Fluorpolümeerpinnete tehnoloogiliste omaduste uurimine ja kasutamine

Seoses tööstuse ja tootmise pideva arenemisega on tänapäeva seadmetes palju detaile, mis peavad töötama ekstreemsetes tingimustes. See seab materjalidele kõrgeid nõudmisi. Materjalid peavad olema kõrgtehnoloogilised omadused, kuid ükski materjal pole samaaegselt kõrgete mehaaniliste ja füüsikaliste omadustega, sellepärast tuleb vajalike omadustega materjali saamiseks kasutada pindamist. Pindekihi pihustamine annab materjalile vajalikud omadused. Erinevate pindematerjalidega saavutatkse näiteks tugevaid ja korrosioonikindlaid materjale. Samuti on võimalik pindamisega taastada detaile ja anda neile uus elu ja väljanägemine. Lõputöö eesmärgiks on võrrelda lahustipõhiste ja pulbriliste fluorpolümeerpinnete tehnoloogilisi omadusi ja kasutust saadud labori tulemuste põhjal. Käesolevas lõputöös uuriti kolme erineva pindamistehnoloogiaga saadud tehnikas enamkasutatavaid fluorpolümeerpindeid. Katsekehade põhimaterjaliks kasutati alumiiniumi ja terast. Lahustipõhiste fluorpolümeerpindematerjalide peale kandmiseks kasutati madalsurvepihustust värvipritsiga. Pulbrilised fluorpolümeermaterjalid kanti peale elektrostaatilise pihustusega seadme eurotec ultra-com 300-ga ja metallikihtide pindamiseks kasutati gaasleekpihustust seadmega CastoDyn DS 8000. Saadud katsekehadel uuriti pinnakõvadust ja struktuuri. Pindematerjalidest kasutati lahustipõhiseid Whitford Plastics toodetud Xylan 1052, kahekomponentne Xylan 8221/8224. Ühe katsekeha, mille pindematerjaliks kasutati Xylan 8221/8224, valmistamisel pihustati fluorpolümeerpindekihtide alla Castolin Eutectic 29029 NiAl ja Castolin Eutectic 19400 Fe+Cr metallipindematerjale. Elektrostaatilise pihustusega kanti katsekehadele pulbrilised fluorpolümeerpindematrejalid Whitford Xylan Plastics toodetud Dykor 810 ja Dykor 830. Pindamistehnoloogia valikust sõltub pinde struktuur ja kõvadus. Pulbriliste fluorpolümeeride nakkuvus alusmaterjaliga on parem kui lahustipõhistel fluopolümeermaterjalidel. Kuna elektrostaatiline pindamine katab põhimaterjali ühtlasemalt, saadakse kõvadus ja struktuur parem kui madalsurvepihustusega. Parem kõvadus on tingitud ka sellest, et elektrostaatilise pihustuse käigus saadud pindeid tuleb kuumutada kõrgematel temperatuuridel, Kuumutamisel sulavad pulbriosakesed ühtlasemalt ja ristsildavad ennast tugevamalt põhimaterjali osakestega. Ka tehtud uuringud andsid sama tulemuse. Pulbripõhised fluorpolümeerpinded olid kõvemad ning struktuurilt tihedamad kui lahustipõhised fluorpolümeerpinded.

With the constant development of the industry and the production, the modern equipment contains details that need to operate in extreme conditions. This sets high standards for materials. Materials must have high technical characteristics. However, not a single material has high mechanical and physical properties at the same time. This is why coating is used for getting material with necessary characteristics. Coating provides the base material with necessary characteristics. For example different strong and corrosion resistant materials are obtained with coating. With coating it is also possible to restore details and to give them new life and appearance. This thesis gives an overview of fluoropolymers and their history. Also well-known fluoropolymers and their characteristics are outlined. Coal of this thesis is to compare solvent-based and powder fluoropolymer coatings technological characteristics and their use according to laboratory test results. In this thesis the three different coating techniques for most frequently used fluoropolymers are examined. Basic materials for test specimens were aluminium and steel. Low-pressure spraying with paint sprays where used for solvent-based fluoropolymer coating. Powder fluoropolymermaterial coating was carried on with electrostatic spraying equipment (eurotec ultra-com 300) and flame thermal spraying device (CastoDyn DS8000) was used for metal layer coatings. Hardness and structure of test specimen was examined. Solvent-based Xylan 1052 and double component Xylan 8221/8224 from Whitford Plastics were used for coating. One specimen was sprayed with metal layer materials Castolin Eutectic 29029 NiAl and Castolin Eutectic 19400 Fe+Cr before it being coated with Xylan 8221/8224. Electrostatic spraying was used for coating specimen with powder fluoropolymer materials Dykor 810 and Dykor 830 (Whitford Plastics). Coating structure and hardness depends from coating technology being used. Powder fluoropolymers have better adhesion with base material than solvent-based fluoropolymers. A improved hardness and structure is obtained because electrostatic coating covers the base material more evenly than low-pressure spraying. Improved hardness is also due the fact that the electrostatic coating has to be heated at an elevated temperature. Powder melts more evenly when heated and it cross-links itself strongly with base material particles. Studies confirmed this result. Powder based fluoropolymers were harder and had firmer structure than the solvent based fluoropolymer coatings.