Research On The Wear Behavior Of UC24 Conveyor Chain Based On Tests

Abstract:UC24-a kind of conveyor chain made of plastic material is commonly used in automatic transferring, assembly and packing food, can, drink, and dairy food, etc. This thesis is sponsored by Tetra Pak aiming to research the wear problem of UC24 conveyor chain and PC23 conveyor chain. Tetra Pak is a well known transnational corporation headquartered in Lausanne, Switzerland; it has 11 research and development centers in the world, and supply best solutions for the liquid food companies, including processing equipment, packing and distribution production line.The main contents of the thesis are as follows:1. The background of the thesis is described. The features of conveyor chain are introduced. The present research situation in and abroad on friction and wear of plastic material is summarized, and factors influencing the friction and wear of plastics are stated, such as coefficient of friction, load, temperature, speed, lubrication, surface roughness, sliding distance, pv value and thermal behavior.2. A serial of material experiments are finished. UC24 and PC23 conveyor chains and their sliding rails are identified. And their thermal property, physical and mechanical properties are characterized. Element analysis, infrared spectrum (IR), differential scanning calorimetry (DSC), thermal gravity (TG), x-ray diffraction (XRD), density measuring, coefficient of friction, hardness, vicat softening point, tensile strength and bending stress are included.3. A friction and wear test rig is researched and developed aiming to do friction and wear tests of UC24 and PC23 wear pairs, which is capable of simulating reciprocating linear sliding. A constant-diameter cam mechanism is designed to realize reciprocating sliding of UC24 and PC23 in this test rig, and dead weight loading mode is employed. Infrared sensor is employed to test the contacting temperature of the wear pair; balance is employed to measure the weight of UC24 and PC23 conveyor chains and sliding rails; ultrasonic thickness meter is employed to thickness of UC24 and PC23 conveyor chains. 4. Friction and wear tests of UC24 and PC23 are designed employing orthogonal experiment design method. Seven factors are advanced based on field investigation to the application of the conveyor chain to design the tests, such as grain, load, water, milk, the area of sliding rail, the width of conveyor and connection.5. Research on tests is performed. After a 350 hours'pre-test,3 groups of orthogonal tests of UC24 and PC23 are performed, and every group of tests lasts 200 hours.2109 test data of weight loss, thickness variation and contacting temperature variation are got. And 393 detailed graphs of wear and SEM photographs are got.6. Two commonly used analysis methods to the orthogonal experiment are employed, range analysis and variance analysis. Analysis to the test data is finished, based on analysis to the test result, the conclusion can be got:water is a very important factor influencing the wear of UC24 and PC23 conveyor chains; the effect of load, width of conveyor and the connection on wear is not obvious. The wear of UC24 and PC23 mainly occurs on the conveyor chain, but the wear of sliding rails can be ignored.