Pressure over Vacuum Casting Machine, Double Chamber

TVCd is the pressure over vacuum casting machine designed to meet the more severe needs in lost wax casting production.
This machine works with a new, revolutionary double chamber concept. This innovative system gives several advantages compared with the traditional single chamber suction system currently available in the market.

In TVCd melting chamber and flask chamber are completely independent and at the moment of casting the machine can control the metal injection into the mold by applying a differential pressure during pouring.
This yields to a faster injection compared to the simply gravity pouring with the benefit to cast items at lower temperature.
This will result in better surface finishing of the cast parts and reduced shrinkage porosity.

Moreover, thanks to the absence of residual gas in the mould, flasks can be filled even in counter-gravity mode, giving to our customers the chance to mount pieces upwards for a better tree yield and turbulence reduction.

The casting cycle takes only few minutes and, while the previous flask is cooling down in protective gas for no oxidation, the next charge can be loaded into the crucible and melted, thus overlapping two cycles for no time waste.

Moreover, the operator can decide to load the flask in the flask chamber when the alloy is already melted, just few seconds before casting.
This leads to a low temperature drop in the flask and avoid excessive flask overheating to compensate this risk.

The consumption of the graphite crucible is greatly reduced thanks to the gas washing process, which removes the oxygen within seconds from the charge being loaded.

The heart of the power electronics is the heating system which consists of a medium frequency induction generator expressly designed for precious metals, guaranteeing a very high homogeneity and quick melts.

The machine is fully automatic and it can be optionally equipped with an HMI in concept of Industry 4.0.

This extraordinary machine is the synthesis of the most advanced engineering and years of experience in casting that TOPCAST can bring into your factory.

Technology & Features

Gas Wash Procedure

• Crucible loading operation introduces oxygen
• The Gas Wash Purge procedure removes the oxygen in a very fast and efficient way and then refills back the chambers with Argon or Nitrogen gas 
• Compared with the traditional crucible protection with flow-meter regulation, gas consumption is dramatically reduced, alloys oxidation is minimized and crucible life is greatly increased.
• Moreover the crucible life is increased: TVC series crucible last up to 250 – 400 casting cycles according to the graphite quality

Melting

• Advanced Self Tuning thermoregulation (AST™) with accurate temperature control of the melted alloys
• Two Set-Points available: Homogenization and Casting Temperature
• Medium frequency induction heating stirs the melted alloy and leads to a very high homogeneity
• Pulse Stirring Management (PSM™) for an extremely low frequency stirring
• Highest power density in the market features strong stirring and low gold losses

 Injection and Compression

• When the stopper lifts up. it is very important to control the injection rate to avoid turbulences
• TVC has the unique feature to have the injection rate controllable and programmable (IRC™)
• The metal enters smoothly inside the mould. Then, after filling and during the solidification phase, a strong compression takes place on the tree
• Low turbulences in filling and high compression rate lead to a large reduction of shrinkage porosity phenomena

Tree protection after casting

• Thanks to the double chamber concept, after the solidification phase, the flask cools down in a protective atmosphere while at the same time you can load your alloy in the melting chamber for the next melting. This operation will allow an overlapping of the casting cycles which will give you the ability to protect longer the tree before removing it without losing time and productivity.

 

Technical data

	TVC3d	TVC5d	TVC10d	TVC12d
	Consumables	Consumables	Consumables	Consumables
Number of casting programs	100	100	100	100
Crucible working capacity	200g Bronze 250g Silver 500g Gold	200g Aluminum 400g Bronze 500g Silver 1000g Gold	500g Aluminum 1500g Bronze 1500g Silver 3000g Gold	750g Aluminum 2300g Bronze 2500g Silver 5000g Gold
Flask max. diameter (mm)	90	150 /  200
Flask max. height (mm)	120	300 /  400
Induction heating power	2.5 kW	4.9 kW	10 kW	12 kW
Vacuum pump	Ext. 4 m3/h	Built-in 25 m3/h
Pressure over vacuum	3 bar	3 bar	3 bar	3 bar
Max. temperature	1250°C	1250 °C   /   1600 °C
Granulation unit	-
Industry 4.0	-
Automatic feeder for crucible replenishing	-	-	-
Autotest with data report
Monitoring system for data acquisition	-
Flask check before casting
Vacuum leakage detector
Oxygen Analyzer	-
Remote interface	-
Main alloys	Gold (Au), Silver (Ag), Copper (Cu), Brass, Bronze, Aluminium (Al) and their alloys,  Magnesium

 Provided -  Available on request