| 摘要 |
<p>An oil filter (10) utilizes a thermoplastic material (22) having oil oxidation and acidification arresting additives mounted in a casing (11) between particulate filtering material (19) and a felt pad (21). The thermoplastic material is desirably high molecular weight polypropylene in the form of rice-shaped pellets, or spaghetti-shaped strands. The additives include about 10-17 weight % of the thermoplastic material/additive combination, and as the thermoplastic material is dissolved by the above ambient temperature oil, the additives are released. The thermoplastic material pellets or strands are formed by mixing anti-oxidation and anti-acidification additives with liquid thermoplastic material to form a mixture, extruding the mixture into spaghetti-like strands having a thickness of about .0625-.125 inches, cooling the strands, cutting the strands into discrete elements, and then placing the discrete elements into an oil filter held in place to contact oil to gradually dissolve to release the additives.</p> |
