الفهرس 
Chapter One: Introduction And Literature ReviewOnly 14 pages are availabe for public view
 |  | from | 121 |  |  |
| | | from | 121 | | |
Abstract
Polymeric materials are widely used in floor material in hospitals, factories and detention centers. This is because of the low cost of these materials, the high friction coefficient, the ease of replacement or change and the high resistance to the formation of bacteria.
This study aims to reduce the electrostatic charge generated on the polypropylene shoe when walking against floor material (A and B), and enhance the coefficient of friction. By configuring strips of copper and stainless steel by 5 x 200 mm² and thickness 0.1 mm in different numbers of strips (0, 1, 2, 3, 4, 5, 6), the copper strips conducted in series with 0.5 mm copper wire while stainless steel conducted in series with 0.5 mm wire with 70 % concentration of tin. The metal strips were added in the back of floor material (A and B) sheets of 300 × 400 mm² area and 2 mm thickness, the tests were carried out at room temperature and under the different normal loads ranging from 20 : 200 N. The experimental tests were carried out by using (ungrounded and grounded) strips in both: dry medium and Water + 1.0 % chlorine dilution medium. The first test was contact to 10 seconds followed by separation to measure the electric field (generated charge) by using (Ultra Stable Surface Voltmeter). On the other hand, the second test was a sliding test to 200 and 300 mm against floor material to measure the electric field and friction coefficient by using (friction test rig), the friction coefficient is determined by dividing each friction force over its normal force.
Besides, on the experimental results it was observed that:-
• At dry contact, voltage significantly increased by increasing normal load and by increasing the number of copper strips, because the increase of copper area collected double layer of ESC generated on the floor material higher than that observed during using floor material free of strips.
• The voltage decreased more in the presence of water/chlorine film because of the relative good conductivity of water.
• At dry sliding, thus, an electric field is generated leading to the generation of an extra ESC, especially in the presence of copper strips. The increase of ESC consequently increases the adhesion force between the two surfaces, which leads to the increase of friction coefficient.
• The grounding system significantly decreases the voltage in floor material fitted by six strips. On the other hand, the presence of water/chlorine wet surface decreased the voltage where the water distributed the ESC. The friction coefficient slightly decreased 7 %, which confirms the safety of the floor material and prevents slip accidents during walking especially in the presence of water.
• When using stainless steel strips, it was observed that the ESC and friction coefficient were lower than that generated when using copper strips, because the electrical conductivity of the stainless steel was lower than the copper.
• The grounded stainless steel strips increased the charge by 3 % and reduced the friction coefficient by 4-5 % compared to ungrounded strips.
• The floor material B generated ESC lower than that observed in floor material A.
That may be attributed to the relatively higher electrical resistance of material B than A.