The Complete HDPE Construction Waste Chute Production Process

Longkang HDPE plastic construction waste chutes are produced by extrusion molding, with strict control through multiple processes from raw material to finished product. Understanding the production process helps customers appreciate product quality. This article presents the complete production flow.

1. Production Process Flow

Longkang construction waste chute production flow:

1. Raw material selection → 2. Batching and mixing → 3. Extrusion molding → 4. Cooling and sizing → 5. Cut-to-length → 6. End machining → 7. Connector injection molding → 8. Assembly and inspection → 9. Packaging and storage
2. Raw Material Selection
3. Main material

• HDPE extrusion-grade resin
• Grade: 5502 or equivalent
• Melt flow rate 0.3–0.7 g/10min
• Density 0.945–0.955 g/cm³
• Virgin material; no recycled material is used

2. Auxiliary materials

• Carbon black masterbatch: 2%–3% (weather resistance)
• Antioxidant: 0.2%
• UV absorber: 0.3% (optional)
• Flame retardant: optional (flame-retardant type)

3. Raw material inspection

• Incoming inspection for every batch of raw material
• Check appearance, melt index, and density
• May be used only after passing inspection

III. Batching and Mixing

1. Weigh HDPE pellets and masterbatch according to the formula
2. Feed into a high-speed mixer
3. Mixing temperature 60–80 °C
4. Mixing time 5–10 minutes
5. Uniform mixing with consistent color
6. Ready for use after mixing
7. Extrusion Molding
8. Extruder

• Single-screw extruder
• Screw diameter 65–90 mm
• L/D ratio 25:1–33:1
• Heating zones: 4 zones, temperature 180–220 °C

2. Die

• Annular die head (pipe die)
• Diameter matched to the product specification
• A 500 mm pipe diameter corresponds to a die of about 650 mm
• Mandrel sizing ensures wall thickness

3. Extrusion process

• Material melting and plasticating
• Pipe parison extruded from the die head
• Enters the vacuum sizing sleeve
• Vacuum adsorption sizing
• Wall thickness controlled by the die gap

1. Cooling and Sizing
2. Vacuum sizing sleeve cooling
3. Multi-stage cooling water tanks
4. Water temperature: first stage 20–30 °C, subsequent stages at ambient temperature
5. Sufficient cooling to prevent deformation
6. The sizing sleeve ensures roundness and diameter accuracy
7. Cut-to-Length
8. Automatic cut-to-length cutting
9. Per-section length 1.5 m (standard)
10. Cut with a saw, producing a smooth cut surface
11. Length tolerance ±5 mm
12. Clean end face free of burrs

VII. End Machining

1. One end machined into a socket (flared end)
2. The other end is the spigot (standard outer diameter)
3. The socket inner diameter is 3 mm larger than the pipe outer diameter
4. Socket-and-spigot insertion depth 50 mm
5. End chamfered for easy installation
6. Joint area ground smooth

VIII. Connector Injection Molding

1. Buckle injection molding

• Injection molding machine produces quick-release buckles
• Material: PP or reinforced nylon
• High die precision
• Strength testing

2. Sealing ring

• Purchased EPDM rubber sealing rings
• Cross-section Φ8 mm
• Cut to the circumference
• Joint bonded with adhesive

1. Assembly and Inspection
2. Each section is trial-assembled at the joint to check sealing performance
3. Measure wall thickness, diameter, and length
4. Visual inspection (no bubbles or cracks)
5. Fitted with sealing rings and buckles
6. Identification label
7. Packaging and Storage
8. Each section strapped and packed
9. End protection (to prevent transport damage)
10. Product information spray-printed (specification, date, batch)
11. Stored in the warehouse
12. Awaiting shipment
13. Longkang Process Advantages
14. Virgin raw material, stable quality
15. Extrusion process, uniform wall thickness
16. Vacuum sizing, precise dimensions
17. Each section inspected, factory-quality
18. Short production cycle, fast supply