Why Do Meyer Rods Produce Streaks And Uneven Coating Thickness?

I. Issues with the Meyer Rod Itself  

1.1. Rod body impact damage, wire deformation, or groove defects  

1.2. Clogged wire gaps, dried residue buildup in coating  

1.3. Long-term use causes top wire wear and flattening  

1.4. Rod body bending, failing straightness requirements  

II. Coating Slurry Issues  

2.1. Excessively high slurry viscosity, poor leveling performance  

2.2. Presence of bubbles, solid particles, pigment agglomerates, or impurities in slurry  

2.3. Slurry settling, excessively high solids content or thixotropy  

2.4. Fluctuating slurry temperature leading to unstable viscosity  

III. Mechanical Equipment Factors  

3.1. Improperly installed Meyer rod (not parallel), inconsistent pressure on end rollers  

3.2. Excessive coating speed  

3.3. Equipment vibration from transmission or bearing wear  

3.4. Back roller surface with pits or damage  

3.5. Unstable feed flow rate or liquid level in the hopper  

IV. Substrate-Related Factors  

4.1. Poor substrate flatness or significant thickness variation  

4.2. Dust or electrostatically attracted contaminants on substrate surface  

4.3. Insufficient substrate dyne value, poor wetting performance  

4.4. Film warping, resulting in loose adhesion  

V. Environmental and Drying Factors  

5.1. Excessive hot air velocity at oven inlet, directly blowing onto wet film  

5.2. Sudden temperature rise in initial drying section, causing rapid solvent evaporation  

5.3. Severe fluctuations in workshop temperature and humidity

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