**Processing Technology of Film-Grade Double-Layer EVA low melt point Bags:** - Film Blowing - Film Printing - Bag Making - Finished Product Inspection
**Performance of Film-Grade Double-Layer EVA Valve Bags:**
- Ultra-Soft Type
- High Elongation at Break
- High Weather Resistance
- High Adhesion
- High Compatibility
- Double-layer design, offering enhanced flexibility (compared to single-layer)
**Softening Effect of EVA Flexible Film Bags:**
With a relatively low melting point, EVA retains some flexibility even at 60°C, reducing the overall rigidity of hot-melt coatings.
**Reduction in Compressive Strength:**
Traditional hot-melt coatings (petroleum resin + fillers) exhibit high hardness at 60°C (≥2 MPa). However, after adding 2.5 kg of double-layer film bags, the plasticizing effect of the flexible film may lower the compressive strength of the hot-melt coating to approximately **1.5–1.8 MPa** during on-site application. *(This does not affect the field sampling inspection of hot-melt marking coatings.)
**Toughening Effect of Flexible Film Bags**
**Enhanced Stress Dispersion Capacity:**
The high elongation rate of double-layer flexible film bags enables them to absorb stress caused by road contraction or traffic vibration, thereby reducing crack propagation.
**Improved Low-Temperature Crack Resistance:**
Even at temperatures below -20°C, the double-layer flexible film bags retain their flexibility, minimizing the risk of brittle cracking.
**Practical Performance**
**Reduced Cracking Rate in New Hot-Melt Markings:**
Compared to pure petroleum resin systems, the probability of cracking decreases by **30%-50%**.
**Fewer Microcracks:**
The marking surface becomes smoother, reducing peeling issues caused by crack formation.
