scholarly journals The impact of molded pulp product process on the mechanical properties of molded Bleached Chemi-Thermo-Mechanical Pulp

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Claire Dislaire ◽  
Yves Grohens ◽  
Bastien Seantier ◽  
Marion Muzy

AbstractThis study was carried out using bleached softwood Chemi-Thermo-Mechanical Pulp to evaluate the influence of Molded Pulp Products’ manufacturing process parameters on the finished products’ mechanical and hygroscopic properties. A Taguchi table was done to make 8 tests with specific process parameters such as moulds temperature, pulping time, drying time, and pressing time. The results of these tests were used to obtain an optimized manufacturing process with improved mechanical properties and a lower water uptake after sorption analysis and water immersion. The optimized process parameters allowed us to improve the Young’ Modulus after 30h immersion of 58% and a water uptake reduction of 78% with the first 8 tests done.

2020 ◽  
Author(s):  
Claire Dislaire ◽  
Yves Grohens ◽  
Bastien Seantier ◽  
Marion Muzy

Abstract This study was carried out using bleached softwood Chemi-Thermo-Mechanical Pulp to evaluate the influence of Molded Pulp Products’ manufacturing process parameters on the finished products’ mechanical and hygroscopic properties. A Taguchi table was done to make 8 tests with specific process parameters such as moulds temperature, pulping time, drying time and pressing time. The results of these tests were used to obtain an optimized manufacturing process with improved mechanical properties and a lower water uptake after sorption analysis and water immersion. The optimized process parameters allowed us to improve the Young’ Modulus after 1h immersion of 58% and a water uptake reduction of 78% with the first 8 tests done.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Catarina S. P. Borges ◽  
Alireza Akhavan-Safar ◽  
Eduardo A. S. Marques ◽  
Ricardo J. C. Carbas ◽  
Christoph Ueffing ◽  
...  

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.


2011 ◽  
Vol 314-316 ◽  
pp. 1944-1947 ◽  
Author(s):  
Jozef Maščeník ◽  
Stefan Gaspar

Production of components, necessary for the construction of the machine resp. or device is a demanding manufacturing process. One of the possibilities of increasing efficiency and production quality is the introduction of unconventional technologies to the production process. Knowing the dependence of the impact of non-conventional technologies on the mechanical properties of products and their subsequent verification is an important aspect when designing and manufacturing them. The article deals with the impact of used unconventional technology, that means laser, plasma and water jet on the roughness of a cutting edge and microhardness of material S 355 J2 G3.


2015 ◽  
Vol 21 (5) ◽  
pp. 604-617 ◽  
Author(s):  
Antonio Lanzotti ◽  
Marzio Grasso ◽  
Gabriele Staiano ◽  
Massimo Martorelli

Purpose – This study aims to quantify the ultimate tensile strength and the nominal strain at break (ɛf) of printed parts made from polylactic acid (PLA) with a Replicating Rapid prototyper (Rep-Rap) 3D printer, by varying three important process parameters: layer thickness, infill orientation and the number of shell perimeters. Little information is currently available about mechanical properties of parts printed using open-source, low-cost 3D printers. Design/methodology/approach – A computer-aided design model of a tensile test specimen was created, conforming to the ASTM:D638. Experiments were designed, based on a central composite design. A set of 60 specimens, obtained from combinations of selected parameters, was printed on a Rep-Rap Prusa I3 in PLA. Testing was performed using a JJ Instruments – T5002-type tensile testing machine and the load was measured using a load cell of 1,100 N. Findings – This study investigated the main impact of each process parameter on mechanical properties and the effects of interactions. The use of a response surface methodology allowed the proposition of an empirical model which connects process parameters and mechanical properties. Even though results showed a high variability, additional ideas on how to understand the impact of process parameters are suggested in this paper. Originality/value – On the basis of experimental results, it is possible to obtain practical suggestions to set common process parameters in relation to mechanical properties. Experiments discussed in the present paper provide a variety of data and insight regarding the relationship among the main process parameters and the stiffness and strength of fused deposition modeling-printed parts made from PLA. In particular, this paper underlines the shortage in existing literature concerning the impact of process parameters on the elastic modulus and the strain to failure for the PLA. The experimental data produced show a good degree of compliance with analytical formulations and other data found in literature.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 919 ◽  
Author(s):  
Črtomir Donik ◽  
Jakob Kraner ◽  
Irena Paulin ◽  
Matjaž Godec

We have investigated the impact of the process parameters for the selective laser melting (SLM) of the stainless steel AISI 316L on its microstructure and mechanical properties. Properly selected SLM process parameters produce tailored material properties, by varying the laser’s power, scanning speed and beam diameter. We produced and systematically studied a matrix of samples with different porosities, microstructures, textures and mechanical properties. We identified a combination of process parameters that resulted in materials with tensile strengths up to 711 MPa, yield strengths up to 604 MPa and an elongation up to 31%, while the highest achieved hardness was 227 HV10. The correlation between the average single-cell diameter in the hierarchical structure and the laser’s input energy is systematically studied, discussed and explained. The same energy density with different SLM process parameters result in different material properties. The higher energy density of the SLM produces larger cellular structures and crystal grains. A different energy density produces different textures with only one predominant texture component, which was revealed by electron-backscatter diffraction. Furthermore, three possible explanations for the origin of the dislocations are proposed.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
JuYoun Kwon ◽  
Namhun Kim

AbstractAdditive manufacturing (AM) which can be a suitable technology to personalize wearables is ideal for adjusting the range of part performance such as mechanical properties if high performance is not required. However, the AM process parameter can impact overall durability and reliability of the part. In this instance, user behavior can play an essential role in performance of wearables through the settings of AM process parameter. This review discusses parameters of AM processes influenced by user behavior with respect to performance required to fabricate AM wearables. Many studies on AM are performed regardless of the process parameters or are limited to certain parameters. Therefore, it is necessary to examine how the main parameters considered in the AM process affect performance of wearables. The overall aims of this review are to achieve a greater understanding of each AM process parameter affecting performance of AM wearables and to provide requisites for the desired performance including the practice of sustainable user behavior in AM fabrication. It is discussed that AM wearables with various performance are fabricated when the user sets the parameters. In particular, we emphasize that it is necessary to develop a qualified procedure and to build a database of each AM machine about part performance to minimize the effect of user behavior.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2977
Author(s):  
Aleksandra Kuźmińska ◽  
Dominika Kwarta ◽  
Tomasz Ciach ◽  
Beata A. Butruk-Raszeja

This work presents a method of obtaining cylindrical polymer structures with a given diameter (approx. 5 mm) using the phase inversion technique. As part of the work, the influence of process parameters (polymer hardness, polymer solution concentration, the composition of the non-solvent solution, process time) on the scaffolds’ morphology was investigated. Additionally, the influence of the addition of porogen on the scaffold’s mechanical properties was analyzed. It has been shown that the use of a 20% polymer solution of medium hardness (ChronoFlex C45D) and carrying out the process for 24 h in 0:100 water/ethanol leads to the achievement of repeatable structures with adequate flexibility. Among the three types of porogens tested (NaCl, hexane, polyvinyl alcohol), the most favorable results were obtained for 10% polyvinyl alcohol (PVA). The addition of PVA increases the range of pore diameters and the value of the mean pore diameter (9.6 ± 3.2 vs. 15.2 ± 6.4) while reducing the elasticity of the structure (Young modulus = 3.6 ± 1.5 MPa vs. 9.7 ± 4.3 MPa).


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Andrzej Ambroziak ◽  
Paweł Kłosowski

The impact of water-induced degradation on the mechanical properties of the chosen two PTFE-coated, glass threads woven fabrics is investigated in this paper. The paper begins with a survey of literature concerning the investigation and determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of flat and curved grips to establish the proper values of the ultimate tensile strength and the longitudinal stiffness of groups of specimens treated with different moisture conditions. Despite the water resistance of the main materials used for fabrics manufacturing, the change of the mechanical properties caused by the influence of water immersion has been noticed. The reduction in the tensile strength resulting under waterlogged is observed in the range from 5% to 16% depending on the type of investigated coated woven fabric and direction of weft or warp.


Author(s):  
Aznizam Abu Bakar ◽  
Nurul Nazihah Mohmed Rosli

Perkembangan nanokomposit berasaskan polimer dan pengisi bersaiz nano telah menjadi pendekatan yang menarik untuk mencapai sifat komposit yang baik. Kesan nano–termendak kalsium karbonat (NPCC) terhadap sifat mekanikal matrik berlainan kemuluran telah dikaji. Poli(vinil klorida) tanpa pemplastik (PVC–U) dan PVC–U/akrilik telah digunakan sebagai matrik pada kajian ini. Untuk menghasilkan komposit, resin PVC, additif, akrilik dan NPCC pada mulanya diadun-kering menggunakan pencampur berkelajuan–tinggi berskala makmal sebelum diadun menjadi kepingan dengan menggunakan pengadun dua pengguling. Spesimen–spesimen ujian kemudiannya ditekan panas, selepas itu sifat mekanikal komposit dan morfologi permukaan patah komposit ditentukan. Modulus lenturan dan modulus Young meningkat dengan penambahan NPCC, tetapi telah menurunkan kekuatan regangan. NPCC telah menunjukkan kesan pengukuhan yang baik pada matrik PVC–U/ akrilik dan kesan kekakuan yang baik pada matrik PVC–U. Kekuatan lenturan kedua–dua komposit tidak dipengaruhi dengan penambahan NPCC. Kekuatan hentaman kedua–dua komposit telah mencapai nilai maksimum apabila 15 phr NPCC ditambah. Kata kunci: Poli(vinil klorida), nano–termendak kalsium karbonat, sifat–sifat mekanikal, akrilik Developing nanocomposites based upon polymers and nano–sized fillers has been an attractive approach to achieving good properties. Effects of nano–precipitated calcium carbonate (NPCC) on the mechanical properties of different ductile matrices were investigated. Unplasticised Poly(vinyl chloride) (PVC–U) and PVC–U/acrylic were used as the matrix in this study. To produce the composites, PVC resins, additives, acrylic and NPCC were first dry–blended using a laboratory high–speed mixer before being milled into sheets on a two–roll mill. Test specimens were then hot pressed, after that the mechanical properties and morphology of fracture surface of composites were determined. The flexural modulus and Young modulus of both the composites were enhanced after the addition of NPCC, but the tensile strength was decreased. The NPCC showed good toughening effect and stiffening effect on PVC–U/acrylic and PVC–U matrix, respectively. The flexural strength of both the composites was not significantly affected by the addition of NPCC. The impact strength of both the composites reached the maximum value when 15 phr NPCC was incorporated. Key words: Poly(vinyl chloride), nano–precipitated calcium carbonate, mechanical properties, acrylic


2014 ◽  
Vol 606 ◽  
pp. 125-128 ◽  
Author(s):  
David Joguet ◽  
Yoann Danlos ◽  
Rodolphe Bolot ◽  
Ghislain Montavon ◽  
Christian Coddet

Selective Laser Melting (SLM) has become a widely used process for manufacturing metal part prototypes. This process, also known as additive manufacturing or rapid prototyping, allows the production of complex pieces using a layer by layer technology. Each layer is build by a laser irradiation providing a local melting (and resolidification) of a thin powder bed presenting a thickness of a few tens of microns. In the present work, two different materials used in biomedical applications were processed by SLM (namely pure titanium and Co28Cr6Mo alloy). The process parameters were set in order to adjust the materials porosity levels. The influence of the porosity level on the material effective mechanical properties was then quantified by experimental measurements using a two point bending test and by applying numerical modeling. The numerical model is based on the use of cross-sectional SEM micrographs of the material. These micrographs were used as meshes (each pixel is a FEM element) and the ANSYS software was then used to perform virtual loadings on the material with the objective to provide its effective mechanical properties. A comparison of the predicted and measured Young modulus was then performed. The provided results confirm that the process parameters may be adjusted in order to control the porosity level of the material and subsequently to adjust its effective mechanical resistance.


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