Fundamental study of the effect of the fiber wall thickness and inner diameter on the structure of polyamide and polypropylene hollow fibers

2004 ◽  
Vol 92 (3) ◽  
pp. 2017-2022 ◽  
Author(s):  
Donatas Petrulis
Keyword(s):  
Wall Thickness ◽  
Hollow Fibers ◽  
Fundamental Study ◽  
Fiber Wall ◽  
Inner Diameter

New model for predicting tensile strength and density of eucalyptus handsheets based on an activation parameter calculated from fiber distribution characteristics

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Iiro Pulkkinen ◽  
Juha Fiskari ◽  
Ville Alopaeus
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Wall Thickness ◽  
Water Retention ◽  
Activation Parameter ◽  
Water Retention Value ◽  
Data Set ◽  
Network Activation ◽  
Fiber Wall ◽  
Fiber Segment

Abstract The activation parameter developed is based on the fiber wall thickness distribution, fiber curl distribution, and water retention value of the unrefined fibers. The mechanical properties of paper that contain chemical pulp depend, among other things, on the free fiber segment activation between fiber-fiber crossings that is created during drying. Experimental data revealed that the degree of fiber swelling is responsible together with the fiber shape factor (curl) and fiber wall thickness for the extent of fiber network activation. The amount of bonding between fibers also affects fiber segment activation. Based on the experimental data, it was deduced that interfiber bonding ability of fibers, characterized as the water retention value, was mainly responsible for the development of handsheet density. Tensile index development was more affected by the morphology of fibers, which was the main determinant for high activation potential of fibers. Factor analysis was used to identify the main causes of variation for a refining data set of 20 Eucalyptus grandis samples. Three independent descriptors were found to be responsible for the majority of the variation: the bonding and activation factor, the factor of microcompressions, and the factor of fiber wall thickness and fiber curl. The activation parameter developed in this study can be used to determine the effect of fiber segment activation and inter-fiber bonding on the inplane mechanical properties of paper.

Equidirectional Umbrella Diameter Changing Mechanism for Ultrasonic Inspection of Seabed Pipelines

2010 ◽  
Vol 163-167 ◽  
pp. 2927-2933
Author(s):  
Chong Zhen Cao ◽  
Feng Qin Wang ◽  
Qi Fa Tian ◽  
Jia Lan Zhuang ◽  
Feng Chun Li
Keyword(s):  
Wall Thickness ◽  
Ultrasonic Inspection ◽  
Machine Experiment ◽  
Oil Pipelines ◽  
Inner Diameter

Ultrasonic inspection is a key method of inspecting wall thickness flaw of seabed oil pipelines. How to lay out ultrasonic probes to fit for three inner diameter pipelines of Φ195mm, Φ247mm and Φ297mm was analyzed detailed. Diameter changing principle feasibility of ultrasonic inspection adopting 10 parallelogram mechanisms was discussed, and the key parts of structure of equidirection umbrella diameter changing mechanism were analyzed. In the end model machine experiment verified that equidirection umbrella diameter changing technology is feasible.

Fabrication of NiO Nanorings by Bubble-Bursting Bubbles as Templates

2013 ◽  
Vol 464 ◽  
pp. 54-57
Author(s):  
Yun Feng Guo ◽  
Zhi Hua Feng ◽  
Zhi Hao Yuan
Keyword(s):  
Growth Mechanism ◽  
Wall Thickness ◽  
Low Cost ◽  
Heat Treating ◽  
Wire Diameter ◽  
Bubble Bursting ◽  
Inner Diameter ◽  
Average Wall Thickness ◽  
20 Nm

A simple and low-cost method based on a heat-treating of Ni (NO3)2/SiO2film has been developed for fabricating NiO nanorings. The as-prepared nanorings have an inner diameter of 150-250nm and an average wall thickness (namely wire diameter) of approximately 20 nm on the surface of SiO2matrix. Furthermore, a growth mechanism, namely bubble-bursting bubbles as templates was tentatively proposed for understanding the formation of the NiO nanorings.

Structural characterization of the fullerene nanotubes prepared by the liquid–liquid interfacial precipitation method

2005 ◽  
Vol 20 (3) ◽  
pp. 688-695 ◽  
Author(s):  
Kun'ichi Miyazawa ◽  
Jun-ichi Minato ◽  
Tetsuro Yoshii ◽  
Masahisa Fujino ◽  
Tadatomo Suga
Keyword(s):  
Linear Relationship ◽  
Wall Thickness ◽  
Structural Characterization ◽  
Tube Wall ◽  
Precipitation Method ◽  
Outer Diameter ◽  
Tubular Structures ◽  
Growth Axis ◽  
Inner Diameter

Fine tubular fibers composed of C60 and C70 fullerene molecules were successfully fabricated by the liquid–liquid interfacial precipitation method. The walls of the tubular fibers were crystalline, and the fullerene molecules were densely packed along the growth axis of tube wall. The tubular structures are called “fullerene nanotubes.” The inner diameter and the outer diameter of C70 tubes showed a linear relationship, suggesting a constant wall thickness of the tubes. The tubular structures composed of C70 molecules could be formed when their diameter was larger than about 240 nm. The fullerene tubes were successfully fabricated by using a C60-C70 soot as well. The formation of fullerene nanotubes can be understood by assuming a mechanism of core dissolution of the solvated fullerene nanowhiskers.

Remote Measurement of the Pipe Thickness Reduction by Microwaves

2007 ◽  
Author(s):  
Yang Ju
Keyword(s):  
Resonance Frequency ◽  
Wall Thickness ◽  
Large Scale ◽  
Microwave Signal ◽  
Thickness Reduction ◽  
Remote Measurement ◽  
Copper Pipe ◽  
Inner Diameter

A method which can inspect a pipe in a large scale and measure the thickness reduction remotely was demonstrated. A copper pipe having 17 mm inner diameter, 1 mm wall thickness, and 900 mm length was measured. The thickness reduction having the value from 10% to 80% of the wall thickness was detected significantly. By building up a resonance for the microwave signal propagated in the pipe, it is possible to determine the thickness reduction using the measured resonance frequency.

State Analysis on the Main Components of Reformer Furnace Pipe Used for a Design Cycle

2012 ◽  
Vol 550-553 ◽  
pp. 3121-3124
Author(s):  
Li Feng Ma ◽  
Xiao Fei Ding ◽  
Jun Zhang ◽  
Mao Kai Tian ◽  
Li Jing Gong
Keyword(s):  
Wall Thickness ◽  
Element Distribution ◽  
Lower Grade ◽  
Riser Pipe ◽  
Service Period ◽  
Design Cycle ◽  
Inner Diameter ◽  
Grade Material ◽  
Main Components ◽  
State Analysis

Comprehensive state analysis and life evaluation of the main components of reformer furnace run over service period by EPMA, microstructure and high temperature rupture property. The results show that element distribution and microstructure of reformer pipe, riser pipe, low collecting pipe and socket is normal and the remaining life is longer. The material of furnace pipe for the HK40 are able to meet the process requirement, but the wall thickness of reformer pipe is too large, affecting the thermal efficiency and the inner diameter is small to limit the catalyst and flow. It is good proposal to production enterprises that higher level of material such as ZG50Ni35Cr25NbM is selected to reduce the wall thickness properly, expand the diameter and improve efficiency. Similarly, it can also be appropriate for the riser pipe to choose a lower grade material and reduce the wall thickness and save cost.

Measurement of inner diameter and wall thickness for micro-capillary by digital holographic tomography

2013 ◽  
Vol 21 (7) ◽  
pp. 1643-1650 ◽  
Author(s):  
潘哲朗 PAN Zhe-lang ◽  
李仕萍 LI Shi-ping ◽  
钟金钢 ZHONG Jin-gang
Keyword(s):  
Wall Thickness ◽  
Inner Diameter

scholarly journals Cross-sectional analysis of tubular polymer semi-finished products using ultrasound in comparison with other measuring methods

2020 ◽  
Vol 6 (3) ◽  
pp. 151-154
Author(s):  
Olga Sahmel ◽  
Stefan Siewert ◽  
Wolfram Schmidt ◽  
Klaus-Peter Schmitz ◽  
Niels Grabow
Keyword(s):  
Wall Thickness ◽  
Biomedical Engineering ◽  
Measuring Method ◽  
Outer Diameter ◽  
Micro Computed Tomography ◽  
Cross Sectional ◽  
Biodegradable Poly ◽  
Ultrasonic Measuring ◽  
Inner Diameter ◽  
Sectional Analysis

AbstractIn the sector of biomedical engineering and implant technology, high-precision geometry is often decisive for successful end product functionalization. Especially in the production of tubular polymer semi-finished products, e.g. for stent fabrication, it is important to assure the desired parameters, such as inner and outer diameter and wall thickness. Within the current study we analyzed semifinished products for manufacturing of polymeric stents using three different methods. Biodegradable poly-L-lactide (PLLA) tubes were examined by means of micro computed tomography, ultrasonic scanning and scanning electron microscopy. The final evaluation presents clear advantages of the ultrasonic measuring method for the measurement of outer and inner diameter and wall thickness.

Changes in the fiber wall during refining of bleached pine kraft pulp

Holzforschung ◽  
2004 ◽  
Vol 58 (3) ◽  
pp. 233-240 ◽  
Author(s):  
C. Laine ◽  
X. Wang ◽  
M. Tenkanen ◽  
A. Varhimo
Keyword(s):  
Wall Thickness ◽  
Kraft Pulp ◽  
Hydrolytic Enzymes ◽  
Bleached Kraft Pulp ◽  
Fiber Wall ◽  
Fiber Fractions ◽  
Fiber Dimensions ◽  
Thin Walled ◽  
Fibril Aggregates ◽  
Cellulose Surface

Abstract The effect of refining on the fiber wall was studied for bleached kraft pulp fractions from pine first thinnings and pine sawmill chips. Hydrocyclone fractionation of both pulps produced fractions enriched in earlywood and latewood fibers. Some external fibrillation but no changes in fiber wall thickness were observed for the thin-walled earlywood fibers during refining. Refining the thick-walled latewood fibers led to extensive external fibrillation and a decrease in fiber wall thickness. The pore structure of the fiber wall opened up during refining for all pulp fractions. Earlywood fibers were more porous than latewood fibers, and fibers from first thinnings more porous than those from sawmill chips. The earlywood fibers from first thinnings had more large pores than the other fiber fractions. In the region of the smaller pores, the pore volume did not change significantly with refining, whereas in the region of the larger pores it increased markedly. In all the fractions investigated, specific hydrolytic enzymes hydrolyzed cellulose more easily after refining. This is an indication of an increase in cellulose surface area and/or disordering of cellulose as a result of refining, probably due to local disorder of the cellulose in the fibril aggregates. Bonding developed most strongly for the earlywood fiber fraction from first thinnings. This is concluded to be due to a combination of fiber dimensions and fiber wall porosity.

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