I. System Architecture: The Entire Process of Material Flow

　　In the injection molding workshop, material flow—from “injection molding → material discharge and conveyance → buffering/sorting → packaging and positioning → finished-product output”—must be seamlessly integrated. The entire process is divided into three major modules: a belt conveyor section, a transition connection section, and a roller-packaging section, each tailored to meet the specific conveying requirements of different stages.

　　 II. Core Module Design

　　1. Belt conveyor section (from injection molding machine feeding → buffering/sorting)

　　Function: Receives plastic parts discharged from the injection molding machine, enabling short-distance, flexible, and low-noise conveying, and supporting sorting/caching.

　　Key selection criteria:

　　Material: PU/PVC belt (anti-static, high-temperature resistant; the residual temperature of injection-molded parts is approximately 50–80℃; select a material with a temperature resistance of 100℃ or higher).

　　Bandwidth: Add a 50mm margin based on the product dimensions (e.g., if the product is 150mm wide, select a bandwidth of 200mm).

　　Structure: Side guard + guide strips (to prevent small items from tipping over); adjustable speed (frequency conversion control, 0–30 m/min).

　　Sorting Design: If sorting multiple models is required, the conveyor belt system should be equipped with branch lines (T-shaped or Y-shaped), paired with photoelectric sensors and pneumatic cylinders to automatically sort items.

　　2. Transition connection section (belt → roller)

　　Function: Smoothly connects the belt to the roller conveyor, preventing products from getting stuck or falling off.

　　Design highlights:

　　Height alignment: The height difference between the belt end and the roller’s starting end shall be ≤5mm (adjusted by raising or lowering the support legs);

　　Transition structure: Install a “transition plate” (plastic/stainless steel, with a smooth surface) or a “miniature roller assembly” (with a spacing ≤ 1/2 of the product’s minimum dimension);

　　Detection interlock: A photoelectric sensor is installed at the end of the belt. Once the product is detected as being in place, it triggers the roller conveyor to start (preventing idle running).

　　3. Roller Packaging Section (Cache/Sorting → Packaging Positioning → Finished Product Output)

　　Function: Long-distance, high-load conveying with precise positioning at the packaging station, accommodating both manual and automated packaging requirements.

　　Key selection criteria:

　　Roller types: Electric rollers (with built-in motor, high integration) or motor + chain/belt drive (for long distances and heavy loads);

　　Roller spacing: ≤ 1/2 of the product’s minimum dimension (e.g., if the product length is 200 mm, the spacing ≤ 100 mm to prevent tipping).

　　Packing positioning: A “positioning stopper” (cylinder-driven lift) is installed in front of the packing workstation. When the photoelectric sensor detects that the product has been properly positioned, the stopper rises to secure its location.

　　Operating Space: The spacing between the rollers in the bundling area can be locally adjusted (e.g., from 50 mm to 80 mm) to facilitate manual wrapping with strapping bands or placement of stretch film. If using an automatic strapping machine, sufficient operating space must be reserved for the robotic arm; the roller conveyor line should feature a "synchronous belt connection" at its interface with the strapping machine (after the product is positioned, the strapping machine will clamp and rotate it for bundling).

　　III. Control Logic: Automation and Interlocking

　　Electrical Control: Centered around a PLC, the system integrates sensors (photoelectric, proximity switches), a frequency converter, and pneumatic cylinder solenoid valves to achieve coordinated operation of “conveying—sorting—positioning—packaging.”

　　Typical process:

　　Injection molding machine feeding → Belt conveyor starts, transporting parts to the sorting area;

　　The sensor detects the product model → The cylinder pushes the parts onto the corresponding belt branch for sorting.

　　After sorting, the conveyor belt transports the products to the transition section → triggering the roller conveyor to start.

　　The conveyor belt transports the items to the packing station → The positioning stopper rises, and the sensor triggers either the automatic packing machine or manual packing.

　　After packaging is complete, the barrier lowers → the roller conveyor transports the finished products to the finished goods area.

　　Human-Machine Interface (HMI): The touchscreen displays the conveyor line status (running/fault/speed), production statistics, and fault alarms (such as belt misalignment or roller blockage). It also supports parameter settings (speed, sorting logic).

　　IV. Safety and Maintenance Design

　　Security protection:

　　Install “protective nets/fences” around the conveyor line (height ≥ 1.8m, to prevent accidental human contact);

　　Emergency stop button: One emergency stop (red mushroom-head, hardwired to the PLC safety circuit) should be installed every 5–10 meters.

　　Overload protection: The motor is equipped with a thermal relay that automatically shuts down and triggers an alarm in the event of stalling or overload.

　　Cleaning and Maintenance:

　　For belts and rollers, select “easy-to-clean materials” (such as mirror-finish stainless steel rollers or antistatic PU belts). Equip the ends with “chip collection trays” (to collect injection-molded scrap material).

　　Bearing lubrication: Lubricate roller bearings monthly, and inspect belt roller bearings quarterly.

　　Belt Tension: Adjust belt tension every quarter (to prevent slippage). Inspect the tension of roller chain/belt drives every six months.

　　V. Scenario Adaptation of the Solution

　　Small-batch, multi-variety production: The belt conveyor is enhanced with advanced sorting capabilities (multiple branches + sensors); the roller conveyor features a buffer section (with “accumulation-type rollers” added in the middle) to temporarily store products when the production rate exceeds the packing rate.

　　Large-volume, single-product sorting: Simplified sorting using belt conveyors (linear transport); extended roller conveyors (10–20 m) directly connected to packaging machines, matching high-speed production rhythms (e.g., producing one unit every 30 seconds, with packaging time ≤ 25 seconds).

　　By combining "flexible belt conveyance with precise roller positioning," we strike a balance between the flexibility required in injection molding workshops for "multiple product varieties in small batches" and the efficiency demands of the "packaging stage." At the same time, automated control reduces human intervention, thereby enhancing the overall production line performance.