Vacuum sealed molding sand processing system

V method
high precision casting dimension limits
improve the utilization rate of 20%
the equipment is simple, less investment
Vacuum sealed molding sand processing system

Vacuum seal modelling method
is also called suction modelling method or decompression modelling method, a foreign country of Vacuum English word "Vacuum, referred to as V, originated in Japan. Vacuum airproof molding is made of plastic film vacuum forming, so dry sand as the third generation of modelling method, i.e. physical model. Because the airproof molding is not used binder, simple modelling, sand material consumption to a minimum, reduce the waste of sand, improve working conditions, and improve the precision and surface quality of castings, reduce the consumption of casting production. Is a promising advanced foundry process.
V law process principle diagram
1 model
The appearance of hollow plate, appearance on lots of open air vents, when the vacuum, these holes helps to make plastic film on the appearance against.
2 the film heating
Will stretch, plastic deformation ratio of plastic film, heater.its heating soften. Heating temperature in general 80 ~ 120 degrees.
3 film forming
Will soften the mulch in appearance, through the air holes on the surface in the vacuum suction 500mmHg 300 ~ to make films in surface model.
4 and put sand box
Spray brush paint and drying process (may), also need not be special sand box in a film on the model.
5 sand-up vibration compaction
To better efficiency, filling for 100-200 purpose dry sand add sand box, then, for the vibration of sand compaction to higher density.
6 and cover
Koubei free-opening and sand layer surface, cover with plastic film, sand box sealed.
7 and mold
Vacuum flasks in atmospheric pressure, the effect of the casting. Stripping, release negative potential, remove the template for vacuum film adsorption, then, a stripping roof-box casting.
8 and box pouring
In case the need according to the process before the core and cold iron, fluctuation box together, forming a watering riser and the mold casting, in vacuum condition pouring.
9 the box down sand
The proper cooldown state of atmospheric vacuum recovery after cancel, free flow of sand, sand block to save a no, no mechanical adhering sand castings of clean. The sand cools can be used.
V method features and benefits and characteristics
plastic molding sand, through to make casting sand box type vacuum.
Due to the above characteristics make modelling, sand, cleaning processes, need not greatly simplified sand and binder supply equipment, modelling and sand processing system.
High precision castings
metal high efficiency
Because V method adopts a smooth surface castings, high precision casting dimension limits.

Because of liquid metal in responding to slow cooling cavity, metal castings, so the supply can be reduced, improve the riser metal casting, can improve the utilization rate of 20%, iron castings can improve 25%.
the equipment is simple, less investment
Because in addition to modelling method of V vacuum pump and use appropriative sand box, the equipment is simple, and can save fell sand, sand mixing machine and other auxiliary equipment, less investment, equipment maintenance convenience.
4, saving material and power
Due to the use of dry sand, v. method of sand, sand fell to recovery above 95%, use the power consumption method of V shape smaller, only 60% of the wet method can reduce labor 35%.
[5], shape and sand box long use life
Look for protection, have plastic mold force is small, only the seismic and high temperature and high pressure, so look deformation and damage.
[6], improve the working environment
Adopts modelling and pouring process of trace gases are mostly vacuum pump, air pollution.
Responding to fall, after a sand sand processing without.
In the meantime, facilitate management and organization
V method casting production cycle is short, the technology is simple, easy operation, need not very skilled technical workers.
8), suitable scope wide
V method adopts the manual applies casting piece small batch production, also suitable for mass production mechanization of automation.
Can be used in cast iron, cast steel responding to such black metal, also used for copper, aluminum, magnesium, and other nonferrous metals.
V casting technology method
1, model
Will look in the plate, tighten combination model is installed on the negative potential, using metal mould, appearance, synthetic resin, mould, in order to absorb model, plastic film on the model has many 0.8 ~ 1.5 drill holes in uniform model, mm to the corner, holes for good. Model can use semipermanent, surface should be smooth. If use wooden type, when the surface temperature rises to about 60 ° c will burst and distortion, so must adopt deformation rigid wood drying.
2, plastic film
The method for V of plastic film must consider the following conditions:
Responding to cheap price.
Responding to have good strength and elongation.
Responding to film thickness.
When responding to film burning gas, which starts less pollution.
Plastic film materials: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), a vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), polystyrene (PS), etc.
EVA type plastic film specifications:
Width: 2400