A customer considers many factors while opting a new car such as stylish design, premium material quality, and comfort. While considering the quality of the car, one of the major customer concern is annoying and frustrating squeak noise of interior plastic parts. In this study, many factors such as environmental conditions like humidity and temperature variations, vibration & weather ageing and surface texture were included which may affect squeak characteristic of plastic part's material over a period of usage.
To check compatibility of plastic materials, two materials were rubbed with each other using SSP-04 machine at different normal force & velocity and generate result as Risk Priority number. Based on RPN value, different material combinations were categorized into three squeak zones as No Risk, Low Risk & High Risk based on which squeak free material combination is finalized. Also, Environmental conditions such as temperature & relative humidity were included while performing material compatibility test and RPN variation was observed with change in temperature & humidity. To analyze weather ageing effect on plastic material, artificial thermal ageing of PC-ABS was conducted for 1500 hours as per test standard SAE-J2412 and same aged sample were tested to evaluate squeak characteristic of material. Similarly, to check vibration ageing effect; plastic material sample like PPTD20, PC-ABS were collected from vibration aged component and same compatibility test was conducted to analyze material performance regarding squeak risk.
Some prevention solutions such as anti- squeak spray & felt were explored which helped in elimination of squeak risk. But implementation of these solutions is not always possible due to aesthetic point of view and constraint in accessibility of materials. Therefore, worked on two new solutions to avoid squeak risk: (a) surface texture and (b) material damping. Good results were observed in terms of reduction in impulse rate, acceleration and coefficient of friction.
Mr. Amit Kumar, Mahindra & Mahindra Ltd, INDIA; Mrs. Edlin Lewis, Mahindra & Mahindra Ltd., INDIA; Mr. Mohammed Riyazuddin, Mahindra & Mahindra Ltd., INDIA; Mr. Raghavendran Prasath, Mahindra & Mahindra Ltd., INDIA; Mr. Sandeep Shukla, Mahindra & Mahindra Ltd., INDIA