(1) Early tile line
The production of single-sided corrugated board is an independent process, separate from the gluing process of the second layer of paper, which is then slit, creasing and cross-cut according to the final board specification. The single-sided corrugated paper roll is transferred to the gluing machine, and then made into double-sided corrugated cardboard, which is then cut into a certain size of finished cardboard by a flat hot plate, a slitting machine and a terminal cross-cutting machine. These machines have a width of about 1 meter, and the final cardboard is creasing, cut and grooved on a separate machine, usually a cross-bar hand-operated machine. Of course, the sequence of these processes can be varied, but the main principle remains the same.
The early single-sided corrugating machine did not have a pressure roller, but extruded the corrugated core paper to shape, and then sent it to the glued surface paper for bonding. These two processes were independent. In this way, the corrugated distance and the corrugated height will be very different, forming a gap between the corrugated tip and the surface paper. It is precisely because the corrugated type is rough and too much glue that it can "fill" this gap. Later, the pressure roller type single-sided machine appeared, and the overhead bridge installed on it provided a variable buffer space for the single-sided corrugated paper web, so that the paper web transportation was very flexible. Likewise, previously separate processes such as gluing the backing paper to single-face corrugated board, heating, cutting (rotary knives were used at the time) and hand stacking could be installed in-line, making the production of the board a continuous process. This technological development announced that the corrugated board production line has entered a modern development period. Like the paper machine, the tile line is also divided into 2 sections. One is the wet end, which is used to make the cardboard and steam heated, including from the single-sided machine to the double-sided machine end. The other is the cadre, where the cardboard is slit, cross-cut and stacked according to the size requirements, and then transported to the processing area.
(2) to the 1970s
The cardboard production line has become the focus of industry development again, and a new production method has begun to enter the stage of history. Japan developed the first "intermittent tile line", which brought the production line's cardboard output and quality, as well as production flexibility to a new level. The line has no limit on order size, and can even complete single carton orders, and carton count tolerances are completely eliminated (quantity tolerances of around 10% were common for deliveries in the past). Warped cardboard is greatly reduced as no downtime is required to change orders. In the past, 85 inches (perhaps 87 inches) was the standard width that tile wires could be processed (this is a manifestation of the huge impact of American standards on the industry). However, such lines were obsolete at the time, and were replaced by European lines with a width of 244 centimeters (or 96 inches), which were larger, more automated, and operated continuously.
(3) The tile line in the 1980s
The main achievements in the development of the tile line: Before the mid-1980s, the main achievements in the development of the tile line (corrugated cardboard production line) were: the use of starch paste glue in the 1960s; automatic stacking machine; no guide claw type Single-sided machine; automatic slitting and creasing machine; central control concept; quick adjustment of preheater and double-sided heat input; direct drive cross-cutting machine. In addition to the application of starch paste glue, the tile line in the 1970s experienced many other developments, among which the North American Carton Enterprise Alliance (cid) played a pivotal role in promoting these major innovations.
In the late 1980s, the 2.8-meter-wide tile line became popular again after decades of hiatus. Richardpratt's visy cardboard mill was the starter when it wanted to increase its output from a new type of machine. Visy already enjoys the highest average speed and production worldwide. However, such efficiencies are still insufficient for the planned installation of equipment at Coolaroo, near Melbourne. At that time, langston and bhs were able to manufacture such wide tile lines, which accounted for 25% of the total manufacture of bhs until the 1990s. bhs also has the intention to manufacture 3.3 meters wide tile line. The world's first 3.3m watt line was commissioned in Europe in the summer of 2002. It is not a millugator, its original paper roll is transported by road. In general, the important technological progress of increasing the width puts forward higher requirements for single-sided and cross-cutting machines, and other machines only need to be consolidated and strengthened. At present, the most advanced corrugated cardboard line in the world, the cardboard processing width is expanded to 2800~3300mm, and the running speed is as high as 375~400m/min. Corrugated cardboard. At present, the box-making technology and equipment supporting the cardboard production line have also been developed relatively well. Overprinting a variety of colors, the operation speed can process 250~280 cartons per minute. Various other technical equipment corresponding to the manufacture of corrugated packaging containers, such as die-cutting, folding, stapling, gluing, coating, adhesive, printing, plate making, design, testing and many other links of high-tech and equipment are almost everything. At present, higher manufacturing technology can effectively ensure the inherent quality of corrugated packaging products, and higher production efficiency enables corrugated packaging to have lower production costs. In the packaging field of the product, it has better demonstrated its superior packaging function. The development of cut marks in corrugated board production has opened up the possibility of using pre-printed cartons. The degree of automation of technological processes is getting higher and higher, and computer design and mechatronics control are widely used.
(4) Development history of corrugated type
In the more than half a century after the appearance of double corrugated cardboard, the scientific development of corrugated structure has become more perfect and mature. Western corrugated structure technology has only been transmitted to China for only 30 years, and now it has basically reached the modern level.
The first type of flute developed is about 4.5 mm high, which is a flute. This type of flute was used in large numbers at the turn of the 19th and 20th centuries. The b flute came out in 1910, and the flute height is about 2.5 mm. These two flutes were the standard for three-ply and five-ply boards until the 1960s. This alphabetical classification system does not name the corrugated corrugated according to the height of the corrugated pattern. It was disrupted with the birth of another flute type. The height of the new corrugated type is between a corrugated and b corrugated, and the corrugated height is 3.5 mm, which is called c corrugated. In the 1960s, E-type corrugated was born. F-type corrugated appeared in the early 1990s, and the remaining corrugated types were also born in the next five or six years. At the end of 2000, the smallest corrugated at that time - O-shaped corrugated came out. So far, ten corrugated types have become the industry's recognized standard.
The following table lists the flute type, flute height, flute distance and flute ratio (the length of the corrugated core required to produce a unit length of cardboard, also known as the traction factor). Many carton mills have developed their own corrugated profiles to meet customer-specific needs. These data are different for corrugated cardboard or cardboard for different purposes produced by different manufacturers. The data in the table below are all recognized standards in the industry.
By using double or multi-flute single-sided machines and various types of paper, thousands of corrugated cardboards can theoretically be produced, and one can be selected for any product packaging. As a key functional component of corrugated board production lines and single-sided corrugating machines, corrugating rollers are also constantly improving and developing rapidly in terms of structural form, precision quality, economic indicators, manufacturing materials and manufacturing processes.
(5) Adhesives on early tile lines
Early machines used a paste-like binder, which contained a paste of starch granules. Around 1900, sodium silicate (ie soda silicate) binder was used for cardboard bonding, which was made by dissolving white sand in soda ash, and the result was soluble in water. After curing, it is similar to glass (the origin of the common name "water glass") and the curing speed is very fast - this speed is enough for the early tile line. The single-sided machine has a set of interchangeable "transfer rolls", each of a different length that is slightly smaller than the width of the paper to be processed. The purpose of the transfer roller is to rotate with an application roller, which in turn is in contact with another roller whose bottom is immersed in a sodium silicate rubber disk. The transfer roll determines the width of the film to the glue roll, which applies the glue to the flute tips. The core paper is attached to the corrugating roller by a brass half-moon-shaped "guide claw".
(6) Development trend of corrugated industry
As early as 160 years ago, the British discovered the corrugated structure, and thus invented the corrugated packaging. After another 15 years, Americans invented single-sided corrugated cardboard. In the next half century, the scientific development of corrugated structure has become more perfect and mature, and it has become half of the entire commodity packaging. The Western corrugated structure technology was introduced to China, only ten years of history, and now it has basically reached the modern level.
Rapid innovation has been a hallmark of the corrugated box industry for the past four decades. Looking back over the past four decades, we can find some general trends: the weight of cardboard is decreasing; recycled waste paper is replacing virgin material, and the application rate is increasing; computer-aided design technology and technological progress in the carton industry have led to the increasing application of die-cut carton design ;High-strength materials have begun to replace wood in many fields and have achieved greater development; the continuous development of new corrugated types is mainly because the carton factory can complete the replacement of corrugated rollers of different corrugated types in a very short time, and corrugated cardboard It is a strong competitor of boxboard in many fields. Automation control, the greatly improved speed of production equipment and the application of digital technology have become the main driving forces for the great changes in carton factories.
Although corrugated boxes have only a history of more than 100 years, however, due to the mechanical properties of corrugated boxes, such as light weight, compression resistance, puncture resistance, tear resistance and cushioning, shock resistance, easy processing and forming; and good decorative printing suitability, they can be recycled and reused. It has the advantages of no pollution to the environment; it is economical, portable and easy to stack, so its use range is getting wider and wider, and the development speed is getting faster and faster. At present, corrugated board has become one of the most widely used packaging materials in modern packaging. Whether it is used for production materials or living materials, whether it is transportation packaging or sales packaging, the corrugated boxes processed from it have become the packaging materials of commodities. Bulk commodities are necessary for the packaging of export commodities and domestic market commodities. They have become the most widely used packaging containers in modern commerce and trade, and are also one of the most important packaging forms adopted by countries around the world today.