Structure analysis of tee
The following figure is the drawing of the through pipe parts of the mechanical casting manufacturer, which is made of gray cast iron. This is a medium-sized pipe body part with uniform wall thickness symmetrical structure. Therefore, the mold adopts vertical parting, the foam pattern is half of the part. Then, it can be glued into a complete pattern for sand box casting.
Steam pre foaming
Principle of steam pre foaming: before the resin beads are heated to softening temperature by steam, the beads do foam, but the foaming agent escapes. When the temperature rises to the softening temperature of resin, the bead begins to soften has plasticity. As the foaming agent in the bead is heated vaporized to generate pressure, the bead expands forms a honeycomb structure which is connected with each other. Once the bubble hole is formed, the vapor permeates into the bubble hole to gradually increase the pressure in the bubble hole further expand the bubble hole. In the process of cell expansion, the foaming agent also diffuses outwards escapes until the pressure inside outside the cell is equal. After cooling, the size of the beads is fixed.
The foaming process operation parameters bead pre foaming is carried out in the intermittent foaming machine. The process is as follows: → preheating → feeding → heating foaming - → discharging → drying → cleaning the silo.
The purpose of preheating is to reduce the moisture in the pre hair cylinder shorten the pre hair time. When the preheating temperature reaches the requirements, the prepared materials can be added to the pre hair machine.
After the mechanical casting manufacturer adds materials, continue to add steam, the resin beads are in boiling state in the foaming cylinder. When the material level reaches a certain height the heating time reaches the set value, stop heating.
Start the discharge valve to discharge. The discharging is completed under the double action of mixing compressed air.
The process parameters of mechanical casting manufacturer are: EPS preheating temperature 85 ℃, steam pressure 0.12mpa, pre delivery temperature 50-60 ℃, compressed air 0.5MPa. The density of beads after pre delivery shall be controlled at 20-25gl. When the density exceeds the set density, the amount of beads shall be adjusted in time. The beads after pre delivery shall be fully mixed dried in the fluidized bed, then transported to the hopper for storage for a period of time. The aging time shall be more than 12h, then sent to other hopper for storage through pneumatic conveying pipeline.