High-speed milk aseptic filling technology

The scale of Hood's factory in Winchester has been expanding. As of 2004, the original design of the factory has been fully realized. After completing the major equipment additions, the factory now has five product processing systems and six independent filling lines. The factory operates non-stop seven days a week and can process more than 70 million gallons of product per year.

The factory has two Evergreen roof box fillers: one is EH2 and the other is EH3, which is used to fill half a gallon of product. The factory also used three Serac ESL fillers capable of filling 12 to 96 ounce plastic bottles. In addition, three Sidel blow molding machines can produce 44,500 PET bottles per hour. And all machines are equipped with a dedicated in-situ cleaning system.

In the latter part of the filling machine, the factory introduced many secondary packaging machines for corrugated carton packaging and palletizing. The company uses Fuji's sleeve labeler to shrink the bottles, Douglas's carton packers use the dishes, and the Alvey palletizers create pallets.

In addition, palletizing is performed in two refrigerated areas of the plant, and the second refrigerated area is part of the plant's recent expansion. The original warehouse had a narrow roadway system that was guided by a manual crane. The new system uses an automatic crane that can horizontally and vertically stack the product to 10 units high.

In the Winchester factory, milk and other ingredients are generally transported to the factory through five reception bays. Fresh milk is stored in 4 silos with a total capacity of 240,000 gallons. After pasteurization of the milk, the other ingredients were mixed into one of the five metering systems. Following a set of VTIS systems, the product was UHT treated and the product was sent to six filling machines for filling.

The milk is sterilized up to 175°C in a heat exchanger, then pumped out and sent to the steamer. Inside, high-temperature, high-pressure steam is injected to further disinfect the product. In a moment of 2 seconds, the temperature is increased to 280°C. A vacuum tank was then sprayed with cool air to reduce the temperature to 175°C. The plate heat exchanger then pumped the product back and quickly cooled it to 37°C. The milk is then sent to an aseptic pressure tank where it is pneumatically moved to the filling machine.

Shibuya Kogyo's workflow for a sterile plastic bottle filling line

The Winchester plant recently introduced a sterile plastic bottle filling line. The new filling line is equipped with a 81-head sterile rotary filling machine manufactured by the Japanese company Shibuya Kogyo. The production line installed at this Winchester plant was Shibuya's first landing in the US dairy industry. There are 22 such systems in operation worldwide.
Leigh Pehrson, head of ESL production at Hood, said: "The expansion of the factory and the introduction of the new aseptic production line have brought significant changes to the company."
Lee Baker, Hood's engineering director, said: "This 81 sterile rotary filling machine is a high-speed rotary filling machine. Its speed is dazzling. It can fill 600 16-ounce plastic bottles every minute. ."

Baker briefly introduced the workflow of this filling system:

1. The product is ultra-high temperature sterilized in batches. This process is carried out by a slightly modified VTIS machine of the Tetra Pak direct air injection system.
2. The blow-molded plastic bottle is fed by a screw feeder into a series of rotors with grippers that grip the plastic bottles and transport them into the aseptic filling and capping process.
3. The plastic bottle is sprayed into the heated disinfectant for internal and external disinfection and then injected into the disinfectant to rinse. Heating the bottle is to activate the disinfectant and also to dry the bottle.
4. The dry bottle is filled by a rotary filling machine. The filling machine adopts the form of net weight filling, and the filling accuracy error is not higher than 0.5 g.
5. The bottle after filling is capped. The lid is also sterilized in the same way and an internal servo-driven capper presses the lid on each bottle. The entire capping process is carried out in the interior of the sterilized machine, and the entire sterile closure process is completed by pressing the cap on the plastic bottle.

In addition, the hygienic interior of the filler is sealed and only the operator is allowed to touch the equipment inside through the glove box. Since plastic bottles are delivered with neck clips, there is very little clogging, but if necessary, the operator can correct plastic bottles through the glove box because the mechanism of the machine allows the intervention outside the machine. At the same time, the sensors attached to the machine can detect and reject defective bottles before they are filled. As for the thorough washing process of the machine, the pipeline and the milk line are equipped with an on-site cleaning system, and the surface of the machine room is also handled by an automated cleaning and disinfection system.

Baker believes that even if all the disinfection equipment in the production line is running, the production line can easily continue to work for more than 24 hours. According to Shibuya's data, some of their machines can be produced without interruption for 120 hours.

HOOD company is most satisfied with the speed and sealing of the new line

Baker said that there are also suppliers in the United States who can provide packaging lines for the production of plastic bottles of sterile milk, but the Shibuya system can better meet Hood's requirements. Baker said that the new filling line has benefited HOOD in two ways.

First, production speed is the primary factor. The capacity of this device to fill 600 16-oz plastic bottles per minute has brought us more benefits. Second, because Shibuya's filling equipment employs a direct capping system, this allows us to reduce operations and maintenance. Baker gave an example: “We have an existing ESL milk line that can produce 600 bottles of milk per minute. We need to stamp out the foil and seal the bottle. But sometimes this method creates an invalid seal. For the system, a good seal can be made if done properly, but the direct gland system is easier to operate and maintain than the foil seal."

Source: "Packaging Materials and Containers"