[en] The environmental protection, with special emphasis on CO2 emissions reduction, is a growing demand that the transport industry has to fulfill. Carbon fibre reinforced polymers (CFRP) are interesting candidates as they can reduce 70% of the vehicle weight and can dissipate five times higher impact energies than metals. Composites are already employed in this industry, especially in low benefits application. However, its expansion to more structural parts is not possible in part due to process limitations. Resin Transfer Moulding (RTM) is a well-established processing method. Nevertheless, there are still some difficulties in fabricating high fibre volume parts. Increasing the fibre content, decreases the permeability of the preform, leading to a long filling time, incomplete impregnation and high void content. One of the most promising alternatives is to combine compression and Resin Transfer Moulding which is known as Compression Resin Transfer Moulding (CRTM). In CRTM, the mould is partially closed when resin injection begins, generating a small gap between the fibre surface and the mould wall, which facilitates further the resin flow. Once the required amount of resin penetrates into the gap, the inlet is closed and the mould platen moves down to close the mould and to squeeze the resin into the preform to achieve the desired volume fraction. Therefore, instead of the resin flowing through the planar directions as in RTM, in CRTM the preform is impregnated through the thickness direction. This means a reduction of several orders of magnitude as far as flow length is concerned. This modification in the impregnation sequence is the reason for the decrease in the filling time associated with the CRTM. Considering the high potential of the CRTM, the objective of this thesis is to generate the necessary knowledge to understand the behaviour of the flow in all the phases of the process, in order to be able to design the press installations, obtaining low porosity parts and reducing the cycle time and the set-up costs. In order to develop this process, it has been necessary to use a holistic strategy that encompasses both injection and compression strategies, such as mould design and press configuration using advanced experimental techniques (material characterization, process parameter control and monitoring). Basic research is done using a flat plate, and finally, the knowledge obtained is applied to a real part of automotive. This study has shown that the injection and compression strategies influence in the flow behaviour and in the requirements of the installation. The most influential parameters of the injection phase in the impregnation pattern are also determined. In addition, a new compression strategy approach is proposed where two different compression velocities are used, that reduces the cycle times and closing forces. Finally, a process monitoring system is proposed, which has shown that the cost of an automotive part manufactured in CRTM is lower than in the RTM.

[eu] Ingurumenaren babesa, arreta berezia CO2 isurien murriztapenean ipiniz, garraio industriak aurre egin beharreko beharra da. Arazo honen aurrean, karbono zuntzez indartutako polimeroak (CFRP) abantailak erakusten dituzte, ibilgailuen pisua 70% murriztera iritsi daitezkelako eta inpaktu baten aurrean metalak baino bost aldiz energia gehiago xurgatzen dutelako. Dagoeneko garraio industria konpositeen onuretaz baliatzen da, batez ere, aplikazio ez estrukturalentzat (zuntz motza). Hala ere, pieza estrukturaletarako hedapena ez da posible izan prozesuen mugengatik. Resin Transfer Moulding (RTM) ondo ezarritako prozesu bat da, hala ere hainbat muga ditu, batez ere, zuntz portzentaje altuko piezak fabrikatu nahi direnean. Zuntz portzentaje altuak preformaren permeabilitatea murrizten du, betetze denborak luzatuz, inpregnazio arazoak sortuz eta poro maila handituz. Alternatiba itxaropentsuenetariko bat RTM-a konpresioarekin konbinatzea da, Compression Resin Transfer Moulding (CRTM) deitua. CRTM-ko injekzio fasean moldea partzialki irekia mantentzen da, zuntz gabekoz zona bat sortuaz, erretxina errazago ixurtzea ahalbideratzen duena. Beharrezko erretxina kantitatea injektatu ostean, moldea itxi egiten da, erretxinaz preforma bustitzera behartuz, saturatu eta amaierako dimentsioak lortuaz. Beraz, fluxuaren inpregnazio direkzioa planoan izatetik, lodieran izatera pasatzen da, fluxuaren luzeran magnitude murrizpena lortuz. Inpregnazio sekuentzia aldaketa hau CRTM-an inpregnazio denboran murrizpenaren arrazoia da. CRTM-aren potentziala ikusiz, tesi honen helburua prozesuko fase guztietan fluxuaren portaeraren ezagutza lortzea da, poro gutxiko piezak lortzeko eta pentsen instalazioak diseinatzeko, ziklo denborak eta prestaketa kosteak murriztuz. Prozesu hau garatzeko, ikuspegi holistiko bat erabiltzea beharrezkoa da, bai injekzio eta konpresio estrategiak aztertzen dituenak, nola moldearen diseinua, prentsaren konfigurazioa eta teknika esperimental aurreratuak erabiltzen dituenak (materialen karakterizazioa, prozesuko parametroen eta fluxuaren jarraipen kontrola). Oinarrizko ikerketa, plaka lauaz egiten da, eta azkenik lortutako ezagutza automobilgintzako pieza erreal bati aplikatzen zaio. Eginiko ikerketak, injekzio eta konpresio estrategiak fluxuaren portaeran eragina duela erakutsi du, baita instalazio-baldintzetan ere. Era berean, injekzio faseko inpregnazio patroian eragin gehien duten parametroak definitu dira. Horrez gain, konpresio estrategi berri bat proposatzen da, non bi abiadura erabiltzen diren ziklo denbora eta itxiera indarrak murriztea ahalbidetzeko. Azkenik, prozesuko fluxuaren jarraipen-sistema bat proposatzen da, non automobilgintzako pieza erreal baten kostua estimatzen den, ikusiaz CRTM piezen kostua RTM-koa baino txikiagoa dela.