How to Accelerate the Drying Time of Water-based Ink?

Date: Mar 07 2025 From: Star Color

In the current context where the concept of environmental protection has taken root in people's hearts, water-based ink has been widely used in packaging, labeling, book and periodical printing and other fields due to its environmental protection and low VOC emission advantages. However, its slow drying speed hinders the improvement of production efficiency. Especially during high-speed printing or in a high-humidity environment, this problem becomes more serious, severely affecting the production progress and economic benefits of enterprises. To help the printing industry break through this bottleneck, we will start from several key directions such as equipment optimization, ink formula improvement and process adjustment, and deeply and systematically analyze the methods to accelerate the drying time of water-based ink.

Drying Principle and Influencing Factors of Water-based Ink

1. Drying Mechanism

The drying process of water-based ink mainly relies on two stages: water evaporation and resin film formation. In the evaporation stage, water and cosolvents in the ink, such as ethanol, gradually volatilize under the action of heating or ventilation. In the film formation stage, resin particles gradually aggregate to form a continuous film layer, completing the drying and curing of the ink.

2. Key Influencing Factors

Temperature, humidity and wind speed have a great impact on the drying time of water-based ink. An increase in temperature can significantly accelerate the evaporation rate of water, but if the temperature is too high, it is likely to cause deformation of the substrate. An increase in humidity will bring greater resistance to the evaporation of water, thus prolonging the drying time. The acceleration of air flow can quickly take away the water vapor on the surface of the ink, but too high a wind speed may have an adverse effect on printing accuracy.
The composition of the ink, including the type of resin, solid content and the proportion of cosolvents, also has an important effect on the drying efficiency. For different substrates, substrates with strong water absorption, such as paper, have a relatively fast drying speed; while non-absorbent substrates, such as PE films, dry more slowly.

How to Accelerate the Drying Time of Water-based Ink?

How to Accelerate the Drying Time of Water-based Ink?

Equipment Optimization: Upgrading the Drying System

1. Hot Air Drying System

In the hot air drying system, reasonable temperature control is of vital importance. Adopting a gradient heating method, for example, setting a three-stage temperature, gradually increasing from 40°C to 60°C and then decreasing to 50°C, can effectively avoid substrate warping due to excessive temperature. At the same time, by using a variable frequency fan to accurately adjust the wind speed to 8 - 12 m/s, it is possible to balance energy consumption while improving drying efficiency.

2. Infrared (IR) Drying

The principle of infrared drying technology is to directly heat the ink layer with infrared rays. It has strong penetrability and can effectively improve the evaporation efficiency of water inside the ink. In practical applications, the mid-infrared band with a wavelength of 2.5 - 3.5μm is usually selected, and the power density is maintained at 15 - 25 kW/m². This drying method is especially suitable for thick ink layer printing.

3. Combined Drying Technology

The ingenious combination of different drying technologies can give play to greater advantages. For example, in the IR + hot air combination method, IR is first used to quickly evaporate the surface moisture, and then hot air is used to thoroughly dry the bottom layer, achieving efficient drying from the surface to the inside. For water-based inks containing UV resin, the UV + hot air combination can be adopted. First, pre-cure with UV and then assist drying with hot air. Relevant data shows that the combined drying technology can greatly shorten the drying time of water-based ink on PE films from the original 120 seconds to 45 seconds, and the drying efficiency has been qualitatively improved.

Ink Formula Optimization: Scientific Acceleration

1. Increasing Solid Content

Increasing the solid content of the ink is one of the effective ways to shorten the drying time. The core goal is to reduce the water content in the ink, thus directly shortening the time required for water evaporation. The key to achieving this goal lies in using high-solid and low-viscosity resins, such as resins with a solid content of 40% - 50% and a viscosity not exceeding 100 cps.

2. Adding Quick-drying Additives

Adding specific quick-drying additives is also an important means to accelerate the drying speed of water-based ink. Low-boiling solvents, such as ethanol and isopropanol (boiling point 78 - 82°C), with an addition amount of 5% - 10%, can drive the evaporation of water in the ink through their own rapid volatilization. Film-forming additives, such as propylene glycol phenyl ether (PPH), with an addition amount of 2% - 4%, act to reduce the film-forming temperature of the resin and accelerate the film-forming process. Surface tension adjusters, with an addition amount of 0.1% - 0.5%, can reduce the surface tension of the ink and further accelerate the evaporation of water. Experimental data shows that after adding 8% ethanol to the ink, the drying time of the ink on paper is greatly shortened from 60 seconds to 35 seconds, with remarkable results.

3. Optimizing the Resin System

Optimizing the resin system can also improve the drying efficiency. Self-crosslinking resins, such as waterborne polyurethane-acrylic hybrid resins, can form a crosslinked network during the drying process, greatly accelerating the film-forming speed. Nano resins, due to their particle size not exceeding 100nm and large specific surface area, greatly shorten the diffusion path of water therein, thus accelerating the drying process.
How to Accelerate the Drying Time of Water-based Ink?

Printing Process Adjustment: Details Determine Efficiency

1. Controlling the Ink Layer Thickness

Strictly controlling the ink layer thickness is one of the key details to improve drying efficiency. The goal is to control the thickness of a single-color ink layer to no more than 2μm to reduce the total amount of water in the ink. In actual operation, it can be achieved by using a high-line anilox roller. For example, in flexographic printing, an anilox roller with 250 - 400 LPI is selected. At the same time, for gravure printing, accurately adjusting the doctor blade pressure to 0.2 - 0.4 MPa can also effectively control the ink layer thickness.

2. Reducing the Printing Speed

When the drying capacity is insufficient, it is very necessary to adopt a balanced strategy of appropriately reducing the printing speed. For example, reducing the printing speed from 300 meters per minute to 200 meters per minute can provide more sufficient time for the drying of the ink, ensure the drying effect, and avoid quality problems caused by insufficient drying.

3. Environmental Control

Good environmental control also plays an important role in the drying of water-based ink. By using a dehumidifier and an air conditioning system, the workshop temperature is maintained at 22 - 25°C and the humidity is controlled to not exceed 60%.

Substrate Pretreatment: Accelerating Drying from the Source

1. Corona Treatment

For non-absorbent materials such as PE, PP and BOPP, corona treatment is an effective pretreatment method. Through corona treatment, the surface energy of these substrates can be increased, making their dyne value not less than 40 mN/m, thereby enhancing the wettability of the ink on the substrate surface, reducing water residue, and laying a good foundation for the subsequent drying process.

2. Pre-coating Primer

Pre-coating a primer on the substrate is also an effective method to accelerate drying. The principle is to coat a porous primer on the substrate surface, such as a silica-modified water-based coating. The thickness of the primer is generally controlled at 1 - 3μm, and the porosity after drying is not less than 30%. Such a porous primer can accelerate the penetration of water into the substrate, thus accelerating the drying speed.

Zhongzhixing Water-based Ink: An Excellent Choice for Drying and Quality

Zhongzhixing water-based ink has an outstanding performance in terms of drying properties. While ensuring its environmental protection advantages, it has greatly optimized the drying efficiency. At the same time, its precise control of the solid content enables the ink to maintain good fluidity and printability while having a high solid content, effectively reducing the water content and directly accelerating the water evaporation and drying process.

When dealing with different substrates, Zhongzhixing water-based ink shows strong adaptability. For absorbent substrates such as paper and cardboard, Zhongzhixing water-based ink can quickly penetrate and closely combine with the substrate, ensuring excellent adhesion and printing effects while achieving efficient drying. For non-absorbent plastic films such as PE, PP and PET, Zhongzhixing water-based ink has successfully overcome the problem of insufficient adhesion of traditional water-based inks, forming a firm and uniform adhesion effect on the surface of these substrates. Moreover, during the drying process, it can effectively resist the drying obstacles caused by substrate characteristics and achieve rapid and stable drying.

Zhongzhixing water-based ink provides a comprehensive solution for printing enterprises with its excellent drying performance, wide substrate adaptability and reliable quality. Choosing Zhongzhixing water-based ink means choosing an efficient and high-quality printing experience, helping enterprises stand out in the fierce market competition and promoting the printing industry to develop in a more environmentally friendly, efficient and high-quality direction.

Accelerating the drying time of water-based ink is a comprehensive project that requires coordinated efforts from multiple aspects such as equipment upgrading, formula optimization, process adjustment and substrate pretreatment. Enterprises should select the most suitable and cost-effective solutions according to their actual production conditions, including equipment types, substrate characteristics and environmental restrictions. With the continuous development and popularization of innovative means such as microwave drying and nanotechnology, the drying efficiency of water-based ink will be further improved, thus strongly promoting the development of the green printing industry in a more efficient and sustainable direction.