5 major types of cultural paper: double copper paper, white cardboard, matte paper, kraft paper, double offset paper

Double copper paper

Double coated paper refers to double-sided coated paper. Double-sided coated paper is a kind of coated paper, which is coated on both sides and has good smoothness on both sides. Coated paper also includes single copper, cuprous copper, high gloss copper, artistic copper and so on.

The main raw materials of coated paper are coated base paper and paint. The requirements for the copperplate base paper are uniform thickness, low flexibility, high strength, and good water resistance; the paper surface must not have spots, wrinkles, holes and other paper defects. The coating used for coating is made of high-quality white pigments (also called white clay, containing kaolin, talc, calcium carbonate, titanium dioxide, etc.), adhesives (polyvinyl alcohol, casein, modified starch, synthetic latex, etc.), And other auxiliary materials (such as gloss agent, hardener, plasticizer, dispersant, wetting agent, opalescent agent, fluorescent brightener, toner, etc.) , It is applied to the base paper thinly and evenly by the coater, then dried, rolled into a roll on the reel, and then sent to the super calender for calendering and finishing, finally slitting, paper selection, and packaging .

White cardboard

At present, imported white cardboard occupies a considerable market share in the domestic market, but domestic white cardboard has the potential to squeeze out this part of the market. After China joined the WTO, although the import tax rate of white cardboard decreased, because white cardboard is high-value paper (generally the normal price is USD950-1100/MT), the absolute amount of import tax is still high, even if domestic white cardboard All production is made of imported wood pulp. Because the tariff on wood pulp is zero, domestic white cardboard still has certain advantages in price. White cardboard is a firm, thick paper with a larger basis weight. In the past, someone planned to use quantitative as a basis to divide: paper, cardboard and cardboard.

Matte paper

Matte pink paper, the official name is matte coated paper, when viewed under sunlight, it is less reflective than coated paper. Although the patterns printed with it are not brightly colored with coated paper, the patterns are more delicate and high-end than coated paper. Generally, matte paper will be thinner and whiter than copper plates, more ink-resistant, and harder. Unlike coated paper, which is easily deformed, books with uneven pages must be copper plates. Matte paper is only used for color printing. For black and white, it is definitely copperplate or double offset paper (recycled paper).

Kraft paper

Kraftpaper (kraftpaper) is used as packaging material. The intensity is high. Usually yellowish brown. Semi-bleached or fully bleached kraft pulp is light brown, cream or white. Quantitative 80～120g/m2. The fracture length is generally above 6000m. The tear strength, rupture work and dynamic strength are high. Mostly roll paper, but also flat paper. Using kraft softwood pulp as raw material, it is made by beating on a Fourdrinier paper machine. It can be used as cement bag paper, envelope paper, glue sealing paper, asphalt paper, cable protection paper, insulation paper, etc.

Kraft paper is a tough, water-resistant packaging paper. It is brown and has a wide range of uses. It is often used to make paper bags, envelopes, workbooks, record sleeves, files and sandpaper. The basis weight range is from 80 g/m² to 120 g/m². There are differences between web and flat paper, single-sided light, double-sided light, and stripe. The main quality requirements are flexibility and strength, high burst resistance, and ability to withstand greater tension and pressure without breaking. Kraft paper has high tensile strength, including single gloss, double gloss, stripes, and no grains. Mainly used for packaging paper, envelopes, paper bags, etc. and printing press drum linings, etc.

Double offset paper

Double offset paper refers to printing paper, also called offset paper. Cultural and printing paper is one of the typical representative paper types. In commerce, the product name for double-sided offset paper (double-sided offset printing paper) was formerly known as Daoling paper/Dawlin paper, and it is also called rough paper in Taiwan. Double offset paper refers to the paper in which sizing material is applied on both sides of the paper to improve its surface properties during the papermaking process. It has small stretchability, uniform ink absorption, good smoothness, compact and opaque texture, and strong water resistance.