scholarly journals Effect of Mold Temperature on the Impact Behavior and Morphology of Injection Molded Foams Based on Polypropylene Polyethylene–Octene Copolymer Blends

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 894 ◽  
Author(s):  
Santiago Muñoz-Pascual ◽  
Eduardo Lopez-Gonzalez ◽  
Cristina Saiz-Arroyo ◽  
Miguel Angel Rodriguez-Perez
Keyword(s):  
Impact Resistance ◽  
Mold Temperature ◽  
Impact Behavior ◽  
Critical Parameters ◽  
Crystalline Morphology ◽  
Copolymer Blends ◽  
Opposite Trend ◽  
Izod Impact ◽  
Injection Molded ◽  
The Impact

In this work, an isotactic polypropylene (PP) and a polyethylene–octene copolymer (POE) have been blended and injection-molded, obtaining solids and foamed samples with a relative density of 0.76. Different mold temperature and injection temperature were used. The Izod impact strength was measured. For solids, higher mold temperature increased the impact resistance, whereas in foams, the opposite trend was observed. In order to understand the reasons of this behavior, the morphology of the elastomeric phase, the crystalline morphology and the cellular structure have been studied. The presence of the elastomer near the skin in the case of high mold temperature can explain the improvement produced with a high mold temperature in solids. For foams, aspects as the elastomer coarsening in the core of the sample or the presence of a thicker solid skin are the critical parameters that justify the improved behavior of the materials produced with a lower mold temperature.

scholarly journals Impact Resistance of Epoxy Composites Reinforced with Amazon Guaruman Fiber: A Brief Report

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2264
Author(s):  
Raphael H. M. Reis ◽  
Fabio C. Garcia Filho ◽  
Larissa F. Nunes ◽  
Veronica S. Candido ◽  
Alisson C. R. Silva ◽  
...  
Keyword(s):  
Fiber Composite ◽  
Impact Resistance ◽  
Fiber Composites ◽  
Epoxy Composites ◽  
Impact Performance ◽  
Electron Microscopy Analysis ◽  
Ballistic Properties ◽  
Microscopy Analysis ◽  
Izod Impact ◽  
The Impact

Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.

IMPACT RESISTANCE PROPERTIES OF KEVLAR/GLASS FIBER HYBRID COMPOSITE LAMINATES

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Norazean Shaari ◽  
Aidah Jumahat ◽  
M. Khafiz M. Razif
Keyword(s):  
Glass Fiber ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Impact Damage ◽  
Impact Resistance ◽  
Impact Behavior ◽  
Slight Reduction ◽  
Depth Of Penetration ◽  
Damage Degree ◽  
The Impact

In this paper, the impact behavior of Kevlar/glass fiber hybrid composite laminates was investigated by performing the drop weight impact test (ASTM D7136). Composite laminates were fabricated using vacuum bagging process with an epoxy matrix reinforced with twill Kevlar woven fiber and plain glass woven fiber. Four different types of composite laminates with different ratios of Kevlar to glass fiber (0:100, 20:80, 50:50 and 100:0) were manufactured. The effect of Kevlar/glass fiber content on the impact damage behavior was studied at 43J nominal impact energy. Results indicated that hybridization of Kevlar fiber to glass fiber improved the load carrying capability, energy absorbed and damage degree of composite laminates with a slight reduction in deflection. These results were further supported through the damage pattern analysis, depth of penetration and X-ray evaluation tests. Based on literature work, studies that have been done to investigate the impact behaviour of woven Kevlar/glass fiber hybrid composite laminates are very limited. Therefore, this research concentrates on the effect of Kevlar on the impact resistance properties of woven glass fibre reinforced polymer composites.

Impact Strength of High Density Solid-State Microcellular Polycarbonate Foams

2000 ◽  
Vol 123 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Chris Barlow ◽  
Vipin Kumar ◽  
Brian Flinn ◽  
Rajendra K. Bordia ◽  
John Weller
Keyword(s):  
Solid State ◽  
Impact Strength ◽  
Cell Size ◽  
High Density ◽  
Gas Content ◽  
Impact Behavior ◽  
Strong Function ◽  
Impact Tests ◽  
Izod Impact ◽  
The Impact

The effect of density (relative densities 0.33 to 0.90) on the impact behavior of microcellular polycarbonate (PC) was investigated. Cell size and foaming gas content were also considered. Flexed-beam Izod impact tests were conducted and the impact strength of these foams appears to be a strong function of both density and cell size. The impact strength was observed to improve over the unprocessed polycarbonate’s impact strength for foams with relative densities of 60 percent and above. In terms of cell size, the impact strength increased with increasing cell size at a given density.

Experimental and Numerical Study of Basalt FRP Strip Strengthened RC Slabs under Impact Loads

2020 ◽  
Vol 20 (06) ◽  
pp. 2040001 ◽  
Author(s):  
Wensu Chen ◽  
Thong M. Pham ◽  
Mohamed Elchalakani ◽  
Huawei Li ◽  
Hong Hao ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Study ◽  
Impact Resistance ◽  
Basalt Fiber ◽  
Impact Behavior ◽  
Impact Loads ◽  
Quantitative Measurements ◽  
Rc Slabs ◽  
The Impact

Basalt fiber-reinforced polymer (BFRP) has been applied for strengthening concrete structures. However, studies on reinforced concrete (RC) slabs strengthened by BFRP strips under impact loads are limited in open literature. This study investigates the efficiency of using BFRP strips with various strengthening layouts and anchoring schemes on the impact resistance of RC slabs. A total of 11 two-way square slabs were prepared and tested, including one reference specimen without strengthening and ten slabs strengthened with BFRP strips and/or anchors. The RC slabs were impacted by a drop weight with increasing height until slab failure. The observed failure modes include punching shear failure, BFRP sheet debonding and reinforcement fracture. The failure modes and the effects of using various strengthening schemes on the impact resistant capacity of RC slabs were examined. The quantitative measurements, such as impact velocity, indentation depth and diameter, were compared and discussed. In addition, numerical studies were carried out by using LS-DYNA to simulate the impact tests of RC slabs with and without BFRP strengthening. With the calibrated numerical model, the impact behavior of slabs with various dimensions and strengthening layouts under different impact intensities can be predicted with good accuracy.

Can ultrasonic parameters affect the impact and water barrier properties of nano-clay filled glass fiber/polyester composites?

2020 ◽  
pp. 152808372096073
Author(s):  
AA Megahed ◽  
MA Agwa ◽  
M Megahed
Keyword(s):  
Glass Fiber ◽  
Impact Resistance ◽  
Impact Behavior ◽  
Water Barrier ◽  
Nano Clay ◽  
Polyester Matrix ◽  
Ultrasonic Parameters ◽  
Polyester Composites ◽  
Sonication Parameters ◽  
The Impact

Good dispersion of the nanoparticles into the polymer is considered a critical issue, as it can provide higher strength and stiffness while poor dispersion is seen to decrease those properties. In the present work, the effect of three ultrasonic parameters (amplitude, time and cycle of sonication) on sonication technique for dispersing 1 wt.% nano-clay in polyester matrix was investigated. To disperse the nano-clay into the polyester matrix, sonication frequencies of 40% and 80%, sonication times of 0.5, 1 and 2 hours and pulse of 0.5 and 1 cycle were used. The effect of these ultrasonication parameters on water barrier and impact behavior of unfilled and filled glass fiber (GF)/polyester with nano-clay under dry, distilled and seawater conditions was studied. Results showed that, water absorption of nano-filled composites dispersed with all sonication parameters is lower than that of unfilled glass fiber/polyester composites immersed in distilled and seawater. Nano-clay filled GF/polyester composites showed an improvement in impact resistance under dry, distilled and seawater conditions with all sonication parameters. Among the used sonication parameters; time of 2 hours, amplitude of 40% and 0.5 cycle was found as the best parameter which resulted in the maximum enhancement in impact resistance, due to the addition of nano-clay to GF/polyester, of 8.2%, 14% and 19.6% under dry, distilled water and seawater conditions, respectively. Nonlinear minimization approach was exploited using MAPLE commercial software in order to find the suitable fit to the models of Fick and Langmuir. Diffusion coefficients for different sonication times were computed.

Preparation of auxetic warp-knitted spacer fabric impregnated with shear thickening fluid for low-velocity impact resistance

2020 ◽  
pp. 152808372092701 ◽  
Author(s):  
Wanli Xu ◽  
Biao Yan ◽  
Dongmei Hu ◽  
Pibo Ma
Keyword(s):  
Shear Rate ◽  
Energy Absorption ◽  
Impact Resistance ◽  
Shear Thickening ◽  
Weight Fraction ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Shear Thickening Fluid ◽  
Spacer Fabric ◽  
The Impact

This paper reports the preparation of auxetic warp-knitted spacer fabric impregnated with shear thickening fluid and studied its impact behavior under low-velocity impact loading. The shear thickening fluids have been prepared by mechanically dispersing 12 nm silica particles with weight fraction of 10, 15, 20, and 25% in various carriers (PEG200, PEG400, and PEG600). Rheological results indicate that shear thickening fluid experiences shear thickening transition at a specific shear rate. The critical shear rate reduces, and initial viscosity and maximum viscosity increase with the increase of silica weight fraction. The higher molecular weight of polyethylene glycols can lead to lower critical shear rate. The impact process of composite under impact loading can be divided into three stages. The warp-knitted spacer fabric with different negative Poisson’s ratio has a significant effect on the impact behavior. The warp-knitted spacer fabric with better auxetic performance endows composite better impact resistance, the specific performance is the deformation depth, and energy absorption and peak load increase with the increase of auxetic effect of fabric. The silica weight fraction of shear thickening fluid can increase the energy absorption of composite due to the shear thickening transition of shear thickening fluid. Shear thickening fluid has a synergistic effect with the auxetic warp-knitted spacer fabric on impact resistance of composite. The various carriers have no obvious influence on the overall energy absorption and impact load of composites.

scholarly journals TO DEVELOP AND EVALUATE IMPACT BEHAVIOR OF JUTE FIBRE REINFORCED COMPOSITE

2014 ◽  
pp. 80-83
Author(s):  
A.K. SRIVATAVA ◽  
SANDEEP MISHRA ◽  
ROHIT KANAUJIYA ◽  
RAVI SHUKLA ◽  
TOOFAN SINGH
Keyword(s):  
Water Absorption ◽  
Fibre Composite ◽  
Matrix Material ◽  
Natural Fibre ◽  
Impact Behavior ◽  
Reinforced Composite ◽  
Water Absorption Test ◽  
Izod Impact ◽  
The Impact ◽  
Specific Impact

The objective of this study is to investigate the impact behaviors of composites, metals and water absorption of composite. The Water absorption test is used to determine the amount of water absorbed under specified conditions .These composites (JRFC) are made of natural fibre (Jute) by volume 10% reinforcing in Epoxy (Matrix) Material. The Izod impact conditions have been considered .The result shows the specific impact energy of fibre composite is higher than the other materials.

EFFECT OF EMBEDDED TUNGSTEN PARTICLES ON IMPACT RESISTANCE OF DIAMOND COATING

2021 ◽  
pp. 2150108
Author(s):  
NAICHAO CHEN ◽  
DONGMEI LIU ◽  
FAN ZHOU ◽  
PING HE ◽  
MUSEN LIU
Keyword(s):  
Impact Load ◽  
Impact Resistance ◽  
Vital Role ◽  
Impact Testing ◽  
Impact Behavior ◽  
Diamond Coating ◽  
Novel Method ◽  
Softening Process ◽  
The Impact ◽  
First Time

For diamond coating, natural fragile property easily leads to fracture, delamination and peeling, which seriously inhibits the applications in many industrial fields. In order to prolong the lifetime, improving the toughness under impact load is essential for diamond coating. In this work, a novel method was proposed by the conventional CVD diamond technique combining with the particles, with which the nanocrystalline diamond (NCD) coating with W particles (W-NCD) was fabricated to evaluate the impact behavior. The pure NCD coating was also produced for comparison. Repeating impact testing was performed to evaluate the impact resistance of the as-deposited NCD coatings. The results showed that the diamond coating can be fabricated on the substrate with W particles. The indentation scar revealed that the W-NCD coating had the stronger impact resistance than the NCD coating. Ratcheting effect was employed to discuss the impact properties of NCD coating for the first time. The coating integrity played a vital role in ratcheting displacement. Repeating impact can make the NCD and W-NCD coatings soft, and the W particles can accelerate the softening process. Hence, embedding particles can provide a potential and valid method to enhance the impact resistance of diamond coating that was very important for the fragile coating.

Evaluation of Temperature Influence on Tensile Strength and Izod Impact Resistance on Poly Methyl Methacrylate (PMMA)

2020 ◽  
Vol 1012 ◽  
pp. 100-105
Author(s):  
Gilmar Cunha da Silva ◽  
Foluke Salgado de Assis ◽  
Sergio Neves Monteiro ◽  
Verônica Scarpini Candido ◽  
Alisson Clay Rios da Silva
Keyword(s):  
Methyl Methacrylate ◽  
Impact Resistance ◽  
Sem Analysis ◽  
Temperature Influence ◽  
Tempered Glass ◽  
Poly Methyl Methacrylate ◽  
Aggressive Environment ◽  
Izod Impact ◽  
The Impact ◽  
Scanning Electron

The increasing use of poly methyl methacrylate (PMMA), often replacing tempered glass, is a consequence of its high rigidity, practicality, lightness and transparency. However, current manufacturing standards in the polymer industry recommend specific tests on these materials. The present study aims to mechanically test the properties of poly methyl methacrylate (PMMA) material under conditions that simulate a much more aggressive environment than usual. Infrared spectroscopy (FTIR), thermogravimetric (TG/DTG) tests, Izod impact tests, and scanning electron microscopy (SEM) analysis were performed. The results showed that poly (methyl methacrylate) (PMMA) maintained its tensile mechanical properties up to 105°C. Regarding the impact tenacity, the temperature negatively influenced the performance of this polymer.

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