Scope of Application: Industrial plastic sheets and pipes including PP, PE, UPVC, ABS, UPE for model selection, processing, installation and maintenance.

1. Basic Material & Performance

Q1: What is the difference between virgin material and recycled material? How to distinguish them?

Answer: • Performance: Virgin material has better temperature resistance, impact resistance, aging resistance and corrosion resistance, with a service life of 5-10 years under conventional working conditions. Recycled material has unstable physical properties, which is easy to crack, deform and embrittle, with a service life of only 1-3 years. • Appearance: Virgin material features uniform color, transparent texture and smooth surface without impurities, bubbles or pits. Recycled material is dark and gray with black spots, rough surface and concave-convex defects. • Identification Methods: Observe color and impurities; smell odor (recycled materials usually have pungent odor); bend samples (virgin materials have high toughness and are not easy to break); combustion test (recycled materials produce heavy black smoke and irritating smell). • Cost: The unit price of recycled materials is 20%-50% lower than virgin materials. However, due to high failure rate and frequent replacement, the comprehensive operating cost is much higher.

Q2: What are the core differences between PP, PE, UPVC, ABS and UPE? How to select materials?

Answer: • PP (Polypropylene): Excellent acid and alkali resistance, good weldability, long-term temperature resistance ≤80℃. Mainly used for chemical tanks, ventilation pipes and pickling equipment. Moderate hardness and poor UV resistance. • PE (Polyethylene): Extremely high toughness, outstanding impact resistance, wear resistance and low-temperature resistance. The maximum working temperature is ≤60℃. Commonly used for sewage pipes, conveying pipes and lining plates. • UPVC (Unplasticized Polyvinyl Chloride): Low cost, high rigidity and good corrosion resistance. Working temperature ≤45℃ and non-weldable. Suitable for water supply, drainage and low-pressure chemical pipelines. • ABS (Acrylonitrile Butadiene Styrene): High hardness, excellent mechanical strength and easy processing. Poor weather resistance, ideal for equipment shells, tooling plates and structural parts. • UPE (Ultra-high Molecular Weight Polyethylene): Extreme wear resistance, impact resistance and self-lubricating property with excellent low-temperature performance, but poor high-temperature resistance. Applied for conveying chutes, wear-resistant lining plates and anti-stick plates.

Q3: How to judge the acid and alkali corrosion resistance of plastic materials?

Answer: 1. PP & PE: Excellent corrosion resistance, resistant to most weak acids, weak alkalis and salt solutions; not resistant to strong oxidants such as concentrated nitric acid and concentrated sulfuric acid. 2. UPVC: Good acid and alkali resistance, not suitable for high-temperature and strong corrosive media. 3. ABS: Unable to resist strong acids and organic solvents, only applicable to neutral and dry environments. 4. UPE: Corrosion resistance is close to PE, resistant to acids, alkalis and partial organic solvents.

Q4: What is the continuous working temperature of common industrial plastics?

Answer: • PP: -10℃ ~ 80℃ • HDPE: -40℃ ~ 60℃ • UPVC: 0℃ ~ 45℃ • ABS: -20℃ ~ 70℃ • UPE: -80℃ ~ 65℃ Note: Long-term over-temperature use will cause aging, deformation and strength decline of plastic materials.

Q5: Are plastic sheets and pipes UV resistant? Can they be used outdoors?

Answer: • Ordinary PP, PE and UPVC: Poor UV resistance. Long-term outdoor exposure will cause yellowing, brittleness and aging. • ABS: Very poor weather resistance, easy to age and crack under sunlight. • UPE: Medium UV resistance, better than ordinary polyethylene. • Suggestion: Add anti-UV additives for outdoor use, or adopt surface coating and sunshade protection; it is recommended to use carbon black modified UV-resistant materials for long-term outdoor projects.

2. Processing & Welding Technology

Q6: Which plastic materials can be welded? Which cannot?

Answer: • Weldable materials: PP, PE, UPE. They have good hot melt fusion performance, suitable for hot plate welding, extrusion welding and butt welding. • Non-weldable materials: UPVC, ABS. UPVC is prone to brittle fracture after heating; ABS is easy to decompose and deteriorate at high temperature. Adhesive bonding is the conventional connection method. Tips: Welding temperature must be strictly controlled; excessive temperature will cause material carbonization and strength reduction.

Q7: Why do cracks appear after plastic welding? How to avoid it?

Answer: • Main Causes: Unclean welding contact surface, unreasonable temperature setting, excessive cooling speed, unqualified raw materials (recycled materials), and uneven stress during splicing. • Solutions: Use virgin materials; polish and clean the welding surface; control the welding temperature within the standard range; avoid forced rapid cooling; keep uniform stress during assembly.

3. On-site Installation & Construction

Q8: Why do plastic pipes deform and sag after installation?

Answer: • Common Reasons: Excessive pipe spacing, lack of fixed brackets, high medium temperature, overweight external load and unreasonable installation gradient. • Improvement Measures: Install fixed brackets in accordance with industrial standards; control the medium temperature below the material limit; avoid heavy pressure on the pipeline; reserve thermal expansion gaps to reduce thermal deformation.

Q9: What are the requirements for plastic pipe installation slope?

Answer: • Sewage and wastewater pipes: Slope ratio 2‰~5‰ to ensure smooth drainage and prevent sediment accumulation. • Chemical conveying pipes: Keep horizontal or slight slope, and set drain outlets at the lowest point. • Ventilation pipes: Slight upward slope to avoid condensed water backflow. Note: Excessive slope will cause local pressure concentration and pipeline wear.

4. Daily Maintenance & Troubleshooting

Q10: How to clean and maintain industrial plastic plates and pipes?

Answer: • Daily Cleaning: Use clean water or neutral detergent to wipe the surface; avoid strong corrosive detergents such as concentrated acid and concentrated alkali. • Regular Inspection: Check welding seams, joints and brackets every 3 months to find leakage, cracks and looseness in time. • Anti-aging Maintenance: Avoid long-term direct sunlight; paint anti-corrosion and anti-UV coating for outdoor equipment. • Storage: Keep plastic plates flat during storage to prevent bending deformation; avoid sharp object scratching.

Q11: What are the common failure forms of plastic products in industrial use?

Answer: • Aging & Brittleness: Caused by ultraviolet rays, high temperature and long-term service. • Deformation & Warping: Caused by over-temperature, overload and unreasonable fixing mode. • Leakage: Weld seam cracking, aging of adhesive joint and loose flange connection. • Surface Scuffing: Friction of conveying materials, suitable for UPE wear-resistant lining replacement.

5. Purchase & Customization Suggestions

Q12: What key parameters need to be confirmed before purchasing plastic plates and pipes?

Answer: • Working condition parameters: Medium composition, PH value, temperature and pressure. • Product parameters: Material type, thickness, diameter, density and raw material grade (virgin/recycled). • Environmental parameters: Indoor or outdoor use, with or without UV and weather resistance requirements. • Processing requirements: Welding forming, cutting size, surface treatment and customized accessories.

Q13: Is it necessary to choose thickened plates and pipes for industrial corrosive environments?

Answer: • For long-term corrosive working conditions, thickened materials are recommended to extend service life and reduce maintenance frequency. • For low-pressure and short-term use, conventional thickness can meet the demand to control cost. • It is forbidden to use recycled materials for chemical tanks, high-pressure pipelines and sealed containers to avoid safety leakage risks.