Sealing Ring

Sealing Ring Purpose/ Function: 1. Its function is to make the cluster water/ air tight. 2. It prevents damage/ Breakage to crystal by absorbing shocks. 3. It is employed when glass is used as crystal material. 4. It is wrapped around the edges of crystal and crystal is placed in the slot provided in the housing. Possible Modes of Failure: 1. Damage/ breakage of sealing ring due o excessive tightening. 2. Sealing ring comes out of crystal due to vibrations and other fitment defects. 3. Damage to sealing ring due to environmental conditions such as moisture, water entry etc. 4. Oversize / undersize of sealing ring. This leads to problems in fitment and leakage of water/ dust from outside. 5. Tearing of ring by edges of crystal 6. Development of cracks due to atmospheric OZON or UV rays. Design Procedure: 1. Determine the accurate length of sealing ring to be used by calculating profile length of crystal. 2. Determine thickness of ring from strength point of view. 3. Provide slot in the housing / crystal equal to thickness of sealing ring. 4. Design the 3D model to make it water tight. Draw sections at possible areas of leakage and check layout to ensure that joint is water tight. 5. The material should hold the glass firmly. 6. Select suitable material which can withstand effects of environment. 7. Generally Nitrile rubber or NEPE foam is used as material for sealing ring. Material: 1. Nitrile Rubber 2. NEPE foam

Properties of Material: Properties of Nitrile Rubber: Non-vulcanized physicals Mooney data Plasticity, Ms (1+4) @ 100°C Scorch @ 121°C Rheometer, Monsanto @ 150°C Minimum viscosity, inch-lbs. Maximum torque, inch-lbs Cure time T-90, minutes Vulcanized properties Tensile, daN/CM2 Elongation, % 100% Modulus, daN/CM2 Durometer (International) Compression, % Degree of abrasion, MM3 Tear resistance, daN/CM2 Aged physicals, 7 days @ 100°C Tensile, daN/CM2 Elongation, % Durometer (International)

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Norsolene® S-95

89.0 12.5

80.0 25.5

31.8 152.4 6.5

16.0 100.5 10.0

266.0 195.0 136.0 81.0 26.0 122.0 51.0

216.0 278.0 85.0 75.0 28.0 116.0 46.0

263.0 120.0 87.5

219.0 162.0 82.0