Skeleton oil seal manufacturing quality points

The focus of quality control of skeleton oil seal manufacturing is the quality of raw materials, mould quality, mixing quality, metal skeleton surface treatment and adhesive coating quality, vulcanization quality, lip cutting quality, and product quality control before warehousing.

1. raw material quality; raw material quality is generally tested by physical and chemical analysis and small fit test, but in actual production there will be physical and chemical properties of raw materials (such as component content, melting point, ash, heating reduction, etc.) and small fit rubber performance to meet the requirements but the product quality is not satisfactory. For this reason, in addition to physical and chemical analysis of raw materials and small fit tests, the company also conducts large fit tests and product trials, and follows up the quality of the whole trial process to ensure that no production and product quality problems arise before putting the raw materials into use.

2. Mould quality; mould quality not only affects product geometry, dimensional accuracy and appearance quality, but also affects material loading and product demoulding, so quality inspection of new moulds and old moulds after using for a certain period of time (mould trial) is an extremely important quality control point in the oil seal manufacturing process. This quality control point is equipped with vulcanisation equipment and relevant technical documents such as product drawings, mould drawings and rubber performance test reports.

The products made during the mould trial are subjected to dimensional measurement, slice projection test and bench simulation test, and the mould can be put into use if the size and performance of the products are qualified. In addition, during the mould trials, the vulcanisation temperature, time, pressure, shape and quality of the semi-finished product, mould loading and demoulding procedures are determined and incorporated into the process documentation.

3. Kneader quality; Kneader quality control points are configured with work instructions, kneading process cards, kneader performance indicators, charge records, quality control frequencies and other relevant technical documents. The quality inspection of the compounding rubber includes process inspection and performance inspection. The process inspection items include mixing operation procedures, addition sequence, temperature and time, etc. The performance inspection items include the quality of each truckload of rubber, vulcanization curve and parameters, hardness, density and dispersion, etc.

4. metal skeleton surface treatment and adhesive coating quality; metal skeleton surface treatment and adhesive coating quality not only affect the rubber and skeleton bonding performance, but also affect the vulcanization process performance. This process point is a weak link in the production of oil seals, and the quality control point is configured with work instructions, quality control indicators, charge records and other relevant technical documents. The quality control point mainly controls the phosphate treatment of alkaline washing, acid washing, cold water rinsing, table conditioning, phosphating, passivation, drying temperature and time, the total acidity of the phosphate solution, free acidity and adhesive concentration, etc., while recording these parameters, no less than two times per shift.

5. Vulcanization and lip cutting quality; vulcanization is a more concentrated quality problems in the process, the process in addition to review the quality of semi-finished products from the previous process, it is more important to strictly control the vulcanization temperature, time, pressure and the vacuum and hot plate parallelism of the vulcanizer. The control of cutting quality of oil seal lip is focused on cutting angle speed, feed speed, tool sharpness and positioning of fixed oil seal tire or head. 6. Product quality before warehousing; product quality inspection before warehousing is the last level of network control, for common products, it is generally sampling inspection of size and appearance quality; for key products (such as engine oil seal, etc.), it is necessary to gradually inspect size and appearance For key products (e.g. engine oil seals, etc.), the dimensional and appearance quality must be tested gradually, and at the same time, 6 samples of each batch of products must be taken out for 240h bench operation test, and the batch of products can be stored and delivered only after passing the test.