Blogs Collection

Burn Marks - Problem Solving Guide

Use the following as a checklist for potential solutions:

• Check mold venting
• Remove “fines” from material
• Reduce back pressure
• Reduce injection velocity
• Reduce screw speed (RPM)

Weld Lines - injection Molding – Problem Solving Guide

Use the following as a checklist for potential solutions:

• Increase mold temperature
• Check vents (increase?)
• Runners and/or gates too small
• Sprue or nozzle opening too small
• Increase material temperature
• Increase injection speed
• Check melt for inconsistencies

Flash - Injection Molding - Problem solving Guide

Use the following as a checklist for potential solutions:

• Reduce injection velocity
• Clean parting lines
• Reface parting lines
• Mold faces are not parallel
• Land too large (no shut off)
• Reduce material temperature
• Reduce mold temperature
• Reduce material pressure (pack and/or hold)
• Reduce packing time
• Increase clamp pressure (check for consistency)

Sink mark – Injection Molding – Problem Solving Guide

Use the following as a checklist for potential solutions:

• Increase gate size
• Reduce material temperature
• Texture mold surface (hidden)
• Reduce flow lengths (add gates)
• Increase runner size
• Increase injection pressure
• Check for a “cushion”, increase shot size
• Increase injection/pack time
• Increase injection velocity

Short Shot – Injection Molding – Problem Solving Guide

Use the following as a checklist for potential solutions:

• Increase mold temperature
• Increase injection velocity
• Runner too small
• Inadequate cold slug well
• Gate too small (note enough)
• Inadequate venting
• Hesitation (non – uniform walls, etc.)
• Not enough plastication capacity
• Insufficient feed
• Material temperatures too low
• Increase injection/packing pressure
• Increase packing time
• Increase back pressure

Flow lines – Injection Molding – Problem Solving Guide

Use the following as a checklist for potential solutions:

• Increase gate size
• Increase clamp pressure
• Increase melt temperature
• Increase mold temperature
• Maintain a more consistent cycle