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Physico-Mechanical Performance Evaluation of Large Pore Synthetic Meshes with Different Textile Structures for Hernia Repair Applications

Liu P., Shao H., Chen N.-L., Jiang J.-H.

Fibres & Textiles in Eastern Europe

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2018

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Vol. 26, no. 2 (128)

79--86

EN

This paper studied the relationship between the textile structure of warp knitted hernia repair meshes and their physico-mechanical properties to solve the problem of hernia patch application evaluation and clear the mechanism of hernia patch structure-performance for clinical application. Six different prototypes of large pore meshes were fabricated, including four kinds of meshes with different pore shapes: H (hexagonal), D (diamond), R (round) and P (pentagonal); and two kinds of meshes with inlays: HL (hexagonal with inlays) and DL (diamond with inlays), using the same medical grade polypropylene monofilament. All meshes were designed with the same walewise density and coursewise density. Then the influence of other structural parameters on the physico-mechanical properties of the meshes was analysed. The physico-mechanical properties of these meshes tested meet the requirements of hernia repair, except mesh DL, whose tear resistance strength (12.93±2.44 N in the transverse direction) was not enough. Mesh R and P demonstrated less anisotropy, and they exhibited similar physico-mechanical properties. These four kinds of meshes without inlays demonstrated similar ball burst strength properties, but mesh HL and DL exhibited better ball burst strength than the others. All in all, uniform structures are expected to result in less anisotropy, and meshes with inlays, to some extent, possess higher mechanical properties. And the ratio of open loop number to closed loop number in a repetition of weave of fabric has marked effect on the physico-mechanical properties. Thus we can meet the demands of specific patients and particular repair sites by designing various meshes with appropriate textile structures.

PL

W pracy przeanalizowano zależność między strukturą chirurgicznych siatek przepuklinowych a ich właściwościami fizyczno-mechanicznymi. Opracowano sześć różnych prototypów siatek o dużych porach, w tym cztery rodzaje oczek o różnych kształtach porów: H (sześciokąt), D (romb), R (okrąg) i P (pięciokąt); oraz dwa rodzaje oczek z inkrustacją: HL (sześciokątne z inkrustacją) i DL (romb z inkrustacją), z wykorzystaniem tego samego monofilamentu z polipropylenu klasy medycznej. Wszystkie oczka zostały zaprojektowane z taką samą gęstością. Następnie analizowano wpływ pozostałych parametrów strukturalnych na właściwości fizyczno-mechaniczne oczek. Właściwości fizyczno-mechaniczne badanych siatek spełniają wymagania, z wyjątkiem siatki DL, której wytrzymałość na rozdarcie (12,93 ± 2,44 N w kierunku poprzecznym) nie była wystarczająca. Siatki R i P wykazywały mniejszą anizotropię i podobne właściwości fizyko-mechaniczne. Powyższe cztery rodzaje siatek bez inkrustacji wykazywały podobne właściwości wytrzymałości na pękanie, a siatki HL i DL wykazywały lepszą wytrzymałość na rozerwanie niż pozostałe. Stwierdzono, że jednolite struktury charakteryzują się mniejszą anizotropią, a siatki z inkrustacją, do pewnego stopnia, mają lepsze właściwości mechaniczne.

2

Effects of Holding Conditions on Microstructure of Al-5Ti-1B and Its Refining Efficiency on Al-Cu Alloy

Huang Y., Shao H., Xiao Z., Ren X.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 2

647--652

EN

A series of Al-5Ti-1B master alloys were obtained via fluoride salt process by holding them between 780°C and 880°C for 10-90 min. The influence of holding temperature and time during preparation on the microstructure and its refining performance were investigated by X-ray diffractometer, optical microscopy and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The results indicated both the morphology and the distribution of TiB22and Al3Ti were seriously affected by holding conditions. Inadequate TiB2 particles were generated when holding time was short. However, Fe-containing impurity particles that aggregated along the matrix grain boundaries were found after the prolonged holding time. The refining and microhardness test results revealed that Al-5Ti-1B, the one held at 820°C for 30 min showed the optimum refining efficiency on Al-Cu alloy.

3

Computer modelling of the Lyocell fibre spinning process

Shao H., Liu R., Hu X.

Autex Research Journal

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2003

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Vol. 3, no. 1

16--22

EN

The cellulose Lyocell fibre spinning process can be divided into two processes, a dry spinning process in the air gap, and a wet spinning process in the coagulation bath. In order to simulate the process in the air gap, the heat capacity Cp, the density ρ, and the elongational viscosity ɳ were measured by experiments carried out as a function of temperature and concentration of cellulose. The calculated diameters and temperature profiles along the spinning path were compared with the experimental results. The concentration of N-methyl-morpholine-N-oxide (NMMO) in the fibre (in the coagulation bath) was also measured during the experiments, and the diffusion coefficient was then calculated. Using the data obtained, the time during which the NMMO content in the fibre reaches the equilibrium state in the coagulation bath can be predicted.