Sticker labeling machine is the most common type of labeling machine in recent years, and its technology is also rapidly increasing. For pharmaceutical manufacturers, both the labeling of production equipment, and the self-adhesive labeling and the bottle to be bottled, will raise higher requirements. Now faced with the domestic market of adhesive labeling machines, how pharmaceutical companies can choose a more cost-effective self-adhesive labeler will be a concern for people. This article will discuss the selection points of self-adhesive labeling machine from four aspects: main function and control, label delivery speed, printing speed and output, special purpose, and labeling quality.

Overview of self-adhesive labeling machines at home and abroad, their working principle are similar, are made by the label stripping transfer rolling paste, but its control and manufacturing are not the same. General stickers labeling machine consists of a labeling mechanism, a roll-on mechanism, a hot stamping printing mechanism, a conveying mechanism, a transmission mechanism, a rack, and a control system. Among them, the roll-stick mechanism is also divided into roll-rolling methods suitable for flat bottles and roll-mounting methods suitable for round bottles. At the same time, self-adhesive labeling machine according to the state of the bottle discrete, horizontal; according to the speed of the sub-standard low-speed, medium-speed, high-speed; according to the characteristics of the container is divided into round bottles, flat bottles, square bottles, bottles, etc. (special The bottle is less in the pharmaceutical industry; according to the requirements of the veneer, it is divided into single-sided and double-sided stickers; according to the characteristics of the label, it is divided into general labels and transparent labels.

1, from the main function and control on the choice

In the past, self-adhesive labeling machines detected the labeling position as the photosensitive point on the front edge of the bottle body. Bottles of different diameters need to be changed by the corresponding electric eye movement or labeling time. Without this change, the labeling cannot be ensured. Each bottle is in the required position. Today's products are equipped with an "auto-calculate label length" function, which effectively compensates for these weaknesses. “Automatically calculate label length” is an automatic control technology formed on the combination of PLC and servo motor technology. When the conveyor belt bottle passes the detection of electric eyes, it measures the radius of the bottle and takes the most sudden point on the outside edge of the bottle as a sticker. The sensing point of the target signal, that is, no matter how small the bottle diameter is, is the sensing point of the labeling signal at the most protruding point on the outer edge of the bottle, so that the distance between the electric eye and the peeling plate does not need to be adjusted mechanically. The standard time also does not need to be adjusted at all. This is the automatic control principle of “Automatically Calculate Label Length”. This is also the preferred point for people to have a function on a sticker labeler.

In terms of synchronization of control speed, self-adhesive labeling machines shall, in addition to the above-mentioned function of “automatically calculating the length of labels,” automatically adjust the speed of conveyor belts, the speed at which the labels are exported, the length of the labels, etc. The difference between self-adhesive labeling machines is the guarantee of labeling quality stability. The speed of control of traditional sticker labelers is adjusted by human experience, and the difficulty of manual adjustment is that all actions are difficult to synchronize. If it is not synchronized, the labeling process will change frequently, resulting in poor labeling quality.

In the control system, the control system of PLC (human-machine interface) is the first choice. Compared to the early single-chip microcomputer (SBC), the general-purpose PLC is used as the main control device to enable the PLC control system to achieve the following objectives: 1) It is more stable and reliable; (2) It is more convenient for later maintenance, and the upgrade is simpler; (3) It can be easily controlled online and on-line.

In addition, it is also necessary to consider adding visual systems, which can perform real-time detection, control, and alarming on the integrity of the print, the condition of the particle size, and whether or not the label after the labeling is complete or not.

2, from the sending speed, printing speed and yield on the choice

When choosing a sticker labeler, people often only pay attention to the output of the labeling (ie, the number of labels that can be attached per minute), but they cannot comprehensively consider the labeling speed, the printing speed, and the roll speed. Of course, the labeling output covers other indicators, but other speed indicators play a key role in the use of quality and production development. People can observe the pros and cons and potential dynamics of various agencies from their analysis. This is also a choice for adhesives. The labeling machine should be comprehensively investigated.

(1) The speed of labeling by self-adhesive labeling machines. Nowadays, when the output of the self-adhesive labeling machine is matched, it cannot be comprehensively confirmed based on the label width and the printing speed. The maximum output index in the manufacturer's sample is only used. It is also unreasonable to make a choice because the maximum yield indicator given in the sample of the general manufacturer is based on a certain label length and some kind of printing method. Therefore, in the output selection of sticker labeling machine should first consider the speed of its delivery, from the theoretical relationship between the speed of labeling and labeling yield: Q = 1000V / (L + a)

Where: Q is the maximum labeling yield calculated at the maximum delivery speed, pieces/minutes; V is the maximum delivery speed, m/min; L is the length of a single label, mm; a is the spacing between labels, mm.

For example, when labeling a bottle with a diameter of φ36, L=52 mm, a=3 mm, and V=25 m/min, then Q=454/min. That is, when you choose V = 25m/min, taking into account other factors, the labeling length L = 52mm, the maximum labeling yield can only be in the 400 / min range, not to think about speeding up later or replacing longer labels.

On the domestic market, the maximum labeling speed of general labeling machine products is 38m/min, and the company with technical strength sets the maximum delivery speed of the product to 70m/min. This indicator can indicate that: In the case of standard output, the rotary pump can also adapt to the length change of the label (longer length); the high feed rate is based on the mechanical hardware quality, component configuration and servo control technology, not the average manufacturer can produce, the value of It reflects the manufacturer's professional and technical standards.

(2) The printing speed of adhesive labeling machines. For the labeling machines used in the pharmaceutical industry, it is particularly important that the label can be printed on the position. Therefore, when the adhesive labeling machine delivers the speed and the speed of the paste, the printing speed of the printer to be used must also be taken into account, and the smallest one can be regarded as the actual labeling capacity value.

Printed lot numbers on stickers are generally based on hot-stamping in the pharmaceutical industry. Hot-stamped printing is a technique that prints text using ribbons by heating the head. Why is hot stamping the preferred method for the labeling of batches in the pharmaceutical industry? Compared with the recent ink-jet printing methods, one of the hot-stamping printing methods is that the production cost and equipment maintenance cost of the hot-stamping printing are low; the second is that the hot-seal printing does not affect the odor emitted from the solvent when printed by a similar portion of the ink-jet printing device. The cycle of the air-conditioning system; the third is the recycling of the ribbon, which has an environmental protection aspect.

Although hot stamping has its own characteristics, it also has weaknesses, that is, its printing speed has a certain limit. The fastest speed of domestic hot stamping machines is generally 400 beats/min. After this value is printed, the text is not clear. Some people think that the highest output of self-adhesive labeling machines with hot stamping can only be set at 400 pcs/min. Self-adhesive labeling machines with output exceeding 500 pcs/min will be equipped with inkjet printing.

3, from a special use point of view to choose

When the bottles are labelled, they often encounter special-purpose problems. For pharmaceutical production, they may encounter: (1) double-sided stickers; (2) the label adhesion to the surface of plastic bottles is reduced due to the release agent. There is a "bubble" phenomenon on the label surface. This puts forward special requirements for the selection of self-adhesive labeling machines.

3.1. Consideration should be given to the selection of double-sided stickers

When double-sided sticking is required for flat bottles, square bottles and round bottles, the following points should be taken into account at least: (1) The label head can realize multi-dimensional space adjustment to ensure the accuracy of labeling, such as the adjustment of 6-dimensional space; (2) The label head adopts a double-pressure roller design to increase the tension of the label so as to facilitate the export of the long label.

3.2. Considerations for the ease of “bubble” problems on labeling surfaces

(1) The effect of static electricity should be eliminated. Electrostatic ion blower can be used to statically treat the bottle body, and the static electricity brush can be used to remove the static electricity of the label; (2) Increase the labeling pressure of the label and increase the label and bottle as much as possible. Adhesion; (3) In the labeling process, make the label and the bottle in line contact as much as possible to completely drive off the “bubbles”.

4, from the labeling quality of choice

The generally accepted labeling quality requirements are: (1) The labeling error is ≤±1mm, even if the reclosing position of repeated labeling can reach this value again; (2) After labeling, the label and the bottle surface should be attached and should be flattened. No wrinkles, no “bubbles” phenomenon; (3) Print batch number handwriting is legible, no overlapping and blurring, and the batch number error is <±1mm.

To be able to achieve the above labeling requirements, in addition to label quality and reasonable operation, but also related to the device, so the choice should consider the following: (1) the flatness of the labeling, mainly depends on the rational design and high precision For the processing, under the rolling pressure, it is necessary to ensure that the label is in line contact with the surface of the bottle body; (2) The high configuration requirements of the drive element, because the core of the labeling operation is a high-precision ultra-low inertia servo motor, in order to ensure the The quality of the system, the application of closed-loop system control, while the motor itself can always correct their own position in the self-compensation; (3) detection methods and detection components, but also to ensure the quality of labeling and labeling the basis for the output, a technical strength of the manufacturer In the past, the detection element only detected the imperfections caused by the label printing. Now the detection method is changed to measure the thickness, which uses the thickness variation generated by the gap between the label and the label to control the servo-electric operation. This is The current best detection method is more reliable. (4) To achieve perfect labeling, the control of the whole machine is also very critical, especially the bottle conveying speed and the delivery speed. degree. In the selection control, it should be noted that the production speed signal can be sent to the system synchronously, and then sent to the servo motor through analysis and calculation, which requires the matching of the running speeds of the two; (5) Component configuration, since the high-speed labeling is based on the continuous operation of the machine. It requires that all components react quickly and all actions are to be completed in an instant. This also imposes requirements on the configuration of the detection element. For example, for labeling servomotors, labeling motor drivers, conveyor motors, delivery motors, split motors, frequency converters, labeling eyes, label detection sensors, delivery stop proximity switches, programmable controllers, human-machine operations Interface components have configuration requirements.