The hottest VPS laser labeling system brings new c

VPS laser labeling system brings new changes to fruit labeling

last October, Sinclair Systems International (), the leader in labeling fresh fruit and vegetable products, launched a VPS laser labeling system based on laser diode array technology. VPS system is well combined with Sinclair's existing labeling function to print various bar codes, PLU (product identification) codes and graphics according to different fruit categories (see Figure 1)

Figure 1. Laser marking sticker for navel orange

the core of the system is an ultra wide laser diode array, produced by intensity, which can emit hundreds of independently addressed laser beams, so that the label printing can be completed in one step without galvanometer scanning technology. Sinclair has successfully completed field trials in California, USA, and is preparing to promote the product to their customers

for some time, the fruit and vegetable industry has recognized the importance of on-demand printing technology, that is, it can create information on labels in real time according to the needs of label applications. So far, most labels are still printed in advance. The labels not only contain brand information, but also indicate various product data. The technology of printing various labels on demand has brought great convenience to fruit and vegetable packers and retailers

benefits for fruit packers

in order to add more information to the fruit label, such as marking PLU, country of origin, bar code, etc., it is necessary for Sinclair's customers to hold a large number of inventory labels and strive for the main drafting power of relevant product standards. On demand printing technology not only saves inventory and transportation costs, but also greatly improves operational efficiency

Sinclair also faced a unique product development challenge when it decided to launch on-demand printing technology. If the alternative new technology is introduced into the current factory, the equipment originally installed by the company will have the problem of outdated products. Therefore, the new technology must be designed to upgrade the existing labeling machine, that is, only a small amount of improvement work is required

on demand label printing also reduces the number of labeling machines required by fruit packers. So far, each fruit sorter has applied different label labelers, and each is equipped with a special label. For example, each Fruit Sorter may be equipped with three labeling machines, which are equipped with fruit labels of different sizes, large, medium and small. Fruits are sized by an automatic screening system before being transported to the labeling machine. The information of this size is used to guide the labeling machine to choose the appropriate label to stick on the fruit among the three sizes

Figure 2. Improved VPS laser labeling application system

in this example, the original three labeling machines can be replaced by a single labeling machine equipped with VPS improved system (see Figure 2). The new labeling machine is equipped with a roll of labels, which contain brand information and a blank space to indicate different product materials. The size data is used to inform the VPS system to print out the appropriate PLU code and/or barcode

in addition to reducing the inventory of labels and the number of labeling machines, on-demand printing technology has also brought a series of saving measures. Inventory management is greatly simplified, requiring fewer SKUs and reducing the scrap rate. Shorter or special product labels are no longer a problem. The cost loss caused by excessive inventory or shortage has also been reduced. The operational errors and working hours during label replacement have also been improved

benefits for retailers

food safety and tracking performance are becoming increasingly important. In recent years, the media has reported a large number of food safety issues and incidents. VPS system can mark product data and origin information in addition to printing PLU and bar code, making it possible to record and track ★ 8) sensor static accuracy: tracking a single fruit within load limits

available technologies

sinclair decided to use the dlam diode array technology of intensity company to develop a new system after widely considering many different technologies

Table 1 contains some available technologies that have been considered. Table 1. Available technologies for fruit labeling

many Sinclair competitors have tried to install inkjet printers and thermal printers, but they cannot provide the necessary product quality and reliability at feasible commercial costs

laser labeling provides a solution to avoid other technical defects. Laser labeling is non-contact, and laser marking is non-contact, so wear and degradation of printing quality are not problems (this happens from time to time when direct thermal printing is used); There are no consumables (in inkjet technology, the ink viscosity must be carefully controlled); And there is no direct contact with the fruit epidermis, which will not cause damage to the fruit (this will occur in direct laser marking of fruits)

direct thermal sensitivity or thermal transfer

by definition, the print head of the thermal printing system should contact the label when printing. This leads to the wear of the print head and the decline of print quality. Especially in the relatively harsh environment, this problem is more prominent, such as in a packaging factory where pollutants and dust are common

when the print head is worn, the loss of printed content is a common phenomenon. In this case, printing barcode is absolutely unacceptable

the label base material used by Sinclair company is very important to its technology and products. If you want to be able to stick labels to fruits reliably, the flexibility and compatibility of labels are very important. Due to the contact characteristics of thermal printing, heat will be generated, which leads to the need to use thicker and stronger labels. However, this also has a side effect - because the label is harder, which reduces the adhesion performance

when the label passes through the thermal printer and labeling system, it is necessary to maintain accurate control over the label. This means that labels must be printed in advance before the fruit is delivered to the labeling machine. On average, labels are pre printed before 10 fruits. If the fruit conveyor belt stops, or a fruit falls from the conveyor belt, it will cause trouble

it can be easily painted on the substrate

perhaps the biggest problem of thermal printing labels is the management of costs and consumables. Because the print head needs to be replaced every 10000 copies, so it needs to be replaced every week

inkjet printer

because inkjet printing is a non-contact printing technology, the space between ink and medium is very small (less than 5 mm). This is better than heat transfer or direct thermal sensitivity, but the effect is negligible. Inkjet printers are easily blocked by dirt and dust in the packaging plant. The consequence of blocking is the lack of print pixels, so the barcode can not be read. Like the thermal printing system, inkjet printing also needs to label the fruit before it arrives

inkjet system can achieve higher speed. However, under the speed requirements of Sinclair company, the drying time is also a question and has the function of maximum torque display; The ink is often wiped off in the process of application

as mentioned above, the polyethylene label used by Sinclair company is a key part of the whole technology. It is a paper label with superior performance. Food grade inks that can be quickly dried on polyethylene labels are difficult to find. Moreover, ink is also a consumable, which needs to be maintained by the customer, and the ink cartridge must be replaced frequently

solid state laser

fiber or diode pumped solid state (DPSS) laser systems are often used for product marking. However, considering the comprehensive requirements of high-speed and large width printing, they are not suitable for Sinclair's applications. Because the scanning technology can not move the beam in the whole printing range, nor can it ensure the printing quality at the required printing speed

diode laser marking system

vps system is built on a huge LED laser array, and its power supply circuit ensures that each laser can be driven independently. Customized optical elements are used to transmit laser beams to the label to complete printing (Figure 3)

Figure 3. Schematic diagram of VPS laser labeling system

the label itself is developed by Sinclair company, which includes a laser markable layer. The design of chemical formula can absorb laser energy to the maximum extent, so as to ensure high-speed printing. The label has passed the food safety certification

the system is designed to improve Sinclair's existing labeling machine RM6. After years of use, the RM6 machine has proved to be a fast and reliable device. The system adopts the proprietary technology developed by Sinclair company. It can take out a piece of label from a roll, and then be gently transferred and pasted on the fruit, without risk of damage. This can be operated through a set of wheel operated retractable rubber tubes

after the VPS printing system is installed on the labeling machine, when the label is moved from the label roll to the fruit surface, the laser beam array can be directly printed on the label. This means that labels can be printed immediately when needed

intensity () is a leading supplier of semiconductor lasers to the printing industry, serving many well-known companies in the fields of CTP, digital printing and direct marking. In terms of hundreds of high-power, independently addressable transmitting tube laser arrays, intensity's DALM technology is unique in the laser industry. Diode array technology is highly reliable, which has been proved in the past many years

advanced chip alignment technology allows intensive to install a variety of laser array chips adjacent to each other, which can maintain a constant distance in the whole array. The technology has been modularized and can create a large array of several inches, which can provide more than 500 MW of laser emission power

field testing

sinclair once conducted field testing in a citrus packaging plant in California, USA. The system was installed and operated in August, 2009. When the citrus harvest season came in October of that year, the label test began. The experiment was carried out smoothly, and the production quality of the system was also recognized by the packaging factory, and the formal production began in January 2010

this packaging factory uses the new system to produce three different barcode labels, which are used for small, medium and large navel oranges. In order to evaluate the system, Sinclair company measures from two aspects: the scanning percentage of bar code and the labeling percentage. In the past production and operation, the company has achieved 100% barcode scanning rate, and more than 95% of the fruits have been labeled (this is the typical success rate of normal labeling operations)

conclusion

laser diode array labeling system has been successfully introduced into highly demanding applications. The diode array labeling technology has wider printing range, better reliability, higher linear printing speed (greater than 1.5 m/s) and better printing quality, which will enable the diode array direct labeling system to win a wider range of new product labeling opportunities in the future

the author of this article, Mr. Steve Gorton (e-mail: steve_gorton@), is the production line director of intensive company, and Dr. M. Scott Howarth is the R & D director of Sinclair systems