Of course, while we pay attention to whether the product design is beautiful or not, we must also put the safety of food packaging in a pivotal position, especially those packaging materials that directly contact food. Today we will talk about the little knowledge about food-grade packaging paper to understand what is meant by real food-grade packaging paper.
01What is flexo printing? What is water-based ink?
Flexo printing is a direct printing method that uses a flexible raised image printing plate, which can transfer liquid or grease ink to almost all types of materials, and belongs to light pressure printing. Flexo printing is unique and flexible, economical and environmentally friendly, and meets the hygienic standards of food packaging printed matter. It is the main printing method for food packaging paper.Water-based ink is a special ink for flexo printing machines. Because of its stable performance, bright colors, environmentally friendly, non-polluting, safe and non-flammable, it is especially suitable for printing on food and pharmaceutical packaging papers that have strict hygiene requirements.
02What is corrugated cardboard? What are the advantages?
Corrugated cardboard, a thick and rough paper, corrugated and elastic. Because the packaging container made of corrugated cardboard has its unique performance and advantages for beautifying and protecting the goods inside, it has become one of the main choices for the fast-developing and enduring food packaging paper so far.corrugated board is made by bonding face paper, lining paper, core paper and corrugated paper processed into corrugated corrugated. According to the needs of commodity packaging, it can be processed into single-layer, 3-layer, 5-layer, 7-layer, 11-layer corrugated cardboard.
Single-layer corrugated cardboard is generally used as a lining protective layer for product packaging, or to make a lightweight pad, etc., to avoid vibration or collision during storage and transportation of the product.3-layer and 5-layer corrugated cardboard are often used in the production of corrugated boxes; while the 7-layer or 11-layer corrugated cardboard is mainly used to make packaging boxes for electromechanical, flue-cured tobacco, furniture, motorcycles, and large household appliances.
03What is kraft paper? Why are kraft paper boxes more durable?
Kraft paper is paper produced from unbleached softwood kraft pulp. High strength, usually yellowish brown. Semi-bleached or fully bleached kraft pulp is light brown, cream or white.
The wood fiber of conifer is the main raw material for making kraft paper, and the fiber of this tree is relatively long. In order not to damage the toughness of the fiber as much as possible, it is usually treated by caustic soda and alkali sulfide chemicals. The fiber and fiber are tight. Closely dependent, so that the toughness and firmness of the wood fiber itself can be well maintained, so the strength of the produced kraft paper is much higher than that of ordinary paper, and it is more durable.Kraft paper packaging boxes are highly sought after in the packaging industry due to their unique colors, environmental protection properties, and strong physical properties, and their development trends are also very fierce.
04What is a fluorescent agent? How to detect the fluorescence reaction of food packaging paper?
Fluorescent agent is a kind of fluorescent dye, which is a complex organic compound. It can excite incident light to produce fluorescence, making the matter seen by the naked eye appear whiter, brighter and more vivid. In the paper industry, liquid brighteners are more common in papermaking, because it can improve the overall aesthetics of paper products under sunlight.For food packaging paper, the presence of fluorescent agent does not meet the food safety requirements. Moreover, food packaging paper containing fluorescent agents may migrate into the food during use, thereby being absorbed by the human body, not easily decomposed, and accumulating in the human body will endanger human health.
To test whether our food packaging paper contains obvious fluorescent substances, you can choose ultraviolet light. It only needs to irradiate the packaging paper with a handheld dual-wavelength ultraviolet lamp. If the irradiated paper undergoes a significant fluorescent reaction, it is proved that it contains fluorescent substances.05
Why must virgin wood pulp be used as raw material for food-grade packaging paper?When food packaging paper is in direct contact with food, food safety issues are particularly important. The food packaging paper using virgin wood pulp does not have the risk of contamination, can safely contact food, and will not transfer harmful ingredients to the food.
Moreover, the virgin wood pulp fiber has good toughness, high density, good strength and better processing performance. There is no need to add special ingredients in the process of processing to improve the appearance, color, performance, etc. of the paper. Not only improves the use efficiency of resources, but also the paper has a good touch, natural color (even color, no mildew, no black spots, etc.), good printing effect, and no odor.06
What standard must the virgin wood pulp (base paper) required for food-grade packaging paper meet?
must meet the requirements of the new GB 4806.8-2016 standard (opened on April 19, 2017). Special reminder: GB 4806.8-2016 "National Food Safety Standard Food Contact Paper and Cardboard Materials and Products" has replaced GB 11680-1989 "Hygiene Standard for Raw Paper for Food Packaging".It clearly stipulates the physical and chemical indicators that must be met by the base paper for food contact, including lead and arsenic indicators, formaldehyde and fluorescent substance residue indicators, microbial limits and total migration, potassium permanganate consumption, heavy metals and other mobility indicators.