NON-WOVENS FROM COTTON FIBRES FOR ABSORBENT PRODUCTS OBTAINED BY THE NEEDLE-PUNCHING PROCESS
The use of non-wovens as absorbent products is increasing, as is the consumption of cotton fibres as raw materials for these products. This paper presents some results concerning the obtaining of absorbent non-woven products made from cotton fibres. A fibrous web was formed by the superposition of cotton bands as a short layer. Special needle types supplied by SINGER Spezialnadelfabrik GmbH & Co. KG were used during the needle-punching process.
Equations of variation of liquid absorption speed and surface weight have been analysed in order to optimise the needle-punching process of the cotton fibrous webs.
TEXTILE SLOW-RELEASE SYSTEMS WITH MEDICAL APPLICATIONS
In the development of medical drug delivery systems, attention has been increasingly focused on slow- or controlled delivery systems in order to achieve an optimal therapeutic effect. Since the administration of drugs often requires a defined or minimum effective dosage in the human body, more conventional delivery systems such as tablets require relatively high doses, which can result in undesired toxic effects. Subsequent degradation of the drug in the human body will result in a drug concentration below the minimum effective level. Furthermore, there are situations where oral administration is less advisable, such as in cases of prolonged treatment or with people that are forgetful, which again results in ineffective treatment. Textile slow-release systems have the potential to overcome these negative aspects. Drugs containing transdermal patches for ex-vivo applications are already familiar; however, this paper will not deal with such applications, but with more advanced in-vivo textile slow-release systems. Due to enormous progress over the years in the fields of supramolecular chemistry, nanotechnology, and polymer science & technology, a number of promising drug delivery technologies have been developed. This review will focus on the opportunities of textiles bearing cyclodextrins, aza-crown ethers or fullerenes, as well as ion-exchange fibres, drug-loaded hollow fibres, textiles treated with nanoparticles and fibres with bioactive compounds in their embodiment. In this paper, the delivery systems will be discussed and compared in terms of biostability, biodegradability, controllability, toxicity, carcinogenicity, interface reactions, material costs and the fabrication process.
A COMPREHENSIVE PHYSICAL MODEL FOR LIGHT REFLECTION IN TEXTILES FOR COMPUTER GRAPHICS APPLICATIONS
This paper is concerned with the optical properties and 3D modelling of textile structures (yarn, woven and knitted product). A method for establishing a set of statistical surface parameters for a fibre from atomic force microscopy measurement is proposed. This technique is adapted for yarn. Nevertheless, AFM measurements are impossible for this structure, so a virtual profiler has been developed. Finally, several reflectance models are compared. The Lafortune model is the most adapted to predict reflectance properties of yarn. The correlation of estimated and measured surface parameters is processed to make the model physically plausible for textile materials. Once this task has been achieved, this modified model is implanted in a ray tracing program for more realistic computer graphic application in the field of textiles.
SMART TEXTILES FOR WEARABLE MOTION CAPTURE SYSTEMS
The implementation of truly wearable instrumented garments capable of recording biomechanical variables is crucial to several fields of application, from multi-media to physical rehabilitation, from sporting to artistic fields.
Here we report on wearable devices which are able to read and record the posture and movements of a subject wearing the system. The sensory function of the garments is achieved by fabric strain sensors, based on threads coated with polypyrrole or carbon-loaded rubbers. The presence of conductive elements gives these materials piezoresistive properties, enabling the detection of local strain on the fabric.
Strips of strain fabrics are applied together with conductive tracks at strategic points in a shirt and a glove in order to detect the movements of the principal joints.
The 'smart shirt'-sensing architecture can be divided into two parts: a textile platform, where a wearable device acquires biomechanical signals, and a hardware/software platform, to which a wireless communication system sends the acquired data after electrical conditioning.
THE DEVELOPMENT AND MANUFACTURE OF POLYMERIC ENDOPROSTHETIC MESHES FOR THE SURGERY OF SOFT TISSUES
'Esfil' endoprosthetic meshes made of polypropylene monofilaments, 'Eslan' made of lavsan multifilaments and 'Ftorex' made of lavsan multifilaments with waterproofing fluoropolymer coating have been developed and manufactured for the plasty of soft supporting tissues after tumour resection and herniotomies, by damage to the abdominal wall and the diaphragm and in other surgical procedures.
'Esfil' polypropylene endoprostheses are biologically inert and resist the action of tissue fluids. The hydrophoby and solidity of the threads prevent the meshes from becoming infected. Prompt spreading of the fibroblasts along the filaments promotes the reparation of soft tissues. The 'Eslan' meshes are substantially softer and can be used when so-called 'gentle' implants are required. However, the capillarity of lavsan filaments may cause wound infections. The 'Ftorex' prostheses do not suffer from this disadvantage, due to impregnation of the pores between multifilaments with fluoropolymer. At the same time, the manipulation properties of the prostheses remain stable and their biocompatibility and bioresistance increase. Physico-mechanical, medical, biological and clinical tests allowed us to determine the optimal knitting structures of the endoprostheses we developed.
PHENOMENA OCCURRING DURING LONGITUDINAL TENSION PULSES IN VISCO-ELASTIC LINEAR TEXTILE PRODUCTS
A feasible possibility exists of generating longitudinal loads in the form of tension pulses during the processing and use of visco-elastic linear textile products. The propagation of such pulses can be accompanied by hitherto unexamined phenomena different from those occurring over the time of static loading; among other such, the phenomenon of potential destruction can appear. The generation and propagation of tension pulses in a linear textile object fastened between two insuperable barriers are discussed in this work. The investigation's results allow us to state that during the time of tension pulse propagation, the selection of the tension pulse (which is only one of the longitudinal loads acting on a linear textile product) is fully justified. The destruction of thread can be accompanied with tension pulse propagation, but in contrast to other typical longitudinal loads, this destruction can differ along the whole length of the pulse. Under conditions of repeated one-directional pulse stimulation, and considering the attenuation of this forcing, a linear aniso-destruction of the tread can appear as the result of its destruction. In the case when only one insuperable barrier exists, two different zones of potential destruction of the linear textile product will occur, whereas three different zones are observed with two barriers.