In the modern packaging industry, various machines are used to automate different processes that ensure products are properly labeled, sealed, and protected for distribution. Labeling machines, shrink-wrapping machines, sealing machines, and strapping machines each perform essential functions in the packaging line, optimizing efficiency and maintaining product integrity. From applying labels to containers to shrinking film tightly around items and securing cartons for transport, these machines help improve packaging quality and streamline production. Understanding the features, types, and applications of each machine is essential for businesses aiming to enhance their packaging processes and meet industry standards.
Labeling machine
A labeling machine is a device that affixes a label printed with the name, ingredients, function, instructions for use and opening, trademark patterns, etc., to a specific part of a food container. Please refer to the picture of the labeling machine.
There are many types of labeling machines depending on the packaging purpose, the type of packaging container used, and the type of labeling label.
The commonly used labeling machines are classified as follows:
(1) According to the level of operational automation, it is divided into semi-automatic labeling machines and automatic labeling machines.;
(2) According to the type of container, they can be divided into thin tinplate round steel-canned labeling machines, glass bottle labeling machines, tin can labeling machines, etc.;
(3) According to the direction of container movement, they can be divided into horizontal labeling machines and vertical labeling machines; (4) According to the shape of container movement, they can be divided into straight-line labeling machines and turntable labeling machines.
The commonly used labeling machines are as follows:(1) Gantry labeling machine; (2) rotating fork labeling machine; (3) vacuum suction and pressure labeling machine; (4) rotary labeling machine; (5) vacuum drum labeling machine, etc.
Gantry labeling machine
As shown in the diagram, the labels are stored in label box 2; they are pressed by weight 3 and slide down the slope. The label takes the continuously rotating roller 1, which feeds out the labels one by one, passes them under label-pulling roller 4 and coating roller 5, applies adhesive, and then guides them into label-dropping guide 8 to ensure they are upright. When the bottle is passed through the gantry, i.e., the label drop guide, by the conveyor belt, the label is picked up by the bottle, and then it passes through the channel between two rows of brushes 10, and is smoothed onto the bottle surface by the brushes.
This labeling machine is only suitable for applying labels whose width is approximately equal to half the circumference of the bottle body. It is not suitable for labels that are too wide or too narrow, and can only be used on cylindrical bottles. The production capacity is approximately 1,500 to 1,800 bottles per hour, which is suitable for small and medium-sized food factories.
Rotary fork labeling machine
As shown in the diagram, the rotating tines 7 rotate alternately. When they are in the correct position as shown in the diagram, they are coated with adhesive by roller 6, roller 5, and coating roller 3 in adhesive tank 2. When the rotating fork is turned to the upper position, labels are taken from the label tray 4. When the fork moves to the lower position, the bottle pusher mechanism 1 pushes the bottle, and then a bottle brush passes through the body.
Vacuum label pick-up and labeling machine press
Refer to the diagram, which consists of vacuum label suction head 1, label box 3, adhesive roller 5 and adhesive roller 6, pressure pad 8, and guide rail 11. The label suction head moves left and right along the guide rail and is constrained by buffer blocks 9 and 10. When the suction probe is at the left end of the label, the vacuum box is activated and vacuum suction occurs. To ensure that only one label is sucked up at a time, nozzle 4 and brush 2 are provided on the top of the label box. After picking up a label, the label suction head moves to the right, and glue rollers 6 and 5 apply glue to the label as it moves. When it encounters block 9, it stops moving and lowers to deliver the label to the bottle. The vacuum is cut, the label is applied to the bottle, the label suction head returns, and then pressure pad 8 descends, and the rubber-coated pressure pad presses the label onto the bottle. The labeling machine has a production capacity of 2,400 bottles per hour and is highly flexible.
Rotary labeling machine
It consists of a bottle-feeding mechanism, a vertical turntable, an adhesive mechanism, a label box, and iron devices, as shown in the diagram. When it rotates to a specific position, it completes the gluing, labeling, and capping operations, respectively, and then the products are conveyed out by the conveyor belt.
Vacuum drum labeling machine
Working process: Bottles and cans are conveyed by conveyor belt 1, and then the bottles in the line are spaced at set intervals and delivered to vacuum drum 3 by bottle-feeding screw 2. When a bottle passes through bottle-feeding screw 2, the "no bottle, no label" device is triggered and the circuit is broken. At this time, label box 6 performs oscillating and regular compound movements to remove the labels. Vacuum drum 3 rotates counterclockwise, and there are six labeling stations on the drum's cylindrical surface.
Each section has a set of vacuum holes that serve to remove labels. Vacuum connection and cutoff are achieved by the movement of the slide valve in the vacuum drum. When a bottle is fed in, label box 6 moves toward the drum, and the roller on the label box bracket contacts the vacuum drum's sliding valve, connecting the vacuum drum to the corresponding vacuum port at the label box's position and drawing the label from the label box 6 mounted thereon. After that, the label box moves away from the drum, and the label passes through the code printing device 5 and the glue coating device 4, and the factory date and an appropriate amount of glue are printed respectively. The drum continues to rotate, and the glue-coated label fills the bottle delivered by bottle feeding screw 2. For this reason, the speed of the bottle feeding screw must be well-matched with the rotational speed of the drum, so that the bottle and the drum labeling station meet precisely. At this time, the valve in the drum switches the vacuum label suction port from being connected to a vacuum to being connected directly to the atmosphere. The label loses its vacuum suction and is released from the vacuum drum and adheres to the bottle. When the bottle and label meet, the bottle is clamped between the drum's rubber part and the rubber sponge 8. Driven by the drum's friction, the bottle begins to rotate around its own axis, and the label is rolled onto the bottle.
The labeled bottles are continuously conveyed forward by the plate conveyor belt and enter the channel formed by the abrasive conveyor belt 7 and the second sponge rubber pad. The bottles are abraded forward, and the labels are rolled flat and more securely.
Small Packaging Machine
Heat shrink packaging (also known as shrink packaging or heat shrink packaging) is the use of plastic film with heat shrinkability as a wrapping material to wrap items, and then quickly passing the package through a box-type heating chamber (or heat shrink tunnel) at a specific high temperature. Through rapid heating, the packaging film shrinks to a specific degree and snugly conforms to the wrapped item to facilitate transportation or sale.
It can be seen that the performance of plastic films plays a decisive role in shrink packaging. Common plastic films are typically produced by extrusion, calendering, and solution casting. Heat-shrink films are sheet (or tube) films made in this way, which are then stretched several times in the longitudinal or transverse direction, so that the film's molecular chains or certain crystal planes are oriented parallel to the film surface, thereby increasing the film's strength and transparency. At the same time, if a certain temperature is applied while the film is stretched, the film's stretch ratio before shrinkage is increased to 1:4 to 1:7 (the stretch ratio of a normal film is 1:2), which gives the film the required heat shrink performance for packaging.
Shrink films are roughly divided into two categories based on manufacturing methods and application scope: one is films in which shrinkage in the longitudinal and transverse directions during processing is nearly equal, called biaxial heat-shrink films. The other is films that are stretched in only one direction during manufacturing, called uniaxial heat-shrink films.
The scope of applications for biaxial films is very broad, and they can be used for wrapping fresh foods or for food tray packaging, etc. Uniaxial films are often used for shrink packaging and tube film label packaging, such as labeling wine bottles, sealing plastic bottles with glass bottle caps, and wrapping fresh fruits and vegetables.
There are three heat-shrink packaging methods: (1) overlapping shrink packaging method; (2) sleeve shrink packaging method; (3) end-seal shrink packaging method.
There are two methods for heating shrink film: a heat shrink tunnel and a hot air gun.
Heat shrink packaging method
(1) Overlap method. As shown in Figures (1) and (2), the wrapped object is placed in a heat-shrink film bag 1, sealed, and shrunk through a heating channel 2, or as shown in Figure (2), the heat-shrink film is closed over the wrapped object, folded from the four corners toward the lower part of the wrapped object into shape 1 or onto conveyor belt 3.
(2) Arm method. Wrap food in a cylindrical or rectangular shape with tubular shrink film, roll the film in about 20 mm, and leave a 30–50 mm margin in the longitudinal direction. First heat and seal both ends, then shrink the entire package, as shown in Figure 3.
(3) Covering method. It is used for packaging containers with edges. It is a method of heating and shrinking the bottom of the container or tray. As shown in Figure (4).
Thermal shrinkage heating method
(1) Heating of the heat-shrink channel. See figure. It consists of a heater box 6 lined with insulating material, a conveyor belt 7, a drive roller 9, and a cool-air blower 8. There is no heating element 4 inside the heater box. Hot air circulation is achieved by fan 2 and temperature control device 5. The package is fed in by conveyor belt 7; it is heated as it passes through the channel. To ensure the packaging film is heated evenly, an electric fan is used to circulate the air, and the temperature inside the box is stabilized by the temperature control device (temperature variation within ±5 °C). After heating and shrinkage, it is cooled by a cold air blower.
(2) Manual heating with a hot air gun For shrink packaging of small batches that are not suitable for constructing a dedicated heating channel, a hot air gun can be used for manual heating. The structure of the hot air gun is shown in the diagram above.
Medium-sized four-side sealing packaging machine
For packaging with dimensions of 200–500 mm in width and 250–1500 mm in length, a medium-sized four-side sealing packaging machine as shown in the diagram can be used.
The upper and lower rolls of films 3 and 8 are guided to cross-seal 4 for heat sealing by guide roller 7. Material 2 is fed by conveyor belt 1. After it moves against the film to the predetermined length, the cross-sealer is activated to complete the cross-sealing of the front and back sections; it can also cut the film and, after cross-sealing, simply close it (longitudinal sealing). Then, the belt-type longitudinal sealer 5 completes both side seals and then feeds it for heating and shrinkage.
External packaging machine
In the mechanization of food industry packaging, food packaging and inner packaging were developed earlier, gradually forming a complete production line with machinery for upstream process processing. Outer packaging machinery has evolved in the modern era in response to the urgent demands of industrial production development. The mechanization of outer packaging not only reduces labor intensity but also increases labor efficiency.
Outer packaging operations typically encompass four aspects: the preparation of outer packaging boxes (for example, opening and forming stacks, flat-folded cartons); the packaging containers holding the food; sealing boxes; bundling; and four other processes. The machines that perform these four operations are called case formers, cartoners, carton sealers, and bundling machines (or strapping machines). In modern times, as these single machines have been continuously improved and developed, fully automatic packaging lines have emerged, integrating the arrangement, packaging, and bundling of packaged food—that is, collecting small pieces of food into boxes—so that sealing and bundling become a single step.
Because packaging containers—including cans, bottles, bags, boxes, cups, etc.—come in various shapes and materials, there are many types and models of external packaging machines. However, since the external packaging operation involves no more than the four aspects mentioned above, the working principles and operating procedures of many similar machines are essentially the same.
Case packaging machine
Case packers typically pack cans, bottles, bags, boxes, etc. into corrugated cardboard cartons. The method of packing into boxes varies according to the shape and requirements of the products. For example, bottled products are usually placed upright, and after being pushed against each other, they are fed into a channel to form the required arrangement, then pushed into the box from top to bottom or from bottom to top in a vertical direction.
Canned products can be packaged in the same way as the bottled products mentioned above. Tin products can also be rolled horizontally through the divider. The resulting arrangement is aligned only with the position of the box's opening section. The lying, neatly arranged tins are pushed into the box transversely. When using a box with an opening at one end, the tins are pushed or clamped into the box vertically.
The case packers used for cartonized dairy products are also a type of specialized machine. These case packers use grippers to pack cartons vertically into a case, arrange the cartons in a specific order along the vertical axis, and use the machine to push the container into the required position at the designated time.
There are many types of carton machines, which can be roughly divided into three categories:
(1) Corrugated empty carton box machine. Flat corrugated cardboard boxes are arranged on a rack and folded. Each time a blank is fed in, it is erected into a box shape, loaded with packaged food, and then sealed. The food inside the box is supplied manually or automatically.
(2) Corrugated cardboard box packaging machine that forms boxes. The corrugated cardboard boxes are formed in the same way as the first type. During transportation, the box feeding machine is operated simultaneously by the conveyor that supplies the packaged food, and the food is loaded and then sealed.
(3) Corrugated cardboard box packaging machine. This is a machine that feeds single sheets of corrugated cardboard with the fold lines arranged on a rack one by one, pushes the packaged food into specific sections of the cardboard, then forms the box along the cardboard's fold lines and applies glue sealing. After the box is sealed, it is released to complete the operation. This is commonly called the push-wrap method.
Since the purpose of packaging is to prevent food from spoiling during transportation, to deliver it to the retailer intact, and to facilitate unpacking before sale, packaging technology must be continuously improved.
According to current packaging operations, it can be divided into: folding packaging machines; press packaging machines; and drop packaging machines.
Sealing machine
The sealing machine is a pneumatic automatic sealing device. It is used to seal and label cartons that have been packed with canned food or other packaged foods.
Machine structure: primarily consists of rollers, lift-arm cylinders, step-type feeders, folding tongues, upper and lower paper tray racks, upper and lower water cylinders, pressure rollers, upper and lower paper cutters, pneumatic system, etc.
The main working process of the machine is as follows: an open cardboard box filled with canned food, bags, cartons, and other packaged foods is directly inverted by the cardboard support plate of the carton-packing machine onto the machine roller, and then the operator of the carton-packing machine adds the pusher, causing the cardboard to slide along the inclined roller to the front end and touch the travel switch. At this time, the lifting-arm cylinder beneath the roller begins to rise under pneumatic system action, and the carton is delivered to the top of the ring beam by a step-type conveyor. After the carton is placed, the signal is connected, the action command is issued, and the step-type conveyor starts moving.
The step-type pusher mechanism is driven by a cylinder to reciprocate two push rods. Each time a carton arrives, it reciprocates once, and the carton is gradually pushed from this process to the next by the pusher nails on the push rod. The opened carton is pushed into the curved frame by the step-type pusher nails. First, the small folding flaps at the back of the box are swung by the folding hooks, and the front folding flaps of the carton are closed by the fixed folding device during the pushing process. After that, the large folding flaps of the box are closed by folding plates on both sides and pressed flat by the stop at the tail. The carton is pushed under a pressure roller and sent to the next sealing process. The paper tape used as the seal is mounted on the upper paper tray. After the paper tape is fed out through a clamp, it is moistened by a water-coating device, then brought to the top of the carton (the bottom of the carton also has the same sealing device), and pressed onto the box by the upper pressure roller. As the box is transported forward by the pusher nails, the paper tape is gradually applied to the box from front to back. A stepping-type pusher claw then pushes the carton forward to the paper cutting section. After the box stops, the cutter moves down (the lower cutter moves up) to cut the paper tape. Rollers mounted on both sides of the cutter then roll the paper tape from the back end of the previous box and the front end of the next box into the box, so that the top and bottom seals form a "door" and "U" shape to enclose the box. The sealed carton is then transported to the next process by a pusher claw. If a self-adhesive applicator can be used, a water-based coating device can be used.
Automatic carton sealing machines are commonly used in production to increase production efficiency.
Binding machine
A strapping machine is a device used to strap various cartons or packaged goods of different sizes using various straps and belts. Strapping machines have evolved rapidly, with a wide variety of types and styles. The main classification methods for these machines are: A. By the level of machine automation, it is divided into automatic strapping machines and semi-automatic strapping machines; B. By the method of tight belt insertion, it is divided into through-feed tight machines and winding strapping machines; C. By the material of the strapping belt, it is divided into paper strapping machines and automatic strapping machines.
Conclusion
The use of labeling machines, shrink packaging, sealing, and strapping in the packaging industry significantly increases the speed, accuracy, and efficiency of packaging operations. Whether it's applying precise labels to containers, shrinking film to fit the product, securely sealing cartons, or strapping them for transport, these machines work together to ensure products are packaged safely and professionally. As automation continues to evolve, packaging machines will play an even greater role in optimizing production lines and meeting the growing demand for high-quality packaging solutions across industries.
English 
Malay