As additive manufacturing technologies advance,new opportunities are opening up for their application in the furniture industry.Wood remains one of the leading raw materials in the furniture industry;therefore,possibl...As additive manufacturing technologies advance,new opportunities are opening up for their application in the furniture industry.Wood remains one of the leading raw materials in the furniture industry;therefore,possible options for combining it with 3D printing have been researched.The bonding of 3D-printed polymer parts with wood or 3D printing with wood-plastic composites is already known,but in our research we attempted to directly 3D print polylactic acid(PLA)on wood surfaces.The effect of printing parameters,as well as the surface preparation of wood on the shear strength of the bond between wood and on-printed material was tested.Microscopic images of cross-sections of samples were analyzed.The results show that with a lower initial layer thickness(0.1 mm),a higher printing temperature(220℃),and with the use of polyvinyl acetate(PVAc)primer on the wood surface before 3D printing,a higher bond strength(5.4 MPa)was achieved,but the values for the bond strength remain low compared to the conventional bonding of wood to wood with PVAc adhesive(around 10 MPa).Microscopy studies revealed barely visible penetration of PLA into the lumens of the wood cells.However,the PVAc adhesive used as primer penetrated more into the cell lumens and served as interface layer between deposited melted PLA and the wood,thus creating stronger joints.展开更多
Various crosslinking agents can be added to the formulations of natural-based adhesives for wood bonding in order to achieve better durability and higher strength of the formed joints.In the present study,the effect o...Various crosslinking agents can be added to the formulations of natural-based adhesives for wood bonding in order to achieve better durability and higher strength of the formed joints.In the present study,the effect of hexamethylenediamine(HMDA)addition on the performance of liquefied wood(LW)adhesive for wood bonding is investigated.Differential scanning calorimetry showed the improved thermal stability and crosslinking of the LW adhesive with HMDA.The intensified presence of amide linkages(C–N bonds)was found in LW+HMDA with attenuated total reflection Fourier transform infrared spectroscopy.Analysis of the bonded joints using an automated bonding evaluation system showed that a higher press temperature resulted in stronger bonds for both types of adhesives.Moreover,the addition of HMDA to LW adhesive improved the bond strength of the joints and accelerated the crosslinking of the adhesive.However,with a tensile shear strength of(6.76±2.16)N×mm^(−2)(for LW)and(6.89±2.10)N×mm^(−2)(for LW+HMDA),both adhesives were found to be unsuitable for interior non-structural use.In addition,the acidity of LW resulted in relatively high wood failure(70%)in the adhesive joints tested.Improved crosslinking of LW with HMDA was reflected in improved resistance of LW+HMDA adhesive joints to water degradation.In conclusion,HMDA is a promising additive for improving the adhesive performance of LW adhesives.展开更多
文摘As additive manufacturing technologies advance,new opportunities are opening up for their application in the furniture industry.Wood remains one of the leading raw materials in the furniture industry;therefore,possible options for combining it with 3D printing have been researched.The bonding of 3D-printed polymer parts with wood or 3D printing with wood-plastic composites is already known,but in our research we attempted to directly 3D print polylactic acid(PLA)on wood surfaces.The effect of printing parameters,as well as the surface preparation of wood on the shear strength of the bond between wood and on-printed material was tested.Microscopic images of cross-sections of samples were analyzed.The results show that with a lower initial layer thickness(0.1 mm),a higher printing temperature(220℃),and with the use of polyvinyl acetate(PVAc)primer on the wood surface before 3D printing,a higher bond strength(5.4 MPa)was achieved,but the values for the bond strength remain low compared to the conventional bonding of wood to wood with PVAc adhesive(around 10 MPa).Microscopy studies revealed barely visible penetration of PLA into the lumens of the wood cells.However,the PVAc adhesive used as primer penetrated more into the cell lumens and served as interface layer between deposited melted PLA and the wood,thus creating stronger joints.
文摘Various crosslinking agents can be added to the formulations of natural-based adhesives for wood bonding in order to achieve better durability and higher strength of the formed joints.In the present study,the effect of hexamethylenediamine(HMDA)addition on the performance of liquefied wood(LW)adhesive for wood bonding is investigated.Differential scanning calorimetry showed the improved thermal stability and crosslinking of the LW adhesive with HMDA.The intensified presence of amide linkages(C–N bonds)was found in LW+HMDA with attenuated total reflection Fourier transform infrared spectroscopy.Analysis of the bonded joints using an automated bonding evaluation system showed that a higher press temperature resulted in stronger bonds for both types of adhesives.Moreover,the addition of HMDA to LW adhesive improved the bond strength of the joints and accelerated the crosslinking of the adhesive.However,with a tensile shear strength of(6.76±2.16)N×mm^(−2)(for LW)and(6.89±2.10)N×mm^(−2)(for LW+HMDA),both adhesives were found to be unsuitable for interior non-structural use.In addition,the acidity of LW resulted in relatively high wood failure(70%)in the adhesive joints tested.Improved crosslinking of LW with HMDA was reflected in improved resistance of LW+HMDA adhesive joints to water degradation.In conclusion,HMDA is a promising additive for improving the adhesive performance of LW adhesives.
