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Investigation of nonisothermal fusion bonding for extrusion additive manufacturing of large structural parts
Author(s) -
Tagscherer Nevine,
Consul Patrick,
Kottenstedde Ingo Leonard,
Latiri Houyem,
Zaremba Swen,
Drechsler Klaus
Publication year - 2021
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.26216
Subject(s) - materials science , extrusion , differential scanning calorimetry , composite material , process window , crystallinity , fusion , thermogravimetric analysis , thermal , glass transition , crystallization , polymer , thermodynamics , chemical engineering , linguistics , philosophy , physics , lithography , optoelectronics , engineering
Fusion bonding is understood to be the decisive mechanism for the interlayer strength in extrusion additive manufacturing. This study links the characteristic temperatures of semicrystalline thermoplastics, namely, PA6 with 40% carbon fibers, to the bond formation in respect to real‐world processing conditions. Based on theoretical investigations, a process window is proposed for bonding to occur without polymer degradation. This range from the glass transition to the initial degradation temperature was determined through differential scanning calorimetry and thermogravimetric analysis. A second process window for optimal bonding is proposed from the extrapolated onset crystallization temperature, T eic , to the melt temperature, T m . The validation of these process windows was conducted by bending tests according to DIN EN 178. T m was confirmed as the upper limit, with the part's geometric integrity compromised at higher temperatures. T eic had to be refuted as lower limit as no discrete reduction in bond strength was determined in alignment with T eic . Authors suggest the lower limit is defined by the lowest substrate temperature to lead to interface temperatures above the onset of melt temperature. By utilizing thermal analyses, less time and resources are required to detemine a suitable process window for extrusion additive manufacturing.