iifonti

Plastic Inaliti Ukubumbela Shrinkage

Plastic ziphene yokubumba shrinkage yenye iipropati xa ubushushu eziphathekayo ithontsiza. Ireyithi yenaliti yokubumba shrankage iyafuneka ukumisela imilinganiselo yokusebenza. Ixabiso libonisa isixa sesithintelo esiboniswa ngumsebenzi emva kokuba sisuswe kwisikhunta kwaye emva koko sipholile kwi-23C kangangexesha leeyure ezingama-48.

Ukunciphisa kunqunywe ngolu hlobo olulandelayo:

S = (Lm-Lf) / Lf * 100%

apho i-S inqanaba lokuncipha kwesikhunta, Lr ubungakanani bokugqibela bemisebenzi (kwi. okanye mm), kunye ne-Lm ubungakanani besikhunta (ngaphakathi okanye mm). Uhlobo kunye nokuhlelwa kwezinto zeplastiki kunexabiso eliguqukayo lokuncipha. Ukuncipha kunokuchaphazeleka kwinani lezinto eziguqukayo njengokupholisa amandla okusebenza, isitofu kunye noxinzelelo lokuhlala. Ukongezwa kweefiller kunye nokuqiniswa, njengeglasi yefayibha okanye ukufakwa kwamaminerali, kunokunciphisa ukuncipha.

Ukuncipha kwemveliso yeplastikhi emva kokuqhubekeka kuqhelekile, kodwa i-crystalline kunye neepolima ze-amorphous zincipha ngokwahlukileyo. Zonke izinto zokusebenza zeplastikhi ziyancipha emva kokuqhubekeka nje ngenxa yokunyanzeliswa kunye nokuncipha kobushushu njengoko zipholile kubushushu bokuqhubekeka.

Izinto ze-Amorphous zine-shrinkage esezantsi. Xa izinto amorphous kupholile ngexesha lesigaba sokupholisa inkqubo yokubumba ngenaliti, baphindela kwi-plymer engqongqo. Imixokelelwane ye-polymeri eyenza izinto ezinama-amorphous ayinalo ulwazelelo oluthile. Imizekelo ye-pf amorphous materials zi-polycarbonate, i-ABS kunye ne-polystyrene.

Izinto zokukrelekrele zinendawo yokunyibilika kwekristalline. Amatyathanga e-polymer azimisa ngokwendlela yokuhlelwa kwemolekyuli. Ezi ndawo zi-odolwe ziikristale ezenza xa ipolymer ipholile kwimeko yayo etyhidiweyo. Kwizixhobo ze-semicrystalline polymer, ukuyilwa kunye nokupakisha okwandisiweyo kweetyathanga zeemolekyuli kwezi ndawo zekristalline. i-injectio yokubumba shrinkage yezixhobo ze-semicrystalline iphezulu kunezinto ze-amorphous. Uluhlu lwezinto zeplastiki, zombini i-amorphous kunye ne-semicrystalline, kunye ne-mold shrinkage yazo.

Umncinci we-thermoplastics /%
izinto ukuncipha komngundo izinto  ukuncipha komngundo izinto ukuncipha komngundo
IABS 0.4-0.7 IPolycarbonate 0.5-0.7 I-PPO 0.5-0.7
Acrylic 0.2-1.0 I-PC-ABS 0.5-0.7 IPolystyrene 0.4-0.8
I-ABS-nylon 1.0-1.2 I-PC-PBT 0.8-1.0 IPolysulfone 0.1-0.3
Unyango I-2.0-3.5 Ikhompyuter yePET 0.8-1.0 PBT 1.7-2.3
Nylon 6 0.7-1.5 Polyethylene 1.0-3.0 I-PET 1.7-2.3
Nylon 6,6 1.0-2.5 Polypropylene 0.8-3.0 TPO 1.2-1.6
I-PEI 0.5-0.7        

Iziphumo eziguqukayo ze-shrinkage zithetha ukuba ukuqhubekeka nokunyamezeleka okunokufezekiswa kweepholima ze-amorphous kubhetele kakhulu kunezo zeeplastikhi zekristale, kuba iikristallites ziqulathe ngakumbi uku-odolwa kunye nokupakisha okungcono kweetyathanga zepolymer, ukutshintsha kwesigaba kukonyusa ukuncipha kakhulu. Kodwa ngeplastiki ye-amorphous, le nto kuphela kwento kwaye ibalwa ngokulula.

Kwiipolima ze-amorphous, amaxabiso e-shrinkage awanelanga kuphela, kodwa ukuncipha kukodwa kuyenzeka ngokukhawuleza. Kwipolymer eqhelekileyo ye-amorphous efana ne-PMMA, ukuncipha kuya kuba ngokokulandelelana kwe-1-5mm / m. Oku kungenxa yokupholisa ukusuka kwi-150 (iqondo lobushushu linyibilike) ukuya kwi-23C (igumbi lobushushu) kwaye inokunxulunyaniswa nomlinganiso wolwandiso lwe-thermal.


Ixesha Post: Sep-19-2020