In 2015, 96.7 million tonnes of textile fibres were produced world-wide. Our high consumption of textiles leads to an increased amount of textile waste. In Sweden, the majority of used clothing and textiles are incinerated due to the lack of recycling techniques. A large amount of post-consumer textile waste is made from blended materials. One of the most common blends, used in as near as all workwear and service textiles, is cotton/polyester. To enable chemical recycling of such textiles, cotton and polyester must first be separated. The aim of this thesis was to separate the materials by depolymerizing the polyester using alkaline hydrolysis. The focus of the work was on how such a process should be performed without a catalyst, in order to result in both a high yield and a high purity of the cotton residue. In order to recycle the residue as a raw material for manufacturing of man-made cellulosic fibres, the cellulose chains in the cotton must also be maintained as unaffected as possible. The polyester in new sheets was completely depolymerized after 390 min at a temperature of 90ºC using a 10% sodium hydroxide concentration and a 1% material-to-liquor concentration. The separation using these conditions gave high yields (above 96%) of the cotton residue regardless of the material fineness used in the process. Furthermore, the separation performed on old sheets show that a pure cotton residue could be produced using higher material concentrations. It was shown that the cotton residue from old sheets, laundered around 50 times, had an intrinsic viscosity comparable to dissolving pulps used for viscose fibre spinning. This study concludes that alkaline hydrolysis without the use of a catalyst could be used to separate cotton and polyester in blended textiles. Furthermore, the findings show that cotton percentage in old sheets only decreased slightly after 50 launderings. Characterization of the materials using ATR FTIR spectroscopy indicate that an integrated textile recycling of hospital bed sheets could be performed since the sheets only contain cotton and polyester in all parts of the sheets.

As space exploration has advanced, time spent in space has increased. With the building of the International Space Station and plans for exploration missions to the Moon and Mars, astronauts will be staying in space for longer periods of time. With these increased stays in space comes an increase in fire safety concerns. One area of fire safety interest is flammability. While current flammability test procedures are in place, they are all performed on the ground and may not be representative of flammability in microgravity. In addition to this, limited research into the severity of skin burn injury in a microgravity environment has been performed. <p>An apparatus was designed to be flown on a low gravity parabolic aircraft flight to assess the flammability of cotton and 50% cotton/50% polyester fabrics and the resulting skin burn injury that would occur if these fabrics were to ignite. The apparatus, modelled after a Canadian General Standards Board standard flammability test, was also used on the ground for experiments in 1-g. Variables examined in the tests include gravity level, fabric type, air gap size, oxygen concentration, apparatus orientation, ignition source, and method used to secure the specimen. Flame spread rates, heat fluxes, and skin burn predictions determined from test results were compared. <p>Results from test in 1-g indicated that the orientation of the apparatus had a large effect on flame spread rate, heat flux and predicted skin burn times. Flame spread rates and heat fluxes were highest when the fabric was held in the vertical orientation, which resulted in the lowest predicted times to produce skin burns. Flame spread rates and heat fluxes were considerably lower in microgravity than in 1-g, which resulted in higher predicted times to produce skin burns.

As space exploration has advanced, time spent in space has increased. With the building of the International Space Station and plans for exploration missions to the Moon and Mars, astronauts will be staying in space for longer periods of time. With these increased stays in space comes an increase in fire safety concerns. One area of fire safety interest is flammability. While current flammability test procedures are in place, they are all performed on the ground and may not be representative of flammability in microgravity. In addition to this, limited research into the severity of skin burn injury in a microgravity environment has been performed. <p>An apparatus was designed to be flown on a low gravity parabolic aircraft flight to assess the flammability of cotton and 50% cotton/50% polyester fabrics and the resulting skin burn injury that would occur if these fabrics were to ignite. The apparatus, modelled after a Canadian General Standards Board standard flammability test, was also used on the ground for experiments in 1-g. Variables examined in the tests include gravity level, fabric type, air gap size, oxygen concentration, apparatus orientation, ignition source, and method used to secure the specimen. Flame spread rates, heat fluxes, and skin burn predictions determined from test results were compared. <p>Results from test in 1-g indicated that the orientation of the apparatus had a large effect on flame spread rate, heat flux and predicted skin burn times. Flame spread rates and heat fluxes were highest when the fabric was held in the vertical orientation, which resulted in the lowest predicted times to produce skin burns. Flame spread rates and heat fluxes were considerably lower in microgravity than in 1-g, which resulted in higher predicted times to produce skin burns.