scholarly journals Calcium Carbonate Particles Filled Homopolymer Polypropylene at Different Loading Levels: Mechanical Properties Characterization and Materials Failure Analysis

2021 ◽  
Vol 5 (11) ◽  
pp. 302
Author(s):  
Yucheng Peng ◽  
Munkaila Musah ◽  
Brian Via ◽  
Xueqi Wang

Calcium carbonate (CaCO3) particles have been widely used in filling thermoplastics for different applications in automotive, packaging, and construction. No agreement has been reached in the research community regarding the function of CaCO3 for enhancing toughness of homopolymer polypropylene (HPP). This study was to understand the effect of different loading levels of CaCO3 on HPP toughness, including notched and unnotched impact strength. A batch mixer was used to thermally compound CaCO3 particles with HPP at loading levels of 10, 20, 30, 40, and 50 wt.%, followed by specimen preparation using an injection molding process. The mechanical properties of the composites, including tensile, flexural, and impact were characterized. The results indicated that tensile strengths decreased significantly with increasing loading levels of CaCO3 particles while the tensile and flexural modulus increased significantly with increasing particle loadings. The composite tensile properties changed linearly with increasing CaCO3 loadings. The notched Izod impact strength of the composites was sustained by adding CaCO3 particles up to 40 wt.% while the unnotched impact strength decreased significantly with the addition of CaCO3 particles. Different deformation mechanisms between notched (fracture propagation) and unnotched (fracture initiation and propagation) impact tests were proposed to be the reason.

2016 ◽  
Vol 53 (1) ◽  
pp. 25-44 ◽  
Author(s):  
Tarik Sadik ◽  
Caroline Pillon ◽  
Christian Carrot ◽  
José A Reglero Ruiz ◽  
Michel Vincent ◽  
...  

Relationships for the prediction of various linear mechanical properties of polymeric sandwich foams obtained in injection processes were studied in comparison with shear, tensile, and flexural tests. The samples were obtained by a core-back foam injection molding process that enables one to obtain sandwich materials with dense skins and a foamed core as revealed by the morphological analysis. Tensile, shear, and flexural moduli were investigated for the skin, the core, and the overall foamed structure. In addition, the Poisson’s ratio of the skin was also determined. The core properties were specifically analyzed by machining the samples and removing the skins. Tensile and shear properties of the core can be well described by the Moore equation. The tensile modulus can be calculated by a linear mixing rule with the moduli of the skin and of the core in relation to the thickness of the layers. Shear and flexural moduli are described by a linear mixing rule on the rigidity in agreement with the mechanics of beams. Tensile modulus, out-of-plane shear modulus, and flexural modulus can finally be predicted by the knowledge of only very few data, namely the tensile modulus and Poisson’s ratio of the matrix, the void fraction, and thickness of the core. The equations were proved to be physically meaningful and consistent with each other.


2012 ◽  
Vol 579 ◽  
pp. 134-141 ◽  
Author(s):  
Hoang Van Thanh ◽  
Chao Chang Arthur Chen ◽  
Chia Hsing Kuo

This paper is to investigate the optimization of mechanical properties for the maximum tensile strength, elongation, and impact strength of Polycarbonate and Polymethyl methacrylate (PC/PMMA) blends by injection molding process. The PC/PMMA plastics composites with different blending percentage are first blended have been injected as the tensile and impact specimens designed according to ASTM, type V by injection molding machine. Taguchi’s method is then used to find the optimal parameters for the maximum tensile strength, elongation and impact strength. The control factors selected in this study are melt temperature, packing pressure, mold temperature and cooling time. An ANOVA table has been used for determining the significance of injection molding parameters. Results of experiments show that the melt temperature is the most significant parameter for improvement of mechanical properties of PC-PMMA plastics composites. Blends with high PC concentrations result in low tensile strength and high impact strength. Illumination testing of the tatol internal reflection (TIR) of PC/PMMA blends has been proceeded and the TIR lens illumination intensity is compared with three compositions of the PC/PMMA blends. Illumination results show that the PC/PMMA 80/20 blend has the highest intensity of illumination. Results of this study can be applied on the optimization of injection molding parameters for polymer blends of LED lens.


2021 ◽  
Vol 11 (12) ◽  
pp. 5317
Author(s):  
Rafał Malinowski ◽  
Aneta Raszkowska-Kaczor ◽  
Krzysztof Moraczewski ◽  
Wojciech Głuszewski ◽  
Volodymyr Krasinskyi ◽  
...  

The need for the development of new biodegradable materials and modification of the properties the current ones possess has essentially increased in recent years. The aim of this study was the comparison of changes occurring in poly(ε-caprolactone) (PCL) due to its modification by high-energy electron beam derived from a linear electron accelerator, as well as the addition of natural fibers in the form of cut hemp fibers. Changes to the fibers structure in the obtained composites and the geometrical surface structure of sample fractures with the use of scanning electron microscopy were investigated. Moreover, the mechanical properties were examined, including tensile strength, elongation at break, flexural modulus and impact strength of the modified PCL. It was found that PCL, modified with hemp fibers and/or electron radiation, exhibited enhanced flexural modulus but the elongation at break and impact strength decreased. Depending on the electron radiation dose and the hemp fibers content, tensile strength decreased or increased. It was also found that hemp fibers caused greater changes to the mechanical properties of PCL than electron radiation. The prepared composites exhibited uniform distribution of the dispersed phase in the polymer matrix and adequate adhesion at the interface between the two components.


2012 ◽  
Vol 532-533 ◽  
pp. 234-237
Author(s):  
Wei Lai Chen ◽  
Ding Hong Yi ◽  
Jian Fu Zhang

The purpose of this paper is to study the effect of high temperature in injection molding process on mechanical properties of the warp-knitted and nonwoven composite fabrics (WNC)used in car interior. Tensile, tearing and peeling properties of WNC fabrics were tested after heat treatment under120, 140,160,180°C respectively. It was found that, after 140°C heat treatment, the breaking and tearing value of these WNC fabrics are lower than others. The results of this study show that this phenomenon is due to the material properties of fabrics. These high temperatures have no much effect on peeling properties of these WNC fabrics. It is concluded that in order to preserve the mechanical properties of these WNC fabrics, the temperature near 140°C should be avoided possibly during injection molding process.


2017 ◽  
Vol 69 (3) ◽  
pp. 414-419
Author(s):  
Mimi Azlina Abu Bakar ◽  
Siti Norazlini Abd Aziz ◽  
Muhammad Hussain Ismail

Purpose This paper aims to investigate the vital characteristic of an innovative ceramic injection molding (CIM) process for orthopedic application with controlled porosity and improved tribological and mechanical properties which were affected by complex tribological interactions, whether lubricated like hip implants and other artificial prostheses. The main objective is to maximize the usage of palm stearin as a single based binder as the function of flow properties during injection molding process. Design/methodology/approach The binder used in this present study consists of 100 per cent palm stearin manufactured by Kempas Oil Sdn Bhd and supplied by Vistec Technology Sdn Bhd. The feedstock was prepared by using a Z-blade mixer (Thermo Haake Rheomix OS) and Brabender mixer model R2400. The feedstock prepared was injection molded using a manually operated vertical benchtop machine with an average pressure of about 5-7 bars. The firing step included the temporary holds at intermediate temperatures to burn out organic binders. At this stage, the green molded specimen was de-bound using a single-step wick-debinding method. Findings The maximum content of ceramic material is applied to investigate the efficiencies of net formulation that can be achieved by ceramic materials. The longer the viscosity will change with shear rate, the higher the value of n obtained instead. From the slope of the curves obtained in Figure 3, the value of n for the feedstock was determined to be less than 1, which indicates a pseudoplastic behavior and suitability for the molding process. Moreover, high shear sensitivity is important in producing complex and intrinsic specimens which are leading products in the CIM industry. Originality/value The feedstock containing HAp powder and palm stearin binder was successfully prepared at very low temperature of 70°C, which promoting a required pseudo-plastic behavior during rheological test. The single binder palm stearin should be optimized in other research works carried out, as palm stearin is most preferred compared to other polymeric materials that provided high energy consumption when subjected to the sintering process. Besides the binder is widely available in Malaysia, low cost and harmless effect during debinding process.


Author(s):  
Ying Yu ◽  
Manabu Nomura ◽  
Hiroyuki Hamada

Recent years, thermoplastics incorporated with particulate fillers have been gained high interests. To improve the mechanical properties of the natural particle reinforced polymer plastics, hybrid structure has been applied on the composite combining natural particle with stronger synthetic fibers. However, the reinforcing mechanism of the hybrid composite is quite complicated. Experiments on it may become time consuming and cost prohibitive. Therefore, researchers are interested in studying variable models to predict the elastic properties of the composites. In this study, glass short fiber/wood particle/pp hybrid composites were prepared by injection molding process at a fixed reinforcement to matrix ratio of 51:49. 4 kinds of hybrid specimens with glass fiber/wood particle ratios of 41:10, 31:20, 21:30 and 11:40 were fabricated. The effect of hybridization content on the mechanical properties of the composites was evaluated based on tensile test. Theoretically, the elastic modulus of hybrid composites was predicted by using the rule of hybrid mixtures (RoHM) equation and classical lamination theory (CLT) and the accuracy of the two estimation models has been discussed. Results showed that it can be considered the hybridization of wood powder into glass/PP composite could contribute to a similar high elastic modulus with high green degree. On the other hand, the fiber orientation factor, fiber length distribution factor, powder dispersion factor were very important factors and need to be considered in the prediction model.


2012 ◽  
Vol 602-604 ◽  
pp. 627-630 ◽  
Author(s):  
Kyu Sik Kim ◽  
Kee Ahn Lee ◽  
Jong Ha Kim ◽  
Si Woo Park ◽  
Kyu Sang Cho

Inconel 713C alloy was tried to manufacture by using MIM(Metal Injection Molding) process. The high-temperature mechanical properties of MIMed Inconel 713C were also investigated. Processing defects such as pores and binders could be observed near the surface. Tensile tests were conducted from room temperature to 900°C. The result of tensile tests showed that this alloy had similar or somewhat higher strengths (YS: 734 MPa, UTS: 968 MPa, elongation: 7.16 % at room temperature) from RT to 700°C than those of conventional Inconel 713C alloys. Above 800°C, however, ultimate tensile strength decreased rapidly with increasing temperature (lower than casted Inconel 713C). Based on the observation of fractography, initial crack was found to have started near the surface defects and propagated rapidly. The superior mechanical properties of MIMed Inconel 713C could be obtained by optimizing the MIM process parameters.


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