Ua cov hnab khib nyiab drawstring yog ib txoj haujlwm nyuaj tshaj plaws hauv cov hnab ntim khoom muag. Tsis zoo li lub hnub qub niaj hnub- zoo li lub hnab sealing lossis tiaj tus- cov hnab hauv qab, cov hlua khi yuav tsum muaj kev sib xyaw ua ke ntawm cov yeeb yaj kiab tshuab, luas, channel fabrication thiab elastic tso tawm. Yog li kev xaiv cov khoom siv tsis yog tsuas yog tus nqi xwb. Nws yog lub hauv paus tseem ceeb uas txiav txim siab seb lub tshuab ua haujlwm thiab qhov ua tau zoo ntawm cov khoom kawg. Paub tias cov ntaub ntawv dab tsi ua haujlwm nrog lub tshuab traction hauv lub tshuab txhais tau tias saib cov khoom ntawm cov khoom siv polymer, cov qauv tsim kev txwv, thiab cov cai tshiab. Phau ntawv qhia no tsom mus rau cov hom resin tseem ceeb, cov txheej txheem ntxiv, thiab cov kev xaiv tshiab uas muaj kev ruaj ntseg uas tsim cov hnab ntim khoom niaj hnub.
Polyethylene Resins: Kev Lag Luam Foundation
Polyethylene tseem yog cov khoom tseem ceeb rau drawstring hnab khib nyiab. Qhov no yog vim nws muaj zog sib npaug, sealability thiab yooj yim ntawm kev ua. Tab sis tsis yog txhua tus polyethylene plays tib lub luag haujlwm hauv txoj haujlwm no. High density polyethylene (HDPE) yog dav siv rau nws lub zog tensile siab thiab nruj. Qhov no tso cai rau cov tuam txhab tsim cov hnab nyias nyias uas tseem tuaj yeem nqa cov khoom hnyav. Cov qauv siv lead ua ntawm high density polyethylene (HDPE) muaj qhov zoo puncture tsis kam. Txawm li cas los xij, nws cov ntsiab lus melting siab dua yuav tsum tau ceev faj tswj qhov kub thiab txias thaum winding thiab sealing.
Linear low-density polyethylene (LLDPE), tshwj xeeb tshaj yog metallocene-catalyzed hom (LLDPE), tau txais kev lag luam tseem ceeb. Qhov no yog vim zoo elongation thiab dart cuam tshuam lub zog. Cov resins stretch es tsis tsim kua muag nyob rau hauv cia li loads. Qhov no yog ib qho tseem ceeb ntawm kev nyab xeeb ntawm cov hnab khib nyiab sib xyaw. Thaum teeb tsa aDrawstring khib nyiab hnab tshuab, tus neeg teb xov tooj yuav tsum cuam tshuam nrog qhov sib txawv yaj viscosity thiab txias zog ntawm txhua cov resin. Tsawg-density polyethylene (LDPE) feem ntau yuav tsum muaj qhov qis qis thaum pib sealing kub, tab sis nws yuav siv sij hawm ntev kom khaws cov cua sov dua siab dua - ntom polyethylene (HDPE). Yog li ntawd, lub hemming thiab hauv qab - sealing chaw yuav tsum tau adjustable cua sov profiles. Cov ntaub ntawv kev lag luam los ntawm American Chemistry Council qhia txog 28% nce hauv kev siv LLDPE, cov hlau tsis tshua muaj hauv ntiaj teb, hauv cov hnab khib nyiab los ntawm 2019 txog 2023. Qhov no feem ntau yog los ntawm kev siv zog txo cov khoom siv yam tsis muaj kev cuam tshuam kev ua haujlwm [1].
Kev sib xyaw ua ke ntawm high-density polyethylene (HDPE) thiab qis-density polyethylene (LLDPE) yog twb muaj lawm. Qhov no tso cai rau lub converter los kho qhov tawv nqaij - toughness tshuav nyiaj li cas rau cov hom phiaj ntsuas. Cov kev sib tov no yuav tsum tau ua tib zoo xyuas kev sib raug zoo. Yog tias ob qho khoom tsis sib xyaw ua ke zoo, kev sib cais theem tuaj yeem tsim qhov tsis muaj zog hauv cov kev sib tw downswing qhov twg lub drawstring nyob. Rheological kuaj capillary viscometry pom zoo ua ntej khiav qhov sib xyaw tshiab. Qhov no ua kom muaj kev ruaj khov los ntawm cov pwm extrusion thiab txawm tias cov yeeb yaj kiab tuab thoob plaws lub vev xaib dav. Rau ib qho twgDrawstring khib nyiab hnab tshuab, kev sib xyaw ua ke validation tseem yog ib qho tseem ceeb ua ntej - theem tsim khoom.
Additive Systems thiab Functional Modifiers
Basal resin tsis tshua muaj siv nyob rau hauv kev tsim cov hnab drawstring ib leeg. Additive masterbatches yog qhov tseem ceeb los xyuas kom muaj kev ruaj khov, zoo nkauj zoo nkauj thiab ua haujlwm tshwj xeeb. Slides, feem ntau alucamide lossis oleamide, tseem ceeb heev. Lawv txo kev sib txhuam ntawm qhov chaw ntawm zaj duab xis. Yog tsis muaj kev nplua txaus, zaj duab xis tuaj yeem ua ke los yog tsis qhib kom zoo thaum lub qhov txhab. Tab sis ntau dhau los tiv thaiv -skid tuaj yeem txav mus rau saum npoo thiab tawg cov ntsaws ruaj ruaj. Nws tseem tso cai rau lub drawstring swb rau hauv hem channel. Lub malfunction ua rau lub hnab tsis siv.
Containment additives, feem ntau yog hluavtaws silica lossis diatomaceous lub ntiaj teb, tiv thaiv cov txheej txheem ntawm cov yeeb yaj kiab los ntawm kev ua raws li cov yeeb yaj kiab vim yog yob siab thaum khaws cia thiab thauj. Rau lub hnab drawstring, ntim yuav tsum tau teem kom raug. Ob peb lub laj thawj los thaiv. Thaum rub txoj hlua, txoj hlua ntau dhau yuav ua rau qhov chaw ntawm txoj hlua ntxhib, nce kev sib txhuam. fluoropolymer thev naus laus zis tuaj yeem tiv thaiv cov pob txha tawg ntawm qhov siab extrusion ceev. Qhov no tso cai rau covDrawstring khib nyiab hnab tshuabkhiav nrawm dua yam tsis poob qhov zoo. SPE cov lus qhia kev qhia tau hais tias qhov zoo tshaj plaws ntawm fluoropolymer kev pab cuam yog 50 mus rau 200 ppm ntawm cov hnab khib nyiab khib nyiab. Nws qhov kev ua tau zoo nyob ntawm tus nqi shear thiab pwm zoo [2].
Xim masterbatches thiab tsw -neutralizing additives ntxiv ntau qhov sib txawv. Carbon dub pigment feem ntau yog siv hauv cov hnab khib nyiab dub ua tus neeg sawv cev nucleating. Tag nrho cov no hloov crystallization ceev thiab cuam tshuam lub zog foob. Fragrance capsules thiab ntxhiab absorbers tej zaum yuav muaj cov cab kuj resins uas tsis tov nrog lub hauv paus polymer. Qhov no tuaj yeem ua rau gel me ntsis lossis pos huab. Cov kab kos kev sib raug zoo thiab kev ntsuas me me - tseem yuav tsum tau kuaj xyuas txhua yam ua ntej kev tsim khoom tiav.
Cov ntsiab lus rov ua dua tshiab thiab tshaj tawm -Consumer Resins
Cov kev cai thiab cov hom phiaj kev ruaj ntseg ntawm cov tuam txhab tau muab cov khoom siv rov ua dua tshiab hauv cov hnab khib nyiab drawstring. Post-cov neeg siv khoom siv rov ua dua tshiab (PCR) polyethylene yog los ntawm kev rov ua dua tshiab. Nws ua rau muaj teeb meem tshwj xeeb. Piv nrog rau cov resins tshiab, PCR muaj qhov dav dua qhov hnyav ntawm molecular, qhov ntsuas tsis ruaj khov dua, thiab muaj peev xwm ntawm av. Cov yam tseem ceeb no cuam tshuam ncaj qha rau zaj duab xis evenness, kev ntseeg siab ntawm lub foob thiab qhov zoo ntawm cov hlau kos duab channel.
Thaum cuam tshuam nrog kev sib xyaw PCR siab, tshuab compatibility ua qhov tseem ceeb heev. ADrawstring khib nyiab hnab tshuabmuaj cov tshuab lim dej muaj zog, kev kho mob corona los txiav txim siab lub zog saum npoo, thiab kho qhov kub thiab txias tswj los tswj PCR zoo dua li lub tshuab qub tsuas yog rau cov resins tshiab. Kev tshawb fawb hauv phau ntawv Journal of Applied Polymer Science tau pom tias muaj ntau dua 30 feem pua polymerase saw cov tshuaj tiv thaiv PCR) txo qis kev cuam tshuam lub zog. Qhov no tuaj yeem ua tau los ntawm co-extrusion nrog cov txheej khi tshiab lossis los ntawm kev ntxiv cov kev hloov pauv [3]. Coextruded qauv muab PCR nyob rau hauv nruab nrab txheej thiab tshiab resin rau sab nraud. Qhov no tuav cov sealing nto thiab kho qhov muag zoo thaum siv cov khoom siv dua tshiab.
Cov txheej txheem nthuav dav rau SCS Cov Kev Pabcuam Ntiaj Teb thiab Cov Ntawv Pov Thawj xws li UL's ECOLOGO muab - tog thib peb cov tshev uas cuam tshuam rau kev xaiv cov khoom. Kev hloov dua siab tshiab ntawm cov ntawv pov thawj no yuav tsum tau sau tseg rau hauv ib txoj kab ncaj nraim ntawm kev saib xyuas thiab raug soj ntsuam raws sij hawm. Qhov no ntxiv rau cov ntaub ntawv ua haujlwm rau kev yuav khoom.
Biodegradable thiab Compostable Alternatives
Synthetic zones siv cov ntaub ntawv sib txawv heev. Polylactic acid (PLA), polybutylene adipate terephthalate (PBAT) thiab cov hmoov txhuv nplej siab -raws li cov khoom sib tov tsis muaj lub zog melting lossis kub stability ntawm polyethylene. Cov ntaub ntawv no decompose sai heev nyob rau hauv tshav kub thiab mechanical kev nyuaj siab. Yog li ntawd, lawv yuav tsum tau tshwj xeeb ntsia hlau tsim, txo cov txheej txheem kub thiab hloov sealing chaw. Hem channel ua yog tshwj xeeb yog nyuaj ua. Compostable films muaj tsawg thermal viscosity thiab hlawv yooj yim dua.
Lub converter yuav tsum xyuas cov hlau compatibility ntawm lub nruas thiab screws thaum lub drawstring khib nyiab hnab ua hauj lwm tsis lis cov khoom compostable. Qee cov biopolymers tsim cov khoom siv acidic uas xeb cov qauv hlau. Factories uas tsim cov khoom lag luam thiab cov khoom siv compostable yuav xav tau cov cuab yeej tshwj xeeb lossis cov tshuab hloov ceev. Wageningen University & Kev tshawb fawb qhia tau hais tias PBAT / PLA / hmoov txhuv nplej siab ua tiav cov khoom siv kho tshuab zoo nkaus xwb hauv qhov sib xyaw me me. Yog li ntawd, kev sib xws ntawm kev tsim yog qhov tseem ceeb tshaj li cov tshuab polyethylene [4]. Thaum ntsuas aDrawstring khib nyiab hnab tshuabrau lwm cov ntaub ntawv, cov kev txwv kev ua haujlwm no yuav tsum raug muab xam rau hauv kev txiav txim siab yuav khoom.
Kev Ntsuas Cov Txheej Txheem thiab Kev Ua Haujlwm Zoo
Kev xaiv cov khoom siv tsis tuaj yeem ua raws li tus neeg muag khoom daim ntawv tshaj tawm. Nws yuav tsum tau sim nyob rau hauv cov kev hloov tiag tiag. Cov qauv kev ua haujlwm yooj yim tau teeb tsa los ntawm kev ntsuas lub zog sib khi ntawm txhua ASTMF88, dart cuam tshuam ntawm txhua ASTMD1709, thiab Elmendorf kua muag ntawm txhua ASTMD1922. Rau lub hnab drawstring, kev sib txuas ntawm zaj duab xis thiab drawstring yog kuaj los ntawm cov hauv qab channel blasting xeem thiab ntsuas qhov nro drawstring. Accelerated aging kev tshawb fawb tsom rau ntxiv zog thiab ntev -lub sij hawm stability ntawm nyias films. Qhov no nres glitches tom qab ob peb lub hlis ntawm kev tsim khoom. Kev sim sib koom ua ke ntawm cov chaw muag khoom, cov chaw tsim khoom ntxiv thiab cov neeg ua haujlwm tshuab tseem yog txoj hauv kev zoo tshaj plaws kom tau txais cov ntaub ntawv pov thawj -machine match. Cov kev sib tw no yuav tsum ua kom tau raws li qhov yuav tsum tau ua thiab kev tswj hwm txoj cai. Thaum kawg, cov ntaub ntawv zoo tshaj plaws teem rau ib qho twgDrawstring khib nyiab hnab tshuabtshwm sim los ntawm kev sim ua haujlwm, tsis yog los ntawm cov kev qhia tshwj xeeb ib leeg.
Kev siv
[1] American Chemistry Council (2023). Resin Review: Polyethylene Market Trends and Application Shifts. ACC Plastics Division Technical Report.
[2] Society of Plastics Engineers (2022). Kev Ua Haujlwm Pab Kom Zoo Tshaj Plaws hauv Blown Film Extrusion rau Nyias -Gauge Applications. SPE Kev Sib Tham Txhua Xyoo Kev Ua Haujlwm.
[3] Phau ntawv Journal of Applied Polymer Science (2023). Cov khoom siv hluav taws xob ntawm cov ntawv tshaj tawm -cov neeg siv khoom siv rov ua dua cov yeeb yaj kiab polyethylene rau kev ntim khoom yooj yim. Wiley Periodicals.
[4] Wageningen University & Kev Tshawb Fawb (2022). Biodegradable Polymer Blends ntim: ua qhov rais thiab Kev Ua Haujlwm Zoo. WUR Food & Biobased Research Publications.
