scholarly journals Study on Foaming Quality and Impact Property of Foamed Polypropylene Composites

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1375 ◽  
Author(s):  
Wei Gong ◽  
Hai Fu ◽  
Chun Zhang ◽  
Daming Ban ◽  
Xiaogang Yin ◽  
...  
Keyword(s):  
Low Temperature ◽  
Impact Property ◽  
Impact Properties ◽  
Polypropylene Composites ◽  
Polyolefin Elastomer ◽  
Pp Composites ◽  
The Impact ◽  
Foaming Technology ◽  
Thermoplastic Rubber

In the present work, foamed polypropylene (PP) composites were prepared by chemical foaming technology, and the foaming quality and impact property of the foamed PP composites were studied. The results showed that the foaming quality was significantly improved after the introduction of thermoplastic rubber (TPR) and polyolefin elastomer (POE). Meanwhile, it was found that the impact property depended on the intrinsic toughness and contribution of foams (cells) to the PP composites. Furthermore, the data regarding impact property in low temperature showed that when the temperature was between −80 and −20 °C, the impact properties of the foamed PP composites were higher than that of the unfoamed sample, which was due to the impact property being completely contributed by cells under this condition. Meanwhile, when the temperature ranged from −20 to 20 °C, the impact property of the unfoamed sample was higher, which was due to the PP matrix contributing more to the impact property under this temperature. This work significantly improved the foaming quality of foamed PP composites and provided reliable evidence for the improvement of impact property.

A New Air Dehydration Process for Wood Dryers. Part I. Kinetic and Quality of Drying

Holzforschung ◽  
2000 ◽  
Vol 54 (2) ◽  
pp. 201-206 ◽  
Author(s):  
L. Chrusciel ◽  
E. Mougel ◽  
A. Zoulalian
Keyword(s):  
Mass Transfer ◽  
Low Temperature ◽  
Triethylene Glycol ◽  
Dehydration Process ◽  
Wood Drying ◽  
Drying Kinetic ◽  
Hydrocarbon Gas ◽  
Air Dehydration ◽  
The Impact

Summary In conventional wood dryers, air is dehumidified by condensation or by its partial remove. A new air dehydration process is proposed for low temperature convective wood drying. This process consists in using an absorber working with an organic absorbent, the triethylene glycol (TEG) that is pulverised in a venturi type of device. The adaptation of this process well known for hydrocarbon gas dehydration and its interest for wood drying operations are discussed. The prototype installation is presented and the impact of the absorption on the evolution on drying cycles are investigated. The performances of the absorber are evaluated quantitatively and qualitatively. The average drying kinetic is quantified with a global mass transfer coefficient and the drying quality is characterised through the measurements of defects generated during drying.

Study on Ramie Fiber Reinforced Polypropylene Composites (RF-PP) and its Mechanical Properties

2008 ◽  
Vol 41-42 ◽  
pp. 313-316 ◽  
Author(s):  
Li Ping He ◽  
Yong Tian ◽  
Lu Lin Wang
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Fiber Content ◽  
Ramie Fiber ◽  
Fiber Reinforced ◽  
Polypropylene Composites ◽  
Environmental Friendly ◽  
Pp Composites ◽  
Pre Treatment ◽  
The Impact

Natural fiber reinforced polypropylene composites (NF/PP) have attracted a lot of attention because of their light weight, good mechanical properties, recyclable and environmental friendly features. This work has successfully fabricated ramie fiber reinforced polypropylene composites (RF/PP) with a hybrid method of melt-blending and injection molding. Different RF/PP eco-materials have been fabricated by varying the fiber length, fiber content and way of fiber pre-treatment. This paper studied the mechanical properties of the fabricated RF/PP composites in depth by investigating the mechanical behaviors of RF/PP and microstructures of the ruptured surfaces. The results show that the increases of fiber length and fiber content can improve the tensile strength, flexural strength and compression strength apparently, but result in negative influences on the impact strength and elongation behaviors of RF/PP composites. The optimal addition amount of ramie fiber is around 20 wt%. The pre-treatment of ramie fiber in 10%~15% NaOH is good to the mechanical properties of RF/PP. The fiber length can be varied in the range of 3-8 mm. It is expected that the fabricated RF/PP composites can be applied to automobile industry as environmental friendly eco-materials.

Effect of Foaming Temperature and Holding Time on Foam Glass

2013 ◽  
Vol 712-715 ◽  
pp. 897-900 ◽  
Author(s):  
Long Wu ◽  
Yi Long Zhao ◽  
Rong Fa Chen ◽  
Hua Yang ◽  
Qing Qing Li ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Low Temperature ◽  
Pore Structure ◽  
Foam Glass ◽  
Holding Time ◽  
Uniform Size ◽  
Heat Preservation ◽  
Foaming Temperature ◽  
Foaming Technology

In the paper, the effects of the foaming temperature and holding time on the quality of the foam glass were investigated by means of the different foaming technology. The results indicated that lots of the defects, such as the non-uniform size of the bubbles, big hole and the pit at the bottom, were caused by the high foaming temperature. The fine pore structure was formed by the low temperature. The molding and properties of the foaming glass was affected by the length of the heat preservation time. The rate of acceptability and the mechanical property of the foam glass can be effectively improved by the optimized foaming technology.

Improvement in Toughness of Transportation and Storage Cask Steel for Spent Nuclear Fuel

2007 ◽  
Author(s):  
Hee Kyung Kwon ◽  
Byoung Koo Kim ◽  
Kuk Cheol Kim ◽  
Keun Ho Song ◽  
Jeong Tae Kim
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Radioactive Material ◽  
Low Alloy Steels ◽  
Tempering Temperature ◽  
Impact Properties ◽  
Temperature Impact ◽  
The Impact

Nuclear power plants have been operated for fifty years. Currently the managements of spent fuel are on progress vigorously. Casks for transportation and/or storage of spent nuclear fuel are usually made of SA350 low alloy steels. The wall thickness of the casks are greater than 300mm. But because leakage of nuclear fuel or radioactive material from unexpected brittle fracture is not acceptable, Nil-ductility transition temperatures of colder than −150°F are needed. The effects of chemical composition and heat treatment on low temperature impact properties of SA350 are investigated in this study. The microstructure of SA350 steel is composed of ferrite and pearlite. The variations of microstructure, low temperature impact properties and strength at room temperature with carbon, vanadium and manganese content are analyzed. To improve the low temperature impact properties, heat treatment at an temperature between quenching and tempering temperature is introduced. With the optimum combination of alloying elements and heat treatment, the impact properties can be improved down to the level of nil-ductility transition temperature −150°F.

Effect of Tempering on Bendability and Impact Property of Hot Rolled Low-Carbon Martensitic Steel

2018 ◽  
Vol 941 ◽  
pp. 474-479
Author(s):  
Sung Il Kim ◽  
Seok Jong Seo ◽  
In Shik Suh
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Impact Property ◽  
Alloying Elements ◽  
Bending Test ◽  
Low Carbon ◽  
Martensitic Steels ◽  
Tempering Temperature ◽  
Impact Properties ◽  
The Impact

We examined the effects of tempering process and alloying elements on the microstucture, tensile properties, bendability and impact property of direct quenched (DQ), and re-austenitizing and quenched (RQ) low-carbon martensitic steels. For this purpose, four low carbon martensitic steels (Fe-0.07C-1.8Mn-Cr-Nb-Ti-B) were selected. We have investigated the effects of tempering temperature and alloying elements of chromium (Cr), titanium (Ti) and niobium (Nb) on mechanical properties and microstructures. Mechanical properties and microstructures were analyzed as well using tensile test, V-bending test, charpy V-notched impact test and electron microscopy for DQ, DQ and tempered (DQ-T), RQ and RQ and tempered (RQ-T) low-carbon martensitic steels. It has been found that the as-quenched microstructures of the DQ and RQ specimens were fully martensitic structure. Prior austenite grain size and effective grain size after quenching were larger in the case of RQ steel. In both cases, tempering made the needle-shaped carbides. It is shown that the strength decreased when the tempering temperature increased. The strengths of the DQ and DQ-T steels were 30~50MPa higher than those of the RQ and RQ-T steels. Despite the higher strength of the DQ and DQ-T states, both had similar impact properties with the RQ and RQ-T states. However, the impact properties of the Nb added RQ and RQ-T steels with fine martensite morphology exhibited higher than those of DQ and DQ-T steels.

Effect of Different Tempering Temperatures on Microstructure and Impact Property of 20CrMnTi Steel

2014 ◽  
Vol 900 ◽  
pp. 92-95
Author(s):  
Sheng Xu Liu ◽  
Yi Qiang Xiao ◽  
Ming Long Kang ◽  
Jian Min Zeng ◽  
Guo An Wang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Low Temperature ◽  
Fracture Morphology ◽  
Optical Microscope ◽  
Impact Property ◽  
Medium Temperature ◽  
The Impact ◽  
Type Of Fracture ◽  
Scanning Electron

The effect of different tempering temperatures on microstructure and impact property of 20CrMnTi steel has been studied on Zwick/roell Amsler PKP 450 pendulum machine, SU-8020 scanning electron microscope (SEM) and optical microscope. The results shows that the impact property of 20CrMnTi steel is dramatically improved after high-temperature tempering. However, the minimum value occurs when it was tempered at 350°C because of low-temperature tempering brittlement at this degree. The SEM fracture morphology was typical dimples after high temperature tempering, and the type of fracture was ductile fracture; the type of cleavage characteristic and quasi cleavage characteristic were generated on the fracture morphology at low-temperature and medium-temperature tempering respectively, and the type of fracture was brittle.

The Effect of Hyperdispersant on the Mechanical Properties and Morphology of Sisal Fiber/Polypropylene Composites

2011 ◽  
Vol 250-253 ◽  
pp. 839-842
Author(s):  
Chun He Yu ◽  
Shao Rong Lu ◽  
Zhi You Yang ◽  
Kuo Liu ◽  
Xin Fan
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Flexural Strength ◽  
Water Solubility ◽  
Experimental Results ◽  
Sisal Fiber ◽  
Polypropylene Composites ◽  
Pp Composites ◽  
Flexible Segment ◽  
The Impact

In order to enhance the interfacial interactions between the sisal fiber (SF) and the polypropylene (PP) matrix, a water-solubility hyperdispersant which has amphipathic structure and flexible segment was used. Experimental results revealed that when the content of hyperdispersant is 5 percent, the impact strength of the composites was 27.4 kJ·m-2 and the flexural strength of SF/PP composites was 40.1 MPa, which was 64 and 34 wt% higher than that of unmodified systems, respectively. Meanwhile, the crystallinity of the composites also leads to an increase.

Fracture Behavior of Recyclable All-Polypropylene Composites Composed of α- and β-Modifications

2011 ◽  
Vol 24 (6) ◽  
pp. 805-818 ◽  
Author(s):  
A. Stocchi ◽  
V. Pettarin ◽  
A. Izer ◽  
T. Bárány ◽  
T. Czigány ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Static Loading ◽  
Fracture Behavior ◽  
Processing Temperature ◽  
Reinforced Composites ◽  
Polypropylene Composites ◽  
Strain Behavior ◽  
Pp Composites ◽  
Materials Behavior

The fracture behavior of all-PP composites was studied under quasi-static loading conditions. Fracture toughness was evaluated by means of different fracture mechanics approaches depending on materials’ behavior. Composites consolidated at low temperature exhibited pop-in features and the failure occurs typically by delamination and tape stretching and fracture. With increasing consolidation quality – i.e., with increasing processing temperature – the delamination became less pronounced, and so the tape stretching occurred, before the specimens break. In composites consolidated at the highest temperature investigated (190°C), the laminate-like structure typical of self-reinforced composites produced according to film-stacking method was lost. Accordingly, composites behave as if they were only α-PP and β-PP matrices: α-rPP exhibited typical brittle fracture of α-PP, while β-rPP exhibited the stable behavior with fully yielded ligament before crack propagation commonly observed for β-PP. In general, stress–strain behavior changed from stable to unstable and fracture toughness strongly decreased as consolidation quality increased. Based on these results and previous findings, it can be concluded that the properties of self-reinforced PP composites can be tailored for a given application through the quality of consolidation.

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