Mfundo zisanu ndi imodzi zopangira jakisoni wa pp

Six mfundo zazikulu za pp jakisoni molding.The processing wa zipangizo pulasitiki zopangira makamaka kusungunuka, yenda, mawonekedwe, ndiyeno kuziziritsa kukhala chomalizidwa. Ndi njira yotenthetsera kenako kuziziritsa. Ndi njira yomwe pulasitiki imasintha kuchokera ku pellets kupita ku maonekedwe osiyanasiyana. Zotsatirazi zifotokoza za kukonzedwa kuchokera kumagawo osiyanasiyana. Njira.

1. Kusungunuka

The heater amalola kuti zopangira particles kusungunuka pang'onopang'ono mukuyenda kwamadzimadzi, amene makamaka oyenera kutentha kusintha kwa zipangizo zosiyanasiyana. Kuwonjezeka kwa kutentha kumapangitsa kufulumizitsa kutuluka kwa zipangizo, zomwe zimatha kuwonjezera mphamvu koma sizingatsimikizire zokolola. Iyenera kukhala Balance yoyenera.

Kuphatikiza apo, zotsatira zabwino ndi mawonekedwe a kusweka kwakukulu kwa PP ndikuti ndikwabwino kupangitsa kuti zopangira ziziyenda bwino mpaka kufa panthawi yopanga kupeŵa kudzaza kosakwanira kapena kubwerera m'mbuyo.. Kubwerera kumbuyo kumatanthauza kuti kutuluka kwa zinthu zopangira kumakhala mofulumira kuposa mlingo wotuluka. Kuwonjezeka kwapakati pakuyenda bwino kumafanana ndi kuwonjezeka kwa MFR, yomwe ndi imodzi mwa njira zomwe zilipo pokonza, koma imayambitsanso kugawa kwa MFR kwachilendo, zomwe zingayambitse kusakhazikika, zomwe zingawonjezere kuchuluka kwa chilema.

Komabe, a PP mankhwala sichopangidwa cholondola kwambiri chifukwa chakugwiritsa ntchito, kotero zotsatira zake si zazikulu.

2. Sikirini

Ambiri a PP processing imayendetsedwa ndi screw kuti iyendetse fluidity, kotero mapangidwe a screw ali ndi chikoka chachikulu. Kukula kwa m'mimba mwake kumakhudza zotsatira zake, ndipo chiŵerengero cha kuponderezana chimakhudza mtengo wamtengo wapatali ndi zotulukapo ndi zotsatira za mankhwala omalizidwa. Izi zikuphatikizapo zipangizo zosiyanasiyana. (Mitundu ya masterbatches, zowonjezera ndi zosintha) kusakaniza kwenikweni.

Mayendedwe a zipangizo makamaka zimadalira chotenthetsera, koma kutentha kwapang'onopang'ono kwa zinthuzo kumapangitsanso kutentha kwamphamvu kuti kufulumizitse fluidity, kotero screw compression ratio ndi yaying'ono ndipo kutuluka kwake kumakhala kochepa, ndipo liwiro lozungulira liyenera kuwonjezeka. Kutentha kwapang'onopang'ono kudzakhala kochuluka kuposa kwa screw yokhala ndi chiŵerengero chachikulu cha kuponderezana.

Chifukwa chake, nthawi zambiri zimanenedwa kuti palibe mbuye pakukonza pulasitiki, ndipo munthu amene amamvetsetsa bwino momwe makinawo amagwirira ntchito ndiye mbuye. Kutentha kwa zinthu zopangira sichiri chotenthetsera chokha, komanso kutentha kwapakati komanso nthawi yokhalamo.

Choncho ili ndi vuto lothandiza, ndi zinachitikira zimathandiza kuthetsa mavuto kupanga ndi bwino. Ngati screw iyenera kukhala ndi zotsatira zabwino kwambiri zosakanikirana, nthawi zina zomangira zamagulu awiri kapena zomangira zamitundu iwiri zimapangidwa ndipo zomangira zamitundu yosiyanasiyana zimagawidwa m'magawo kuti akwaniritse zosakaniza zosiyanasiyana..

3. Nkhungu kapena kufa mutu

Kukonzanso kwa pulasitiki kumadalira nkhungu kapena mutu wakufa. Chopangidwa ndi jakisoni chimakhala chamitundu itatu, ndipo nkhungu ndizovuta kwambiri, ndi kuchepa kuyenera kuganiziridwa. Enawo ndi afulati, vula, ndi singano zoboola pakati mankhwala mutu kufa. Ngati ndi mawonekedwe apadera, Amagawidwa ngati mawonekedwe apadera, ndipo ayenera kulabadira vuto la kuzirala ndi kuumba nthawi yomweyo.

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Makina ambiri apulasitiki amapangidwa ngati ma jakisoni, ndipo mphamvu ya extrusion yoyendetsedwa ndi wononga idzayambitsa kupanikizika kwakukulu pazipinda zing'onozing'ono ndikuwongolera kupanga bwino. Pamene mutu wakufa umapangidwa ngati malo athyathyathya, momwe mungapangire zopangira kuti zigawidwe mofanana pamtunda wonse ndizofunikira kwambiri.

4.Kuziziritsa

Kuwonjezera pa sprue chipata kuthira zopangira, a jekeseni nkhungu ilinso ndi njira yamadzi yozizira yoziziritsira kapangidwe kazinthu zopangira. Extrusion akamaumba amadalira njira yamadzi ozizira mu chogudubuza kuti akwaniritse kuziziritsa, kupatula mpeni wa mpweya, madzi ozizira amatsanuliridwa mwachindunji pa thumba lowombera, ndi njira yoziziritsira monga kuwomba mobisa.

5.Kuwonjezera

The reprocessing ndi kuwonjezera wa mankhwala omalizidwa adzawonjezera zotsatira. Mwachitsanzo, lamba womangirira amayendetsedwa ndi zodzigudubuza zakutsogolo ndi zakumbuyo pa liwiro losiyanasiyana kuti apangitse kukulitsa. Kulimba kwamphamvu kwa gawo lowonjezera lazomaliza kumalimbikitsidwa ndipo sikophweka kung'amba, koma ndikosavuta kung'amba munjira yopingasa. Kugawidwa kwa kulemera kwa maselo kumakhudzanso zotsatira zowonjezera panthawi yopanga mofulumira kwambiri. Zogulitsa zonse zowonjezera kuphatikizapo ulusi zimakhala ndi zowonjezera zosiyana. Vacuum ndi kukakamiza kupanga kungathenso kuwonedwa ngati njira ina yowonjezera.

6, kuchepa

Zopangira zilizonse zimakhala ndi vuto la kuchepa. Kutsika kumayamba chifukwa chakukula kwamafuta ndi kuzizira kozizira komanso kupsinjika kwamkati komwe kumapangidwa panthawi yopanga kristalo..

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Nthawi zambiri, kukulitsa matenthedwe ndi kupindika ndikosavuta kugonjetsa, ndipo nthawi yozizira imatha kuchulukitsidwa pokonza, ndipo kupanikizika kungathe kusungidwa mosalekeza. Zida za crystalline zimakhala ndi kusiyana kwakukulu kwa shrinkage kusiyana ndi zipangizo zopanda crystalline, zomwe ndi pafupifupi chikwi chimodzi kwa PP. Khumi ndi zisanu ndi chimodzi, koma ABS ndi pafupifupi zikwi zinayi zokha. This part of the difference is very large. This part must be overcome on the mold, or the shrinkage reduction additives are often added to overcome the extrusion plate. LDPE is often added to improve the necking problem.