Citation: Nicolau, A.; Pop, M.A.;
Cos
,
ereanu, C. 3D Printing
Application in Wood Furniture
Components Assembling. Materials
2022, 15, 2907. https://doi.org/
10.3390/ma15082907
Academic Editors: Ludwig Cardon
and Clemens Holzer
Received: 19 March 2022
Accepted: 13 April 2022
Published: 15 April 2022
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Article
3D Printing Application in Wood Furniture
Components Assembling
Antoniu Nicolau
1
, Mihai Alin Pop
2
and Camelia Cos
,
ereanu
1,
*
1
Faculty of Furniture Design and Wood Engineering, Transilvania University of Brasov, B-dul Eroilor, nr. 29,
500036 Brasov, Romania; antoniu.nicolau@unitbv.ro
2
Faculty of Materials Science and Engineering, Transilvania University of Brasov, B-dul Eroilor, nr. 29,
500036 Brasov, Romania; mihai.pop@unitbv.ro
* Correspondence: cboieriu@unitbv.ro
Abstract:
Additive manufacturing (AM) is used in many fields and is a method used to replace
wood components or wood-jointed furniture components in the furniture industry. Replacing wood
joints by 3D printed connectors would be an advantage, considering the fact that during the process
of assembling furniture, the execution technology of the joints is difficult, time-consuming, and
labor-intensive. Advanced technology of AM applied in furniture manufacturing helps the designers
to create new concepts of product design, with no limits of shape, number of joints, color, or size.
The diversity of 3D printers and AM technologies provides the selection of materials in relation with
the applicability of the 3D printed object. In this respect, the objective of the present research is to
design a 3D printed connector to be used for jointing three chair components, namely the leg and
two stretchers made from larch (Larix decidua Mill.) wood, and to use reinforced polylactic acid (PLA)
fiberglass (20 wt. %) filament for 3D printing this connector using AM with fused filament fabrication
(FFF) technology. The design of the connector, the possibility of using this type of material, and the
deposition method of filament were investigated in this research. For this purpose, several evaluation
methods were applied: microscopic investigation with 50
×
, 100
×
, and 200
×
magnifications, both
of the filament and of the 3D printed connector; mechanical testing of corner joint formed with
the help of connector between chair leg and the two stretchers; and a microscopic investigation
of the connectors’ defects that occurred after applying the compression and tensile loads on the
diagonal direction of the L-type joint. The microscopic investigation of the composite filament
revealed the agglomerations of glass fibers into the core matrix and areas where the distribution of
the reinforcements was poor. The heterogeneous structure of the filament and the defects highlighted
in the 3D printed connectors by the microscopic investigation contributed to the mechanical behavior
of L-type connecting joints. The bending moments resulting from compression and tensile tests
of the 3D printed connectors were compared to the results recorded after testing, under the same
conditions, the normal mortise–tenon joint used to assemble the abovementioned chair components.
The larch wood strength influenced the mechanical results and the conclusions of the microscopic
investigations, as well as the analysis of the broken connectors after testing recommended the change
of connector design and filament deposition direction.
Keywords:
additive manufacturing; wood furniture; 3D printed connector; mortise–tenon joint;
polylactic acid (PLA)
1. Introduction
Additive manufacturing (AM) is a constantly expanding field [
1
] which was first used
in the furniture industry in such applications as 3D printing of furniture pieces, compo-
nents, and joints. The most used 3D printing technologies in furniture manufacturing are
fused filament fabrication (FFF), fused deposition modeling (FDM) [
2
,
3
], and selective laser
Materials 2022, 15, 2907. https://doi.org/10.3390/ma15082907 https://www.mdpi.com/journal/materials
