Glass Automatic Spray Paint Baking Line

1. Equipment Overview

The glass automatic spray paint baking line is a professional automated production line designed for surface coating and curing of various glass substrates (such as flat glass, curved glass, ultra-white glass, and tempered glass). It integrates automatic glass feeding, surface pretreatment, spray painting, film leveling, baking and curing, quality inspection, and automatic unloading into a continuous workflow. By virtue of high-precision mechanical control and intelligent process management, the line achieves precise control of coating thickness (adjustable from 5μm to 50μm) and uniform curing of coatings. It effectively ensures that the coated glass meets performance requirements such as adhesion, weather resistance, hardness, and scratch resistance, and is widely used in the surface treatment of glass products in industries including architectural decoration (curtain wall glass, decorative glass), automotive manufacturing (automotive window glass, interior trim glass), electronic displays (display screen glass, touch panel glass), and household appliances (refrigerator door glass, washing machine panel glass).

2. Core Advantages

2.1 High Automation and Production Efficiency

The line adopts a fully automated assembly line design, equipped with multi-axis robotic arms (with a repeat positioning accuracy of ±0.02mm) and a frequency-conversion adjustable conveying system (conveying speed: 1m/min - 5m/min). It can realize 24-hour continuous operation without manual intervention in the core processes of feeding, spraying, and curing. The daily production capacity of a single line can reach 500㎡ - 2000㎡ (adjustable according to glass size and coating process requirements), which is 4 - 6 times higher than that of traditional manual spraying operations. At the same time, the automated operation reduces the impact of human factors on product quality, and the qualified rate of finished glass products remains stable above 99%.

2.2 Precise Coating Quality Control

Equipped with a high-precision coating control system, including a precision flow controller (control accuracy: ±1%), an automatic atomization adjustment device, and an online film thickness detector (laser-based, measurement accuracy: ±0.1μm), the line can automatically adjust spraying parameters (such as spray pressure, spray distance, and paint flow rate) according to the type of glass substrate and coating (solvent-based, water-based, UV-curable). This ensures that the coating thickness deviation is controlled within ±1μm and the coating uniformity reaches over 98%, effectively avoiding common defects in manual spraying such as sagging, pinholes, orange peel, and color difference.

2.3 Strong Compatibility with Multi-functional Coatings

The line is compatible with a variety of functional and decorative coatings, including anti-glare coatings, anti-fingerprint coatings, self-cleaning coatings, antibacterial coatings, heat-insulating coatings, and colored decorative coatings. By replacing spray gun heads (fan-shaped nozzles, circular nozzles) and adjusting curing process parameters (baking temperature, baking time, UV light intensity), it can quickly switch between different coating production processes without large-scale modification of the production line. This meets the diversified market demands for glass product functions and appearances, and is suitable for small-batch and multi-variety production modes.

2.4 Environmental Protection and Safe Operation

The spray painting section adopts a fully enclosed spray booth with a negative pressure ventilation structure (airflow speed: 0.3m/s - 0.5m/s) to prevent the leakage and diffusion of paint mist. Equipped with a multi-stage paint mist purification system (primary filter cotton + medium-efficiency filter bag + activated carbon adsorption tower), the paint mist capture rate reaches over 98%, and the emission concentration of volatile organic compounds (VOCs) is ≤30mg/m³, which complies with the national standard "Emission Standard of Volatile Organic Compounds for Industrial Coatings" (GB 37822-2019). In addition, the line is equipped with safety protection devices such as explosion-proof electrical components (Ex d IIB T4 Ga explosion-proof grade), electrostatic grounding devices (grounding resistance ≤10Ω), and fire alarm systems (smoke detectors + temperature-sensitive detectors + automatic sprinklers), fully ensuring the safety of the production process and the health of operators.

3. Main Equipment Composition

3.1 Automatic Feeding and Conveying System

Composed of a robotic arm feeding unit, a vacuum suction cup device, and a roller conveyor line. The robotic arm, equipped with a high-strength vacuum suction cup, can stably grasp glass substrates of different sizes (500mm×500mm - 3000mm×2000mm) and thicknesses (3mm - 19mm), and accurately place them on the roller conveyor line. The conveyor line adopts a frequency conversion motor drive, with adjustable conveying speed and a positioning accuracy of ±0.5mm, ensuring the orderly and stable transfer of glass between different process sections.

3.2 Glass Surface Pretreatment System

Including an ultrasonic cleaning tank, a spray rinsing device, a hot air dryer, and a plasma treatment machine. The ultrasonic cleaning tank (ultrasonic frequency: 40kHz - 60kHz) uses high-frequency ultrasonic vibration to remove oil stains, dust, and other impurities on the glass surface; the spray rinsing device uses deionized water to rinse residual cleaning agents on the glass surface; the hot air dryer (air temperature: 60℃ - 80℃, air speed: 2m/s - 5m/s) dries the glass surface to ensure no moisture remains; the plasma treatment machine (plasma power: 5kW - 15kW) performs surface activation treatment on the glass, increasing the surface energy of the glass and improving the adhesion between the glass and the coating (adhesion can be increased by 30% - 50%).

3.3 Automatic Spray Painting Unit

Consisting of a multi-axis spray robot, a paint supply system, and a closed spray booth. The multi-axis spray robot has 6 - 8 degrees of freedom, which can adjust the spray angle (0° - 90°) and spray distance (100mm - 300mm) according to the shape of the glass (flat or curved), realizing 360° dead-angle-free spraying. The paint supply system is composed of a paint mixing tank (with a constant temperature heating function, temperature control range: 25℃ - 40℃), a precision gear pump, and a paint filter (filter pore size: 5μm - 10μm), which ensures the stable and uniform supply of paint without precipitation or stratification. The closed spray booth is equipped with a high-efficiency filter cotton and a negative pressure exhaust system to prevent paint mist from polluting the production environment.

3.4 Coating Baking and Curing System

Configured with different curing equipment according to the type of coating. For solvent-based and water-based coatings, a hot air circulation baking oven is used (baking temperature: 80℃ - 120℃, baking time: 15min - 30min), which adopts a zoned temperature control design to ensure uniform heating of the glass and avoid coating cracking caused by uneven temperature. For UV-curable coatings, a UV curing machine is equipped (UV lamp power: 80W/cm - 160W/cm, irradiation time: 10s - 60s), which uses high-intensity UV light to trigger the cross-linking and curing reaction of the coating, significantly shortening the curing time. The curing system is also equipped with a temperature monitoring sensor and an automatic temperature control module to ensure the stability of the curing process parameters.

3.5 Quality Inspection and Unloading System

Integrating a visual inspection camera, a film thickness detector, a hardness tester, and an automatic unloading robotic arm. The visual inspection camera (resolution: ≥20 million pixels) performs real-time imaging detection on the glass surface to identify defects such as scratches, impurities, pinholes, and sagging on the coating; the film thickness detector uses laser thickness measurement technology to accurately measure the coating thickness and ensure it meets the design requirements; the hardness tester (pencil hardness tester or Shore hardness tester) tests the surface hardness of the coating (usually requiring a pencil hardness of 2H - 4H); the qualified glass products are grabbed by the unloading robotic arm and transferred to the finished product storage area for packaging, while unqualified products are automatically sorted to the rework area for further processing.

4. Typical Process Flow

4.1 Glass Feeding

The glass substrates to be processed are manually placed on the feeding platform. The automatic feeding robotic arm grabs the glass stably through the vacuum suction cup and conveys it to the surface pretreatment system according to the preset program. During the conveying process, the positioning sensor on the conveyor line corrects the position of the glass in real time to avoid deviation.

4.2 Surface Pretreatment

The glass sequentially passes through the ultrasonic cleaning tank (cleaning time: 3min - 5min) to remove surface impurities; then enters the spray rinsing device (rinsing time: 1min - 2min) to rinse residual cleaning agents; after that, it is sent to the hot air dryer (drying time: 2min - 3min) to dry the surface; finally, it undergoes plasma treatment (treatment time: 30s - 60s) to activate the glass surface. After pretreatment, the surface cleanliness of the glass reaches over 99.9%, and the surface roughness is controlled at Ra 0.8μm - 1.6μm.

4.3 Automatic Spray Painting

The pretreated glass is conveyed to the closed spray booth by the roller conveyor line. The central control system adjusts the spray parameters (spray pressure, flow rate, distance) according to the glass size and coating type. The multi-axis spray robot starts the spray gun and sprays the coating evenly on the glass surface according to the preset path. For glass requiring multi-layer coating (such as primer + topcoat), the conveyor line conveys the glass to the spray booth multiple times for layer-by-layer spraying, with a flash drying process (standing at room temperature for 1min - 2min to volatilize part of the solvent) between each layer of spraying.

4.4 Coating Baking and Curing

The glass after spray painting is sent to the baking and curing system. For solvent-based/water-based coatings, it is heated and cured in a hot air circulation oven (temperature: 80℃ - 120℃, time: 15min - 30min); for UV-curable coatings, it passes through the UV curing machine and is irradiated by UV light (irradiation time: 10s - 60s) to complete the curing. During the curing process, the temperature and time are automatically monitored and adjusted to ensure the coating is fully cured and has stable performance.

4.5 Quality Inspection and Unloading

The cured glass is cooled to room temperature (natural cooling or air cooling) and then sent to the quality inspection station. The visual inspection camera checks the coating appearance, the film thickness detector measures the coating thickness, and the hardness tester tests the coating hardness. Qualified glass products are grabbed by the unloading robotic arm and transferred to the finished product storage area for labeling and packaging; unqualified products are sorted to the rework area, and after analyzing the causes of defects (such as uneven coating thickness, surface scratches), they are sent back to the corresponding process (such as pretreatment, spray painting) for reprocessing to ensure the final product quality meets the industry standards (such as GB/T 18915.1-2013, ISO 12236:2007).

5. Application Scenarios and Development Trends

5.1 Main Application Scenarios

5.1.1 Architectural Glass Industry

Used for the surface treatment of architectural glass products such as curtain wall glass, indoor partition glass, and door/window glass. It can prepare functional coatings such as heat insulation, sound insulation, UV protection, and self-cleaning, improving the energy-saving performance and service life of architectural glass. At the same time, through colored decorative coatings, it enriches the color and pattern choices of architectural glass, meeting the personalized design needs of architectural decoration.

5.1.2 Automotive Glass Industry

Applied to the coating of automotive glass products such as windshield glass, side window glass, and rear window glass. It can spray anti-fog coatings (to prevent fogging on the glass surface in rainy or cold weather), anti-glare coatings (to reduce glare during night driving), and antibacterial coatings (to keep the interior glass clean and hygienic), improving the safety and comfort of automotive glass use. In addition, it can also prepare privacy coatings for automotive rear windows to achieve the effect of light transmission and privacy protection.

5.1.3 Electronic Display Glass Industry

Used for the surface coating of electronic display glass such as LCD/OLED display screens, tablet computer touch panels, and smartphone screens. It mainly sprays anti-glare coatings (to reduce screen reflection and improve viewing experience), anti-fingerprint coatings (to prevent fingerprint residue on the screen surface), and scratch-resistant coatings (to increase the surface hardness of the glass and avoid scratches). These coatings effectively improve the usability and durability of electronic display glass.

5.2 Future Development Trends

5.2.1 Intelligent Upgrade of the Production Line

With the integration of artificial intelligence (AI) and industrial Internet technology, the glass automatic spray paint baking line will realize more intelligent operation and management. For example, the AI visual inspection system can automatically identify and classify coating defects (such as scratches, pinholes, color difference) and calculate the defect rate, providing data support for process optimization; the industrial Internet platform can realize remote monitoring of the production line (equipment operation status, production progress, quality data) and remote fault diagnosis, reducing the maintenance cost of the production line and improving the operation efficiency.

5.2.2 Development of Green and Environmental Protection Processes

In response to the national "dual carbon" policy and environmental protection requirements, the line will further promote the application of environmentally friendly coatings (such as water-based coatings, powder coatings, and UV-curable coatings with low VOCs content) and optimize the waste gas treatment system. For example, the use of regenerative thermal oxidizers (RTO) can increase the VOCs removal rate to over 99%, realizing near-zero emission of waste gas; the adoption of a closed-loop paint recycling system can improve the paint utilization rate to over 90%, reducing paint waste and environmental pollution.

5.2.3 Integration of Multi-process and Flexible Production

In the future, the glass automatic spray paint baking line will gradually integrate with other glass processing processes (such as glass cutting, edging, tempering) to form an integrated intelligent production line, reducing intermediate transfer links and shortening the production cycle. At the same time, with the improvement of the flexibility of the production line, it can quickly adapt to the production of glass products of different sizes, shapes, and coating requirements by replacing fixtures, adjusting program parameters, and switching coating types, meeting the market demand for rapid product iteration and personalized customization.

5.2.4 Improvement of Coating Functionality and High Performance

Driven by the market demand for high-performance glass products, the line will focus on the research and application of high-functional coatings, such as ultra-thin heat-insulating coatings (with a thickness of less than 10μm and a heat insulation rate of over 80%), self-healing coatings (able to automatically repair small scratches on the surface), and conductive coatings (applied to smart glass and electronic sensors). The improvement of coating functionality will further expand the application fields of the glass automatic spray paint baking line, such as in the fields of new energy (solar panel glass), smart home (smart dimming glass), and aerospace (aerospace cabin glass).