Alex Fotheringham

Evaluation of nonwoven polypropylene oil sorbents in marine oil-spill recovery.

Mechanical recovery of oil by oil sorbents is one of the most important countermeasures in marine oil-spill response. Polypropylene is the ideal material for marine oil-spill recovery due to its low density, low water uptake and excellent physical and chemical resistance. Different forms of polypropylene nonwoven sorbents were evaluated in this study in terms of initial oil-sorption capacities and oil-retention properties. The investigation revealed that the fibre diameter, sorbent porosity and oil property are the most important factors in the oil-sorption performance of polypropylene nonwoven sorbents.

The application of factorial experimental design to the processing of polypropylene fibres

This paper outlines the application of factorial experimental design to the processing of polypropylene (PP) fibres. Two examples are given. The first covers the effect of melt-extrusion conditions on the overall orientation of the PP macromolecular chains in as-spun fibres. The second covers the effect of drawing conditions on crystallographic order and chain orientation in the first-stage drawing of as-spun PP fibres.

ESEM study of size removal from ceramic fibers by plasma treatment

Plasma treatment has been increasingly used for surface cleaning, activation and polymerisation in many industries. In this study, the oxygen plasma treatment was used to remove the organic size from the ceramic fiber surface. The size removal from the fiber surface was characterized using an environmental scanning electron microscope. The combination of electron microanalysis and energy-dispersive X-ray allowed the observation of the fibre surface and the determination of the change in elements on the fiber surface. The use of low energy plasmas has been shown to be effective in the removal of the organic size from the ceramic fiber surfaces. It has also been revealed that the ESEM is a useful tool for surface characterization.

ESEM Study of Wetting of Untreated and Plasma Treated Polypropylene Fibers

Polypropylene (PP) fibers have been increasingly used in the technical textile industry for a variety of applications. Wetting behavior of PP fibers is of importance in these applications. The wetting behavior of the untreated and oxygen plasma treated polypropylene fibers was studied by the environmental scanning electron microscope (ESEM) in this work. Water droplets were formed on the cooled fibers by directly condensing water from the vapor phase. This was achieved by slowly increasing the vapor pressure inside the chamber towards the dew point for water at the appropriate specimen temperature. By this method small droplets in the micron range were condensed onto fiber surfaces. Contact angles of water on fiber surfaces were measured from the ESEM micrographs. The investigations have shown that the plasma treatment significantly altered the surface wettability of polypropylene fibers and that the ESEM provides a new approach to wetting and contact angle of fibers on the micron scale.

Neural modelling of polypropylene fibre processing: Predicting the structure and properties and identifying the control parameters for specified fibres

This paper describes the application of artificial intelligence to data derived from polypropylene drawing carried out at Galashiels using designed experiments. The topology of the data is visualised in two dimensions with respect to specific properties to be modelled, as a quality check on the process data. A series of neural network models are used successfully to predict the tenacity, elongation, modulus and heat shrinkage and also the crystallographic order and polymer chains orientation of the output fibres from the draw parameters values. A software harness is constructed for using the neural predictors to find the draw parameters which come closest to achieving any specified combination of fibre properties.

Factorial Optimization of the Effects of Melt-Spinning Conditions on As-spun Aliphatic-Aromatic Copolyester Fibers I. Spin Draw Ratio, Overall Orientation and Drawability

According to our previous studies [1,2], the optimum melting conditions have been achieved and lower melt flow index grade has been utilized in this work. In order to characterize the melt-spun AAC fibers, spin-draw ratio, optical birefringence and drawability were measured. The statistical optimization of fiber properties helps to produce the most satisfactory properties in the final fibers as an environmentally friendly attractive alternative to commercial chemical fibers. The importance of this model is in controlling the production process to optimize and enhance fiber properties, which may improve the quality and cost of biodegradable fibers.

Factorial optimisation of the effects of extrusion temperature profile and polymer grade on as-spun aliphatic–aromatic co-polyester fibres III: mechanical properties

The effect of extrusion temperature profile in the melt‐spinning process of as‐spun linear aliphatic–aromatic co‐polyester (AAC) fibres upon their mechanical properties and process productivity was modelled by using factorial experimental designs. After the viscoelastic and morphology characteristics of the polymer were considered using Differential Scanning Calorimetry and Melt Flow Index (MFI), the rheological data were used to determine the enhanced melt‐spinning temperature of the six heating zones in the process. Tensile strength, elongation at break, modulus and fibre productivity (g/min) of the melt‐spinning process have been quantitatively assessed as responses to polymer grades and extrusion zone temperature. The optimisation of mechanical properties and productivity helps in understanding and controlling the most desired properties in the produced fibre. It has been noted that the die head temperature (spinning temperature), the polymer grade and their interaction are the most significant factors affecting the mechanical properties. Analysis of the fibre productivity shows that the polymer grade and its interaction with the die head temperature is significant in terms of influencing the output of the melt‐spinning process, which could be related to the polymer molecular weight and polymer structure. There is an interaction between polymer grade and feeding zone temperature which is related to the material supply action in the feeding zone. The friction between the screw and the material is affected by heating action, which affects the moisture content and the molten material rheology. By adjusting the extrusion temperature profile and selecting the more applicable spin‐able polymer grade through a statistical forecasting model, the combination of the cost related to material grade and processing cost controls the fibre production cost. The fibre made of low MFI grade has better structure and mechanical properties than that made of the higher MFI grade, and the former will be preferred for future work. With previous work related to the effects of extrusion temperature profile on the fibre structure, the present paper will help in developing the production process of biodegradable linear AAC fibres.

Studying the Tensile Properties at the First Break of Multiple-Yarn Structure Fancy Gimp Yarns Using the Design of Experiments

ABSTRACT This study was conducted to identify the factors and the interactions, which affect the load and elongation at the first break of gimp yarns. The experimental design had seven factors: two levels each. It was found that using two single yarns, instead of a similar ply yarn, for the core component, caused the increase of values of load and elongation at the first break. The effect component contributed positively to the load and elongation when it was a cotton yarn rather than a bamboo yarn. This study contributes to a broader understanding of process–structure–property relationships of fancy yarn.

The influence of component stiffness on the structure of multi-thread fancy bouclé yarn

This study examines the relationships between the structure of fancy bouclé yarns and the bending stiffness of the input threads that are used to make those fancy yarns. Four fancy bouclé yarns and an extra two confirmation bouclé yarns were made to test the impact of the bending stiffness of the effect input threads. Six fancy yarns were made to test the impact of bending stiffness of the core thread on the fancy yarn structure. The structure of the fancy yarn was defined by the number of fancy profiles, the size of fancy profile, the circularity ratio of fancy profile and the shape factor of fancy yarn. It was found that increasing the value of the stiffness of the effect thread increased the size of fancy profile but decreased both the number of fancy profiles and the shape factor of fancy yarn. Those relationships were represented by regression models that were significant at α = 0.10. The deviation between the theoretical values and the real values was −14.39% and 2.07%. Further, up to a value of 8.636 g mm2, the bending stiffness of the core thread appeared not to have an effect on the structure of the fancy yarns. This study is important as it is the first that accounts statistically for the impact of bending stiffness of the input threads on the structure of the resultant fancy yarns. Therefore, it aids fancy yarn manufacturers when designing fancy yarns with predicted structures.