Fluorpolümeeride elektrostaatiline pindamine ning tehnoloogiliste omaduste uurimine ja kasutamine

Seoses tööstuse, tootmise, teaduse ja tehnoloogia pideva arenemisega on kaasaegsetes seadmetes palju detaile, mis peavad töötama ekstreemsetes tingimustes ja pikka aega. Seetõttu peavad materjalid olema samaaegselt mitme omaduse poolest kõrge kvaliteediga. Paljud tavalised materjalid aga pole võimelised niivõrd äärmuslikes ja erinevates oludes kõiki neid nõudmisi täita ning sellepärast tuleb vajalike omadustega detailide saamiseks valmistada neid komposiitidest, et kasutada kooskõlas mitme materjali tugevaid külgi. Et kaitsta ühte materjali ümbritseva keskkonna eest või anda talle häid triboloogilisi omadusi, kantakse talle uus pealmine pindekiht. Samuti on võimalik pindamisega taastada detaile ja anda neile uus elu ja väljanägemine. Käesolevas lõputöös on ülevaade fluorpolümeeridest, nende ajaloost, tööeast saamisest kuni lagunemiseni, füüsikalisi omadusi, rakendusalasi ja maailmaturgu. Lõputöö eesmärgiks on võrrelda lahustipõhiste ja pulbriliste fluorpolümeerpinnete tehnoloogilisi omadusi ja kasutust saadud labori tulemuste põhjal. Käesolevas lõputöös uuriti kahe erineva pindamistehnoloogiaga saadud tehnikas enamkasutatavaid fluorpolümeerpindeid. Katsekehade põhimaterjaliks kasutati terast. Lahustipõhiste fluorpolümeerpindematerjalide peale kandmiseks kasutati madalsurvepihustust värvipritsiga. Pulbrilised fluorpolümeerpindematerjalid kanti peale elektrostaatilise pihustusega seadme Eurotec ultra-com 300-ga. Saadud katsekehadel uuriti pinnakõvadust ja mikrostruktuuri. Pindematerjalidest kasutati lahustipõhiseid Whitford Plastics toodetud Xylan 1052, kahekomponentne Xylan 8221/8224. Elektrostaatilise pihustusega kanti katsekehadele pulbrilised fluorpolümeerpindematerjalid Whitford Plastics toodetud Dykor 810, Dykor 815 ja Dykor 830. Pindamistehnoloogia valikust sõltub pinde struktuur ja kõvadus. Pulbriliste fluorpolümeeride nakkuvus alusmaterjaliga on parem kui lahustipõhistel fluorpolümeermaterjalidel. Kuna elektorostaatiline 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 sulavadpulbriosakesed ühtlasemalt ja ristseostuvad tugevamalt põhimaterjali osakestega. Ka tehtud uuringud andsid sama tulemuse. Pulbripõhised fluorpolümeerpinded olid kõvemad ning struktuurilt tihedamad kui lahustipõhised fluorpolümeerpinded.

Due to the constant development of industry, production, science and technology, modern equipment has many parts that must work in extreme conditions and for a long time. Therefore, the materials must be of high quality in several aspects at the same time. However, many conventional materials are not able to meet all these requirements in such extreme and varied conditions, and therefore, in order to obtain details with the required properties, they must be made of composites in order to use the strengths of several materials in harmony. To protect a material from the environment or to give it good tribological properties, a new coating is applied. It is also possible to restore details with coating and give them a new life and appearance. This dissertation provides an overview of fluoropolymers, their history, service life from production until degradation, physical properties, applications and the world market. The aim of the thesis is to compare the technological properties and use of solvent-based and powdered fluoropolymer coatings based on the obtained laboratory results. In this dissertation, the most commonly used fluoropolymer coatings in the technique obtained with two different coating technologies were studied. Steel was used as the base material for the test pieces. Low pressure spraying was used to apply the solvent-based fluoropolymer coatings. Powdered fluoropolymer coatings were applied by electrostatic spraying with a Eurotec ultra-com 300. The obtained test specimens were examined for surface hardness and microstructure. Solvent-based Xylan 1052, a two-component Xylan 8221/8224 manufactured by Whitford Plastics, was used as the coating material. Powders were applied to the test pieces by electrostatic spraying fluoropolymer coatings Dykor 810, Dykor 815 and Dykor 830 manufactured by Whitford Plastics. The structure and hardness of the coating depend on the choice of coating technology. Powdered fluoropolymers have better adhesion to the base material than solvent-based fluoropolymer materials. As the electrostatic coating covers the base material more evenly, the hardness and structure are better than with low pressure spraying. The better hardness is also due to the fact that the surfaces obtained by electrostatic spraying have to be heated at higher temperatures. Upon heating, the powder particles melt more evenly and cross-link more strongly with the particles of the base material. The studies performed gave the same result. Powder-based fluoropolymer coatings were harder and more structurally dense than solvent-based fluoropolymer coatings.