Paint Filling Line Product

Overview

A paint filling line is an integrated production machine that automates the end-of-line packaging process: volumetric dispensing into cans, automatic lid application, and label placement. Lines operate at 1–5 cans per minute, suitable for mid-volume manufacturers producing 100–500 units daily.

The system consists of a can conveyor indexing between three stations (filler, lidder, labeler), a pressurized product tank with circulation pump, and a PLC-based control system. Modern lines are fully automatic and require only operator loading of empty cans at the input and removal of finished cans at the output.

How it works

A batch of paint is pre-mixed and poured into the Product Reservoir. The Tank Mixer circulates at low speed to suspend pigment. The Immersion Heater brings the paint to 25–30°C for optimal viscosity.

Empty cans are manually loaded into Can Holder Nest holders on the Can Conveyor System. The operator presses START on the HMI Touchscreen. The Programmable Logic Controller sequences the line:

Station 1 (Filling): The conveyor indexes a can under the Volumetric Filling Nozzle nozzle. The Gear Feed Pump pressurizes product at 3–10 bar. The Solenoid Shutoff Valve opens for a pre-set duration (controlled by Time-Delay Relay), allowing the Piston Dispenser Pump to dispense the target volume. The Turbine Flow Sensor confirms flow. A Proximity Sensor proximity sensor detects when filling is complete.

Station 2 (Lidding): The conveyor advances the filled can. The Lid Feed Hopper gravity-feeds lids. The Lid Gripper Head vacuum gripper grabs one lid and positions it on the can opening. The Press Cylinder (pneumatic double-acting cylinder or servo press) descends at 5–20 ton force, and the Crimp Die crimps the lid bead onto the can rim. A quick press cycle (2–3 seconds) ensures tight seal.

Station 3 (Labeling): The conveyor indexes the sealed can to the Label Applicator. The Label Servo Motor (servo) advances one label from the Label Material. The Applicator Roll smooths the label onto the can side. The Label Cutter separates the label. The finished can exits and is manually removed.

The HMI Touchscreen displays production count, fill volume, cycle time, and any faults. The Safety Relay Module E-stop halts all motion and pressure immediately.

Key subsystems

Conveyor and indexing: The Can Conveyor System is a simple timing-belt drive indexed by a stepping motor with precision reducer. Each index corresponds to one can position, advancing one station at a time. Index times are programmable; typical 10–60 seconds per station.

Volumetric filler: The Volumetric Filling Nozzle uses a piston pump with adjustable displacement or a fixed-displacement pump with a timed solenoid valve. Piston fillers are more accurate (±2%) but more expensive and sensitive to viscosity; gear pumps are ±5% but robust and low-cost.

Pressure regulation: The Pressure Relief Valve adjusts to maintain safe discharge pressure (typically 5–8 bar). The Turbine Flow Sensor provides feedback to the PLC for error detection (e.g., if flow drops below expected rate, the PLC signals a clog).

Lidding press: Pneumatic presses are fast and simple; servo electric presses offer adjustable force curves and longer life. Dual-acting cylinders ensure consistent speed and force through the entire stroke.

Label application: The servo-driven Label Servo Motor indexes one label at a time. Precision positioning is critical; if the label misaligns, the operator must stop the line and manually remove the malformed can. High-speed lines use vision inspection to detect label placement errors.

Heating and circulation: The Tank Mixer is a low-shear paddle or anchor blade preventing pigment settling over hours. The Immersion Heater maintains temperature at 25–30°C via a Thermostat Valve. Loss of temperature causes viscosity to drift, throwing off volumetric fills.

PLC control: The Programmable Logic Controller monitors all sensors: can presence at each station (via Proximity Sensor), fill completion (flow meter confirmation), lid placement, label position. Any sensor fault triggers a line halt and alarm on the HMI Touchscreen.

Materials and construction

Tank: Stainless steel 304 or 316L, epoxy-lined inside, designed for easy drainage and cleaning. Typical 100–500 liter capacity, allowing 2–8 hour production runs before refill.

Conveyors: Timing belt with stainless steel sprockets; acetal or aluminum guide rails. Belt tensioners are automatic spring-loaded types.

Nests and nozzles: Aluminum or stainless steel, easily customized for different can sizes. A typical production facility owns three sets of nests and conveyor parts, one for each supported can size.

Hoses: All product-contact hoses are food-grade or solvent-resistant SAE 100R2, with smooth bore (not spiral) for easy cleaning. Hose lengths are minimized to reduce dead volume.

Gauges and meters: All pressure and temperature instruments are IP65 rated for paint spray environment. Turbine Flow Sensor output feeds the PLC via 4–20 mA transmitter.

Operating procedure

1. Load paint batch into Product Reservoir; start Tank Mixer and heater.
2. Wait for temperature to reach 25–30°C.
3. Prime pumps by running circulation for 30 seconds.
4. Set fill volume on HMI Touchscreen via timer dial (calibrated in milliliters per time unit).
5. Load empty cans into Can Holder Nest.
6. Press START.
7. Monitor HMI Touchscreen for cycle count and alarms.
8. Periodically sample filled cans, weigh them, and confirm volume accuracy.
9. If volume drift detected (e.g., after 100 cans), adjust timer delay ±0.1 second and restart.
10. After shift, shut down motor and heater; drain tank or allow circulation to pause.

Variants and customization

Semi-automatic lines: Operator manually places lid and label; line handles filling only. Lower cost, slower throughput (2–3 cans/minute).

Fully automatic vision-guided lines: Cameras inspect fill level and label placement, triggecting automated reject arms for defects.

Multi-nozzle fillers: High-speed lines (10+ cans/minute) use two or four nozzles on a rotary table, filling multiple cans in parallel.

Capping vs. crimping: Capping machines screw plastic caps onto threaded openings (faster, 5–10 cans/min); crimping presses indent metal lids onto sealed can rims (slower, 1–3 cans/min, for metal cans).

Labeling alternatives: Roll-fed labels (most common), pre-printed wraparound sleeves (slow but durable for curvy cans), or thermal-transfer direct printing on cans.

Troubleshooting

Volume variance: Check Tank Thermometer for temperature drift (viscosity sensitive); inspect Pressure Gauge for pump wear (pressure drop); run flow meter calibration.

Label jams: Inspect Label Cutter blade sharpness; clean label roller of debris.

Missed lids: Verify Lid Feed Hopper is not depleted; check Lid Detection Sensor alignment.

Slow production: Increase index timing on HMI Touchscreen; reduce fill volume dwell time if acceptable; check pump prime (air in discharge).