title: Additive manufacturing of hygromorphic structures using regenerated cellulose/PLA biocomposites

authors: Gauss, Christian

subjects: 4D printing

abstract: Three-dimensional printing technologies are at the forefront of the current industrial revolution, enabling the production of complex shapes using a wide range of materials without relying on large production facilities. Evolving from these, 4D printing is a new concept in which printed objects respond to environmental stimuli and change shape or other characteristics with time in a controlled and predicted manner. Bioderived and/or biodegradable thermoplastics reinforced with bioderived fibres have compelling attributes for 3D printing applications; they can be recycled, used in smart materials (4D printing) and if necessary, can biodegrade at the end of their life cycle. In this work, we demonstrate the potential use of biocomposites based on poly(lactic acid) (PLA) with a high content of regenerated cellulose fibres (lyocell) in hygromorphic structures, 3D printed using fused deposition modelling (FDM). The shape-change potential was assessed by 3D printing bi-material strips with passive and active layers composed of neat PLA and the composite, respectively and by measuring and modelling the change in curvature with the increase in water absorption. The main mechanism involved in this behaviour is related to the anisotropic swelling of the cellulose fibres that are preferentially aligned in the composite during printing. Using this mechanism and a bi-material layout, prototypes of different sizes with 2D to 3D transformation triggered by moisture were 3D printed.

text: Additive manufacturing of hygromorphic structures using regenerated cellulose/PLA biocomposites Three-dimensional printing technologies are at the forefront of the current industrial revolution, enabling the production of complex shapes using a wide range of materials without relying on large production facilities. Evolving from these, 4D printing is a new concept in which printed objects respond to environmental stimuli and change shape or other characteristics with time in a controlled and predicted manner. Bioderived and/or biodegradable thermoplastics reinforced with bioderived fibres have compelling attributes for 3D printing applications; they can be recycled, used in smart materials (4D printing) and if necessary, can biodegrade at the end of their life cycle. In this work, we demonstrate the potential use of biocomposites based on poly(lactic acid) (PLA) with a high content of regenerated cellulose fibres (lyocell) in hygromorphic structures, 3D printed using fused deposition modelling (FDM). The shape-change potential was assessed by 3D printing bi-material strips with passive and active layers composed of neat PLA and the composite, respectively and by measuring and modelling the change in curvature with the increase in water absorption. The main mechanism involved in this behaviour is related to the anisotropic swelling of the cellulose fibres that are preferentially aligned in the composite during printing. Using this mechanism and a bi-material layout, prototypes of different sizes with 2D to 3D transformation triggered by moisture were 3D printed.

year: 2023

title: Mechanisms & issues

authors: Morgan, Gwyn

abstract: Gwyn has been working in the policy field for over 20 years with Fonterra, Auckland Regional Council, DairyNZ and Federated Farmers. His experience through all of these roles has been working in the sustainable farming area. This has included policy development and implementation as well as extension tools that enable farmers to adapt to policy change in a way that is economically viable. TDR’s are one of these tools available and they can be useful but that is dependent on many variables.

text: Mechanisms & issues Gwyn has been working in the policy field for over 20 years with Fonterra, Auckland Regional Council, DairyNZ and Federated Farmers. His experience through all of these roles has been working in the sustainable farming area. This has included policy development and implementation as well as extension tools that enable farmers to adapt to policy change in a way that is economically viable. TDR’s are one of these tools available and they can be useful but that is dependent on many variables.

year: 2013

title: Voices of the land: Richard Nunns in conversation with Martin Lodge

authors: Nunns, Richard

abstract: Richard Nunns in conversation with Martin Lodge

text: Voices of the land: Richard Nunns in conversation with Martin Lodge Richard Nunns in conversation with Martin Lodge

year: 2008