What are the precautions for making precision liquid Silicone Glass Fiber Tube?

What is a precision liquid Silicone Glass Fiber Tube, today I will give you a preliminary understanding, and then I will explain the key points that need to be paid attention to. There are many differences between liquid silicone and traditional thermoplastic rubber processing, which increases the difficulty of processing. LSR is quite different from traditional thermoplastic materials in terms of shrinkage, mold release, mold materials, cold runner system, and temperature control, which makes the processing of LSR more difficult than ordinary thermoplastics. Most of the waterproof Insulation Tubes of smartphones are secondary molded on the original metal or plastic parts. At the same time, the volume is smaller than the commonly used Insulation Tubes, and the requirements for matching with the casing and accessories are higher, and more precise (trace) parts are required. Injection molding technology.

1. Full mixing of liquid silica gel
①Precise mixing ratio: LSR is a two-component raw material of A and B. Before injection molding, it must be fully mixed according to an accurate 1:1 ratio. If it is a colored precision liquid Silicone Glass Fiber Tube, the color paste ratio must also be precisely controlled.
②Mixer: The static mixer is a key part in injection molding. Only after the A and B glues are fully and evenly mixed by the static mixer can the liquid silicone injected into the mold be completely vulcanized and molded.
2. Sealing and temperature control of injection molding machine components
①Due to the low viscosity of LSR, the screw must be sealed to consider the material backflow and glue leakage.
②Because the mold is heated during the molding process of the precision liquid Silicone Glass Fiber Tube, in order to prevent the lsr from solidifying, a water-cooled nozzle can be used to ensure that the temperature is low enough.
3. Finished product control in the injection molding process
① Parting line: Pre-consider the position and accuracy of the parting line to help avoid air entrainment and welding, and avoid burrs.
②Shrinkage: Although LSR does not shrink during injection molding, due to its extremely high thermal expansion coefficient, it usually shrinks by 2%-3% after demoulding and cooling.
③Position of the injection port: The shrinkage rate of the actual product needs to be considered.
④ Vacuuming: When designing the parting line, ensure that the mold is airtight, and the vacuum pump vacuumizes all the cavities through the clamp under the mold switch.
⑤Demolding: Generally, the demoulding technology of fractionating column tray, ejector pin and air ejector is used, or manual demoulding.
⑥ Mold temperature: LSR is vulcanized and molded in heating, and the temperature distribution in the mold must be controlled evenly. The temperature difference is controlled at ±10°C.