canza ba ba su da kyau, kuma ainihin aikace-aikacen PBT ya kamata a canza shi, wanda, gilashin gilashin da aka ƙarfafa gyare-gyaren maki yana lissafin fiye da 70% na PBT.

1, PBT yana da wani fili narkewa batu, narkewa batu na 225 ~ 235 ℃, shi ne crystalline abu, crystallinity har zuwa 40%.Dankin narkewar PBT ba ya shafar yanayin zafi kamar yadda damuwa mai ƙarfi, sabili da haka, a cikin gyare-gyaren allura, matsa lamba akan PBT narke ruwa a bayyane yake.PBT a cikin narkakkar yanayi mai kyau ruwa, low danko, na biyu kawai zuwa nailan, a gyare-gyaren sauki faruwa "PBT gyare-gyaren kayayyakin ne anisotropic, kuma PBT yana da sauki ragewa a karkashin high zafin jiki a lamba tare da ruwa.

2. Injection gyare-gyaren inji

Lokacin zabar nau'in dunƙule na'ura mai gyare-gyaren allura.Ya kamata a yi la'akari da abubuwan da ke gaba.

① Adadin kayan da aka yi amfani da su a cikin samfurin ya kamata a sarrafa shi a 30% zuwa 80% na ƙimar girman girman allura na injin gyare-gyaren allura.Bai dace a yi amfani da babban injin gyare-gyaren allura don samar da ƙananan kayayyaki ba.

② ya kamata a zaba tare da dunƙule mataki uku a hankali, tsawon zuwa diamita na 15-20, rabon matsawa na 2.5 zuwa 3.0.

③ Zai fi kyau a yi amfani da bututun ƙarfe na kulle kai tare da dumama da na'urar sarrafa zafin jiki.

④ A gyare-gyaren harshen wuta retardant PBT, da dacewa sassa na allura gyare-gyaren inji ya kamata a bi da anti-lalata.

3. Samfurin da mold zane

① Kauri daga cikin samfurori bai kamata ya kasance mai kauri ba, kuma PBT yana kula da ƙima, don haka wurare masu tsaka-tsaki kamar kusurwar dama na samfurori ya kamata a haɗa su ta hanyar arcs.

②Ƙaƙƙarfan gyare-gyare na PBT wanda ba a canza shi ba yana da girma, kuma ƙirar ya kamata ya kasance yana da wani gangare na rushewa.

③Tsarin yana buƙatar sanye take da ramukan shaye-shaye ko ramukan shaye-shaye.

④ Diamita na ƙofar ya kamata ya zama babba.Ana ba da shawarar yin amfani da masu gudu madauwari don ƙara matsa lamba.Ana iya amfani da ƙofofi iri-iri kuma ana iya amfani da masu gudu masu zafi.Diamita na ƙofar ya kamata ya kasance tsakanin 0.8 da 1.0 * t, inda t shine kauri na ɓangaren filastik.Idan akwai ƙofofin da aka nutsar, ana ba da shawarar mafi ƙarancin diamita na 0.75mm.

⑤ Tsarin yana buƙatar sanye take da na'urar sarrafa zafin jiki.Matsakaicin zafin jiki na mold kada ya wuce 100 ℃.

⑥ Domin harshen wuta retardant sa PBT gyare-gyaren, surface na mold ya kamata a Chrome plated don hana lalata.

Saitin sigogin tsari

Maganin bushewa: Abubuwan PBT suna da sauƙin ruwa a cikin babban zafin jiki, don haka yana buƙatar bushewa kafin sarrafawa.Ana bada shawarar bushewa a cikin iska mai zafi a 120 ℃ na tsawon sa'o'i 4, kuma zafi dole ne ya zama ƙasa da 0.03%.

Narke zafin jiki: 225 ℃～275 ℃, shawarar zafin jiki: 250 ℃.

Mold zafin jiki: 40 ℃ ~ 60 ℃ don unreinforced abu.Mold sanyaya ya zama uniform don rage lankwasawa nakasawa na filastik sassa, da shawarar diamita na mold sanyaya kogon tashar ne 12mm.

Matsakaicin allura: matsakaici (gaba ɗaya 50 zuwa 100MPa, matsakaicin zuwa 150MPa).

Gudun allura: Adadin alluran PBT saurin sanyaya yana da sauri, don haka yakamata a yi amfani da ƙimar allurar da sauri.Ya kamata a yi amfani da ƙimar allura mafi sauri (saboda PBT yana ƙarfafawa da sauri).

Gudun dunƙule da matsa lamba na baya: Gudun dunƙule don gyare-gyaren PBT bai kamata ya wuce 80r/min ba, kuma yana tsakanin 25 da 60r/min.Matsi na baya gabaɗaya shine 10% -15% na matsa lamba na allura.

Hankali

①Amfani da kayan da aka sake fa'ida Rabon kayan da aka sake fa'ida zuwa sabon abu shine gabaɗaya 25% zuwa 75%.

②Amfani da gyaggyarawa wakili Gabaɗaya, ba a yi amfani da wakili mai sakin ƙura, kuma ana iya amfani da wakili na sakin siliki idan ya cancanta.

③ Tsarin rufewa Lokacin rufewa na PBT yana cikin mintuna 30, kuma ana iya saukar da zafin jiki zuwa 200 ℃ lokacin rufewa.Lokacin sake samarwa bayan rufewa na dogon lokaci, kayan da ke cikin ganga ya kamata a zubar da su sannan a ƙara sabon abu don samarwa na yau da kullun.

④ Bayan aiwatar da samfurori Gabaɗaya, ba a buƙatar magani, kuma idan ya cancanta, jiyya na 1 ~ 2h a 120 ℃.

PBT na musamman dunƙule

Don PBT, wanda yake da sauƙi don rushewa, mai kula da matsa lamba kuma yana buƙatar ƙara gilashin gilashin, PBT na musamman yana samar da matsa lamba mai ƙarfi kuma yana amfani da nau'i biyu don inganta juriya ga kayan aiki tare da gilashin gilashi (PBT + GF).