Cotton Baling Film Acid-Alkali Resistance Test Procedures

• 1. Sample Preparation

  Key Steps:

  • Cut 10cm × 10cm uniform samples from film
  • Ensure samples are defect-free and clearly labeled
  • Prepare at least 3 replicates for statistical validity

• 2. Solution Preparation

  Acid Solutions:

  Simulate agricultural/industrial exposure:

  • Hydrochloric acid (HCl): 5–10% concentration
  • Sulfuric acid (H₂SO₄): pH 1–2

  Alkali Solutions:

  Reflect alkaline environments:

  • Sodium hydroxide (NaOH): 5–10% concentration
  • Potassium hydroxide (KOH): pH 12–13

• 3. Immersion Test

  Standard Conditions:

  • Room temperature: 23±2°C
  • Exposure durations: 24h, 7 days, 30 days

  Accelerated Testing:

  • Temperature: 50–60°C for long-term simulation
  • Gentle stirring to ensure uniform contact

  Avoid mechanical damage to samples during testing

• 4. Physical Property Evaluation

  • Tensile Strength & Elongation: Use universal testing machine; >10% loss indicates poor resistance
  • Thickness & Weight: Measure with micrometer/balance; swelling/dissolution signals degradation
  • Visual Inspection: Check for discoloration, brittleness, cracks under magnification

• 5. Optional Chemical Analysis

  • FTIR Spectroscopy: Compare spectra for polymer chain degradation
  • pH Measurement: Test solution post-immersion for leaching/reaction

• 6. Control Group Comparison

  Include unexposed samples to isolate acid/alkali effects from variables

• 7. Industry Standards

  Refer to:

  • ASTM D543 (Plastics Chemical Resistance)
  • ISO 175 (Effects of Liquids on Plastics)

  
  

  Pass criteria: Retain ≥90% tensile properties and no visible damage

• 8. Practical Application Considerations

  • Agricultural use: Test with ammonium nitrate (pH 4–5) or lime
  • Industrial storage: Simulate cleaning chemicals/byproducts