The most commonly used packaging materials, derived from paper, are corrugated cardboard and plain cardboard. There are significant differences in their characteristics and it is important that they are well known in order to make the best choice of packaging for a particular application.
Cardboard is a thick material with excellent properties that allow folding and modeling at a much better hardness than paper. It can be easily cut and shaped, and its lightness, strength and recyclability make it ideal for many packaging applications. It is most often used for making small boxes, packages, etc. It can be used to make transport packaging, but it does not provide sufficient protection and it is good to additionally secure the contents with an inner packaging of protective material.
It is made from cellulose, which is often recycled, and various binders, fillers and other ingredients are added to it, depending on the purpose. According to the DIN standards, any paper with a density of more than 150 g / m2 can be classified as cardboard. The most important characteristics that are monitored when managing the quality of the produced cardboard are weight per 1 m2, thickness and humidity. The production of cardboard is very similar to that of paper. The raw material goes through a process of grinding, casting, pressing and drying. A significant difference is that coarser and harder fibrillated celluloses are usually used for cardboard.
Corrugated cardboard or so-called goffered cardboard consists of several layers of material with an intermediate folded layer. The types of corrugated cardboard differ according to the number of layers and the thickness of the wave. The difference in the structure of the corrugated cardboard also leads to the different strength of the material. The more layers and the better quality paper is used, the stronger the packaging material. Important advantages are the combination of lightness, plasticity and impact resistance. Although corrugated cardboard provides a higher level of security than plain cardboard, the load that has to be packed must be consistent with the material limitations.
Corrugated cardboard is an effective means of transporting products of various natures due to its durability. Leading companies in the field of supply conduct engineering testing of strains and deformations and the effect of vibration load on shipments in moving trucks. This allows them to optimize the weight of corrugated packaging and reduce the total weight of packaging by about 9 percent. This in turn reduces the corrugated cardboard waste that goes into recycling. This is just one of the examples of the flexibility and rapid modification of the material – qualities sought by every company focused on resource optimization.
Double-layer corrugated cardboard is a flexible material, a combination of a flat layer of paper and a pleated layer, and can have the sealing and strengthening application of an inner packaging. The three-layer corrugated cardboard consists of two flat layers with one pleated intermediate layer. The most common corrugated cardboard is with profile C, B, E. Three-layer corrugated cardboard with wave profile E (micro corrugated cardboard) has a thickness of up to 1.3 mm. It is used in the production of small or laminated packaging with light and medium weight. It is extremely suitable for punching and can produce an unlimited variety of constructions and designs. Three-layer corrugated cardboard with wave profile B – 3 mm thick is used for medium-sized packages and cardboard boxes with a product weight of up to 10 – 15 kg. It has very good resistance to pressure.
Three-layer corrugated cardboard with wave profile C – 4 mm thick, can withstand loads weighing 20 kg. It is very durable and can be used to make large cardboard boxes, laminated and punched products. The four-layer corrugated cardboard consists of one outer, one inner straight layer and two folded intermediate ones and is used for lamination. The five-layer corrugated cardboard consists of three straight and two intermediate pleated layers of paper. The five-layer corrugated cardboard, which combines C and E profile waves, is 5 mm thick and is the preferred material due to its high strength and high print quality, which gives it a very attractive commercial appearance.
The pragmatism and variety of design makes the tinted and punched packaging of corrugated cardboard and plain cardboard an extremely popular product. During punching, the material is formed by plastic deformation. This is a resource-efficient process that eliminates the need for additional binding materials to assemble the packaging product. Punch packaging is preferred in the food industry, for packaging and transport of fruits and vegetables, cosmetic, pharmaceutical and chemical industries, transport packaging, packaging for electronics, machine elements and more.
Punching is an extremely expedient way of processing in terms of production costs and time spent on it, as the source material can be quickly and efficiently produced into a product with high accuracy of shape and size in series production, which can immediately be put in use. Punch cutting allows the production of specific products, prefabricated packaging with the possibility of lamination and printing.
In general, punching can be divided into two main operations: separation operation (cutting, drilling, etc.) and forming operation (drilling, bending, twisting, drawing, etc.). The process of punching paper products is performed with the help of a tool with built-in sharp steel knives, bent in a complex irregular shape, and a press that provides pressure. A punch mold or matrix is used to cut the material into an irregular shape.
The qualities and efficiency of the production of cardboard and corrugated packaging enable each manufacturer to present their products in a creative, distinctive and functionally effective way in a package with a reliable construction and at the same time to ensure their safe storage and transport.