New Heinrich Wagner Sinto V-process molding line at PROMLIT

Within the PROMLIT program of technical retrofit the out of date green sand HERMAN high pressure molding line was build-down.
This place was used for mounting of new Heinrich Wagner Sinto V-process molding line and sand return system. The equipment of VDK-10 molding line was delivered by the end of 2004, sand return system equipment in summer 2005. Additional materials handling equipment and secondary equipment was delivered by Russian and Ukrainian suppliers in April - September 2005. The equipment of the molding line and sand return system was mounted under the supervision of HWS specialists in February - October 2005. Total tonnage of mounted equipment is over 2000 tn.
VDK-10 molding line is intended for making large size steel casings for freight railroad cars (side frame and bolster) and different large size steel casings for machine building industry.

Basic molding line data:
- annual output of castings - 55 thousand tn.
- production rate - 20 molds per hour
- flask clear dimension 3000x1800x500/500 mm
- maximum specific quantity of metal in mold - 2 tn
- sand circulation rate - 220 tn per hour

Molding system configuration:
- VDK-10 V-process molding line
- Sand return system
- Mold pouring system
- Casting transportation system
- Materials handling and auxiliary equipment

German HWS company also supplied: C510E manipulator for taking solidified castings from molds, core knockout unit, fluid-bed sand cooling unit with water cooler and two dust-collecting units
The existing computerized monorail Cleveland Crane (USA manufacturing) casting handling system was rebuild so as to handle large-size castings of side frame and bolster to the trimming department.

Brief description of mold making.
The pattern sets are installed on 6-position turn table. The pattern is covered with preheated plastic film, the elements of gating system are installed on the pattern, the pattern set is sprayed with mold wash and dried. Then the pattern is transferred to 4-position mold making turn-table. Flask is set on pattern and filled with dry sand without any binders. Sand in the flask is compacted by vibration. Excess sand is cut off and flask is covered with backing plastic film. Vacuum is applied to the flask and sand is compressed by atmospheric pressure. Flask with mold is lifted from the pattern, turn over and sent to core setting area. After core setting the molds enter mild close unit. The closed molds with a transfer car delivered to one of the pouring lines. Pouring of molds is made using pouring crane with 30 tn pouring ladle. Ladle nozzle positions over the pouring cup of the mold within 2 mm accuracy.
Poured molds are delivered by a transfer car to one of three cooling lines. The cooled molds are transferred to mold stripping unit.

Hydraulic manipulator takes castings from the opened mold and puts them in the core shakeout unit. Then manipulator loads the castings into Cleveland Crane buckets to be transported to the trimming department. Hot sand is returned to sand system. There it is screened, separated from metal particles, cooled from 200 down to 40OC and returned to the molding unit. In the sand system sand fractions about 0,5-2 mm are separated and removed from sand system to be substituted with fresh sand which is supplied with pneumatic transport. Dust fraction of sand from air cleaning units is returned back to sand system since it is necessary for proper molding.

Main advantages of V-process molding:
- high quality of casting surface and casting geometry
- considerable reduction of surface defects and improvement of casting solidity
- reduction of finishing and machining operations
- use of inexpensive wooden patterns
- reduction of molding material consumption
- high ecological compatibility of the molding process
- high level of molding process automation