Fast, stable pillow packing Accurate product weighing system Testing and packing technology
Blue Diamond Growers (California, USA) recently purchased a packaging line to produce pillow bags for packaging casual dried almond products. This line replaces the previous two lower capacity lines and is able to package 8 ounces of dried almonds at 80 bags per minute. In addition, this line can also pack 2 oz or 23 g pillow bags at 120 packs/minute.
The starting point of this assembly line is the VPK260 vertical form-fill-seal machine provided by Rovema. This machine is equipped with servo drives and programmable logic controllers. It is the most versatile vertical bag bag on the market. Weighing integrated equipment. A roll of film is placed on a reel at the rear of the machine, and the friction drive belt and vacuum assisted assembly mounted on the front of the machine pull the film through the entire body. The machine is equipped with a sensor for positioning the edge of the film. When the film leaves the roller, the entire film box moves in a horizontal direction, maintaining the correct trajectory of the film in the machine. The smart date inkjet printer provided by Markon printed the date of the code when the film left the roller. An encoder equipped with the printer constantly measures the speed of film movement and automatically adjusts the printing speed to suit the advancement speed of the film.
The film passes through a series of rollers and tension adjustment rods on the top of the machine, continuously moving forward through the machine. These components, along with the airbag inside the shaft, maintain the proper pressure on the film. The film is wrapped around a forming tube at the front of the machine. A continuous heat sealer moves back and forth between the two ceramic rolls to complete the vertically overlapping seal. Dried almonds fall from the top of the machine's weighing device in an intermittent manner, through a forming tube, into a continuously moving, formed film tube, and then out of the vertical forming work area.
Next, the film is formed into a D-type configuration by servo-driven sealing clips. The sealing clamp grips the film and horizontally seals the film with inductive heat. The sealing clip, together with the film, moves downwards, stays for a certain period of time to form a seal, then moves away from the film and returns to the upper part to begin the next sealing action cycle. At the end of each sealing cycle, a pneumatic cutter in the center of the clip stretches before the sealing clip disengages, cutting the formed pillow bag off the film. When the pillow pouch is spit out of the machine, the back side faces up, and the turning mechanism in the device turns the bag over and lays it flat on the conveyor belt.
A sensor is also installed on the film storage box to detect the perforation marks on the film. It compensates for any minor differences in the length of the film and ensures that the size and alignment of each bag are consistent. The basic function of this system is to indicate when the coded date printing device is activated whenever the capper and cutter are instructed to move. The entire equipment is under the control of a Control Logix programmable logic controller from Allen-Bradley (abbr. AB), and includes three sets of 1394 Servo Drivers from AB, which are responsible for operating the vertical sealer and the two left and right. Traction belts, as well as sealing jaws and cutters are integrated.
The product was filled with a 14-piece rotary table vertical bag feeding and weighing machine supplied by Multipond. The system was installed on the platform above the machine. The product passes through a loading hopper located on the plane above the electronic scale and falls onto a vibratory conveyor and then into the vibrating cone above the weighing system. A programmable loading chamber located below the center cone is responsible for starting or ending the product filling action and maintaining the optimum height of the product in the cone.
The weighing system contains 14 separate weighing heads mounted around the top vibrating cone. Each weighing head consists of two main components: a loading cylinder and a unloading cartridge with a weighing cell located below it. The vibratory tray expands according to a preset time and amplitude, and sends a specific amount of product from the cone into the loading cylinder. The vibration amplitude of the tray can be automatically adjusted to adapt to the change of product flow and maintain the accuracy and efficiency of loading.
In order to improve the weighing accuracy, the equipment can monitor the material drop characteristics and response time of the weighing unit at any time, and remove the abnormal vibration through the electronic filter to ensure that the weighing signal is evaluated quickly and accurately. The number of products that enter the weighing cylinder at a time is about one fourth of the final weight of the package. For each weighing action, the control system will select three or four weighing cylinders to be combined so that the total weight is closest to the full bag weight without being insufficient. Each dosing process is displayed on a computer screen, which includes the fill weight, which electronic weigh scale products are selected, and other statistical data. The electronic scale puts the product into the filling tube of the vertical bag machine located directly below the weighing table.
Multipond's weighing system continuously performs automatic zeroing and self-calibration during the work process to ensure feeding accuracy. The DMS weighing cell attached to the weighing cylinder further ensures this accuracy. Each weighing cell is equipped with a precise reference weight for the electronic scale to periodically perform on each weighing cell during normal operation. Recalibrate. The weighing system includes a color HMI and a built-in printer to provide production status and configuration reports. The system includes a comprehensive data package that includes long-term and short-term history, production process logs, self-diagnostics, I/O device troubleshooting, and help manuals. The control system monitors the long-term average weight and automatically adjusts the target to keep the loss to a minimum.
The pillow bag completed by Rovema equipment passes through a detection system provided by ACHorn & Co., which has a swing door, calculates the number of pillow bags, and places them on two parallel conveyor belts. To the packing workshop. The system can identify empty bags and blow them off the conveyor.
The two workers manually placed the finished pillow bag in the carton and pushed the carton onto another conveyor belt and sent them to the carton automatic bottom sealer provided by Bestpack. When the box enters this unit, there will be a pull rod pressing down the front flap of the box and then pressing the back flap with the hemming arm. The box continued to move forward, the pull rod lowered the cover on both sides, and finally the gap between the bottom and the bottom of the box was sealed with tape. The boxes were hand-knotted and then packaged in shrink film.
Source: Packaging Machinery