How is a good corrugated board made?

Corrugated paperboard is the hottest “star” in the packaging industry today. With its excellent environmental performance, strong plasticity, strong bearing capacity, and light weight, it is becoming the most favored star packaging material in the packaging industry. It is also rapidly covering. Speed ​​has become a premium alternative to a variety of traditional packaging materials.

However, a simple corrugated cardboard that looks like it is made up of several layers of corrugated cardboard is not easy to have good quality. By accepting the opportunity of an interview with the reporter of China Press and Publication, Zhang Huizhong, the deputy general manager of Packaging Products (Suzhou) Co., Ltd., led him to take a look at the current domestic advanced corrugated board inspection technology and uncover how to make a good cardboard. The mystery of success.

Waterproof detection

Corrugated cardboard is denatured by means of special processes such as coating, and its basic properties are still a piece of cardboard. Therefore, the waterproof performance of cardboard is the most important aspect of considering whether a piece of cardboard is superior or inferior.

There is a simpler and faster detection instrument for the packaging process than the national inspection process. The imported equipment is made of a glass-made water tank. The tubular distilled water is dropped on the slope of the paperboard at a 45-degree angle and forms a water column. After that, the water droplets form sliding marks on the paperboard. The trace of the trace can be used to determine the waterproof performance of the paperboard. Good or bad. This detection method can be said to be faster and immediate.

Adhesive water resistance detection

The main reason for the soft failure of damp paperboard is that the bonding point absorbs the moisture in the air circulation, and then spreads from a place where the water gradient is high to a place where the water gradient is low, so that the cardboard fails within a week or two. Therefore, it is very important to solve the adhesive water resistance problem of cardboard.

According to reports, foreign companies attach great importance to the adhesiveness and water resistance of corrugated cardboard. In the foreign orders for the packaging contract, the customers of the United States, Sweden and other countries have higher requirements for the waterproof performance of the cardboard, and usually need to meet the international ISO1038 standard promulgated in 1975.

Relative to foreign countries, the domestic adhesive water resistance testing and standards lags more than 30 years. At present, the basis for judging the water-repellent performance of paperboard in the industry is the water-resisting paperboard standard issued by China on September 1, 2009. Achieved the package has the only imported cardboard adhesive water resistance testing equipment. Therefore, it is regrettable that so far this performance has not been able to achieve third-party testing in China. The packaging is initially delivered to Switzerland for testing.

According to Zhang Huizhong, the principle of adhesive water repellency testing is to cut the cardboard into a standard sample block, then cut it from the middle, lift it from the top of the five force points in the water, and hung below a 250-gram weight. hammer. After measuring the time from the suspension of the board to the breakage, the paper evaluates the water resistance of the board.

With this device, the adhesive water resistance of the cardboards produced in packaging has also been continuously improved. Zhang Huizhong recalled that without this equipment, because the weight of the hammer was heavy, the cardboard it produced was generally dropped into water within 2 to 5 minutes, and the cardboard layers were separated. Now through continuous R&D, we have applied for patented products and passed third-party testing. The best glue-resistant and water-repellent cardboard can be hung for up to 230 hours, which is the leading domestic level.

Air permeability testing

Zhang Huizhong admits that the general carton factory does not test the air permeability of cardboard, because most customers do not require the product to have this test data.

But nowadays, recruitment is difficult, and carton packaging companies are no exception. Nowadays, many upstream companies and large domestic companies have adopted packaging lines, of which dyestuff companies have the largest volume of business, usually requiring at least a few million cardboard sheets per month, and each carton has a weight of 25 kilograms. In this way, an ordinary company needs to carry at least 2000 cartons a day. However, the reality is that there is a shortage of porters and packers on a large number of packaging lines, and the cardboard lines are moved to the trays to carry them. Dirty, tired and hot, it is difficult for a hauler to receive a monthly salary of 4,000 yuan. Under such market conditions, many companies have started to use automatic packaging lines.

However, there is a technical requirement for the end of the fully-automatic packaging line. The packaging line will use an automatic sucker to suck up the 25-kilogram box and transfer it to the tray. This poses a problem for the traditional carton factory. Because the surface of the carton is rough and the air permeability is good, an effective vacuum cannot be formed and the suction cup cannot suck it up. At this point, air permeability becomes another important indicator of high-quality cardboard.

Achieving the package has been combined with the Canadian Packaging Academy to launch a new research topic. The way to solve the problem that the paperboard cannot be sucked up is to coat the surface of the paperboard to completely fill the voids in the surface of the paper and form a vacuum suction cup during the suction process so that the suction cup can suck and transfer the paperboard. The instrument for this performance is a vacuum tester.

In particular, the packaging is located in Jiangnan area where the air is wet and once the product is transported to a dry place, the performance will change. Therefore, the test results and indicators are more demanding.

Intermediate inspection

There are only 7 operators in each corrugated board production line for packaging, but the production process is not simple. Carton performance is different, the process is also different, especially the special carton, some cardboard need to coat the metal layer, and some need to apply anti-static layer, coating times can reach more than a dozen times, and even some need to be removed Heavy metal and other environmental protection technologies, all using automatic programming. Therefore, the middle of the process detection is also necessary to ensure that nothing goes wrong.

According to reports, the coating of many high-end carton boxes will greatly increase the added value of carton plant products and increase the profitability of products.

Terminal detection

Terminal inspection is a task that every packaging factory must do. Zhang Huizhong example, heavy-duty corrugated cardboard packaging first in the testing process to do the circuit experiment, then the board will print the finished product after testing. The use of automatic optical typesetting equipment introduced from Australia at the end of the package took place in the four-color printing, six-color printing in each edition of the test, you can control the difference between the version and version within 1 mm.