Imibhobho yePolyurethane, njengomgangatho ophezulu wezinto -zokusebenza kwepolymer, zisetyenziswa kakhulu kwipetrochemical, kwimoto, kwisakhiwo sobonelelo lwamanzi kunye nokuhambisa amanzi, kunye namashishini ezixhobo zonyango ngenxa yokunganyangeki kwawo okugqwesileyo, ukumelana neoyile, ukuxhathisa kwikhemikhali, kunye nokuguquguquka okuhle. Ngoko ke,{3}}kuphando olunzulu kwinkqubo yokubumba imibhobho yepolyurethane ineempembelelo ezibalulekileyo zobunjineli.
Iimpawu eziSisiseko kunye neeMfuno zokuBumba kwiMibhobho yePolyurethane
I-Polyurethane (PU) yinto yepolymer eveliswa yi-polymerization reaction of polyols kunye ne-isocyanates. Ngokusekelwe kumlinganiselo we-soft to hard segments, inokwahlulwa ibe yi-thermoplastic polyurethane (TPU) kunye ne-cast polyurethane (CPU). Imibhobho yePolyurethane iveliswa kusetyenziswa inkqubo yokuphosa. Inkqubo yokubumba ifuna ulawulo olungqongqo lomlinganiselo wezinto ezikrwada, ubushushu bokusabela, uyilo lokungunda, kunye neemeko zokusetyenzwa{3}}zesithuba sokuqinisekisa ukuxinana kombhobho, amandla, kunye nokugqiba komphezulu.
Iimfuno eziphambili zokubumba kwimibhobho ye-polyurethane ziquka:
1. I-Raw material pretreatment: Iipolyols kunye ne-isocyanates kufuneka zixutywe ngokucokisekileyo kwiqondo lobushushu elithile ukuphepha amaqamza omoya ashiyekileyo;
2. Ulawulo lwe-reaction: Indlela yokunyanga ye-polyurethane ikhupha ubushushu obukhulu, ifuna ukulungiswa kobushushu bokubumba kunye nesantya sokugalela ukuthintela ukufudumeza kwendawo kunye nokuqhekeka;
3. Ukwakhiwa kunye -nonyango: Imibhobho ebunjiweyo idinga isithuba esifanelekileyo{2}}sokwenziwa kwe-vulcanization okanye ukupholisa ukuphucula ukuzinza kwe-dimensional.
IiNkqubo eziphambili zokuBumba kwiMibhobho yePolyurethane
1. Inkqubo yokuBumba
Ukubumba ukubunjwa yeyona nkqubo isetyenziswa ngokuqhelekileyo kwimibhobho ye-polyurethane. Amanyathelo ayo aphambili abandakanya:
• I-Raw Material Mixing: I-prepolymer (i-isocyanate component) kunye ne-chain extender (i-polyol component) ixutywe kumlinganiselo othile, kwaye ama-bubbles omoya asuswe ngexesha lokuxuba inkqubo usebenzisa i-vacuum degassing.
• Ukulungiselela i-Mold: I-mold idinga ukufudumala kwiqondo lokushisa elifanelekileyo (ngokuqhelekileyo i-60 ~ 80 degree), kwaye i-agent agent isetyenziselwa ukunciphisa ukunamathela.
• Ukugalela kunye nokuNyanga: Izinto ezixutyiweyo ekrwada zitofwa kumngundo kwaye zinyangelwe phantsi koxinzelelo oluthile (ngokuqhelekileyo kumoya okanye uxinzelelo oluphantsi). Ixesha lokunyanga lixhomekeke kububanzi bombhobho kunye nobukhulu bodonga, ngokubanzi ukusuka kwimizuzu emininzi ukuya kumashumi emizuzu.
• Ukulungiswa: Emva kokuba umbhobho uphiliswe ngokupheleleyo, uyadilizwa kwaye unqunywe.
Le nkqubo ifanele -ibhetshi, ezininzi-imveliso eyahlukeneyo, ingakumbi kwimibhobho yokwenziwa kwepolyurethane enezakhiwo ezintsonkothileyo.
2. Inkqubo ye-Extrusion Molding
Ukwenziwa kobunzima bemibhobho ethe tye okanye -imibhobho ye-polyurethane elula yolwakhiwo, ukubumba i-extrusion kungasetyenziswa. Inkqubo ibandakanya:
• Ukunyibilika kwemathiriyeli ekrwada: Iigranule zeThermoplastic polyurethane (TPU) ziyafudunyezwa kwaye zinyibilike kusetyenziswa isikrufu se-screw extruder;
• Ukubunjwa kwe-Extrusion: Isixhobo esityhidiweyo sikhutshwa ngedayisi ethile ukwenza ulwakhiwo oluqhubekayo lwe-tubular;
• Ukupholisa kunye nokubunjwa: Ityhubhu ekhutshiweyo ipholiswa ngokukhawuleza ngamanzi okanye ukupholisa umoya, emva koko yolulwe kwaye isikwe kubude obufunekayo ngomatshini wokutsala.
I-Extrusion isebenza kakuhle kwaye ifanelekile ukuvelisa iityhubhu ze-polyurethane ezisemgangathweni, kodwa inikeza ukuguquguquka okuncinci kwisakhiwo semveliso.
3. Inkqubo ye-Reaction Injection Molding (RIM).
Kwityhubhu enkulu okanye ephezulu yepolyurethane eqinileyo, ukugoba isitofu sokusabela kungasetyenziswa. Le nkqubo ibandakanya ukugcina iipolyols kunye ne-isocyanates ngokwahlukeneyo kwimibhobho ephezulu{2}}yoxinzelelo, ukuzixuba ngesantya esiphezulu phantsi koxinzelelo oluphezulu, kwaye emva koko utofe umxube kumngundo. Umxube uyasabela kwaye uqina ukwenza ukumila kokugqibela. I-RIM ilungele iityhubhu-engqingqwa kwaye inomjikelo omfutshane wokubumba kunye nokomelela kwemveliso ephezulu.
Imiba ephambili echaphazela iNkqubo yokuBumba
1. I-Raw Material Ratio: Isalathisi se-isocyanate (i-NCO / OH ratio) ichaphazela ngokuthe ngqo ubuninzi be-crosslinking ye-polyurethane, ngaloo ndlela ichaphazela ubunzima kunye nokuqina kombhobho.
2. Ulawulo lobushushu: Ubushushu obugqithisileyo bokungunda bunokukhokelela kumaqamza ashiyekileyo okanye iziphene zomhlaba, ngelixa ubushushu obuphantsi kakhulu bunyusa ixesha lokunyanga.
3. I-Mold Design: Uyilo lwembaleki olufanelekileyo kunye nenkqubo yokukhupha umoya inokunciphisa iziphene kunye nokuphucula ukuhambelana kwemveliso.
4
Ukukhethwa kwenkqubo yokubumba kwimibhobho ye-polyurethane ifuna ukuqwalaselwa ngokubanzi kweemfuno zokusebenza kwemveliso, umlinganiselo wemveliso, kunye neendleko. Ukuphosa kufanelwe ukuchaneka okuphezulu -, okuntsokothileyo -kwimibhobho yesakhiwo, i-extrusion ilungele imveliso esemgangathweni enkulu- ngelixa i-RIM (I-Reverse Molding Injection) ineengenelo ekwenziweni kwemibhobho -enkulu, ephezulu{5}}esebenzayo. Kwixesha elizayo, ngophuhliso lwetekhnoloji yokuguqulwa kwemathiriyeli ye-polyurethane, iinkqubo zokubumba ziya kuphuculwa ngakumbi ukuhlangabezana neemfuno ezingqongqo zokusetyenziswa kwemizi-mveliso.
