scholarly journals Effect of the Process Parameters on the Adhesive Strength of Dissimilar Polymers Obtained by Multicomponent Injection Molding

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1039 ◽  
Author(s):  
Luciano Pisanu ◽  
Leonardo Costa Santiago ◽  
Josiane Dantas Viana Barbosa ◽  
Valter Estevão Beal ◽  
Marcio Luis Ferreira Nascimento

The growing demand in the consumer market for products with sustainable technologies has motivated new applications using overmolded natural fiber composites. Therefore, studies have been conducted mainly to understand the adhesive properties of overmolded parts. In the present study, a polypropylene (PP) composite with 30% coconut fibers without additives was developed with the aid of a corotating twin screw extruder. Subsequently, a multicomponent injection mold was developed based on the geometry of the ISO 527 type I specimen, in which samples overmolded with PP and PP–coconut-fiber composite, with the overlap in the central area, were obtained to evaluate the adhesive strength of dissimilar materials. The objective of this study was to evaluate the bond between PP and PP–coconut-fiber composite under different processing conditions using an adhesive strength testing device to perform a pure shear analysis. The experimental conditions followed a statistical design considering four factors in two levels and a significance level of 5%. The results indicated that adhesive strength increased significantly as the overlap area increased. It was observed that temperature and injection flow rate were the factors that most contributed to strengthening the bonds of dissimilar materials.

Author(s):  
Faris M. AL-Oqla

The available potential plant waste could be worthy material to strengthen polymers to make sustainable products and structural components. Therefore, modeling the natural fiber polymeric-based composites is currently required to reveal the mechanical performance of such polymeric green composites for various green products. This work numerically investigates the effect of various fiber types, fiber loading, and reinforcement conditions with different polymer matrices towards predicting the mechanical performance of such natural fiber composites. Cantilever beam and compression schemes were considered as two different mechanical loading conditions for structural applications of such composite materials. Finite element analysis was conducted to modeling the natural fiber composite materials. The interaction between the fibers and the matrices was considered as an interfacial friction force and was determined from experimental work by the pull out technique for each polymer and fiber type. Both polypropylene and polyethylene were considered as composite matrices. Olive and lemon leaf fibers were considered as reinforcements. Results have revealed that the deflection resistance of the natural fiber composites in cantilever beam was enhanced for several reinforcement conditions. The fiber reinforcement was capable of enhancing the mechanical performance of the polymers and was the best in case of 20 wt.% polypropylene/lemon composites due to better stress transfer within the composite. However, the 40 wt.% case was the worst in enhancing the mechanical performance in both cantilever beam and compression cases. The 30 wt.% of polyethylene/olive fiber was the best in reducing the deflection of the cantilever beam case. The prediction of mechanical performance of natural fiber composites via proper numerical analysis would enhance the process of selecting the appropriate polymer and fiber types. It can contribute finding the proper reinforcement conditions to enhance the mechanical performance of the natural fiber composites to expand their reliable implementations in more industrial applications.


2011 ◽  
Vol 471-472 ◽  
pp. 291-296 ◽  
Author(s):  
Piyush P. Gohil ◽  
A.A. Shaikh

Composites are becoming essential part of today’s material because they offer advantages such as low weight, corrosion resistance, high fatigue strength; faster assembly etc. composites are generating curiosity and interest all over the worlds. The attempts can be found in literature for composite materials high strength fiber and also natural fiber like jute, flax and sisal natural fibers provides data but there is need of experimental data availability for unidirectional natural fiber composite with seldom natural fiber like cotton, palm leaf etc., it can provide a feasible range of alternative materials to suitable conventional material. It was decided to carry out the systematic experimental study for the effect of volume fraction of reinforcement on longitudinal strength as well as Modulus of Elasticity (MOE) using developed mould-punch set up and testing aids. The testing is carried out as per ASTM D3039/3039M-08. The comparative assessment of obtained experimental results with literature is also carried out, which forms an important constituent of present work. It is also observed through SEM images and theoretical investigations that interface/interphase plays and important role in natural fiber composite.


2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Sri Hastuti ◽  
Catur Pramono ◽  
Yafi Akhmad

The Eichornia crassipes fiber have potentially as a composite reinforcing material. The advantage of composites with natural fibers like to light weight, corrosion resistance, water resistance, attractive performance, and without machining process. The purpose of using natural fiber as an alternative material to replace glass fiber composite material with Eichornia crassipes fibers are friendly and cheap. The research material used Eichornia crassipes fiber, NaOH, Etanol, and H2O. Processing of Eichornia crassipes fiber is washing with water, natural drying ± 10 days in eviromental, fiber taking with steel brush. Dry fibre were subjected to 10%, 20%, 30% NaOH and ethanol solution with variations of immersion time of 2, 4, 6 hours, neutralization with H20, and drying at room temperature. The Single fiber tensile test specimens were made with variations of treatment type in NaOH and Ethanol solution (10%, 20%, 30%), immersion time of 2, 4, and 6 hours. Single fiber test specimens refer to standard ASTM D 3379. Optimum tensile strength test results on NaOH treatment 20% variation of immersion time 4 hours: 28.402 N / mm2 and on ethanol treatment 20% variation of immersion time 2 hours: 48.197 N / mm2.


2021 ◽  
Vol 18 (1) ◽  
pp. 1-17
Author(s):  
Seyed Ehsan Samaei ◽  
◽  
Hasan Asilian Mahabadi ◽  
Seyyed Mohammad Mousavi ◽  
Ali Khavanin ◽  
...  

2020 ◽  
Author(s):  
Jeff Miller

Contrary to the warning of Miller (1988), Rousselet and Wilcox (2020) argued that it is better to summarize each participant’s single-trial reaction times (RTs) in a given condition with the median than with the mean when comparing the central tendencies of RT distributions across experimental conditions. They acknowledged that median RTs can produce inflated Type I error rates when conditions differ in the number of trials tested, consistent with Miller’s warning, but they showed that the bias responsible for this error rate inflation could be eliminated with a bootstrap bias correction technique. The present simulations extend their analysis by examining the power of bias-corrected medians to detect true experimental effects and by comparing this power with the power of analyses using means and regular medians. Unfortunately, although bias-corrected medians solve the problem of inflated Type I error rates, their power is lower than that of means or regular medians in many realistic situations. In addition, even when conditions do not differ in the number of trials tested, the power of tests (e.g., t-tests) is generally lower using medians rather than means as the summary measures. Thus, the present simulations demonstrate that summary means will often provide the most powerful test for differences between conditions, and they show what aspects of the RT distributions determine the size of the power advantage for means.


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