CARPET WASTE, AN EXPENSIVE LUXURY WE MUST DO WITHOUT!
In the U.K. the carpet industry accounts for L935 million of income each year. About 7% or L65 million of would-be extra earning is annually lost in the form of waste produced during manufacturing processes and fittings.
In a recent confidential study made under the Environmental Technology Best Practice Programme landfill was identified as the main destination for most carpet waste with incineration a close second. Cost of disposal to landfill is currently estimated at about L750,000 a year. However, with increasing public concern for the environment, this figure is already rising due to introduction of large tax duties on the use of landfill. Manufacturers are consequently under pressure to reduce waste and find alternative means of utilising their waste.
This paper, in the first instance, investigates the sources of waste along the entire carpet manufacturing route and assesses their quantitative measurement. It then critically reviews the current methods of dealing with processed and post consumer wastes, exploring the various methodologies applied. In conclusion the paper recommends short and long term solutions with respect to current legislative and environmental issues and calls for novel and prime quality products utilising carpet wastes as valuable raw materials rather than cheap secondary implants.
Life Cycle Assessment ENVIRONMENTAL PROFILE OF COTTON AND POLYESTER-COTTON FABRICS
The aim of this study was to increase the knowledge of environmental impact associated with producing fabrics for hotel textile services. The project was carried out in two parts: studies on hotel textiles and on textile services in three major Scandinavian laundering companies. This paper presents the results of the hotel textile study. The environmental impact was studied by applying the main principles of the life cycle assessment (LCA) methodology. Life-cycle assessments provide useful information on the quantities of energy and resources consumed and emissions associated with production systems. The impact assessment is still under development but some scenarios have been made to describe possible local, regional and global environmental consequences of the system under study. The inventory calculations proved that cotton fibre production consumes about 40% less energy than polyester fibre production. Cotton growing requires, however, huge amounts of water: irrigated amounts vary from 7 to 29 tons per kg of raw cotton fibres. Pesticides and fertilizers used in traditional cotton cultivation have ecotoxic effects in contrast to organic cotton cultivation, where natural alternatives to agrochemicals are used. It could also be concluded that 50/50 CO/PES sheets in hotel use have fewer environmental impacts than 100% CO sheets. This is due to the higher durability as well as lower laundering energy requirements of 50/50 CO/PES sheets.
PROCESS CONTROL FOR TOTAL QUALITY IN CIRCULAR KNITTING
This paper deals with a problem of major concern to the knitting industry, which is fabric defects. When a defect occurs, the knitting machine has to be stopped and the fault corrected, thus resulting in time loss which is uneconomic. Eventually, the knitted fabric may be rejected if quality requirements are not met. An effective monitoring of the knitting process is required in order to avoid or detect and locate a defect and its cause as soon as possible, avoiding productivity and quality losses.
In circular knitting machines the yarn input tension (Ti) can be used as a means of process control, so that defects may be prevented or quickly detected. This was found to be a valuable approach to accomplish this task, since it reflects the general behaviour of the knitting machine. A measuring system is presented, along with the results obtained. Considerations are made around the problem of automatic detection and some approaches are suggested. Finally, some conclusions are drawn from the work developed.
POSSIBILITIES TO MEASURE THE CONCENTRATION OF SODIUM DITHIONITE IN TEXTILE APPLICATIONS BY MEANS OF AMPEROMETRIC SENSORS
By using linear sweep voltammetry and chronoamperometry at a rotating disc electrode it was found that sodium dithionite can be oxidised at several electrode materials. At platinum, palladium, glassy carbon and gold an oxidation reaction was observed that showed promising characteristics for analytical purposes and sensor development. The limiting current signal at a potential of +0.3 V vs. SSE is proportional to the concentration of sodium dithionite, the electrode reacts almost immediately on a change of concentration of sodium dithionite and experimental proof is given that the electrode is stable for at least 3 days without recalibration. The electrode can be calibrated by a one point calibration because the calibration curve is linear and goes through the origin.
INVESTIGATIONS OF THE STRUCTURE AND PROCESS PARAMETERS OF SEWING OPERATION
Original measuring equipment is presented, together with the systems aimed at investigating process parameters of the operation structure and establishing optimal working methods to evaluate properly real working conditions of the man-machine system in garment engineering and technologies. The measuring equipment consists of the system for measuring and storing data on process parameters and bi-plane system of video recording. The system for measuring and data storage is equipped with four sensors, which measure rotation speed of the main shaft, arm movements in the taking and laying-off zones, as well as the movements of pedal regulator, used to manage and control the overall sewing dynamics, all in a simultaneous and contactless manner. Bi-plane system of video recordings is used to record simultaneously the working movement systems (working methods) at the workplace analysed. The operation of seam sewing on the front part of a ladies' costume is analysed on a designed workplace, using the above described measuring equipment and system of measuring. The whole cycle of recording the technological operation included 10 consecutive executions, while the operation is performed by an operator of an average level of skill (KPZ = 1,00, coefficient of proficiency). On the basis of process parameter measurements, employing computer processing of the signals from the sensors, graphs are obtained for the technological operation structure, with the duration of individual suboperations indicated, and also showing the changes occurring in the course of sewing caused by pedal regulator movements (which manage and control the overall dynamics of sewing and the function of the processing microcomputer of the sewing machine. Bi-plane video recording system is used to investigate the working method employed, basic movements and optimal logical sets of movements, as well as the cyclograms of the movements, used to define spatial and temporal values. The results obtained are compared with the system of synthetic normal time (MTM) and indicate negligible discrepancies.