Ultrasonic vuam txheej txheem tsis
Cov txheej txheem tseem ceeb ntawm ultrasonic vuam yog: kev ua kom dav, lub sijhawm vuam, tuav lub sijhawm siab, vuam siab, zaus, thiab lwm yam. Qhov hloov kho ntawm vuam tsis nyob ntawm qhov loj me thiab nruj ntawm qhov sib txawv, tshwj xeeb tshaj yog qhov kev ncua deb ntawm qhov chaw tiv tauj ntawm lub taub hau vuam thiab vuam sib txuas. Lub peev xwm vuam tsuas yog txwv los ntawm kev muaj peev xwm ntawm cov yas xa cov kis ultrasonic kev co (thiab cov ntu tsis puas).
1.Txoj kev ua haujlwm
Nquag siv cov nquag siv rau ultrasound yog 20, 30, thiab 40 kHz, thiab rau cov kab hluav taws xob uas siv hluav taws xob ib nrab, 15 kHz. 20 kHz yog qhov feem ntau siv ultrasonic zaus vim tias nws yooj yim kom tau txais qhov ntau thiab lub zog yuav tsum tau yaj cov thermoplastics ntawm qhov zaus no, tab sis nws yuav tsim ntau cov kev siv tshuab kev co uas nyuaj los tswj thiab lub cuab tam tau loj heev. Ib qhov ntau zaus dua (40 kHz) uas ua rau muaj kev co tsawg dua yog qhov ua tau thiab feem ntau yog siv rau vuam engineering plastics thiab lub zog polymers. Qhov zoo ntawm cov khoom siv vuam ntau muaj xws li: suab nrov qis, qhov me me ntawm qhov loj me, txhim kho feem ntawm kev tiv thaiv (vim txo kev ntxhov siab thiab tsis xaiv cua sov ntawm qhov chaw sab nraud ntawm qhov sib txuam sib txuas), txhim kho kev tswj ntawm lub zog kho tshuab, txo vuam lub zog , thiab kev ua kom nrawm dua. Qhov tsis zoo yog tias nws nyuaj rau kev ua kom deb deb vuam vim qhov me me ntawm qhov seem, txo hwj chim muaj zog thiab txo cov khoom seem. High-frequency ultrasonic welding machine feem ntau yog siv los txuas weld precision qhov me me (xws li cov hloov hluav taws xob) thiab cov ntu uas xav tau cov khoom pov thawj tsawg. Tus 15 kHz qhov txuas tau sai sai weld feem ntau thermoplastics, thiab nyob rau hauv Feem ntau, cov ntaub ntawv tsis zoo tsis zoo li 20 kHz welder. Cov seem uas nyuaj rau weld ntawm 20 kHz (tshwj xeeb yog cov seem ua los ntawm kev ua haujlwm siab ntawm cov roj hmab thiab cov thev naus laus zis thev naus laus zis thiab cov khoom siv) tuaj yeem txuas tau ntawm 15 kHz efficiency. Ntawm qhov qis zaus, qhov ntev ntawm lub taub hau vuam ntev dua, thiab nws tuaj yeem ua qhov loj dua rau txhua qhov ntau thiab tsawg. Lwm qhov kom zoo dua ntawm kev siv 15 kHz yog tias piv rau siv ntau dua, nws muaj peev xwm txo tau ntau lub attenuation ntawm ultrasonic tsis nyob hauv plastics, yog li ntawd softer plastics tuaj yeem tau welded, thiab qhov loj dua nyob deb-ncua kev tuaj yeem ua tiav.
2.Frames
Qhov ua tiav ntawm vuam nyob ntawm txoj kev tsim nyog ntawm vuam taub hau kawg. Rau txhua lub horn / vuam sib txuas lub taub hau, qhov ntau ntxiv tag nrho. Xaiv qhov ntau raws li cov khoom siv los yog welded kom tau txais qhov tsim nyog ntawm melting. Feem ntau hais lus, semi-crystalline plastics yuav tsum muaj lub zog ntau dua li cov uas tsis siv lead ua plastics thiab yog li ntawd xav tau ntau dua cov lus nthuav dav. Cov txheej txheem tswj ntawm cov niaj hnub ultrasonic vuam machine pub rau kev muab qhab nia. Lub siab siv tau siv los pib melting, thiab qhov tsawg kawg yog siv los tswj cov viscosity ntawm cov khoom siv dag. Qhov nce yuav txhim kho lub vuam zoo ntawm chais yaig ntu tsim qhov. Rau cov pob qij txha txuas, raws li lub zog ntxiv, lub vuam zoo yuav txhim kho thiab lub sijhawm vuam yuav tsawg. Thaum siv hluav taws xob qhia kev qws rau ultrasonic vuam, qhov nruab nrab kub poob (Qavg) nyob ntawm cov txheej txheem hluav taws xob tsis zoo (Eʺ), zaus (ω) thiab ua yam tsis ua haujlwm (ε0) ntawm cov khoom siv: Qavg=ωε02Eʺ / 2
Cov sib txuas hluav taws xob tsis tshua suav tawm ntawm cov thermoplastics zoo sib xws nrog rau qhov kub thiab txias. Thaum lub ntsiab lus melting los yog lub iav hloov qhov kub tau mus txog, qhov poob modulus nce thiab ntau lub zog hloov mus rau hauv tshav kub. Tom qab cov cua sov pib, qhov kub thiab txias ntawm lub vuam sib tshuam nce siab (txog li 1000 ° C / s). Cov ntawv thov kev coj ua yog sib npaug rau lub zog ntawm qhov sib txuas ntawm welded, yog li cov cua sov ntawm qhov txuas ntawm qhov txuas tau tswj tau tuaj yeem tswj tau los ntawm kev hloov qhov txawv txav. Amplitude yog qhov tseem ceeb rau kev ntsuas qhov ntws ntawm thermoplastic extrusion. Thaum lub amplitude loj, cov cua kub ceev ntawm vuam interface ua ntau dua, qhov kub nce siab, thiab cov khoom ntws ntawm cov khoom siv ceev nrawm dua, uas ua rau muaj qhov nce ntawm molecular kev taw qhia, nce ntawm flash, thiab txo qis ntawm lub zog vuam. Siab amplitude yog tsim nyog los pib melting. Kev ua kom tsawg tsawg yuav ua rau lub suab tsis sib xws thiab lub teeb meem ntawm lub sijhawm yaj. Thaum lub amplitude nce ntxiv, cov khoom siv thermoplastic yuav siv lub zog kev co ntau dua, thiab cov seem yuav tsum tau welded yuav dais ntau dua kev ntxhov siab. Thaum lub amplitude tseem nyob thoob plaws lub voj vuam, qhov ntau tshaj plaws uas yuav tsis ua rau muaj kev puas tsuaj ntau rau qhov chaw txuas yog feem ntau siv. Rau cov siv lead ua plastics xws li polyethylene thiab polypropylene, qhov cuam tshuam ntawm qhov ntau yog ntau dua li ntawm amorphous plastics xws li ABS thiab polystyrene. Qhov no tuaj yeem yog vim tias melting thiab vuam ntawm crystalline yas yuav tsum muaj zog ntau dua. Lub amplitude tuaj yeem hloov kho kev siv tshuab (los ntawm kev hloov lub tshuab raj lub taub hau lossis lub taub hau) lossis hluav taws xob (los ntawm kev hloov cov voltage uas tau xa mus rau lub tshuab hloov pauv). Qhov tseeb, kev siv tshuab yog siv rau kev kho kom loj dua, thaum hluav taws xob txoj kev siv rau kev kho kom haum. High melting point cov ntaub ntawv, deb-teb vuam thiab semi-crystalline plastics feem ntau yuav tsum ntau dua ntau dua li cov amorphous uas thiab ze-teb vuam. Feem ntau tag nrho amplitude ntawm amorphous plastics yog 30-100 μm, thaum lub sijhawm tag nrho cov qhov ntau ntawm cov nplai crystalline yog 60-125 μm. Amplitude faib tuaj yeem ua tiav melt ntws zoo thiab zoo ib yam siab.Qhov amplitude profile tuaj yeem ua tiav melt ntws zoo thiab ua tau zoo siab vuam lub zog. Txog kev sib xyaw ua ke thiab kev quab yuam qib, siv lub zog loj thiab quab yuam kom pib melting, tom qab ntawd txo qhov nrawm thiab quab yuam los txo cov molecular orientation raws txoj kab weld.
3.Txiav sijhawm
Lub sijhawm vuam yog lub sijhawm thaum kev vibration tau siv. Kev sim los txiav txim siab lub sijhawm tsim nyog vuam rau txhua daim ntawv thov. Kev nce vuam sijhawm yuav ua rau lub vuam muaj zog ntxiv kom txog thaum lub sijhawm ua haujlwm siab kawg. Ib qho kev nce ntxiv ntawm vuam lub sijhawm yuav ua rau txo qis ntawm vuam lub zog lossis tsuas yog nce me ntsis ntawm lub zog, thaum tib lub sijhawm nws yuav nce vuam burrs thiab nce qhov tseem ntawm qee qhov kev poob haujlwm. Kev zam dhau qhov txuas yog qhov tseem ceeb vim tias nws tsim teeb nyem ntau dhau uas yuav tsum tau txiav, uas yuav txo qhov tsis zoo ntawm cov hlau txuas thiab ua rau xau ntawm qhov uas xav tau muab ntim. Lub taub hau vuam tuaj yeem kos cov nplaim. Rau lub sijhawm ua haujlwm ntev dua, lub sijhawm yaj thiab pob txha tawg kuj tseem tuaj yeem tshwm sim nyob rau hauv qhov chaw deb ntawm qhov chaw sib koom tes, tshwj xeeb tshaj yog nyob rau hauv qhov, qhov txuas thiab xaim ntse ntawm cov pwm.
4.Txiav sijhawm
Lub sij hawm tuav yog hais txog lub sij hawm nominal rau qhov chaw kom tau sib xyaw ua ke thiab cov khoom tsis muaj qhov ua kom tsis txhob muaj kev co tom qab vuam. Feem ntau, qhov ntsuas no tsis yog qhov tseem ceeb tsis txaus. Tshwj tsis yog qhov kev thauj khoom sab hauv yog ib qho yooj yim kom rhuav tshem qhov txuas ntawm qhov chaw (xws li lub coil caij nplooj ntoos hlav ua ntej vuam), 0.3 ~ 0.5 s feem ntau yog qhov txaus.
5.Xam Tswvyim
Lub vuam siab muab lub zog zoo li qub xav tau rau kev sib txuas ntawm lub taub hau vuam thiab rau feem, yog li kev co tuaj yeem xa mus rau ntu. Nyob rau hauv lub siab tuav theem ntawm lub vuam mus los, thaum molten khoom ntawm qhov sib koom ua ke solidifies, tib lub qub thauj khoom tuaj yeem ua kom txoj kev sib txuas ntawm cov ntu. Kev txiav txim siab pom qhov siab zoo yog qhov tseem ceeb rau kev ua haujlwm zoo. Yog tias lub siab poob qis dhau, nws yuav ua rau cov neeg pluag lossis tsis txaus siab nthwv dej rau hauv qhov hloov mus rau lub zog, uas ua rau tsis muaj qhov ntev vuam mus ntev. Ua kom lub vuam siab ntxiv yuav txo qhov vuam sij hawm kom ua tiav qhov ua haujlwm tib yam. Yog tias lub siab dhau dhau lawm, nws yuav ua rau muaj qhov sib qhia hauv molecular raws qhov kev taw qhia ntws thiab txo qhov vuam lub zog, uas yuav ua rau indentation ntawm ntu. Nyob rau hauv qhov xwm txheej tshwj xeeb, yog tias lub siab dhau siab ntsig txog qhov kawg ntawm lub vuam taub hau, nws yuav dhau ntau dhau ntawm lub taub hau vuam thiab nres. Hauv ultrasonic vuam, qhov siab nrawm yuav tsum muaj kev siab, thiab tsawg amplitude yuav tsum muaj kev kub siab. Raws li tus amplitude tsub kom, txais tau siab khwv. Yog li no, qhov tseem ceeb tshaj plaws rau kev ua haujlwm siab yog nrhiav qhov siab zoo. Feem ntau cov vuam ultrasonic ua tiav los ntawm kev txiav txim siab tas li lossis lub zog tas li. Rau qee yam khoom siv, koj tuaj yeem hloov lub zog thaum lub voj voog, uas yog, ua lub zog ntsuas qhov ntsuas lub zog, thiab txo lub zog vuam thaum lub zog thov ultrasonic zog rau ntu. Qhov txo qis vuam siab lossis quab yuam ntawm qhov kawg ntawm lub voj vuam yuav ua rau txo cov khoom tawg yooj yim los ntawm qhov sib koom tes, txuas ntxiv lub sij hawm diffusion ntawm molecules, txo cov kev taw qhia molecular thiab nce lub zog welding. Rau cov ntaub ntawv nrog qis yaj viscosity zoo ib yam li polyamide, qhov no yuav ntau ntxiv lub zog weld.
6.Xam txheej txheem
Lub sijhawm vuam hu ua qhov kev qhib lub sijhawm. Ua ntej lub taub hau vuam yog poob thiab kov, seem yuav tsum tau welded yog sib sau ua ke hauv kev kho. Tom qab ntawd, ultrasound yuav ua haujlwm ntawm ntu rau sijhawm ruaj khov, feem ntau yog 0.2 txog 1 s. Vuam tsis tau ua tiav zoo thaum lub sijhawm no. Raws li qhov kev xav tias lub sijhawm vuam ruaj khov ua rau lub zog ruaj khov rau kev sib koom ua ke thiab qhov ua rau tus neeg tuaj yeem tswj tau cov nyiaj melting, kev vam meej vuam yog qhov xwm txheej zoo tagnrho. Qhov tseeb, lub hwj chim nqus tau los ntawm kev tswj lub amplitude los ntawm ib lub voj voog mus rau tom ntej tsis zoo li qub. Qhov no yog vim muaj ntau yam (piv txwv li, haum rau ntawm ob ntu). Txij li thaum lub zog sib txawv nrog lub zog thiab lub sijhawm, thiab lub sijhawm tau hloov kho, lub zog siv hloov los ntawm ib ntu mus rau lwm qhov. Rau huab hwm coj ntau qhov twg sib xws yog qhov tseem ceeb, qhov no yog qhia meej yam tsis xav tau. Lub zog vuam hluav taws xob yog lub voj kev kaw nrog lub tswv yim tswj hwm. Ultrasonic tshuab software ntsuas ntsuas lub zog nqus thiab kho cov sijhawm ua haujlwm kom xa cov lus xav tau ntawm lub zog rau cov pob qij txha. Qhov kev xav ntawm cov txheej txheem no yog tias lub zog siv los ntawm txhua lub vuam yog qhov qub, qhov nyiaj ntawm cov khoom siv ntawm txhua qhov txuas yog tib yam. Txawm li cas los xij, qhov xwm txheej tiag tiag yog tias muaj lub zog poob hauv cov khoom siv vuam siv, tshwj xeeb ntawm kev sib tshuam ntawm vuam taub hau thiab ntu. Raws li qhov tshwm sim, qee qhov chaw yuav tau txais lub zog ntau dua li lwm qhov, uas yuav ua rau tsis muaj qhov vuam txuas nrog lub zog. Vuam los ntawm kev deb tso cai rau ntu tau koom nrog ntawm qhov tshwj xeeb vuam txuas. Hom kev ua haujlwm no tsis nyob ntawm lub sijhawm, nqus lub zog lossis lub zog, thiab tuaj yeem them nyiaj rau txhua qhov kev sib txawv ntawm cov pwm, thiaj li ua kom zoo tshaj plaws tias cov qub yas tau melted nyob rau hauv kev sib koom ua ke txhua zaus. Txhawm rau tswj hwm qhov ua tau zoo, ib qho kev txwv tau teeb tsa lub zog lossis lub sijhawm siv los tsim lub weld.
