With the improvement of our daily life, we are paying more and more attention to the safety and health of food, clothing, housing and transportation. Not only these items themselves, but also for their packaging, we also require safety and health. Usually many items are packaged in kraft paper. Below we will teach you how to distinguish between food grade kraft paper and ordinary kraft paper. So what is the difference between food grade kraft paper and ordinary kraft paper? In fact, the difference between food-grade kraft paper and ordinary kraft paper is difficult to distinguish with human eyes in most cases, and it is necessary to illuminate the paper with fluorescent light. This is because food-grade kraft paper does not contain fluorescent substances, while ordinary kraft paper contains small or large amounts of fluorescent substances.
First of all, let's get to know what a fluorescent agent is. Fluorescent agent, also known as fluorescent whitening agent, is a fluorescent dye, or white dye, and is also a complex organic compound. Its characteristic is that it can absorb incident light to produce fluorescence, so that the substance seen by the human eye is very white, achieving a whitening effect. Fluorescent agents have been widely used in textiles, papermaking, washing powder, liquid detergent and so on.
The paper made of pure pulp is naturally slightly yellow, like traditional Chinese rice paper, the color is yellow, which is pure natural paper without any chemical components. However, the paper in real life is basically white, except for kraft paper. If paper products are made of pure natural pulp, the chromaticity will definitely not meet the requirements, and manufacturers must try their best to make the paper white during paper processing. In the processing technology, the usual way to make things white is bleaching. Food and textile materials are often whitened by bleaching. Similarly, paper can also be bleached, such as adding blue pigment to the yellow puree, and it will be white after mixing. But sometimes the paper still does not meet the white requirements after bleaching, so it is necessary to add fluorescent brighteners.
The relevant papermaking standards allow paper manufacturers to add fluorescent agents to the pulp, but the key is which fluorescent agent is added. As a complex organic compound, there are many types of fluorescent agents. If the manufacturer uses a fluorescent agent that meets the standard, it should not have an impact on human health when the dose is relatively small. But some experts hold the opposite view. They believe that fluorescent substances are not as easily decomposed as general chemical components, but are continuously accumulated in the human body, which greatly weakens the body's own immunity and endangers the health of the human body.
Therefore, from the above-mentioned uses and functions of fluorescent whitening agents, we will know that fluorescent agents have advantages and disadvantages. However, it is recommended to use raw pulp paper that does not contain fluorescent agent for food packaging container paper. Then the biggest difference between food grade kraft paper and ordinary kraft paper is that food grade kraft paper does not contain fluorescent agents.