Parameter Standards for TPU Paint Protection Film (PPF) Products and Production Process Control

Common Testing Items and Parameter Standards for TPU Paint Protection Film (PPF) Products, and How to Ensure These Items Pass During Production

Introduction

TPU Paint Protection Film (PPF) is a high-performance transparent film applied to automotive paint surfaces to protect against stone chips, scratches, acid rain, UV rays, and other damage. A stringent set of quality testing standards and a corresponding production process control system are essential to ensure its exceptional performance and lasting protective capabilities.

1. Common Testing Items and Parameter Standard Requirements

The table below summarizes the core testing items and typical parameter standards that high-end PPF products should meet.

Key Parameter Interpretation:

• Haze ≤ 1.5%: Ensures the film hardly affects the original clarity and visual effect of the paint after application.
• Yellowness Index ≤ 1.5: Ensures the film itself is not yellowish and has excellent anti-yellowing capability under long-term UV exposure.
• Fogging Value ≥ 90%: This is a safety red line, preventing the film from volatilizing substances onto the windshield under high temperatures, which could affect driving safety.
• Self-Healing Performance: A core selling point of PPF products, reliant on its special top coat.

2. How to Ensure Test Items Pass During Production

Product quality is built into the manufacturing process, not just inspected at the end. Controlling each stage of production is essential to ensure the above test items pass.

1. Raw Material Control (Source Control)

• TPU Pellet Selection:
  • Must use Aliphatic TPU, which inherently possesses excellent UV resistance and anti-yellowing properties. This is the foundation for passing Yellowness Index and Weathering Resistance tests.
  • Select TPU grades with low volatile content and high molecular weight. This is key to passing Fogging Value and VOC tests.
  • Suppliers must provide a CoA (Certificate of Analysis) for each batch, with regular third-party authoritative testing.
• Coating and Adhesive Materials:
  • Formulas for self-healing coatings and anti-stain coatings must undergo strict aging and performance tests.
  • Pressure Sensitive Adhesives (PSA) must possess high initial tack, high holding power, aging resistance, and clean removability to ensure perfect removal after long-term use.

2. Production Process Control (Process Stability)

• Co-extrusion Casting/Film Blowing Process:
  • Strictly control processing temperature, screw speed, and cooling rate. Excessively high temperatures can cause TPU degradation, leading to yellowing and volatiles (affecting YI and Fogging Value); uneven temperatures cause variations in film thickness and optical properties.
  • The production environment must be a high-cleanliness cleanroom. Any dust can cause surface defects, affecting appearance and coating adhesion.
• Coating Process:
  • Precisely control the coater’s tension, speed, and oven temperature to ensure uniform coating and complete curing. Incomplete curing leads to reduced coating performance and residual volatiles.
• Curing Process:
  • The finished film requires curing for a specified time in a constant temperature and humidity environment. This allows molecular chains and internal stresses to fully relax, stabilizing the adhesive’s performance.

3. Online and Offline Quality Inspection (Real-time Monitoring)

• Online Inspection:
  • Use online thickness gauges to monitor film thickness uniformity in real-time.
  • Use online defect detection systems (CCD cameras) to capture surface defects like gels, scratches, and bubbles in real-time.
• Offline Inspection:
  • Full Laboratory Testing: Sample each production batch and perform comprehensive testing according to the above items, generating a complete batch inspection report.
  • First-Article Inspection & Patrol Inspection: The first roll produced at the start of each shift must undergo key item checks (e.g., thickness, appearance, basic optical properties) before mass production can proceed. Quality inspectors must conduct regular patrol inspections by sampling during production.

4. Environment and Storage

• All raw materials and finished products should be stored in a constant temperature and humidity warehouse to avoid moisture absorption (TPU is hygroscopic) and high temperatures.
• Finished film rolls should be vacuum-packed using aluminum foil bags or anti-static film to prevent contamination and oxidation.

Conclusion

Yantai Linghua New Material Company is making A high-performance, highly reliable TPU paint protection film , it is the result of the combination of advanced raw materials, precision manufacturing processes, and strict quality control.

• Parameter Standards are the product’s “report card,” defining its market position and customer value.
• Production Process Control is the “methodology” and “lifeline” that ensures this “report card” remains consistently excellent.

By establishing a full-process quality assurance system from “raw material intake” to “finished product shipment,” supported by advanced testing equipment and technology,  Yantai Linghua New Material Company  can stably produce PPF products that meet or even exceed market expectations, standing invincible in the fierce market competition.