The objectives of this research are to study the rate of deterioration of tyre friction coefficient and investigate the quality of new and old tyres that are currently in use. A set of the rolling resistance testing was designed and set up to work with the single dynamometer according to speed 80 km/h tire load 4660 N and inflation pressure 30 psi. There were three tire samples new tire one year used tire and two year used tire to find the rolling resistance coefficients. The finding shows that the rolling resistance was inverse variation with tire aging. For instance the new tire (1st sample) had the highest rolling resistance on the other hand the two year used tire (3th sample) had the lowest rolling resistance. Moreover the rolling resistance coefficients were inverses variation with tire aging. Besides the one year used tire had the average of the decreasing rate of the rolling resistance coefficient at 0.03689 N/kN per a week while the two year had the average of the decreasing rate of the rolling resistance coefficient at 0.03671 N/kN per a week. Furthermore the result also revealed that the rolling resistance coefficients nonlinearly decreased comparing to the tire aging.

Nowadays one of the automotive engineering is conductivity of brake pads playing a role in friction coefficient which means safety of customer. Thus thermal properties have been improved using composited materials. This project aims to study the heat capacity behavior of 3 different brake pads which are supported by the company Compact International (1994) Ltd. For experimental works temperature based on brake condition was simulated from 05 to 003°C at 5 MPa of pressure. By standard JIS D4413 testing condition of pressure was referred. The heat capacity values of brake pads are calculated under the temperature conditions. As a result of testing brake pad made of copper or high metal powders result in relatively low heat capacity. On the other hand brake pads containing fiber and a large amount of fillers result in an increased heat capacity and stability in various temperature conditions. The heat capacity varied according to the operating temperature. In addition the lubricant contained in the brake pads affects the higher heat capacity and stability at various temperatures.

Nowadays one of the automotive engineering is conductivity of brake pads playing a role in friction coefficient which means safety of customer. Thus thermal properties have been improved using composited materials. This project aims to study the conductivity behavior of 3 different brake pads which are supported by the company Compact International (1994) Ltd. For experimental works temperature based on brake condition was simulated from 200 to 400°C and cooled down from 400 to 200°C at 1 5 and 8 MPa of pressure respectively. By standard JIS D4413 testing condition of pressure was referred. The non-linear of conductivity value are calculated from the temperature under steady state condition. As a result of testing there are several of parameters effecting on the non-linear conductivity value. The brake pad that is a mix of high-fiber affects the fluctuation of thermal conductivity. At the same time lubricant in the brake pad cause the stability of conductivity value in different temperature range at the same pressure. On the other hand the brake pad mixed hi-copper inspires the narrow range of conductivity value in different pressures at the same temperature. Moreover the conductivity value as a mention is inversely proportion with the coefficient of kinetic friction.

Nowadays the automotive industry in Thailand has been widely growing. Brake pad is one of the automotive products that play a vital role in automotive industry because it is the most critical seeurity part. Consequently testing products for quality are extremely requested. However the precise equipment and function tests which show the real effects are not available enough and cost a lot. Therefore they cannot response to the deman in the automotive industry development. In this study the frictional test jigs for friction measurement JIS K7125 [5] and the clutch facings for automobiles JIS D4311 [6]. A study of the frictional test emphasizes on the static friction (μs) and kinetic friction (μk) in different condition. There are 3 specimens of brake pad supposted by the industry company. These specimens were tested and the results from the pin-ondisk and those from the friction testing were compared. The results revealed the correspondence of the two-sided results but the pin-on-disk’s friction coefficient is more than the friction testing’s friction coefficient by 19.56%. Moreover the coefficient of friction varies according to the temperature Besides the static friction (μs) is likely more than kinetic friction (μk) and tends to differ considerably under high pressure condition.

Nowadays the Thailand automotive industry widely grows. Brakepad is one of the automotive productions that role to automotive industry because it is the most critical security parts. Consequently testing products for quality are extremely requested. However the equipment and function tests are not enough and are also high cost so it cannot supports to the automotive industry development. In this work the initiation and design of frictional test were carried out. The testing procedure is referred to The special test jigs for friction measurements JIS K7125[5] and Clutch facings for automobiles JIS D4311[6].A study of the frictional test emphasize on the static friction(l-ls) and kinetic friction(l-lk) in different condition. There are 3 specimens of brake pad supported by the industry company. These specimens were test and compared between the pin on disks result and the friction testings result. The two-sided results from the analysis correspond but the pin on disks friction coefficient is more than the friction testings friction coefficient by 19.56%. Moreover the coefficient of friction tends to follow the temperature. Besides the static friction(l-ls) is likely more than kinetic friction(l-lk) and will be high difference in high pressure condition.