Production and 3D printing processing of bio-based thermoplastic filament

Abstract

-In this work, an extrusion-based 3D printing technique was employed for processing of biobased blends of Poly(Lactic Acid) (PLA) with low-cost kraft lignin. In Fused Filament Fabrication (FFF) 3D printing process, objects are built in a layer-by-layer fashion by melting, extruding and selectively depositing thermoplastic fibers on a platform. These fibers are used as building blocks for more complex structures with defined microarchitecture, in an automated, cost-effective process, with minimum material waste. A sustainable material consisting of lignin biopolymer blended with poly(lactic acid) was examined for its physical properties and for its melt processability during the FFF process. Samples with different PLA/lignin weight ratios were prepared and their mechanical (tensile testing), thermal (Differential Scanning Calorimetry analysis) and morphological (optical and scanning electron microscopy, SEM) properties were studied. The composition with optimum properties was selected for the production of 3D-printing filament. Three process parameters, which contribute to shear rate and stress imposed on the melt, were examined: extrusion temperature, printing speed and fiber's width varied and their effect on extrudates' morphology was evaluated. The mechanical properties of 3D printed specimens were assessed with tensile testing and SEM fractography.

Process‐Driven Microstructure Control in Melt‐Extrusion‐Based 3D Printing for Tailorable Mechanical Properties in a Polycaprolactone Filament

“…Additionally, the crystallization process is affected by the short step stress and substantial undercooling, which are related to the processing parameters such as screw rotational speed and melting temperature, respectively. The resulting difference in the lamellar and amorphous fractions of the chains within the extruded filaments influences the strength and elastic modulus of the filaments . Hence, the crystal microstructure is essential to understanding their effects on mechanical properties.…”

Towards green carbon fibre manufacturing from waste cotton: a microstructural and physical property investigation

“…This fact makes waste cotton fibres a favourable candidate as a precursor for manufacturing carbon fibres (CFs) [11]. Carbon fibre based industries and researchers express interest in search of the suitable, low-cost, and effective source of precursors to fulfil the industrial demands of CFs [12][13][14][15]; in the last decade, issues concerning environmental pollution and the increasing awareness of limited resources have motivated the scientific community to study and optimize renewable alternatives to traditional petroleumderived plastics, like biobased composite materials that are sourced from carbon-neutral feedstocks [14]. Towards this, waste cotton fibres are used as a precursor for qualitative and quantitative production of CFs through pyrolysis, an easy and industrially commonly reported method [16][17][18][19] for conversion of waste cotton fibres to CFs.…”

3D Printed Lab-on-a-Chip Diagnostic Systems - Developing a Safe-by-Design Manufacturing Approach

“…Deposition requires that the process takes place at a temperature close to the filament material's melting point. The required geometry is formed layer-by-layer through programmed extrusion of the semi-liquid material and movement of the nozzle and/or the print bed platform, which is usually also heated [2]. The most commonly used Filament materials for FFF processes are Polylactide (PLA) and Acrylonitrile butadiene styrene (ABS).…”