Controls; Functions; Vacuum Function/Additional Vacuum; Gas Function/Additional Gas - Orved n Series Operating And Service Manual

DESCRIPTION OF THE MACHINE AND ITS FUNCTIONS

5.1 CONTROLS

The machines are provided with two different digital controls, all driven by state-of-the-art micro-processors, which allow
multiple functions and programming options.
• VGP25N is equipped with a double 12 digits display and 12 led additional visual signals.
• VGP60N colour LCD with touch capacitive sensor keys.

5.2 FUNCTIONS

5.2.1 VACUUM FUNCTION / ADDITIONAL VACUUM
The machine is provided with a sensor which measures the quantity of vacuum (i.e. the depression) which is created inside
the chamber. This quantity is expressed in percentage. The maximum possible value is 99,99%.
It is possible to add a supplementary vacuum creation time which is expressed in seconds, for obtaining the maximum
possible vacuum.
The additional vacuum can only be activated if the Vacuum parameter is set at 100%
Factors which determine the function yield
The parameter is influenzed by the air volume to be extracted from the chamber and the pump oil depletion degree: the
pump performance drops with increased number of working hours. Since the machine works in function of the percentage
of vacuum created, the time required to complete the phase varies according to the volume of product contained in the
tray as well as the pump oil conditions.
Packaging liquid products
It is a known fact that reduction in atmospheric pressure reduces the boiling point of a liquid, until it reaches 6°C with
the vacuum of 99,99%. Therefore, although liquid products can be packed using this machine, certain preliminary tests
must be carried out before starting with production in series, since, part of the liquid may leak out of the tray as it boils,
smearing the sides and thereby making it difficult to seal the film on the container. The tray filling level must therefore
be optimized by carrying out one or more preliminary tests before proceeding with packaging in series in order to avoid
leakage of liquid. It is important to remember that there is increased risk of suction of vapour by the pump: it is therefore
advisable to check the pump oil and filter as well as the tank filter more frequently and replace these if necessary.
5.2.2 GAS FUNCTION AND ADDITIONAL GAS
Flushing with gas to take the place of the volume of air extracted is not only meant to prevent pressing of the trays du-
ring devacuumation of the chamber: in fact, with packaging in a protective atmosphere, not only is the air which can
cause deterioration of the product removed, but elements like gas are introduced which can actively fight deterioration
of product quality.
The Table shown below contains the list of elements of a part of the gas mixture normally used.
The overpressure which may be envisaged in the programming of the packaging procedures allows a positive pressure
value (i.e. slightly higher than the atmospheric pressure) and makes it possible to make up for the loss of product volume
caused by removal of carbon dioxide which may occur when the vacuum is being created.
Using overpressure can give the packages a swollen appearance.
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Rev. 08 - 04/2017 - Cod. 1500160 - Instruction manual VGP25N / VGP60N