What is Kraft Paper
Kraft paper is a tough, water-resistant packaging paper with a brownish-yellow color and 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 a high tensile strength, such as single gloss, double gloss, stripes, and no grains. Mainly used for packaging paper, envelopes, paper bags, etc. and printing press drum linings, etc.
Flat paper specifications: It is different according to the machine, and the slitting is different. Like a general roll slitting machine, it can cut to a minimum of 460mm and a maximum of 1460mm, and then through the flat cutting machine, you can cut any specifications you want. Common printing specifications are: positive 787*1092mm, generous 889*1194mm.
Kraft paper usually maintains its yellowish-brown color and is suitable for bags and wrapping paper. Depending on the nature and use, kraft paper has various uses. Kraft paper is a collective name for a kind of paper, and there is no certain standard, and it is generally classified according to its nature and use.
According to the different colors, it 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, it 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, it can be divided into: recycled kraft paper, kraft core paper, kraft base paper, rough kraft paper, kraft wax paper, wood pulp kraft paper, composite kraft paper, etc.
Kraft paper color reason
Different sources of kraft paper raw materials, different production batches, different production seasons, different production machines, etc. Many reasons will affect the color of the kraft paper roll base paper. This difference in color is difficult to avoid and cannot be controlled. , Generally, the same batch of kraft paper can guarantee 98% color consistency.
Kraft paper is used in chemical, machinery and other industries, especially in the food packaging industry.
Kraft paper use: Kraft paper is widely used in various packaging products, paper bags, handbags, kraft paper, color boxes, gift boxes, kraft paper, printing kraft paper
Printing kraft paper, notebook kraft paper, workbook kraft paper, special kraft paper for envelopes
Food packaging must follow the principles of convenience and portability. The tensile strength of kraft paper makes it very suitable for packaging needs. 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. Beverage packaging requires a certain degree of resistance to moisture and non-deformation of the materials to prevent deformation and damage due to water absorption.
For the packaging of frozen food, the use of high-strength materials as packaging is also the key consideration. This material must be able to withstand the thermal expansion and contraction during low-temperature freezing and high-temperature melting, and prevent deformation, distortion, wrinkling, and excessive moisture absorption. The condition of the food. From these aspects, the original color kraft paper is even more suitable than SBS paper.
Post-press die-cutting processing
Because of the special structure of the original color kraft paper, its strong strength and predictable fiber characteristics, it has better processing properties such as embossing, die-cutting and die-engraving. However, for high-strength and tough primary color fibers, kraft paper is required to pass through deep indentation lines to avoid rebound. In addition, the die cutter must be sharp. Due to the high fiber strength of kraft paper, a narrower indentation is required on the perforation line, and the nicks required for perforation should be less and smaller.
Reasonable selection of paper
In order to meet the new packaging requirements of food manufacturers, raw kraft paperboard has some characteristics that are different from bleached paperboard, such as household products such as baked goods or convenience foods. The natural brown appearance of the original color kraft paper has a healthy and retro charm. In fact, just the sharp contrast between the unique appearance of kraft paper and the large amount of white packaging can also make the product more prominent. Since many food packaging are designed to provide convenience or practicality, the strength of kraft paper is another advantage. The outer packaging must be strong enough so that it can cover the customer’s meal without falling off. In the same way, the beverage cup must be able to remain unchanged in a humid environment so that the coffee does not flow to the customer’s lap. Strength is also the main factor considered for frozen foods, because the packaging of frozen foods cannot deform, tear, distort or absorb too much moisture during the freezing/thawing cycle. In terms of practicality in this respect, kraft paper is better than homogeneous bleached kraft paper.
The plastic restriction order has promoted the development of kraft paper. People are buying kraft paper bags, which are environmentally friendly and can be used for a long time, making a certain contribution to the country’s resources and environmental protection. Therefore, people advocate the use of kraft paper bags. Kraft paper bags are strong, durable, beautiful and environmentally friendly.
With the strengthening of environmental protection awareness, the consumption of natural color paste products as environmentally friendly paper has been increasing year by year, and the market prospects are promising. Exquisite kraft paper is suitable for packaging of various high-end commodities, such as gift boxes for wine boxes, sportswear, etc.; archive bags, such as culture, education and hygiene, archive preservation of enterprises and institutions, etc.; standard envelopes, such as common postal special seals; can also be processed for shopping Bags, such as shopping bags commonly found in shopping malls and brand stores, or noodle paper used in cardboard boxes.
When autoclaving the microbial culture medium, use moisture-proof paper or kraft paper to wrap the cotton plug of the test tube with the nozzle upward to prevent the cotton plug from getting wet during sterilization. Kraft paper is used because it can effectively waterproof and ensure that the test tube is not wet.