1. Raw Material Types and Characteristics
Bubble film production primarily uses polyethylene-based materials as the base raw material, each with unique properties:
- LDPE (Low-Density Polyethylene): Offers good flexibility, extensibility, transparency, cold resistance, and processability. However, it has poor mechanical strength, moisture/air barrier properties, and heat/light aging resistance, leading to discoloration and performance degradation under high temperatures or sunlight.
- LLDPE (Linear Low-Density Polyethylene): Features high strength, toughness, rigidity, and heat/cold resistance. Its main drawbacks are lower transparency and lack of surface gloss.
- HDPE (High-Density Polyethylene): Can also be used for bubble film extrusion, often in combination with other materials.
2. Raw Material Ratio Principles
In practice, blending ratios are commonly used to achieve optimal results:
- Standard Ratio Recommendation: LDPE 20%, LLDPE 80%.
- Additives Usage: Include auxiliary agents as needed, such as opening agent (0.2%) and antistatic agent (0.5%). Colorants should be added if colored bubble film is required.
3. Key Considerations for Material Selection
When selecting materials for bubble film machine processing, consider the following factors:
- Product Application: Heavier packaging (Z-type) requires material ratios with higher strength; general packaging (Y-type) and light packaging (Q-type) allow ratio adjustments for cost optimization.
- Protection Requirements: For anti-static functionality, incorporate an antistatic agent into the raw materials to produce anti-static bubble film, particularly suitable for packaging electronic components.
- Cost Control: While recycled plastics can be used to reduce costs where performance permits, note their potential impact on product quality.
4. Special Functional Material Treatments
For specific needs, consider these material modification methods:
- Anti-Static Bubble Film: Produced by adding an antistatic agent to LDPE and LLDPE during bubble blowing.
- Composite Bubble Film: By selecting appropriate machine types, multi-layer composite films like bubble film compounded with aluminum foil or bubble film compounded with EPE pearl cotton can be produced.
- Eco-Friendly Bubble Film: Utilize renewable or biodegradable materials to meet environmental requirements.
5. Quality Assessment Criteria
Evaluate the appropriateness of material selection through the following indicators:
- Bubble Quality: Check the number of flat/collapsed bubbles and the presence of air channeling/delamination.
- Physical Performance: Ensure compliance with industry standards (e.g., QB1259-1991) for the corresponding type of bubble film.
- Appearance: Verify the color and odor of the bubble film meet requirements.
Selecting appropriate processing materials is crucial for ensuring bubble film quality and requires comprehensive decision-making based on product use, equipment characteristics, and cost considerations.
