Seals are usually used as spare parts and are stored for a long time. Under the influence of: distortion, oxygen, ozone, light, heat, moisture, oil or solvents, O-rings may fail due to changes in their physical and chemical properties. In DIN7716, ISO2230, DIN9088 and other standards on the size of rubber seals, cleaning, maintenance of the basic provisions. Depending on the type of material, these standards specify storage conditions and recommended values for storage periods.
In order to maintain the physical and chemical properties of elastomers, please follow the following storage rules, the purpose of which is to maintain an optimal storage condition:
◆ Temperature: 5℃ to 25℃ is the ideal storage temperature. Avoid contact with heat sources and sunlight. For seals removed from low-temperature storage, they should be placed in an environment of 20 ° C for a period of time before use.
◆ Humidity: The relative humidity of the warehouse should be lower than 70%, to avoid too wet or too dry, condensation can not occur.
◆ Illumination: Avoid sunlight and strong artificial light sources containing ultraviolet rays. Uv protective packaging provides ****** protection. It is recommended that warehouse Windows be painted with red or orange paint or sunscreen film.
◆ Radiation: To avoid ionizing radiation damage to the seal.
◆ Oxygen and ozone: Rubber materials should avoid exposure to circulating air. This can be achieved by packaging, winding, storage in an airtight container or other suitable means. Ozone is harmful to many elastomers, and the following equipment should be avoided in the storage room: mercury vapor lamps, high-voltage electrical equipment, electric motors, and equipment that will produce sparks or static electricity.
◆ Deformation: The elastomer material should be placed in a free state as far as possible to avoid stretching, compression or other deformation. If the original packaging elastomer is in a non-deformation state, the original packaging should be used as far as possible.
Contact with liquid or semi-solid materials: Rubber seals must not come into contact with solvents, grease, or other semi-solid materials (unless the manufacturer's original packaging).
Contact with metallic or non-metallic materials: Do not contact magnetic materials, cast iron, copper and alloys, or those containing materials that will damage rubber. Do not use PVC material to pack seals. Seals of different materials shall not be mixed together.
◆ Cleaning: According to the need, you can use soap, water to clean the seal. However, water is not allowed to contact fiber reinforced seals, rubber metal bonded seals, AU parts. Disinfectants, organic solvents and tools with sharp edges are not allowed. After cleaning the seal should be dried at room temperature, not close to the heat source.
Retention period and monitoring
The shelf life of elastomers is determined by the type of rubber material. Under recommended storage conditions. The shelf life of these materials is as follows:
Four years of polyurethane, thermoplastic materials
Butadiene rubber, hydrogenated butadiene rubber, neoprene rubber 6 years
Ethylene propylene rubber for eight years
Fluoro rubber, silicone rubber, fluoro silicone rubber 10 years
Ptfe indefinitely
After the above period, it should be checked before use. After inspection, or possibly for a while. Even if stored in the above good condition, rubber with a thickness of less than 1.5mm is easy to oxidize and fail. Therefore, for such products, even in the above years, it is necessary to check and test frequently.