Corrugated carton forming process Q&A (1-4)

Corrugated cartons play an increasingly important role in the packaging of modern products. They are popular for their unique material structure mechanism, unique packaging effects and economic benefits. Corrugated cartons are in the packaging field both at home and abroad. As a result, the paper packaging is pollution-free, meets environmental protection requirements, and has a low cost. It is also favored by businesses.

Needless to say, the prosperity of the commodity economy and fierce market competition make corrugated cartons an important means of marketing and propagating merchandise, and it has been increasingly valued by packaging users and consumers. Corrugated carton forming process as an important part of the production process of corrugated carton, but also naturally has become the concern of the manufacturer and must be resolved in advance, such as: how to choose the molding method? What are the technical requirements for die-cutting blades and die-cut, bottom and rebound glues? What are the problems encountered in the die-cutting process and how can this be solved? This issue of “First Line Attack” adheres to the traditional tradition of “Printing Technology” magazine, in-depth reports on various problems encountered in the molding and processing of corrugated cardboard boxes, and answers the thorny issues facing you through the experts and peers. The guests who participated in this front-line attack were: Mr. Lin Changchun and Mr. Lu Xiangxiang of Hongye Equipment Co., Ltd., Mr. Zhong Yunfang from Zhejiang Shangfeng Group Co., Ltd. and Mr. Qian Luming from Asia (Shanghai) Paper Co., Ltd. They hoped that these professionals’ unique insights Give you inspiration and help.

1Q: What are the common types of corrugated box forming methods in China? What are their characteristics and applications?

A: At present, there are two kinds of corrugated box forming methods: die-cutting and slotting. Among them, die-cutting includes flat-press die-cutting, round-die-cut die cutting, and round-press die cutting.

Circular die cutting uses arc-shaped wood boards and roller knives for making. Because it is die-cutting the corrugated cardboard at the same time as the cutter die rolling, the strength of the die cutter is required to be relatively high (common thickness is 1.42mm, and the service life is up to 600,000 times.) Difficulty in manufacturing and costing die cutters has been relatively high. With the improvement of precision and the application of ancillary equipment, the accuracy of the die has reached the level that most carton users can accept. Its advantage lies in maintaining a certain precision at the same time, the speed is very fast, and the range of cardboard boxes that can be die-cut is very wide, which is suitable for large batches of live jobs, but its cost is high. At present, more and more manufacturers have adopted this method.

The flat die cutter uses flat die cutters, with flat die cutters (thickness 0.71mm or 1.05mm, with a service life of about 300,000 cycles), and the die cuts through the entire piece of corrugated cardboard at the time of die cutting. It has the highest die-cut accuracy and is suitable for fine-cut cartons and small-to-medium-sized cartons, but at a lower cost, but its speed is slower (especially the hand-push flat-press die-cutting machine), and it is limited by the size and cannot be molded. Cut large cartons for small orders.

Circular die-cut die-cutting has been greatly improved on the basis of flat die-cut die-cutting, with various features of flat die-cutting and die-cutting, flat die cutters are used, the production cost and difficulty are not too high, and the precision of die-cutting is high However, the speed is slow, and the investment in technology and cost is large, which is not conducive to large-scale production, so it is generally not commonly used.

Grooving is characterized by fast speed, no need to produce knife mold, low cost, but poor precision, can only handle the carton with less strict precision and shape, this kind of application in the carton factory is also very popular.

2Q: There are many ways to form corrugated cartons. How do users choose ?

A: In terms of accuracy, several molding methods are ranked from high to low: flat die-cut die cutting, round die-cut die cutting, round press die cutting, slotting; in terms of speed, the order from high to low is : Slotted, round pressed circular die cut, round pressed flat die cut, flat pressed flat die cut.

When selecting the corrugated box forming method, the most important thing is to specify which cardboard box is mainly used for die cutting. If all of them are used for processing large-scale and low-precision cartons, the slotting machine should be selected for the lowest cost and faster speed; if the production volume is small and the color corrugated box with high precision is required, the flat pressure die cutting should be selected. In order to ensure the customer's requirements for high precision; if the product is large in volume and accuracy is not very high, it is best to choose circular press die cutting, which can not only improve the production efficiency, but also reduce the production cost and win the market.

3Q: What factors should be considered in the design of a diecut? What are the problems encountered in making a die cut?

A: Before making a die cut version, first of all, be clear about the object of the die-cutting object, such as the thickness of the corrugated cardboard, how the precision requirements, the number of die-cutting, and then determine what kind of molding method, what Die cutter, indentation line and sponge glue and other materials.

In the production of flat knife mold, in order to prevent the fragile corrugated board surface color burst, burst, should use high-quality sponge rubber, the selected indentation line should not be too high, too thin.

Drum cutter die is difficult to produce, and the problems often encountered during production are inaccurate dimension calculations, lines that are not straight when sawing the wood, heights of die cutters, and incorrect tooth selection. Because the drum cutter die is curved, the distance between the straight knife and the line on the cutter die must be calculated in conjunction with the drum diameter, knife height, and board thickness. The height and shape of the die cutter directly affect the smoothness of the edge and the life of the end pad. At present, the commonly used die cutter is 25.4mm or 24.6mm. If there is no special requirement for the trimming, a standard 10 tooth/inch tooth can be used. In addition, the selection of the height of the indentation line is also very important. If it is improperly selected, it will crush the cardboard or cause the cardboard to not fold. Usually, the straight indentation line on the same die must be about 0.5 mm higher than the arc indentation line.

4Q: What are the requirements for the plate material when making the roller blade mold? How to store roller cutters?

Answer: The board used for the roller knife mold has higher requirements than the wood board used for the flat knife mold. It should choose the wood board that is not easily deformed. At present, the commonly used in our country is still the imported round board. As for the preservation of the roller knife mold, if there is a condition, a special storage rack can be made, and the unused roller knife molds can be placed flat separately, do not stack or place them vertically, and keep the humidity in the site stable .

---<Printing Technology>