Discussion on the Paper Technology and Quality Index of Honeycomb Paperboard

Honeycomb paperboard is a new material that began to be transformed from military to civilian use in China in the early 1990s. It is widely used. There are two main types of raw materials needed for honeycomb paperboard, paper and cardboard and glue.
First, the paper industry product standards At present, there are more than 5,000 kinds of domestic paper and paperboard, of which there are about 160 national or industrial standards, and the rest are corporate standards or protocol standards. Because of the short history of "honeycomb paperboard" production in China, there is no special paper and its product standards. The GB/TI3023-91 used in the “Draft for Ratification” is the corrugated paper standard for the quality control of honeycomb cores, and GB/TI3024-91 is the container board standard for the quality control of honeycomb paper (see Annexes I and II for the standards). , I think it can only be used as a reference because honeycomb paperboard and carton are not the same in their use. According to the quality requirements of honeycomb core and paper, they should have their own indicators and numerical requirements.
I have participated in honeycomb paperboard meetings several times. I have learned from exchanges with some manufacturers that some manufacturers use "honeycomb cores" to use imported raw paper and semi-finished products; some also use domestically-made linerboards and corrugated mediums, which generally reflect domestically produced base papers. The strength is not enough, it is difficult to meet the special requirements for different uses of cardboard, such as the export of paper trays more than the Department of maritime transport, boxboard paper standard A and other products absorbent refers to the positive / negative 35.0/50g/m2, analysis of American paper Only 3.0g/m2, most of the domestic selection of face paper in C, D, etc., C and other only positive control of water absorption index of 60.0g/m2, the opposite is not controlled. This indicator has not been specified in the corrugated paper standard. Pallets should be protected from moisture and moisture when soaked in seawater. Whether the additive is added during the production process of the base paper, or the additive is applied on the surface of the paper tray during the use process. Most manufacturers tend to add during the production process of the paperboard (the additive of the imported paper tray is added into the pulp); With "honeycomb" should also take anti-corrosion treatment. Analysis of imported samples revealed that its facial tissue was made of 100% chemical wood pulp, and core paper used 100% water fiberizing machine pulp. The imported sample for analysis was a finished product. A lot of rubber was stuck on the paper, and the size of the core paper was small. Therefore, more index values ​​cannot be tested.
Recently, in the paper and board used by Beijing Fulcrum Composites Co., Ltd., a total of 14 paper samples were taken for testing and physical index analysis, and three samples were used to further analyze the fiber ratio and fiber density and other indicators. Eight samples are marked with sizing. There were 5 single-blood sizing and 3 double-stranded sizing. Further dry and wet strength tests on paper samples were conducted to observe the decrease in strength of paper and paperboard after water soaking. The reduction rate of single-sided sizing paper strength was 85.3-92.5%. The reduction rate of double-sided sizing paper strength is 72.8-92.5%, and the reduction rate of double-sided sizing paper strength is between 72.8-81.8%, which is very regular. The above figures reflect that the double-sided sizing paper has higher retention of strength than water immersed on single-sided sizing paperboard. Through fiber ratio analysis, secondary fibers are used in the three paper samples. The chemical and mechanical pulps are contained in the paper samples. The more chemical pulp, the higher the strength of the paper and the paperboard; when the ratio of pulp and straw is used, The more wood pulp content, the higher the strength of paper and board; the longer the fiber length, the higher the strength of paper and board.
2. Quality requirements for base paper used for "honeycomb" paperboard 1. "Honeycomb" paperboard belongs to the scope of paper products The quantity of packaging paper and paperboard accounts for about 50% in the papermaking industry. There is a large amount of imports each year. In 2000, the proportion of packaging paper and paperboard accounted for 2. The total amount of imports was 72.9%, an increase of 10% in two years. The main varieties are kraft paper, paper bag paper, cardboard paper, white paper, white cardboard, coated white paperboard, corrugated paper and so on, all of which have product standards. These varieties mainly supply the packaging industry for the production of cartons, cartons, cartons, paper cups, paper bowls and so on.
China's product packaging is mainly paper packaging, glass packaging, plastic packaging and metal packaging, etc., while paper packaging accounts for about 50%, China's Taiwan Province accounts for 70%. From the amount of packaging paper, it can also reflect the industrial level of a country, such as the United States in 1998, packaging and paperboard production accounted for 62.8% of the total.
It can be seen that: "Bee Baba" cardboard should belong to the scope of paper products.
2. "Honeycomb" cardboard structure "Honeycomb" cardboard is formed by bonding two layers of paper with an intermediate "honeycomb" paper core.
"Honeycomb" core materials are available in a variety of materials, "honeycomb" cores made of aluminum foil, paper and cardboard, glass cloth or other soft materials, and bonded on both sides of cardboard or metal plates, plywood, fiberboard, decorative plates , Resin plate, glass plate, gypsum board, cement board made of a variety of different uses of plates or components.
3, "Honeycomb" cardboard application range "Honeycomb" cardboard has a wide range of applications, has been developed using the following areas:
——Replacement of wooden boxes and wooden pallets for export goods;
- As buffers, spacers and gaskets;
- Use one-time turnover trays for storage and transportation:
——Building materials used to replace honeycomb sandwich panels such as wooden boards, metal panels, decorative panels, ceilings, ceilings, floors, and movable boards, etc. Gypsum boards are used to make interior walls and can replace clay bricks;
- home wardrobes, bookcases, bookshelves, billiard tables;
——materials for vehicles and ships such as decks, decks, partitions;
- billboards, exhibition boards;
- Hygiene for cremation and cremation.
With the continuous development of the industry, honeycomb cardboard will be used in more areas of packaging. Different uses should have different requirements on the quality of their raw materials.
4, "honeycomb" cardboard on the quality of the original paper "honeycomb" cardboard paper and cardboard boxes have similarities, but also have their own special requirements, its quality indicators can refer to corrugated paper and cardboard specifications, the standard should consider the following points :
(1) Base Paper Name Face Paper - "Honeycomb" Face Paper Core Paper - "Honeycomb" Core Paper (2) Base Paper Index "Honeycomb" Face Paper Index: Quantitative, tightness, crack length, burst index * Ring pressure Index, *Fold resistance, water absorption (positive/negative), delivery moisture.
Note: Use the "honeycomb" cardboard to increase the gold index when producing containers.
"Honeycomb" core paper index:
Quantitative, tightness, folding resistance, transverse pressure index, water absorption (positive/negative), delivery moisture.
Explanation of indicators:
Quantitative - mass per square meter of paper or paperboard expressed in g/m2.
Tightness - The weight of a unit volume of cardboard calculated from the basis weight and the single page thickness in g/m2.
Split-length - the length of the paper with a uniform width and the length needed to break the paper. It is calculated from the tensile strength and constant temperature and humidity after the sample quantitatively expressed in KM.
Burst resistance index - The maximum pressure that the paper or paperboard undergoes in a uniform increase over a unit area causes the specimen to rupture, that is, the bursting resistance of the specimen, divided by the amount of the specimen after constant temperature and constant humidity. Unit: Kpa.m2 /g said.
Folding resistance - refers to the ability of paper or board to withstand 135 degrees of reciprocating folding under a certain tension, expressed as the number of reciprocating folds, unit: times.
Water Absorption—The amount of water absorbed by paper and paperboard (COBB) values, the amount of water absorbed by the surface of paper and paperboard per unit area under certain pressure and temperature conditions, in units of g/m2 (positive/negative).
Ring pressure index - a certain size of paperboard sample, inserted in the sample seat, forming a circular ring, compressed between the two side plates, the maximum force that can withstand before compression, that is, the ring pressure Intensity, divided by the amount of the sample after constant temperature and humidity: Nm/g.
Delivery water—The water content of paper or board, when the sample is dried to constant weight according to regulations, the ratio of the weight reduction to the weight of the original sample, expressed in %.
(3) Index classification Papermaking industry standards are graded, because the board of the peak board has a variety of uses and it should be graded.
A, etc. - International advanced level B, etc. - Domestic advanced level C etc. - Domestic general level III. Some suggestions 1. "Honeycomb" cardboard should have special base paper "Cellular" cardboard should have its own base paper, used fiber raw materials The value of the indicator should be selected according to the product use, and the use of secondary fibers should not be emphasized. Boxboard raw materials range from 100% wood fiber to 100% grass fiber, as well as mixed fibers in different proportions of wood and grass. Generally speaking, the more wood fibers, the higher the strength of the cardboard, grass pulp is more than vice versa. Both wood and grass have secondary fibers, which are generally imported American waste paper. The content is mostly wood fiber, and domestic waste paper is mostly grass fiber. Of course, the price of imported raw materials will also be higher than the domestic price. The production plants should also add different additives according to different purposes. They should be clear when the supply and demand parties order goods.
2. The supply and demand sides should step up cooperation to formulate the "honeycomb" cardboard paper standard. The current conditions are not yet mature and preparations are now underway. In order to grope for the index values, the imported products were analyzed. However, because the samples were mostly finished products, the specifications were small and the glue was coated, some of the indicators could not be tested. The production plant should also conduct a series of follow-up tests, which requires everyone to work together and actively cooperate with each other to continuously accumulate data, and finally work out a realistic paper standard.
3, "honeycomb" board machine and the width of the paper machine convergence problem society is a big cycle, the industry's product is another industry's raw materials. The specifications of the bee cardboard are based on the user's needs, and the product has a specification issue in addition to the quality assurance. Therefore, the "honeycomb" board machine also has a stereotype problem. At present, the specifications of paperboard production cardboard are more than 1600mm in width, 2400mm in width, and 1092MM in a small number. They are not matched with each other and are bound to cause waste or raise product prices. This will be detrimental to both parties. It is suggested that both parties should consider the issue of standardization in terms of machine width. (Text / Li Yuhua China Paper Research Institute) (From China Packaging News)