In the entire process of wine bottling the segment of filling is the most important subject since you actively handle the product you have worked so diligently on for quite some time. In this report we focus on still wine filling. For wine applications you find a speed range for fillers starting from 15 bpm on the lower end to up to 600+ bpm on the high end. Equipment comes in variations of single machines or monobloc arrangements where different machine components have been installed on one main frame with one main drive train. Monobloc configurations can consist of just two components such as filler/corker blocks and go up to as far as four components such as rinser/filler/corker/capper arrangements.

When filling wine several quality parameters are important to be controlled in order to make sure your wine is well bottled and packaged.

The main parameters are:

- Dissolved oxygen pick-up (DO),

- Fill-height accuracy and

- Cork placement.

In the past fillers were mainly “mechanical” fillers where the individual steps of the filling process were mechanically initiated through cams/levers and rollers. Today, electro-pneumatically controlled solenoids are employed on the filling valves. This guarantees a high degree of accuracy, reduces the amount of wear parts on the filler and facilitates product change overs through parameter setting on a filler touch screen.

The most important quality parameter in the filling process is the control of dissolved oxygen pick-up. In order to keep this value to a minimum, several technologies are employed in the industry.

As a first step, bottles are cleaned either with water or dry, compressed, sterile air. On a rotary rinser bottles are turned 180 degrees and a nozzle enters the neck to either spray water or air into the bottle. In an orbit rinser the rotary wheel is in vertical position and bottles are positioned in individual pockets with a nozzle entering into the neck. When using compressed air it is important to have a suction phase on the rinser so the potential dirt particles are effectively removed from the bottle.

As a second step on the rinser, the bottle may be sparged with an inert gas such as nitrogen or argon to reduce the amount of oxygen in the bottle. This process is used mainly with conventional filling technologies which do not offer specific air/gas management as part of the filling process.

For lowest dissolved oxygen pick-up values filling processes have been developed which use several different steps on the filling table. After the bottle enters the filler from the rinser a centering bell seals the bottle. The filler program now initiates multiple process steps performed through the electro-pneumatically controlled valve. As a first step a vacuum is pulled on the bottle which extracts the ambient air or air/nitrogen mix through a separate channel of the filling valve to the outside environment; then the bottle is filled with inert gas. This is an advanced step compared to conventional filling systems which fill either against ambient air or an air/nitrogen mix from sparging at the rinser. The fact that the air is discharged to the environment is also very important; older technologies actually vented the air from the bottle into the filler bowl which resulted into increased DO pick-up values.

For highest quality filling results the KRONES filling technology offers a second pre-evacuation of the bottle; this means the process steps of applying vacuum and sparging with inert gas will be applied a second time before the valve then opens the wine channel for the actual filling. The wine pushes the nitrogen from the bottle back through a separate channel into the filler bowl where it serves as a blanket to avoid air contact in the bowl as well.

The end of the filling process is determined by the contact of the wine with the vent tube. Once the wine channel is closed a short settling phase sets in. In order to achieve highest tolerances in fill level accuracy a fill-level correction process is applied. This effectively uses pressurized inert gas – applied to the headspace – to push excess product back into the bowl. With this step you achieve an accurate fill level which also results in product savings.

After the bottle is released from the filling valve it is conveyed to either the corker or capper. Preferably you want them to be close to the bottle exit of the filling table to allow for shortest exposure to the environment before closing – usually you position the corker first and the capper in second position. Headspace management after the filling process is of utmost importance. For cork applications you can pull a headspace vacuum at the corker before you place the cork in the neck of the bottle; this reduces the amount of air from the bottle headspace and also reduces headspace pressure when the cork is placed. Pulling a vacuum may potentially result in a contamination issue at the corker if at times wine is sucked into the vacuum system. As an alternative process headspace flushing with inert gas is also a high-quality solution. When you have a fill-height corrected application and a well placed cork the headspace pressure will be well controlled. The inert gas then provides you with the dissolved oxygen control you require in the headspace. Using this scenario no vacuum is pulled at the corker.

Screw cap applications are a little more involved since the headspace volume is bigger than with cork applications. Ideally you want to remove the air or air / nitrogen gas mix which resides in the headspace. This is done by dosing liquid nitrogen to the headspace of the bottle. A liquid nitrogen dosing equipment is located close to the location where the bottle leaves the filler valve. Liquid nitrogen needs a certain amount of time to react and push the air out of the headspace; you will actually see a nitrogen “fog” or “smoke” develop in the headspace slightly coming out of the bottle if the dosage is correct. Therefore, a specifically determined amount is dosed into the bottle headspace. The liquid nitrogen reaction happens while the bottle is conveyed to the capper. Since the caps themselves are hollow they do carry air. If you place them on the bottle most of the air actually escapes in the process of pushing the cap onto the bottle; however, to avoid any residual air a Figure 4: Screw Capper nitrogen gas purging of the cap may be applied.