scholarly journals The Influence of the Use of Polymer Lining within the Roller Press Gravity Feeder on Briquette Quality

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2489
Author(s):  
Michał Bembenek
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Material Flow ◽  
Laboratory Tests ◽  
Polymer Materials ◽  
Roller Press ◽  
Fine Grained ◽  
The Impact ◽  
Ultra High Molecular Weight

When considering the operation of roller presses for the consolidation of fine-grained materials, the main problems are disturbances in the proper flow of the material and its bridging in gravity feeders. This is especially true for small and medium capacity presses, where the hoppers for dosing the material are narrow. This article presents innovative laboratory tests of the impact of using a polymer plate lining in the gravity feeder of a roller press. Polymer materials Polyacetal C (POM C) and Ultra-High-Molecular-Weight Polyethylene (UHMW-PE) were used for the tests. The influence of the use of plates on the material flow and quality of briquettes was investigated in comparison with the case where such plates were not used. The research showed an improvement in the flow of fine-grained materials in the feeder and an increase of the briquette strength indexes, as compared to those cases when polymer linings were not used in the feeder.

The Simulation of Ultra-High Molecular Weight Polyethylene Cryogenic Pipeline Stress-Strain State

2021 ◽  
Vol 1031 ◽  
pp. 132-140
Author(s):  
Ekaterina Karyakina ◽  
Ildar Shammazov ◽  
Vladimir Voronov ◽  
Aleksey Shalygin
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Strain State ◽  
Polymer Materials ◽  
Creep Process ◽  
Cryogenic Temperatures ◽  
Stress Strain ◽  
Stress Strain State ◽  
Cryogenic Pipeline ◽  
Ultra High Molecular Weight

At present the production of polymer materials is developing intensively, new materials, comparable with steels in their strength properties have recently appeared. In this connection, the analysis of polymer materials applied in the pipe industry has been carried out, and the use of ultra-high molecular weight polyethylene (UHMWPE) is proposed as a structural pipeline material, allowing pipes to operate at cryogenic temperatures. The focal point of the article is the consideration of the fracture mechanisms of those materials and the nature of the change in the mechanical properties of UHMWPE under cryogenic temperatures, also taking into account the creep process. The expression for determining the value of the creep modulus depending on the temperature and operating time was obtained. A method is proposed for conducting initial strength estimation. Moreover, the computer model of stress-strain state of an underground cryogenic polymer pipeline for liquefied natural gas transportation is obtained. The results of simulation depict the potential possibility of using of UHMWPE for the cryogenic pipeline construction

scholarly journals The low-velocity impact and post-impact properties of ultra-high-molecular-weight polyethylene fiber weft plain knitted structural composites

2019 ◽  
Vol 14 ◽  
pp. 155892501983252
Author(s):  
Cuiyu Li ◽  
Rui Zhang ◽  
Jingyan Jia ◽  
Gaopan Wang ◽  
Yameng Shi
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Contact Force ◽  
Compression Strength ◽  
Impact Compression ◽  
Impact Properties ◽  
Damage Area ◽  
Post Impact ◽  
The Impact ◽  
Ultra High Molecular Weight

This study investigated the impact and post-impact behavior of different layer weft plain knitted composite materials based on modified ultra-high-molecular-weight polyethylene/epoxy composites. The modified ultra-high-molecular-weight polyethylene weft plain knitted composites with 8, 12, 16 layers were prepared by vacuum-assisted resin transfer molding process and then subjected to impact and post-impact compression test. The impact properties were analyzed using the contact force–deflection and energy–time curves, and the post-impact compression was analyzed using the compression strength–strain curves. It can be obtained that the maximum contact force, absorbed energy, and residual compression strength after impact of the 16-layer specimen are 81.40%, 74.18%, and 73.25% more than those in the 8-layer specimen. respectively. According to the ultrasonic C-scan tests for the impact samples, the 16-layer specimen had the least damage area after the impact test, and the 8-layer composites damage area was 117.45% more than the 16-layer specimen.

Ultra-High Molecular Weight Polyethylene Wear Debris Generated in Vivo and in Laboratory Tests; the Influence of Counterface Roughness

1996 ◽  
Vol 210 (1) ◽  
pp. 3-10 ◽  
Author(s):  
J L Hailey ◽  
E Ingham ◽  
M Stone ◽  
B M Wroblewski ◽  
J Fisher
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Wear Debris ◽  
Laboratory Tests ◽  
Polyethylene Wear ◽  
Uhmwpe Wear ◽  
Major Variable ◽  
Ultra High Molecular Weight ◽  
Counterface Roughness

The objective of this study was to investigate the effect of counterface roughness and lubricant on the morphology of ultra-high molecular weight polyethylene (UHMWPE) wear debris generated in laboratory wear tests, and to compare this with debris isolated from explanted tissue. Laboratory tests used UHMWPE pins sliding against stainless steel counterfaces. Both water and serum lubricants were used in conjunction with rough and smooth counterfaces. The lubricants and tissue from revision hip surgery were processed to digest the proteins and permit filtration. This involved denaturing the proteins with potassium hydroxide (KOH), sedimentation of any remaining proteins, and further digestion of these proteins with chromic acid. All fractions were then passed through a 0.2 μm membrane, and the debris examined using scanning electron microscopy. The laboratory studies showed that the major variable influencing debris morphology was counterface roughness. The rougher counter-faces produced larger numbers of smaller particles, with a size range extending below 1 μm. For smooth counterfaces there were fewer of these small particles, and evidence of larger platelets, greater than 10 μm in diameter. Analysis of the debris from explanted tissues showed a wide variation in the particle size distribution, ranging from below 1 μm up to several millimetres in size. Of major clinical significance in relation to osteolysis and loosening is roughening of the femoral components, which may lead to greater numbers of the sub-micron-sized particles.

scholarly journals Optimization of soft armor: the response of single-ply para-aramid and ultra-high molecular weight polyethylene fabrics under ballistic impact

2020 ◽  
Vol 90 (15-16) ◽  
pp. 1713-1729 ◽  
Author(s):  
Calvin Ralph ◽  
Lisa Baker ◽  
Edward Archer ◽  
Alistair McIlhagger
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Wave Velocity ◽  
Hybrid System ◽  
Transverse Wave ◽  
Ballistic Impact ◽  
Image Correlation ◽  
Factor C ◽  
The Impact ◽  
Ultra High Molecular Weight

Typical soft armor systems are constructed of multiple layers of a single fabric type. This empirical research sought to begin optimization of these systems through hybridization, sequencing dissimilar armor fabrics to maximize their ballistic protective performance, by first investigating single plies with a spectrum of properties to determine their behavior and response to impact. Eight individual plain weave fabrics with varying yarns and thread counts were manufactured from para-aramid and ultra-high molecular weight polyethylene (UHMWPE) yarns and physical and ballistic characterizations were conducted. The ballistic impact tests established the specific energy absorption (SEA) of each fabric across a range of impact velocities (340–620 m·s–1) and the transverse displacement wave velocity across the rear of the fabric was found using digital image correlation. Low cover factor ( Cfab) fabrics (0.74–0.84) consistently showed faster transverse wave speed than the high Cfab fabrics (0.84–0.96) for any given yarn type. The relative SEA of the fabrics varied dependent on both the impact velocity and number of plies impacted. It was found that lower Cfab fabrics had the highest SEA, critical velocity and transverse wave velocity. UHMWPE fabrics were not considered suitable for a woven hybrid system as they had a significantly lower SEA compared to all the para-aramid fabrics. Results indicate that a hybrid system, when considered as a theoretical spaced system, would benefit from higher Cfab fabrics as rearward layers. However, transverse wave results suggest the lower response of these fabrics may inhibit lower Cfab fabrics at the front of a combined hybridized system.

FindingNemo Library 1: Modified ULK001 v1

2021 ◽  
Author(s):  
Inswasti Cahyani ◽  
John Tyson ◽  
Nadine Holmes ◽  
Josh Quick ◽  
Nicholas Loman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Large Volume ◽  
Cost Effective ◽  
Input Quality ◽  
Adapter Ligation ◽  
Working Principle ◽  
Ultra High Molecular Weight

This sub-protocol is designed to prepare library from extracted ultra-high molecular weight (UHMW) DNA to obtain ultra-long (UL) reads on Nanopore sequencers. The UL library protocols we tested are based on ONT's rapid kit, i.e., SQK-ULK001, a transposase based adapter ligation kit. Modified ULK001 protocol consistently produced N50 > 100 kb from a good input quality of UHMW DNA and is our recommended route for best output as it is also the most-cost effective. Transposase-based reaction is done in a large volume of up to 1 ml. The working principle of the ULK001 protocol is shown in the diagram below:

The structural effects on the impact response of ultra-high-molecular-weight polyethylene plain weaves

2020 ◽  
pp. 004051752096672
Author(s):  
Yi Zhou ◽  
Hang Li ◽  
Ziming Xiong ◽  
Zhongwei Zhang ◽  
Zhongmin Deng
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Energy Absorption ◽  
Impact Load ◽  
Structural Parameters ◽  
Woven Fabrics ◽  
Impact Response ◽  
Pull Out ◽  
The Impact ◽  
Ultra High Molecular Weight

This paper investigates the penetration and energy absorption mechanisms of ultra-high-molecular-weight polyethylene plain weaves with different fabric properties. Impact tests along with finite element (FE) analysis were used to study the impact response of the fabrics. In this research, the impacting projectile did not cause any fiber or yarn failure on the samples. It was found that structural parameters determine the yarn pull-out behavior and the softness of the resultant fabrics. Fabrics formed by loosely interlaced yarns tend to exhibit higher softness and less resistance against yarn pull-out. When the projectile velocity is not sufficient to initiate yarn pull-out, material softness determines the depth of the backface signature on the clay witness. This trend is more pronounced in a multi-ply fabric system than in a single-ply system; when yarn pull-out occurs, the projectile-slowing mechanism depends on the frictional force between the warp and weft yarns. Therefore, fabric softness becomes less important, and the yarn pull-out behavior of the fabric plays a predominant role in energy absorption. FE prediction showed that tightly woven fabrics exhibit a larger area of stress distribution and material deformation than those with severe yarn pull-out and, consequently, these tight fabrics tend to absorb more kinetic energy and sustain higher impact load from a projectile.

FindingNemo Library 2: Modified RAD004 v1

2021 ◽  
Author(s):  
Inswasti Cahyani ◽  
John Tyson ◽  
Nadine Holmes ◽  
Josh Quick ◽  
Nicholas Loman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Large Volume ◽  
Input Quality ◽  
Adapter Ligation ◽  
Working Principle ◽  
Ultra High Molecular Weight

This sub-protocol is designed to prepare library from extracted ultra-high molecular weight (UHMW) DNA to obtain ultra-long (UL) reads on Nanopore sequencers. The UL library protocol we tested here is based on ONT's rapid kit, i.e., SQK-RAD004, a transposase based adapter ligation kit. This Modified RAD004 protocol consistently produced N50 > 100 kb from a good input quality of UHMW DNA, for when ULK001 is not accessible/available. Transposase-based reaction is done in a large volume of up to 1 ml. The working principle of the RAD004 kit is shown in the diagram below:

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