Juraj Gigac - Academia.edu (original) (raw)

Papers by Juraj Gigac

The influence of velocity gradient on the anisotropy of tensile stiffness index, tensile energy a... more The influence of velocity gradient on the anisotropy of tensile stiffness index, tensile energy absorbance, tensile index, tear strength, tensile stiffness orientation, formation and curl of MG paper, as well as on the anisotropy of coating raw paper, was investigated. The maximum strength of MG paper was achieved in the 0.93-1.05 range of the jet-to-wire speed ratio. The best formation and the lowest curl with fibre orientation ±1.7° was achieved at a jet-to-wire speed ratio around 1.0, while CMT and SCT of fluting from a mixture of semi-chemical pulp and recovered fibres produced at a constant speed difference of the jet and wire are influenced by basis weight and semi-chemical pulp content.

Wood Research, 2010

Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash... more Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash-tree and aspen) was determined by analysis of RGB colour components. Th e acquired data of the digital image were analysed by histograms of the entire colour tone image and of the colour image of R, G, B colour components. Th e colour determined by this procedure is in good accordance with perceptual evaluation of the colour shade of the respective wood species. Moisture content signifi cantly infl uences wood colour intensity which is decreasing with decreasing moisture content. Nevertheless at diff erent moisture content chips of individual wood species are in the same colour region. Results of analyses of wood chips from two samplings confi rmed suitability of the proposed method for identifi cation of wood species present in a chip mixture.

Wood Research, 2019

The main criteria used to select the structural parameters of buildings are generally based on te... more The main criteria used to select the structural parameters of buildings are generally based on technical and economic considerations. Despite such concerns, environmental issues, particularly the water footprint of structures, have received little attention in practice. This paper assesses the effects of structural parameters (area, height, materials, slab, and the lateral load resisting system), along with site classification on the water footprint of residential buildings. Ideas from the life cycle assessment methodology and the approach of the Water Footprint Network are applied. The paper proposes a water footprint framework for residential building assessment. A sample of 45 buildings is analyzed. Water footprints of material extraction, production, transportation, and construction are calculated. The paper shows that, in order to reduce the water footprint of structures, concrete structures perform better than steel structures, short structures are better than tall structures, composite slabs are better than steel deck and cobute precast slabs, and building sites with dense soils are better than building sites with soft soils.

The effect of water prehydrolysis conditions, which was used as the first stage of wheat straw pr... more The effect of water prehydrolysis conditions, which was used as the first stage of wheat straw pretreatment, on the composition of filtrates was analysed. Many of the substances that are present in the prehydrolysis filtrates are broadly used and thus they contribute to improvements in the efficiency of bioethanol production. Prehydrolysis was carried out at temperatures of 140, 160 and 180°C and times of 30, 60 and 120 min. Xylose and its oligomers were the most represented in prehydrolysis filtrates, their yields increased up to 12.1 % with increasing weight of wheat straw removed up to 28.6 %. Besides xylose and glucose, acetic acid, formic acid and the phenolic compounds were also present in the prehydrolysis filtrates. At 160 and 180°C, levulinic acid and furfural and hydroxymethylfurfural, respectively, were also present. The solid fractions of wheat straw were subjected to steam explosion under the same conditions at 200°C for 2 min. Two-stage pretreated wheat straw was subse...

Multivariate data analysis and near-infrared region (NIR) spectroscopy was used to determine the ... more Multivariate data analysis and near-infrared region (NIR) spectroscopy was used to determine the physical and mechanical properties of unbleached and bleached hardwood kraft pulps with different chemical compositions and beaten to different levels. The differences between NIR spectra unbleached and bleached hardwood kraft pulps as well as between unbeaten and beaten pulps are very small. The calibration models developed for determination of pulp properties using NIR spectra analysis and conventional method had excellent predictive ability for tensile index (R=0.977-0.989), tear index (R=0.912-0.975) and stiffness (R=0.894-0.986). However, porosity does not show such good correlation (R=0.835-0.875) between measured and NIR predicted value. The correlation coefficients of calibration models made for combined unbleached and bleached pulps and separately for unbleached and bleached pulps were very similar. Average deviation between measured and NIR predicted properties of unknown hardw...

Wood Research, 2009

A method for determination of hardwood wood species in chips form by NIR refl ectance spectroscop... more A method for determination of hardwood wood species in chips form by NIR refl ectance spectroscopy has been investigated. A series of measurements on chips from seven wood species (beech, acacia, hornbeam, ash-tree, aspen, birch and cherry) with various, controlled amounts of moisture, has been carried out and the spectra were subjected to discriminant analysis (PCA). Wet wood chips had higher rates of successful identifi catio as compared to wood chips, probably due to signifi cant variation of moisture content from species to species rather than minute diff erences in chemical composition. Acacia, birch, hornbeam and aspen were identifi ed with high accuracy. Low identifi catio accuracy has been obsrved with cherryd ash-tre. Th e predicted versus actual relationship for all tested wood species is linear with a coeffi cient of determination R 2= 0,8054.

Fibrous residues from acid and enzymatic hydrolysis of sugar beet pulp can be applied to increase... more Fibrous residues from acid and enzymatic hydrolysis of sugar beet pulp can be applied to increase bonding potential and partial replacement of recovered fi bres. Th e authors investigated the infl uence of original, chemically and enzymatically modifi ed sugar beet pulp on fi bre suspension and paper properties from recovered fi bres. With increasing content of sugar beet pulp in a mixture with recovered fi bres, drainage time and water retention value increased, weighted average fi bre length decreased, tensile and burst index, internal bond strength increased, bending resistance and porosity decreased. Th e eff ect of sugar beet pulp on fi bre suspension and paper properties increased in the sequence original, chemically and enzymatically modifi ed sugar beet pulp. Optimum input of original sugar beet pulp is 15-20%, of chemically modifi ed sugar beet pulp 10-15% and of enzymatically modifi ed sugar beet pulp 5-10%. Addition of sugar beet pulp to recovered fi bres had a similar ef...

Analysis of fl exural rigidity, internal bond strength and porosity of paper off ers a good pictu... more Analysis of fl exural rigidity, internal bond strength and porosity of paper off ers a good picture about fl uting and test liner furnish composition and necessary changes in fi bre treatment. Evaluation of laboratory experiments by these three parameters made possible selection of suitable technology for treatment recovered fi bres which is eff ective and universal for fl uting and test liner manufacture from virgin and recovered fi bres. An optimal technology exploits the natural bond potential of recovered fi bres in combination with nanoparticle retention and drainage system. Th e fi rst component of the nanoparticle retention and drainage system is a natural or synthetic cationic polymer for increase of dry strength. Th e second component is agent based on structured silicic acid. By application of an optimal combined recovered fi bres treatment technology a CMT30 increase by 7-20%, SCT by 6-21% and burst strength by 7-38% was observed in dependence of semichemical pulp content...

Wood Research, 2010

Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash... more Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash-tree and aspen) was determined by analysis of RGB colour components. Th e acquired data of the digital image were analysed by histograms of the entire colour tone image and of the colour image of R, G, B colour components. Th e colour determined by this procedure is in good accordance with perceptual evaluation of the colour shade of the respective wood species. Moisture content signifi cantly infl uences wood colour intensity which is decreasing with decreasing moisture content. Nevertheless at diff erent moisture content chips of individual wood species are in the same colour region. Results of analyses of wood chips from two samplings confi rmed suitability of the proposed method for identifi cation of wood species present in a chip mixture.

International Sugar Journal, 2010

Cationic flours (CF, wheat origin) increased both tensile and burst index plus internal bond stre... more Cationic flours (CF, wheat origin) increased both tensile and burst index plus internal bond strength of handsheets prepared from recovered fibres (RF, from recycled papers and cardboards) without or with 10% fibrous residue from enzymatic hydrolysis of sugarbeet pulp (EHSBP). Strength properties of handsheets from RF were higher with the combination of CF and EHSBP than with CF alone. CF increased bending resistance and reduced air permeation resistance of handsheets. Converse was true for EHSP. CF partially checked the negative influence of EHSBP on drainage time and water retention value of RF suspensions when both were combined. COD and BOD 5 of filtrates was reduced by CF more in case of a furnish containing EHSBP. [Furnish refers to materials (other than water) used as inputs to making paper.].

Wood Research, 2020

The influence of proportions of bleached birch, eucalyptus, beech kraft pulps as well as the blea... more The influence of proportions of bleached birch, eucalyptus, beech kraft pulps as well as the bleached aspen chemi-thermomechanical pulp (BCTMP) in the mixture with bleached pine kraft pulp on tissue paper properties was compared. Increase of bleached beech kraft pulp and aspen BCTMP proportion in a mixture with bleached pine kraft pulp leads to significant rise of porosity ε as well as bulk. The water absorption after immersion increased significantly with increase of aspen BCTMP content in the mixture while other hardwood pulps in the mixture had only moderate impact. Increasing of bleached beech and eucalyptus kraft pulps content in the mixture continually increased initial water absorption. As a result of blending of bleached birch kraft pulp with bleached pine kraft pulp, bulk softness improved and the tensile index increased slightly. The increased content of bleached birch and beech kraft pulp in the mixture increased the brightness while the addition of aspen BCTMP and bleached eucalyptus kraft pulp increased of coordinate b* value. Mixed pulps with properties suitable for different types of hygienic products were selected.

Wood Research, 2020

Conventional papers are not suitable for printed electronics because they have a rougher surface ... more Conventional papers are not suitable for printed electronics because they have a rougher surface than the plastic film commonly used for electronics printing. The paper surfaces were modified by coating and calendering processes to reduce surface roughness and electrical resistance of inkjet-printed UHF RFID antennas. The composition of coatings, the main component which included aluminum oxide pigment, had an influence on the surface roughness, the surface pore content and the electrical resistance of the inkjet-printed UHF RFID antennas on coated papers. Papers coated with a mixture containing 25% polyvinyl alcohol binder in combination with the cationic polymer PDADMAC without glyoxal crosslinker had the lowest surface roughnesses and the lowest electrical resistances of the inkjet-printed antennas. As the coating basis weight increased, the electrical resistance of the antennas increased. Reduction of the electrical resistance of the antennas was achieved after calendering coated paper. The design of the antennas had a significant effect on their electrical resistance, which increased with the length of the antenna.

Cellulose Chemistry and Technology

In the present work, various surface treatments of base paper were investigated in order to make ... more In the present work, various surface treatments of base paper were investigated in order to make it suitable for application in printed electronics. A functional coating based on silica pigment was preceded by PVOH-containing precoating, and differently surface treated papers were characterized in terms of surface roughness, relative area of surface pores, wettability, printability and by FTIR spectroscopy. The precoating had a significant effect on the constriction of through-pores, the reduction of their number, and on the permeability of the functional coating, and it increased the dynamic contact angle of the liquids. Analysis of FTIR spectra of precoated and functionally coated paper confirmed a higher content of polyvinyl alcohol binder and cationic polymer in the functional coating, compared to that of functionally coated paper, without precoating. SEM analysis showed that the silver layer of the RFID antenna printed by inkjet on the precoated and functionally coated paper was continuous. Better printability of the precoated and functionally coated paper, compared to the functionally coated paper, without precoating, was also confirmed by higher electrical conductivity of the dipole of the RFID antenna, which reached the level of the antenna printed on a commercial inkjet PET film.

Wood Research

UHF RFID printed antennas on conventional and experimentally coated papers by thermal transfer an... more UHF RFID printed antennas on conventional and experimentally coated papers by thermal transfer and inkjet technique were not conductive due to high surface roughness. Reducing the surface roughness of paper and hence the electrical resistance of the antennas printed by thermal transfer and inkjet printing was achieved by coating and subsequent calendering process. Papers for thermal transfer and inkjet printed of aluminum and silver antennas were prepared by coating with top functional coating, whose main component was pigment-precipitated calcium carbonate with addition of polyvinyl alcohol, cationic polymer PDADMAC and glyoxal. The desired quality of inkjet-printed silver antennas was achieved by using coated paper with a polyvinyl alcohol barrier layer and a top functional hydrophilic layer. Silver nanoparticles of inkjet ink require a sintering process to obtain a conductive printed trace. The microstructure and thickness of antennas printed by thermal transfer and inkjet technique were compared. Thermal transfer printing created a more homogeneous antenna with greater sharpness of drawing compared to inkjet printing.

The influence of velocity gradient on the anisotropy of tensile stiffness index, tensile energy a... more The influence of velocity gradient on the anisotropy of tensile stiffness index, tensile energy absorbance, tensile index, tear strength, tensile stiffness orientation, formation and curl of MG paper, as well as on the anisotropy of coating raw paper, was investigated. The maximum strength of MG paper was achieved in the 0.93-1.05 range of the jet-to-wire speed ratio. The best formation and the lowest curl with fibre orientation ±1.7° was achieved at a jet-to-wire speed ratio around 1.0, while CMT and SCT of fluting from a mixture of semi-chemical pulp and recovered fibres produced at a constant speed difference of the jet and wire are influenced by basis weight and semi-chemical pulp content.

Wood Research, 2010

Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash... more Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash-tree and aspen) was determined by analysis of RGB colour components. Th e acquired data of the digital image were analysed by histograms of the entire colour tone image and of the colour image of R, G, B colour components. Th e colour determined by this procedure is in good accordance with perceptual evaluation of the colour shade of the respective wood species. Moisture content signifi cantly infl uences wood colour intensity which is decreasing with decreasing moisture content. Nevertheless at diff erent moisture content chips of individual wood species are in the same colour region. Results of analyses of wood chips from two samplings confi rmed suitability of the proposed method for identifi cation of wood species present in a chip mixture.

Wood Research, 2019

The main criteria used to select the structural parameters of buildings are generally based on te... more The main criteria used to select the structural parameters of buildings are generally based on technical and economic considerations. Despite such concerns, environmental issues, particularly the water footprint of structures, have received little attention in practice. This paper assesses the effects of structural parameters (area, height, materials, slab, and the lateral load resisting system), along with site classification on the water footprint of residential buildings. Ideas from the life cycle assessment methodology and the approach of the Water Footprint Network are applied. The paper proposes a water footprint framework for residential building assessment. A sample of 45 buildings is analyzed. Water footprints of material extraction, production, transportation, and construction are calculated. The paper shows that, in order to reduce the water footprint of structures, concrete structures perform better than steel structures, short structures are better than tall structures, composite slabs are better than steel deck and cobute precast slabs, and building sites with dense soils are better than building sites with soft soils.

The effect of water prehydrolysis conditions, which was used as the first stage of wheat straw pr... more The effect of water prehydrolysis conditions, which was used as the first stage of wheat straw pretreatment, on the composition of filtrates was analysed. Many of the substances that are present in the prehydrolysis filtrates are broadly used and thus they contribute to improvements in the efficiency of bioethanol production. Prehydrolysis was carried out at temperatures of 140, 160 and 180°C and times of 30, 60 and 120 min. Xylose and its oligomers were the most represented in prehydrolysis filtrates, their yields increased up to 12.1 % with increasing weight of wheat straw removed up to 28.6 %. Besides xylose and glucose, acetic acid, formic acid and the phenolic compounds were also present in the prehydrolysis filtrates. At 160 and 180°C, levulinic acid and furfural and hydroxymethylfurfural, respectively, were also present. The solid fractions of wheat straw were subjected to steam explosion under the same conditions at 200°C for 2 min. Two-stage pretreated wheat straw was subse...

Multivariate data analysis and near-infrared region (NIR) spectroscopy was used to determine the ... more Multivariate data analysis and near-infrared region (NIR) spectroscopy was used to determine the physical and mechanical properties of unbleached and bleached hardwood kraft pulps with different chemical compositions and beaten to different levels. The differences between NIR spectra unbleached and bleached hardwood kraft pulps as well as between unbeaten and beaten pulps are very small. The calibration models developed for determination of pulp properties using NIR spectra analysis and conventional method had excellent predictive ability for tensile index (R=0.977-0.989), tear index (R=0.912-0.975) and stiffness (R=0.894-0.986). However, porosity does not show such good correlation (R=0.835-0.875) between measured and NIR predicted value. The correlation coefficients of calibration models made for combined unbleached and bleached pulps and separately for unbleached and bleached pulps were very similar. Average deviation between measured and NIR predicted properties of unknown hardw...

Wood Research, 2009

A method for determination of hardwood wood species in chips form by NIR refl ectance spectroscop... more A method for determination of hardwood wood species in chips form by NIR refl ectance spectroscopy has been investigated. A series of measurements on chips from seven wood species (beech, acacia, hornbeam, ash-tree, aspen, birch and cherry) with various, controlled amounts of moisture, has been carried out and the spectra were subjected to discriminant analysis (PCA). Wet wood chips had higher rates of successful identifi catio as compared to wood chips, probably due to signifi cant variation of moisture content from species to species rather than minute diff erences in chemical composition. Acacia, birch, hornbeam and aspen were identifi ed with high accuracy. Low identifi catio accuracy has been obsrved with cherryd ash-tre. Th e predicted versus actual relationship for all tested wood species is linear with a coeffi cient of determination R 2= 0,8054.

Fibrous residues from acid and enzymatic hydrolysis of sugar beet pulp can be applied to increase... more Fibrous residues from acid and enzymatic hydrolysis of sugar beet pulp can be applied to increase bonding potential and partial replacement of recovered fi bres. Th e authors investigated the infl uence of original, chemically and enzymatically modifi ed sugar beet pulp on fi bre suspension and paper properties from recovered fi bres. With increasing content of sugar beet pulp in a mixture with recovered fi bres, drainage time and water retention value increased, weighted average fi bre length decreased, tensile and burst index, internal bond strength increased, bending resistance and porosity decreased. Th e eff ect of sugar beet pulp on fi bre suspension and paper properties increased in the sequence original, chemically and enzymatically modifi ed sugar beet pulp. Optimum input of original sugar beet pulp is 15-20%, of chemically modifi ed sugar beet pulp 10-15% and of enzymatically modifi ed sugar beet pulp 5-10%. Addition of sugar beet pulp to recovered fi bres had a similar ef...

Analysis of fl exural rigidity, internal bond strength and porosity of paper off ers a good pictu... more Analysis of fl exural rigidity, internal bond strength and porosity of paper off ers a good picture about fl uting and test liner furnish composition and necessary changes in fi bre treatment. Evaluation of laboratory experiments by these three parameters made possible selection of suitable technology for treatment recovered fi bres which is eff ective and universal for fl uting and test liner manufacture from virgin and recovered fi bres. An optimal technology exploits the natural bond potential of recovered fi bres in combination with nanoparticle retention and drainage system. Th e fi rst component of the nanoparticle retention and drainage system is a natural or synthetic cationic polymer for increase of dry strength. Th e second component is agent based on structured silicic acid. By application of an optimal combined recovered fi bres treatment technology a CMT30 increase by 7-20%, SCT by 6-21% and burst strength by 7-38% was observed in dependence of semichemical pulp content...

Wood Research, 2010

Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash... more Surface colour region of chips of seven wood species (acacia, birch, beech, cherry, hornbeam, ash-tree and aspen) was determined by analysis of RGB colour components. Th e acquired data of the digital image were analysed by histograms of the entire colour tone image and of the colour image of R, G, B colour components. Th e colour determined by this procedure is in good accordance with perceptual evaluation of the colour shade of the respective wood species. Moisture content signifi cantly infl uences wood colour intensity which is decreasing with decreasing moisture content. Nevertheless at diff erent moisture content chips of individual wood species are in the same colour region. Results of analyses of wood chips from two samplings confi rmed suitability of the proposed method for identifi cation of wood species present in a chip mixture.

International Sugar Journal, 2010

Cationic flours (CF, wheat origin) increased both tensile and burst index plus internal bond stre... more Cationic flours (CF, wheat origin) increased both tensile and burst index plus internal bond strength of handsheets prepared from recovered fibres (RF, from recycled papers and cardboards) without or with 10% fibrous residue from enzymatic hydrolysis of sugarbeet pulp (EHSBP). Strength properties of handsheets from RF were higher with the combination of CF and EHSBP than with CF alone. CF increased bending resistance and reduced air permeation resistance of handsheets. Converse was true for EHSP. CF partially checked the negative influence of EHSBP on drainage time and water retention value of RF suspensions when both were combined. COD and BOD 5 of filtrates was reduced by CF more in case of a furnish containing EHSBP. [Furnish refers to materials (other than water) used as inputs to making paper.].

Wood Research, 2020

The influence of proportions of bleached birch, eucalyptus, beech kraft pulps as well as the blea... more The influence of proportions of bleached birch, eucalyptus, beech kraft pulps as well as the bleached aspen chemi-thermomechanical pulp (BCTMP) in the mixture with bleached pine kraft pulp on tissue paper properties was compared. Increase of bleached beech kraft pulp and aspen BCTMP proportion in a mixture with bleached pine kraft pulp leads to significant rise of porosity ε as well as bulk. The water absorption after immersion increased significantly with increase of aspen BCTMP content in the mixture while other hardwood pulps in the mixture had only moderate impact. Increasing of bleached beech and eucalyptus kraft pulps content in the mixture continually increased initial water absorption. As a result of blending of bleached birch kraft pulp with bleached pine kraft pulp, bulk softness improved and the tensile index increased slightly. The increased content of bleached birch and beech kraft pulp in the mixture increased the brightness while the addition of aspen BCTMP and bleached eucalyptus kraft pulp increased of coordinate b* value. Mixed pulps with properties suitable for different types of hygienic products were selected.

Wood Research, 2020

Conventional papers are not suitable for printed electronics because they have a rougher surface ... more Conventional papers are not suitable for printed electronics because they have a rougher surface than the plastic film commonly used for electronics printing. The paper surfaces were modified by coating and calendering processes to reduce surface roughness and electrical resistance of inkjet-printed UHF RFID antennas. The composition of coatings, the main component which included aluminum oxide pigment, had an influence on the surface roughness, the surface pore content and the electrical resistance of the inkjet-printed UHF RFID antennas on coated papers. Papers coated with a mixture containing 25% polyvinyl alcohol binder in combination with the cationic polymer PDADMAC without glyoxal crosslinker had the lowest surface roughnesses and the lowest electrical resistances of the inkjet-printed antennas. As the coating basis weight increased, the electrical resistance of the antennas increased. Reduction of the electrical resistance of the antennas was achieved after calendering coated paper. The design of the antennas had a significant effect on their electrical resistance, which increased with the length of the antenna.

Cellulose Chemistry and Technology

In the present work, various surface treatments of base paper were investigated in order to make ... more In the present work, various surface treatments of base paper were investigated in order to make it suitable for application in printed electronics. A functional coating based on silica pigment was preceded by PVOH-containing precoating, and differently surface treated papers were characterized in terms of surface roughness, relative area of surface pores, wettability, printability and by FTIR spectroscopy. The precoating had a significant effect on the constriction of through-pores, the reduction of their number, and on the permeability of the functional coating, and it increased the dynamic contact angle of the liquids. Analysis of FTIR spectra of precoated and functionally coated paper confirmed a higher content of polyvinyl alcohol binder and cationic polymer in the functional coating, compared to that of functionally coated paper, without precoating. SEM analysis showed that the silver layer of the RFID antenna printed by inkjet on the precoated and functionally coated paper was continuous. Better printability of the precoated and functionally coated paper, compared to the functionally coated paper, without precoating, was also confirmed by higher electrical conductivity of the dipole of the RFID antenna, which reached the level of the antenna printed on a commercial inkjet PET film.

Wood Research

UHF RFID printed antennas on conventional and experimentally coated papers by thermal transfer an... more UHF RFID printed antennas on conventional and experimentally coated papers by thermal transfer and inkjet technique were not conductive due to high surface roughness. Reducing the surface roughness of paper and hence the electrical resistance of the antennas printed by thermal transfer and inkjet printing was achieved by coating and subsequent calendering process. Papers for thermal transfer and inkjet printed of aluminum and silver antennas were prepared by coating with top functional coating, whose main component was pigment-precipitated calcium carbonate with addition of polyvinyl alcohol, cationic polymer PDADMAC and glyoxal. The desired quality of inkjet-printed silver antennas was achieved by using coated paper with a polyvinyl alcohol barrier layer and a top functional hydrophilic layer. Silver nanoparticles of inkjet ink require a sintering process to obtain a conductive printed trace. The microstructure and thickness of antennas printed by thermal transfer and inkjet technique were compared. Thermal transfer printing created a more homogeneous antenna with greater sharpness of drawing compared to inkjet printing.