The measures to improve the sealing and water resistance of LED point light source die castings include the improvement of sand casting process, casting treatment, structure avoidance, etc.
1. Improvement of sand casting process for LED point light source die castings
There are several methods to improve sand casting process:
(1) Keep pressure and heat preservation for sufficient time, and cool it naturally. Use appropriate force to take parts, and avoid cracks caused by cold cracks and hot cracks in the process.
(2) Optimize the gating system to avoid sand holes.
(3) Select appropriate molding sand to enhance air permeability.
(4) Improve the air permeability of the die and reduce shrinkage.
(5) The molten liquid metal shall be thoroughly filtered and deoxidized.
2. LED point light source die casting processing
The casting treatment measures are as follows:
(1) The inner wall shall be painted with 2-3 roof three proofing paint, or precoated with liquid sealant. Pay attention to uniformity.
(2) It is fully filled with glue, but the cost is high and the waste is serious. Small ones can be used.
(3) For the parts with serious or concentrated leakage, brazing can be adopted, including copper based brazing, silver based brazing, aluminum based brazing, etc., and the purpose of improving pore leakage can be achieved by melting, spreading, wetting, capillary invasion, etc. of solder.
3. LED point light source die casting structure avoidance
The structural avoidance methods are as follows:
(1) Do not directly use the casting as a waterproof shell, or just use the casting shell as a structural fastener, support seat, connector, bracket, etc. in addition, do decentralized and independent structural waterproof, such as inner core waterproof, light source component waterproof, power independent waterproof, drive independent waterproof, etc.
(2) At the proper position of the water outlet, the water can be discharged easily and smoothly even if the water enters.