The Production Process Of Brake Pads
(1) Select recipe: The key to the performance of the brake pads is the formula. Good formula and effective process control can achieve stable performance and high performance products. These two points are the standards that the automobile factory can judge whether the product has the ability to match the original factory.
(2) Ingredients, mixing materials: The raw materials are metered by the computer automatic batching system according to the proportion determined by the formula, and poured into the mixing machine to be fully stirred until uniform. A large number of small factories do not have an automatic batching system, but use manual methods. From the perspective of quality management, there is a possibility of artificial failure, and once it fails, it is a large batch.
(3) Degreasing of steel backing: Steel backing will be oily during the blanking process and cleaned with hot water or ultrasonic wave with cleaning agent. Whether the clean standard can be tested by the water immersion method requires three inspections per shift and a record.
(4) Steel back plate rust removal: The steel back plate cleaned and degreased is placed in a track type shot blasting machine to remove sand and remove the rust on the steel back surface.
(5) Gluing of steel backing plate: uniformly spraying or rolling a layer of thermosetting adhesive on the side of the steel backing plate and the friction material to tightly bond the friction material and the rigid backing plate in the subsequent vulcanization process. Together. This process is a key control node in the production process, and the thickness and uniformity of the glue must be tested and recorded for each shift. Because the loss of control of the process may be caused by the release of the product, resulting in a traffic accident.
(6) Hot pressing: At present, the better hot pressing process of the disc brake pad adopts a one-step forming method, that is, the mixture is poured into the cavity, leveled, and then the steel back is placed in the mold and positioned. Pressed automatically by the press at a given time and temperature. This process is the most prone to non-conformity in the brake pad production process. Temperature, pressure, and process are the three main points of the process. In the daily quality control process, these three elements must be monitored and recorded in real time. Some manufacturers now use the secondary molding process, which is to first press the mixture into a cold billet and then vulcanize it into a vulcanized sheet. The process has a serious drawback, that is, the thickness of the product is determined by the thickness of the vulcanized plate. No matter how much or less you invest, the thickness of the product is the same, but the density varies greatly, which leads to the product. Performance varies greatly.
(7) Heat treatment: The purpose of heat treatment is to fully cure the product in the furnace according to certain process temperature requirements. The physical properties of various components of the brake pad after heat treatment tend to be stable. This process is also a key point of quality control. The heat treatment furnace requirements must be automatic temperature control, uniform temperature in the furnace, and all heat treatment process data must be traceable.
(8) Shape processing: The friction and wear characteristics of the brake pads obtained through the above process have been determined. Subsequent grinding, spray molding, and packaging only change the appearance and basically cannot change their physical properties. However, there are two kinds of processes that need to be explained: first, slotting, chamfering, and muffling. The original intention is that when the main engine factory is equipped, when all the performance meets the requirements but the noise is not ideal, the designer will slot and chamfer. Or the way of muting the sound film changes the natural frequency of the brake pad to achieve noise reduction. The second is the surface ablation process, which is mainly applied to ceramic formula products. As a consumer, the surface of the friction material of the ceramic product is burnt. The method is to ablate the surface of the friction material at 600~800 °C before leaving the factory. The surface organic matter is rapidly decomposed and gasified to prevent thermal decay and air cushion generation when the first foot is braked, and the product can be quickly combined with the disc to ensure the braking effect. Generally, the thickness of the ablation layer is 0.3 to 1 mm.