introductory:
With the development of the food industry, the requirements for the safety and aesthetics of food packaging are increasing day by day. As a key material in direct contact with food packaging, the quality and performance of food-grade offset printing ink directly affect the safety and quality of food. This program aims to provide a comprehensive and feasible set of food-grade offset printing ink application solutions for food packaging printing enterprises to ensure printing quality and food safety.
1. Overview of food-grade offset printing inks
Food grade offset printing ink is an ink specially designed for food packaging printing, which has the characteristics of non-toxic, tasteless, non-polluting, and in line with food safety standards. Compared with traditional offset printing inks, food-grade offset printing inks are more stringent in terms of raw material selection, production process and quality control, which can effectively avoid the migration of harmful substances in the ink to food and protect the health of consumers.
2. Application scenarios
All kinds of food packaging
Including paper packaging boxes, bags, labels for biscuits, candy, chocolate, beverages, dairy products and other foods.
Pharmaceutical packaging
It is also widely used in the outer packaging printing of drugs to ensure the safety and quality stability of drugs.
3. Ink selection
According to the selection of printing materials
Different printing materials have different requirements for the adhesion of ink, drying speed and other properties. For example, paper packaging can be selected with alcohol-soluble or water-based food-grade offset inks; For plastic packaging, special plastic inks are used to ensure that the ink is well combined with the material.
Consider the printing process
The offset printing process is divided into lithographic offset printing, anhydrous offset printing, etc. It is necessary to choose the appropriate ink according to the specific printing process, such as waterless offset printing ink has better printing effect in the waterless printing environment.
Pay attention to ink characteristics
Such as color vibrancy, abrasion resistance, light fastness, etc. For food packaging that needs to be stored or displayed for a long time, inks with good lightfastness and abrasion resistance should be selected to keep the printed patterns clear and beautiful.
4. Preparation before printing
Printing equipment cleaning
Thoroughly clean the ink fountain, ink roller, rubber cloth and other parts of the printing machine to prevent residual traditional ink or impurities from contaminating the food-grade offset printing ink.
Ink blending
Accurately blend ink color and viscosity according to the requirements of the printing process and the ratio provided by the ink supplier. Use professional ink mixing equipment to ensure that the ink is evenly mixed.
Printing material testing
Conduct quality inspection of printing paper or plastic film and other materials, including flatness, pH, surface tension and other indicators to ensure that the materials meet the printing requirements.
5. Printing process control
Printing pressure adjustment
According to the thickness and hardness of the printed material, the printing pressure is reasonably adjusted to ensure the uniform transfer of ink and avoid problems such as unreal printing or dot deformation.
Ink transfer control
By adjusting the ink fountain screw and ink roller speed, the ink transfer amount is precisely controlled to ensure the color consistency and saturation of the printed pattern.
Drying temperature and time control
For water-based or alcohol-soluble inks, strictly control the drying temperature and time to avoid ink adhesion or odor caused by improper drying. Generally, the drying temperature is controlled at 40°C - 60°C, and the drying time is adjusted according to the printing speed and ink characteristics.
6. Quality inspection
Appearance inspection
Check the appearance quality of the printed matter, including pattern clarity, color brightness, whether there are defects such as missing prints and ghosting.
Adhesion test
Use the tape test method or the 100-grid test method to test the adhesion of the ink on the printed material to ensure that the ink is not easy to fall off.
Migration test
Regularly carry out migration test on the printed food packaging, and detect whether there is ink migration in the simulated food after the packaging is in contact with the simulated food for a certain period of time to ensure that it meets food safety standards.
7. Storage and transportation
Storage conditions
Food-grade offset printing inks should be stored in a cool, dry and well-ventilated warehouse, avoiding direct sunlight and high temperature environments. The storage temperature is generally controlled at 20°C - 25°C, and the relative humidity is at 40% - 60%.
Transportation requirements
During transportation, it is necessary to prevent the ink packaging from being collided, squeezed and rained. Specialized transport vehicles are used to ensure the stability and safety of the ink during transportation.
8. Precautions
Operator protection
Printing workshop staff should wear protective gloves, masks and other protective equipment to avoid skin contact and inhalation of ink volatile gases.
Ink service life
Strictly in accordance with the shelf life of the ink, expired ink shall not be used for food packaging printing.
Environmental management
Keep the printing workshop clean and hygienic, and regularly clean up ink residues and wastes to prevent pollution to the environment.
Through the implementation of the above food-grade offset printing ink application scheme, the quality and safety of food packaging printing can be effectively improved, the strict requirements of the food industry for packaging and printing can be met, and consumers can be provided with safe and reliable food packaging products.
9. Recommend products of the same type
Ordinary Economical Offset Ink