Many people will receive kraft paper bags from merchants when going shopping. Kraft paper is a kind of paper made by using conifer wood fibers after people have learned papermaking technology. Firstly we need to put them in a beating machine for beating, adding sizing materials, dyes, etc., and finally making paper in a paper machine. In fact, the manufacturing method of kraft paper and ordinary paper is not much different. But why is kraft paper stronger than ordinary paper? This is mainly because the wood fibers used to make kraft paper are relatively long. And when cooking wood, it is treated with caustic soda and soda sulfide chemicals. In this way, the chemical effect is relatively mild, and the damage to the original strength of the wood fiber is relatively small. Therefore, the fiber of paper made from this kind of pulp are closely dependent, so kraft paper is very strong.
Kraft paper usually maintains its yellowish-brown color and is suitable as a material for bags and packaging. Kraft paper is a collective name for a kind of paper, and there is no certain specification, and it is generally classified according to its characteristics and usages.
According to different colors, kraft paper can be divided into: primary color kraft paper, red kraft paper, white kraft paper, flat kraft paper, single-gloss kraft paper, two-color kraft paper, etc.
According to different uses, kraft paper can be divided into: packaging kraft paper, waterproof kraft paper, moisture-proof kraft paper, anti-rust kraft paper, pattern-making kraft paper, process kraft paper, insulating kraft paper, kraft stickers, etc.
According to different materials, kraft paper can be divided into: recycled kraft paper, kraft core paper, kraft base paper, matte kraft paper, kraft wax paper, wood pulp kraft paper, composite kraft paper, etc.
Kraft paper is used in various industries such as chemicals and machinery, especially in the food packaging industry. Kraft paper is widely used in various supplies, such as paper bags, handbags, kraft paper, color boxes, gift boxes, notebooks, workbooks, envelopes, etc.
Because food packaging must follow the principles of convenience and portability. In order to prevent the bag from being pulled off when consumers carry out food, the packaging material is required to have good tensile strength. The tensile strength of kraft paper makes it very suitable for paper bags. At the same time, beverage packaging requires a certain degree of moisture resistance and non-deformation ability to prevent deformation and damage due to water absorption. The kraft paper is also suitable for the outer packaging of beverages because of its good moisture resistance. For the packaging of frozen food, the use of high-strength materials as the packaging is also the key to consideration. This material must be able to withstand the thermal expansion and contraction during low-temperature freezing and high-temperature melting to prevent deformation and wrinkles. The original color kraft paper can meet these needs.