Mechanical properties of polypropylene/glass weft knitted composites hot pressed in various structures and contents

2013 ◽  
Vol 20 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Dariush Semnani ◽  
Ali Zadhoush ◽  
Matin Mashayekhi

AbstractIn this study, composites of knitted fabric made from side-by-side multiple glass and polypropylene yarns have been investigated. These composites have been produced by a new manufacturing method – the hot press method. By using various knitted fabrics made from different components of glass and polypropylene yarns, several types of knitted structures and yarn components were investigated: rib 1-1, full Milano and full cardigan. The mechanical properties of composites were measured in three directions. The results showed that hot-pressed knitted composites of glass and polypropylene yarns have high strength, impact resistance, work-to-break and elongation, simultaneously. The highest bending resistance and maximum stiffness are achieved for rib-knitted composites consisting of 8 wt% glass and 92 wt% polypropylene yarns. The highest impact energy absorption was obtained with 18 wt% glass content and 82 wt% polypropylene matrix.

2006 ◽  
pp. 59-70 ◽  
Author(s):  
Milanka Djiporovic ◽  
Jovan Miljkovic ◽  
Eva Dingova

New materials based on wood have the advantage in the sense that their properties can be engineered so as to correspond to user demands. The properties which can be engineered are those relating both to their utilisation and machining, in particular - the tensile strength, elongation at break, modulus of elasticity and impact resistance. The research at the Faculty of Forestry and "Hipol" Chemical Industry related to the new type of wood-polypropylene composite. The content of wood filler was varied in the range between 40% and 70% mass contents of beech wood flour. After the highest tensile strength at 50% of filler content was determined, the effect of the wood filler origin was also examined at this content value. Therefore, wood flour of beech, poplar, acetylated pine and the waste MDF was used. The influence of the composition of the wood filler (beech combined with MDF, poplar and acetylated pine) in comparison with pure polypropylene matrix was also examined, as well as the effect of the type of coupling agent. Hopefully, the results obtained in this study might serve as the initial data for production of easily machined high-strength composites.


2018 ◽  
Vol 786 ◽  
pp. 319-324 ◽  
Author(s):  
Markku Kananen ◽  
Antti Järvenpää ◽  
Matias Jaskari ◽  
Kari Mäntyjärvi

Corrugated core panels contain a formed, corrugated core bonded between two skin sheets. These panels are typically used in applications, where a low weight is required with integrity in stiffness. This paper demonstrates the mechanical properties of a simple panel structure (SPS), constructed using strips of work-hardened, austenitic stainless steel (ASS) grade 1.4310 (type 301) with the yield strength (YS) of ~1200 MPa. The 0.5 mm thick strips were formed into a C-shape and subsequently laser welded together by lap joints to form a SPS. The thickness of the SPS was 50 mm. The bending tests for the SPS were carried out transverse and 45-degrees related to the orientation of the web sheet. The results showed that the SPS, as loaded in the transverse direction, has about the same bending stiffness prior yielding as that of the previously tested 6 mm thick, low carbon S355 plain steel sheets, but the SPS is three times lighter than 6mm thick plain steel sheet. Compared with a corrugated core panel made of an annealed ferritic stainless steel (SS-panel) with the YS ~ 250 MPa, the weight of the both panels are roughly the same, but the bending resistance of the SPS is 45% higher. Experimental tests also verified that the benefit in the stiffness is quickly reduced if the load direction differs from transverse. In the 45-degrees loading direction, the SPS and the SS-panel had almost the same bending strength. On the other hand, the SPS and the SS-panel stiffnesses are much better than that of the carbon steel (the YS ~ 300 MPa) panel (CS-panel) in the both loading directions – the SPS being twice as stiff as the CS-panel.


2013 ◽  
Vol 668 ◽  
pp. 630-634
Author(s):  
Xai Mei Lu ◽  
Yun Fei Ma

The composite grid structure, which is highly efficient and strongly designable, posses a variety of excellent performances, such as light weight, high strength, and inherent impact resistance. This paper used experimental methods to investigate the composite grid structure consisting of quadrilateral unit cells. The authors made nine specimens composed of different unit-cell sizes of the grid structure, through a series of static and dynamic load testing on them, examined and further analyzed their mechanical behaviors and energy-absorbing capabilities, as well as compared their mechanical properties, thus found specific (new) correlations between microstructures and mechanical properties in composite grid structures.


1997 ◽  
Vol 105 (1218) ◽  
pp. 152-155 ◽  
Author(s):  
Isamu YASHIMA ◽  
Tetsuhito SATO ◽  
Yukihiro TOCHIO

2005 ◽  
Vol 475-479 ◽  
pp. 1113-1116 ◽  
Author(s):  
Jin Kyung Lee ◽  
Young Chul Park ◽  
Sang Ll Lee

A smart material is used as spectacle frames and brassiere frames, and partly in medical supplies because of its shape memory effect. The smart composite can be used on the wing of an airplane instead of the existing aluminium to control crack propagation. In this study, the smart composite was fabricated by a hot press method. TiNi alloy as reinforcement and Al6061 as matrix were used, respectively. The mechanical properties of the smart composite under thermal shock cycles were evaluated. In addition, Acoustic Emission techniques were also used to clarify the damage behavior of the smart composite under thermal shock cycles nondestructively.


2013 ◽  
Vol 737 ◽  
pp. 67-73 ◽  
Author(s):  
Muhammad Ghozali ◽  
Agus Haryono

The combination between synthetic polyolefin with natural polymer such as cellulose, starch and chitosan can stimulate biodegradation processes of waste plastics such as polyethylene (PE), polypropylene (PP) and other conventional plastics. In this work, PVC (polyvinyl chloride) biocomposite was prepared by compounding cellulose particle into PVC matrix in the presence of PVC-g-maleic anhydride as a compatibilizer. Cellulose nanoparticles were prepared by physical top-down method after milling by using High-Energy Ball-mill. The diameter size of cellulose nanoparticle was obtained as 170 nm. Cellulose particles were added as filler with ratio of 10-30 phr in PVC matrix. PVC biocomposites was prepared as a sheet film with the thickness of 0.3 mm by hot-press method. The addition of cellulose particle into PVC matrix was examined in various filler volumes and various cellulose particle sizes. The obtained PVC composite films were characterized by means of Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and Fourier-Transformed Infrared (FTIR) spectroscopy. The rheological and mechanical properties of PVC and cellulose composites were investigated as a function of surface structure and filler volume fraction.


2016 ◽  
Vol 46 (7) ◽  
pp. 1439-1473 ◽  
Author(s):  
Hossein Hasani ◽  
Sanaz Hassanzadeh ◽  
Mohammad Javad Abghary ◽  
Elahe Omrani

Textile products are considered as an acceptable alternative for commonly used composite reinforcement due to their lightweight as well as relatively high specific strength and stiffness. Among the variety of textile structures which could be employed in composite manufacturing, the role of weft-knitted fabrics is almost very limited. This is because employing the weft-knitting technology would provide such structures with inferior mechanical properties due to their highly looped construction as well as low fiber volume fraction. But on other hand, it is important to be noted that some advantages such as high energy absorption, good impact resistance, and formability of knitted structures made the researchers to focus on investigating different methods by which the inferior mechanical properties of ordinary weft-knitted fabrics could be improved. Inserting the reinforcing yarns through the warp and weft direction of the knitted fabrics is considered as one of the effective solution for improving their mechanical behavior which eventually leads to a high potential product called as biaxial weft-knitted fabrics. In this literature, it is aimed to review different aspects of novel designed biaxial weft-knitted fabrics which could be suitable for a broad area of technical application such as composite reinforcements.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xijun Zhang ◽  
Hongyuan Fang ◽  
Mingrui Du ◽  
Mingsheng Shi ◽  
Chao Zhang

Polymer is a kind of high molecular elastic material. The polymer cement mortar composite material formed by mixing it with cement mortar has the advantages of light weight, high strength, and good durability compared with traditional mortar materials. The effect of polyurethane polymer content on mechanical properties and microstructure of polyvinyl alcohol (PVA) fiber cement mortar was studied by compressive test, flexural test, and SEM analysis. The test results show that as the content of polyurethane increases, the compressive strength gradually decreases, and the flexural strength gradually increases. The addition of polyurethane helps to optimize the microstructure of PVA mortar, improve the compactness of the material, and enhance the bending resistance of the mortar. The mechanical properties of materials obtained from the experiment can provide references for engineering applications.


Sign in / Sign up

Export Citation Format

Share Document