Common Issues in Blow Molding

Expertise Built on Experience ，Dih Hong Plastic Helps You Solve Blow Molding Problems

1. Uneven Wall Thickness

▼ Possible Causes

• Inconsistent heating of the parison
• Poor mold cooling design
• Improper air pressure or blowing time settings

 

▼ Solutions

• Optimize mold cooling channel design
• Adjust parison heating temperature and preheating time
• Use Dih Hong high-precision blow molds to enhance wall thickness stability

 

2. Sink Marks or Dents

▼Possible Causes

• Uneven cooling or insufficient cooling time
• Insufficient blowing pressure
• High material shrinkage rate

 

▼ Solutions

• Extend cooling time
• Improve blowing pressure settings
• Dih Hong optimizes mold and blowing programs based on material properties

 

3. Surface Defects (Bubbles, Wrinkles, Silver Streaks)

▼ Possible Causes

• Moisture in raw materials
• Premature blowing or rough mold surface
• Poor material mixing

 

▼ Solutions

• Dry raw materials before molding
• Improve mold surface polishing
• Use recommended raw material grades and processing parameters from Dih Hon

 

4. Product Burst or Cracks

▼ Possible Causes

• Excessive blowing pressure or overheating of parison
• Insufficient mold clamping force or poor demolding design

 

▼ Solutions

• Adjust blowing pressure and temperature control
• Dih Hong mold design emphasizes demolding angles and stress distribution to effectively prevent cracking

 

5. Dimensional Instability

▼ Possible Causes

• Excessive material shrinkage
• Insufficient mold precision
• Inconsistent molding conditions

 

▼ Solutions

• Stabilize machine parameter settings
• Dih Hong provides high-precision mold manufacturing and mold flow analysis support to ensure product consistenc

 

Dih Hong Plastic，Your Professional Blow Molding Solutions Provider

From blow mold design and equipment parameter adjustments to product inspection recommendations, Dih Hong Plastic delivers one-stop hollow blow molding solutions that effectively resolve process issues, improve product quality, and enhance production yield.