Investigation of the Strength Characteristics of Samples Made of Nylon by FFF Technology

Additive manufacturing of polymer products over the past decade has become widespread in various areas of industry. Using the FFF method, one of the most technologically simple methods of additive manufacturing, it is possible to produce parts from a large number of different materials, including wear-resistant nylon. This article reflects the process of manufacturing samples from nylon using FFF technology with various internal topologies, as well as tensile tests. The analysis of the obtained results is performed and the relationship between the structure of the sample and the limit of its strength is established. The FFF method is promising for developing methods for producing composite materials. The results of this article can be useful in choosing the necessary manufacturing parameters

Effects of the Infill Density on the Mechanical Properties of Nylon Specimens Made by Filament Fused Fabrication

Additive manufacturing of polymer products over the past decade has become widespread in various areas of industry. Using the fused filament fabrication (FFF) method, one of the most technologically simple methods of additive manufacturing, it is possible to produce parts from a large number of different materials, including wear-resistant nylon. The novelty of the work is properties investigation of ±45° filling configuration with different filling degree for nylon, as well as calculating the effect of infill on the strength characteristics, excluding the shell. This article reflects the process of manufacturing samples from nylon using FFF technology with various internal topologies, as well as tensile tests. The analysis of the obtained results is performed and the relationship between the structure of the sample and the limit of its strength is established. To calculate real filling degree and the effect of internal filling on the strength characteristics of the specimen, it is proposed to use a method based on the geometric and mass parameters. The FFF method is promising for developing methods for producing a composite material. The results of this article can be useful in choosing the necessary manufacturing parameters

The effect of build orientation on both flexural quasi-static and fatigue behaviours of filament deposited PA6 polymer

The present paper aims to study the effect of manufacturing build orientation on both flexural quasi-static and fatigue behaviours of semi-crystalline polyamide 6 obtained by Fused Filament Fabrication (FFF), by considering the porosity and surface roughness. The glass transition temperature, melting temperature, and crystallinity degree were measured complementary to understand better the process. Fatigue analysis is here fully described in visco-elastic domain of material. The results highlight that the XZ build orientation is better than the XY one and suggest that porosity plays an important role. The obtained results are also compared with conventional techniques given by the literature review

Flexural quasi-static and fatigue behaviours of fused filament deposited PA6 and PA12 polymers

The present paper aims to compare study the effect of porosity and degree of crystallinity on both quasi-static and fatigue behaviours of PA6 and PA12 specimens obtained by the fused filament fabrication (FFF). The glass transition and melting temperatures were measured complementary to understand better the process. Fatigue analysis is here described in visco-elastic domain of material. The results highlight that the mechanical and fatigue properties of PA 12 are better than those of PA6, in spite of almost amorphous state of PA12. Besides, porosity did not reveal the expected influence on these properties. The obtained results are also compared with conventional techniques given by the literature review

The Setup Design for Selective Laser Sintering of High-Temperature Polymer Materials with the Alignment Control System of Layer Deposition

This paper presents the design of an additive setup for the selective laser sintering (SLS) of high-temperature polymeric materials, which is distinguished by an original control system for aligning the device for depositing layers of polyether ether ketone (PEEK) powder. The kinematic and laser-optical schemes are given. The main cooling circuits are described. The proposed technical and design solutions enable conducting the SLS process in different types of high-temperature polymer powders. The principles of the device adjustment for depositing powder layers based on an integral thermal analysis are disclosed. The PEEK sinterability was shown on the designed installation. The physic-mechanical properties of the tested 3D parts were evaluated in comparison with the known data and showed an acceptable quality

In-nozzle impregnation of continuous textile flax fiber/polyamide 6 composite during FFF process

A simple and customized method is adapted to print the continuous bleached textile flax yarn/polyamide 6 composites by Fused Filament Fabrication. It is allowed to print successfully composite in one shot thanks to in-situ fiber impregnation inside the print head. Three filling patterns (0°, 90° and ± 45°) strategies relative to the tensile loading were adopted to investigate Young Modulus and tensile strength. The best mechanical properties were obtained for the unidirectional composite, where void content and inter-layer delamination decreased with increasing volume fiber fraction. However, the transversal tensile properties remained at their weakest point. Competitive specific elastic properties compared to those of continuous glass fiber/PA printed composites, given by the literature review, were obtained with the potential to compete the latter in infrastructure, automotive industry, and consumer applications. This is possible if only composite void content is decreased, and its yarn/matrix adhesion is improved