Products Description
Semi-Automatic Powder Coating Line
The semi-automatic powder coating line is a powder coating equipment system that combines "manual assistance with automated core processes". Its core logic is to let automated equipment undertake repetitive processes such as spraying, curing, and conveying, while relying on manual intervention to address needs that are difficult for automated equipment to adapt to, such as positioning of complex workpieces, touch-up spraying on irregular parts, and flexible production changeovers. This line avoids the problems of "low efficiency and poor coating consistency" of manual lines, and does not require bearing the "high investment and complex debugging" costs of fully automatic lines. It is widely suitable for the production of small-to-medium batch, multi-variety workpieces with partially complex structures, and is extensively used in fields such as hardware manufacturing, small agricultural machinery parts, furniture metal parts, and electronic equipment enclosures.
I. Composition of Core Equipment
Designed around the principle of "efficiency improvement through automation + manual supplementary support", the semi-automatic powder coating line mainly consists of five functional units, with the degree of automation of each unit allocated according to needs:
Workpiece Positioning and Conveying Unit
Adopts a "manual loading + automated conveyor chain" mode: Operators manually fix workpieces (such as hardware brackets and small agricultural machinery parts) on hangers with high precision (ensuring positioning deviation ≤ ±1mm to avoid displacement during conveying), and the hangers are automatically conveyed to subsequent processes along with the chain.
The speed of the conveyor chain is adjustable (0.5-1.2m/min) to adapt to the spraying and curing time requirements of different workpieces; some lines are equipped with reversible hangers, facilitating manual multi-angle inspection or touch-up spraying of workpieces.
Pretreatment Unit
Automated core processes: Includes degreasing tanks, water washing tanks, phosphating tanks, and drying ovens. Workpieces are automatically conveyed through the conveyor chain to enter each process in sequence. The degreasing temperature (40-60℃), phosphating time (5-10 minutes), and drying temperature (80-120℃) are automatically controlled by the control system without manual intervention.
Manual supplementary support: For workpieces with heavy oil contamination, operators can pre-wipe them before entering the degreasing tank; if there are residual water stains on the workpiece surface after water washing, operators use compressed air to blow them dry quickly to prevent pinholes in the subsequent coating.
Spraying Unit
Automated main spraying: The closed spraying booth is equipped with 2-4 automatic electrostatic spray guns. The spray guns are preset with spraying parameters (electrostatic voltage: 60-80kV, powder output: 50-100g/min) according to the workpiece size, and automatically complete the main coating spraying on the workpiece surface. The initial coating thickness is controlled at 50-120μm.
Manual touch-up station: A touch-up area is set up at the exit of the spraying booth. Through a high-intensity light inspection table, operators check parts of the workpiece that are difficult for automatic spray guns to cover, such as grooves, edges, and deep holes. If there is missing spray or insufficient coating thickness, manual spray guns are used for precise touch-up spraying to ensure 100% coating coverage; at the same time, a powder recovery system (recovery rate ≥ 95%) is equipped to reduce coating waste.
Curing Unit
Fully automated temperature control: A continuous curing oven is adopted. The temperature inside the oven is automatically controlled in three sections: preheating section (120-140℃), curing section (160-220℃), and cooling section (100-120℃). The temperature uniformity is ±3℃, and the heat preservation time can be set as needed (15-30 minutes). Workpieces are automatically conveyed into and out of the oven along with the conveyor chain without manual handling.
Manual auxiliary monitoring: A temperature detection point is set at the exit of the curing oven. Operators regularly sample and test the surface temperature of workpieces (ensuring the temperature is ≤ 40℃ before entering the cooling process) to avoid incomplete coating curing caused by abnormal temperature control.
Cooling and Inspection Unit
Automated cooling: After being sent out of the curing oven, workpieces enter a forced air cooling area (air speed: 2-3m/s) and are automatically cooled to room temperature.
Manual-based inspection: After cooling, operators conduct appearance inspection on workpieces (checking for sagging, pinholes, missing spray) and sample inspection of coating thickness (using a thickness gauge, with deviation ≤ ±5μm). Qualified workpieces are manually unloaded and packaged, while unqualified workpieces are marked and sent to the rework area (to be stripped of paint before re-entering the production line).
II. Application Scenarios
Small-to-Medium Batch, Multi-Variety Production Enterprises
For example, hardware accessory factories with an annual output of 100,000-500,000 pieces need to produce brackets and connectors of different specifications. The semi-automatic line does not require frequent adjustment of automated programs; operators only need to replace hangers and fine-tune spray gun parameters to achieve rapid production changeovers. The changeover time is usually ≤ 30 minutes, much shorter than that of fully automatic lines (which require 1-2 hours of debugging).
With a daily production capacity of 500-2,000 pieces, it can meet the order delivery requirements without bearing the cost of over one million yuan for fully automatic lines.
Production of Workpieces with Complex Structures
For example, automotive sensor enclosures with deep holes and curved furniture metal handles—automatic spray guns are difficult to cover all parts, and manual touch-up spraying can ensure coating integrity. If a fully automatic line is adopted, multiple sets of robotic spray guns are required, resulting in a significant increase in cost.
Start-Up Enterprises or Enterprises in the Trial Production Stage
Start-up enterprises have limited funds. The initial investment of the semi-automatic line (300,000-800,000 yuan) is only 1/5 to 1/3 of that of fully automatic lines, enabling the rapid establishment of production lines.
During the trial production of new products, operators can flexibly adjust process parameters (such as coating thickness and curing time), and the parameters can be solidified into automated programs after successful trial production, reducing trial-and-error costs.
III. Core Process Flow (Taking Hardware Brackets as an Example)
Manual Loading: Operators fix hardware brackets on the hangers of the conveyor chain, ensuring the brackets are level and free from wobbling.
Automated Pretreatment: Workpieces are conveyed by the conveyor chain to enter the degreasing tank (50℃, 8 minutes) → 2-stage water washing (room temperature, 3 minutes per stage) → phosphating tank (45℃, 6 minutes) → drying oven (100℃, 15 minutes) in sequence. During this process, operators pre-wipe brackets with heavy oil contamination.
Automated Spraying + Manual Touch-Up: Workpieces enter the spraying booth, and automatic spray guns complete the main spraying; operators in the touch-up area check the edges of the brackets and use manual spray guns to touch up missed areas.
Automated Curing: Workpieces are conveyed by the conveyor chain into the curing oven (curing section: 180℃, 20 minutes) to complete curing automatically.
Automated Cooling + Manual Inspection: After being cooled by air, operators inspect the coating appearance and sample-test the thickness. Qualified brackets are unloaded and packaged, while unqualified ones are marked for rework.
IV. Core Advantages
Balance Between Cost and Efficiency
Low equipment investment: The initial investment is much lower than that of fully automatic lines, which is easily affordable for small and medium-sized enterprises; low operating costs: automated processes reduce the number of workers (only 2-3 workers are needed per line), and labor is mainly concentrated in key links such as touch-up spraying and inspection, avoiding labor waste.
Efficiency matching needs: The daily production capacity meets small-to-medium batch orders, with efficiency 30%-50% higher than that of manual lines, and coating consistency (color difference ≤ ΔE2.0) better than that of manual lines.
High Flexibility and Adaptability to Multiple Scenarios
Convenient production changeover: When switching between multi-variety workpieces, operators only need to adjust hangers and touch-up parameters, without complex debugging of automated programs.
Adaptability to complex workpieces: Manual touch-up spraying solves the "blind spot" problem of automated equipment, and there is no need to customize dedicated automated modules for special workpieces, resulting in much higher adaptability than fully automatic lines.
Low Operation Threshold and Easy Maintenance
No need for professional technicians: Workers can take up their posts after 1-2 days of training; automated processes are operated automatically by the control system, and operators only need to perform simple monitoring and supplementary support.
Easy maintenance: The equipment structure is simpler than that of fully automatic lines; vulnerable parts (such as spray gun nozzles and conveyor chain rollers) are easy to replace, with low maintenance costs and short downtime (single maintenance ≤ 2 hours).
Environmental Compliance
Equipped with a powder recovery system and closed spraying booth, the dust emission meets environmental protection standards; the dosage of degreasing agents and phosphating agents in the pretreatment process is controlled automatically, avoiding excessive waste caused by manual operation and reducing environmental pollution.
