Film Surface Blooming in Blown Film Production

Film surface blooming refers to the appearance of streaks, spots, or hazy areas on the surface of a blown film during production of film blowing machine . This issue detracts from the film’s visual quality and overall performance. Several factors can contribute to this problem, ranging from raw material issues to environmental conditions.

1. Raw Material Issues 

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  Poor-quality raw materials for film blowing machine:

  Impurities or contaminants in the raw materials can lead to blooming.

  
  

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  Mixing different batches or grades:

  Using raw materials with varying melt flow indices can cause inconsistent film flow and surface imperfections.

  
  

Troubleshooting:

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  Use high-quality raw materials, ensuring minimal impurities and recycled content for flim blowing machine production.

  
  

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  Avoid mixing different batches or grades of raw materials to maintain consistency.

  
  

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2. Improper Extruder of film blowing machine Temperature Control

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  Uneven temperature control:

  Inconsistent temperatures in different sections of the extruder can lead to uneven melt fluidity, causing surface blooming.

  
  

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  Excessive temperature:

  Overheating can cause degradation or oxidation of raw materials, leading to surface imperfections.

  
  

Troubleshooting:

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  Optimize and monitor the temperature settings for each section of the extruder to ensure uniform temperature control.

  
  

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  Avoid extreme temperatures, especially in the die section, to prevent raw material degradation.

  
  

3. Poor Cleanliness of the Die Head of film blowing machine 

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  Carbon deposits and impurities:

  Build-up of residues on the die head can obstruct melt flow and result in an uneven, "flowery" surface on the film.

  
  

Troubleshooting:

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  Clean the die head regularly, particularly during material changes or batch shifts, to remove carbon deposits and impurities.

  
  

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  Ensure the die lip is smooth and flat; polish if necessary to maintain even film flow.  

  
  

4. Uneven Cooling of film blowing machine

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  Inconsistent air volume:

  Uneven air distribution or improper cooling temperatures can result in uneven cooling, causing surface blooming.

  
  

Troubleshooting:

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  Adjust the air volume and direction of the air ring to provide consistent cooling across the entire film.

  
  

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  Monitor and control the cooling air temperature to prevent overcooling or overheating of the film.

      

5. Improper Traction Speed of film blowing machine

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  Mismatch between traction and extrusion speeds:

  If the traction speed is not properly synchronized with the extrusion speed, uneven stretching may occur, leading to surface streaks or spots.

  
  

Troubleshooting:

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  Adjust the traction speed to match the extrusion speed, ensuring uniform film tension during the process.

  
  

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  Check the traction system for stability to avoid fluctuations or mechanical issues that could affect speed consistency.

  
  

6. Environmental Factors of film blowing machine 

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  Production environment:

  Temperature, humidity, and airflow in the production area can impact film surface quality. High humidity or low temperatures can exacerbate surface blooming.

  
  

Troubleshooting:

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  Maintain a controlled production environment with stable temperature and humidity levels.

  
  

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  Avoid direct airflow into the film production area to minimize environmental influences on film surface quality.