Quality and performance testing of polyurethane seals
Quality and performance testing of polyurethane seals 1. Appearance product quality inspection Seals are divided into drum-shaped polyurethane material silicone sealing rings, bud-shaped polyurethane material silicone sealing rings and dust rings and flat washers. The surface layer of the polyurethane material sealing ring is divided into a working surface and a non-working surface. The working table refers to the side that the system presses on the internal structure, and has an immediate sealing effect on the contact area between the engine block and the piston rod, the cylinder port and the hydraulic cylinder, and the non-working table refers to the rest except the working table. The position of the protruding lip in the inner hole of the drum-shaped polyurethane material sealing ring is the leading work surface, and the position of the round protruding lip is the non-working surface: the position of the protruding lip in the inner hole of the bud-shaped polyurethane sealing ring is the main work surface. The table top, the position of the inner hole protruding lip is its non-working table. The working surface and the non-working surface are only relatively speaking. When working, the sealing ring as a whole is in a running state and plays a sealing function. Therefore, the non-working surface is also particularly critical. 1. General Standard for Quality Inspection of Appearance Products (1) Applicable standard. Taking the performance index that does not harm the seal as the rule (2) the work surface is the key to detection. The regulations are strictly enforced, and there is no distinction between all the defects that may endanger the performance indicators of the product: the pressure can be appropriately released for the needs of non-working surfaces: (3) The total number of problems with the sealing ring of the large-aperture series products is smaller than that of the sealing ring. And the size can be moderately released, especially for non-working surfaces, the principle of not jeopardizing performance indicators. 2. Regulations on product quality inspection of appearance (1) The appearance of the sealing ring stipulates that the appearance of the sealing ring should be neat, without deformation, distortion, damage, and should be neat, without burrs, burrs, and damage; the color should be bright, not blurred Clear and turbid: The sealing ring should be smooth and smooth by hand magnetic induction, and should not be rough. When squeezing the sealing ring, it should feel that it has significant ductility and toughness, and the hardness should be moderate; (2) The appearance and quality inspection of the sealing ring work surface requires sealing The surface of the ring work surface is shiny and clean, and all defects such as bubbles, residues, porosity, cracks, scratches, etc. that endanger the performance indicators of the sealing ring are not allowed, otherwise it is judged as a special feature: (3) The sealing ring is not outside the work surface Type judgment stipulates that the size of defects such as bubbles, residues, and convexities and concavities on the non-working surface, the aperture or length should not exceed 2mm, the relative height or depth should not exceed 0.5mm, and the total number of defects on the same sealing ring should not exceed 4; (4) The appearance quality inspection of the dust ring and the flat washer stipulates that the surface must be flat and clean, and no porosity, residue cracks, and burrs are allowed; however, apertures are allowed.<There are 1~2 air bubbles of 1mm.