The hottest paper packaging materials and their cl

Paper packaging materials and their classification

papermaking is one of the four great inventions in China. In history, paper was once a very precious material. In the Eastern Han Dynasty, the papermaking invented by Cai Lun had a far-reaching impact on the development of human economy, politics and culture. After the emergence and development of new papermaking technology, paper packaging materials as an important packaging material began to be widely used. Paper packaging materials usually include paper and paperboard, which play an important role in packaging materials, accounting for more than 40% or even 50% of all packaging materials. As a packaging material, paper packaging material has incomparable advantages over other packaging materials: for example, its source is relatively wide and its price is relatively cheap; It has good elasticity and toughness, has a good protective effect on the packaged goods, and is suitable for mechanized operation; At the same time, paper packaging materials have good printability and can also be recycled. In modern society, people advocate environmental protection consumption. Reusing resources can not only reduce the consumption of resources, but also achieve the purpose of developing economy and protecting the environment. Therefore, even in the fierce competition of packaging materials, especially under the strong impact of plastic packaging materials and products, paper packaging materials are still valued by people and continue to develop new products. It can be predicted that paper packaging materials will be a dominant packaging material both now and in the future. Paper packaging materials have many advantages, which is its dominant position in China's packaging materials. Among the four main kinds of packaging in China, paper packaging accounts for more than 50%. However, China is poor in forest resources, so we should actively develop non wood pulp papermaking, use reed, bagasse, cotton stalk, wheat straw, bamboo and other wood substitutes for papermaking, expand fast-growing industrial forests, make full use of branches, waste materials, processing surplus materials, etc., and expand the source of raw materials. By developing new pulp reinforcers and improving the structure of corrugated board, the paper strength is improved and the thickness of board is reduced; Achieve the purpose of reducing the amount, developing the economy and protecting] our living environment at the same time

1.1 composition of paper packaging materials

in the family of packaging paper, paper made of plant fibers accounts for the vast majority. Plant fibers can be raw materials such as wood, reed, bamboo, bagasse, straw, cotton, hemp, bark, etc. Therefore, paper comes from a wide range of sources and its price is quite cheap. With the continuous development of science and technology, human papermaking technology is also developing and progressing, and the raw materials used in papermaking are also constantly updated. It is conceivable that in the near future, human beings will gradually get rid of the shackles of the original papermaking raw materials and produce new papermaking technologies and methods. Today, we can use synthetic fibers (such as polyethylene, polypropylene, etc.), endless fibers, metal fibers, etc., which is a manifestation of the continuous progress of human papermaking technology

2.1 classification of commonly used paper packaging materials

there are many kinds of paper packaging, some of which are made into paper packaging containers or packaging decoration in the form of paper, some of which are made into packaging boxes, packaging boxes, packaging cups, etc. in the form of paperboard, and some of which are used for product description and advertising printing. This kind of packaging paper includes functional protective packaging paper, packaging and decoration paper, kraft linerboard, whiteboard, corrugated board, etc. In the classification of these paper packaging materials, various packaging materials have their own characteristics. Next, we will briefly introduce:

2 1.1 functional protective packaging paper

① kraft paper kraft paper is named because its quality is as tough and strong as cow leather. Kraft paper is a high-grade packaging paper, which is widely used. However, kraft paper is mostly used to package industrial products, and at the same time, it is also used in other industries. Kraft paper is divided into single-sided light, double-sided light, striped and because the raw material price of polyurethane waterproof coating is much higher than that of other products without striping. The quantity of kraft paper is 40g/m2, 50g/m2, 60g/m2, 70g/m2, 80g/m2, 90g/m2, 100g/m2, 120g/m2 Among them, 60g/m2, 70g/m2 and 80g/m2 kraft paper are the most widely used. With the quantitative increase of kraft paper, its paper thickens, its burst resistance increases, its tear resistance also increases, and its protective performance is also better

② paper bag paper is also called cement bag paper. It is a kind of industrial packaging paper for manufacturing cement bags, fertilizer bags, pesticide bags, etc. Cement wrapping paper is usually sewn with 4-6 layers of paper bags. Paper bag paper requires high physical strength, toughness, good waterproof performance, not easy to be damaged during loading and unloading, etc. because cement must have a certain degree of permeability during storage, paper bag paper is required to have a certain degree of permeability, which is different from general kraft paper

③ chicken skin paper chicken skin paper is a kind of flat thin packaging paper with one side light, which is used for printing trademarks, packaging daily necessities and food. Chicken skin paper is generally 40g/m2, with good gloss on one side, high bursting and folding resistance, and certain water resistance. It is characterized by fine pulp, uniform paper, strong tension, paper binding is not easy to break, and its color is lighter than kraft paper

④ cellophane is different from ordinary paper. It is transparent, just like glass, so it is called cellophane. The reason why it is transparent is that it is different from ordinary paper and paperboard. It is not interwoven with fibers, but the fiber raw materials are made into colloidal liquid after a series of complex processing. Form a film, so some of its forms are similar to plastic film, and some properties are also the same as plastic film

cellophane is mainly used for beautifying packaging of medicine, food, textiles, cosmetics, precision instruments, etc. Its main characteristics are transparent model, high gloss, good printability, etc

⑤ parchment the earliest parchment was made of animal sheepskin. Nowadays parchment is mainly made of plants. Parchment is a kind of transparent high-grade packaging paper, also known as sulfuric acid paper. It is a kind of denatured processing paper obtained from sheepskin base paper after sulfuric acid treatment. It is a kind of high-strength paper, which is generally made of rag pulp or chemical wood pulp. No filler or glue is added in the manufacturing process, so parchment has good water absorption and uniform tissue. Because parchment is treated with sulfuric acid, it has good strength and is widely used in industrial products such as mechanical parts, instruments and chemicals, as well as inner packaging paper such as food, pharmaceuticals and disinfection materials

2. 1.2 packaging and decoration paper

① coated paper is a kind of coating paper, which is mainly made by coating a layer of white paint on the base paper. It is a kind of high-grade packaging and decoration and printing paper. The main raw materials of coated paper are copper base paper and coating. Medium and high-grade coated paper is processed with special base paper. Generally, coated paper is processed with high-quality paper or offset paper. Because coated paper has high smoothness and whiteness, dense texture, small flexibility, good water resistance, good printability, clear printing patterns, bright colors, etc., coated paper is widely used in high-grade trademark paper in commodity packaging, For example, various cans, beverage bottles, wine bottles and other labels, as well as a variety of color packaging, such as high-grade candy, food, chocolate, under the specified state conditioning conditions, temperature, humidity and strain rate, take the same samples, cigarettes, soaps and other daily necessities packaging, coated paper can also be used as the veneer of high-grade cartons and cartons

② offset paper offset paper is a kind of high-grade color printing paper, which is mainly used in offset press, so it has the characteristics of smooth quality, fine and uniform organization, small expansion rate, good water resistance, clear printing pattern, etc., but it is not as close as coated paper, and its smoothness is also worse than coated paper. As a packaging and decoration paper, offset paper is similar to coated paper, but its quality is worse than coated paper, Therefore, offset paper is only used as a general color trademark in commodity packaging. If you buy it, it must be ball screws and color packaging. And carton noodles

③ self adhesive paper self adhesive paper is basically composed of base material, adhesive and backing paper. Self adhesive paper is mainly used to print various commodity trademarks, labels, bar codes, etc. Because the performance base materials they choose are of good quality, the graphics and texts printed on them are very good and clear

2.2 corrugated board corrugated board plays a very important role in modern packaging, so it is necessary to introduce it in detail here

corrugated board is a kind of board with complex structure, which is made of face paper and corrugated paper with adhesive. It is mainly used to make corrugated boxes and cartons. In addition, it can also be used as cushioning material for packaging liner. Corrugated board belongs to various heterogeneous materials, and different directions have different properties. When plane pressure is applied to corrugated board, it is full of elasticity and cushioning properties. When pressure is applied to the vertical direction of corrugated board, corrugated board is similar to rigid materials. In the state of compression, tension and impact, the flat layer of corrugated board plays the role of fixing the corrugated position

2.2.1 shape of corrugation

the shape of corrugation is generally divided into U-shaped, V-shaped and UV shaped. With the different shape of corrugation, the properties and characteristics of the corrugated paperboard formed by it will be different, so it will not be introduced in detail here. See (transportation and packaging, printing industry press, pengguoxun, 2004 Edition)

2.2.2 type of corrugated board

corrugated board is divided into four types: A-type corrugated board, B-type corrugated board, C-type corrugated board and E-type corrugated board according to the height of corrugated board and the number of corrugated boards in a certain length. The first three types are mainly suitable for corrugated boxes, and the latter one is mainly suitable for corrugated boxes. A. The strength of B and C corrugations are different. Using the same material and under the same pressure, the number of corrugations is the most, and the strength of B-type corrugation with lower corrugation height is the highest, followed by C-type corrugation and A-type corrugation

the characteristics of several corrugated boards are compared as follows:

(1) type a corrugated board is high and wide, elastic, with the best cushioning performance and high compressive strength. This kind of corrugated board is suitable for the cushioning packaging of fragile items such as glass products and unsupported items

(2) type B corrugated board is low and dense, and its performance is opposite to that of a corrugated board. The corrugated box made of this kind of corrugated board can withstand large plane pressure and provide a better printing surface, but the pressure resistance strength is poor during multi-layer stacking, which is suitable for the supporting and overstock resistant items of the packaging product itself, such as food cans, bottled items and other hard items

(3) C-shaped corrugated board is between A-shaped corrugated board and B-shaped corrugated board, with moderate strength. The corrugated box made of this corrugated board is suitable for the packaging of general articles. In addition, it should be noted that this kind of corrugated board is widely used in Europe and the United States

(4) the E-shaped ridge is low and dense, with the highest flat pressing strength, and can provide a perfect printing surface. This type of corrugated cardboard is suitable for making corrugated cartons for sales and packaging

according to the different characteristics of the above four kinds of corrugations, A-type corrugation or C-type corrugation is the best for single corrugated box, A-type corrugation or B-type corrugation combined with B-type corrugation is the most reasonable for double corrugated box, and B-type corrugation is used for the outside, so that this kind of corrugated board can withstand greater impact force and provide better printing surface; Use A-type corrugated box or C-type corrugated box on the inside, which has good elasticity and strong cushioning force. The medium packaging corrugated box should use B-type corrugated box, which has low cost and good printing effect