Sedimentation and stratification of corrugated cardboard ink during storage are mainly due to density differences or insufficient dispersibility of components such as pigments, binders, and additives. This problem is closely related to the storage environment, ink formulation, and operational management, and requires systematic control. The following analysis focuses on seven aspects: optimized storage conditions, ink formulation design, regular stirring and maintenance, airtight management, first-in-first-out (FIFO) principle, ink selection and pretreatment, and strengthened operational procedures.
Controlling the temperature and humidity of the storage environment is fundamental to preventing ink sedimentation and stratification. Ink is sensitive to temperature changes; high temperatures accelerate binder flow, leading to pigment sedimentation; low temperatures may increase ink viscosity and even cause gelation. Therefore, the storage temperature should be maintained within a suitable range, avoiding extreme temperature fluctuations. Simultaneously, excessive humidity can cause ink to absorb moisture and clump, while excessively low humidity may cause static electricity or excessively rapid evaporation. Maintaining the stability of the storage environment and reducing physical changes in ink components can be achieved through temperature and humidity control equipment or natural ventilation.
The scientific nature of the corrugated cardboard ink formulation directly affects its storage stability. The fineness of pigment particles, the viscosity of the binder, and the dispersibility of additives need to be optimized synergistically. If the pigment particles are too coarse or too dense, they are prone to settling under gravity; if the binder viscosity is too low, the pigment cannot be effectively suspended, leading to stratification. The anti-settling properties of the ink can be enhanced by selecting highly dispersible pigments, adjusting the binder ratio, or adding anti-settling agents. Furthermore, avoid using solvents or additives that readily react with ink components to prevent precipitation caused by chemical changes.
Regular stirring is a direct means of preventing ink settling. During storage, pigments in corrugated cardboard ink may gradually settle due to gravity, especially when stored statically. Regularly turning the ink container or using dedicated stirring equipment can break up the aggregation of pigment particles, allowing them to be evenly dispersed in the binder. During stirring, it is important to maintain uniform pressure to avoid introducing too much air and creating bubbles, while also preventing vigorous stirring from damaging the ink structure. For inks that have already shown slight settling, their fluidity can be restored by circulating stirring or adding an appropriate amount of thinner.
Sealing is a crucial step in preventing ink stratification. Exposure to air accelerates solvent evaporation, causing changes in binder viscosity and subsequently pigment sedimentation. Simultaneously, oxygen, moisture, and dust in the air can contaminate the ink, affecting its performance. Therefore, ink container lids should be kept tightly closed during storage to avoid frequent opening; if a portion of the ink needs to be used, the remaining portion should be immediately sealed and stored. Furthermore, ink containers must be made of corrosion-resistant and have good sealing properties to prevent leakage or contamination due to container aging.
Following the "first-in, first-out" (FIFO) principle reduces the risks associated with long-term ink storage. Components in corrugated cardboard ink may separate or deteriorate over time, especially inks without preservatives or with poor stability. Prioritizing the use of ink purchased first shortens the storage time per container, reducing the probability of sedimentation and stratification. Simultaneously, establishing an ink inventory management system to record the arrival time, shelf life, and usage of each batch of ink facilitates timely disposal of expired or deteriorated ink.
Ink selection and pretreatment are crucial for preventing sedimentation and stratification. Choose ink types with strong compatibility based on the corrugated cardboard material, printing process, and environmental conditions. For example, water-based inks require attention to their water resistance and drying speed, while solvent-based inks require attention to the volatility and environmental friendliness of the solvent. For special needs, suppliers can be asked to customize ink formulations with higher stability. Furthermore, pre-treatment of inks before use, such as filtering impurities, adjusting viscosity, or adding anti-settling agents, can further improve their storage stability.
Strengthening operational procedures is a long-term measure to ensure the quality of ink storage. Storage personnel need to receive professional training and be familiar with the characteristics of inks, storage requirements, and emergency handling methods. For example, avoid stacking ink drums in high-temperature or humid environments to prevent container deformation due to external pressure; regularly check the sealing of ink drums and the storage environment, and promptly clean up any leaked or contaminated ink. Standardized operating procedures can reduce the impact of human factors on the quality of ink storage and ensure its stable performance.
