Troubleshooting Hot Press Laminating

The following information is a summary of potential issues and recommendations. Check out our complete Lamination Gluing Guide for additional recommendations!

Issue: Spotty bonds
Possible Causes:

• ‍Low spread | Recommendation: Increase adhesive spread
• ‍Uneven core thickness |Recommendation: Calibrate cores to uniform thickness
• ‍Low pressure | Recommendation: Increase pressure
• ‍Cold spots in platen | Recommendation: Check temperature with surface thermometer

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Issue: Glue bleeds through face veneers
Possible Causes:

• ‍Excessive spread | Recommendation: Reduce adhesive spread
• ‍Excessive pressure | Recommendation: Reduce pressure
• ‍Wrong adhesive type | Recommendation: Please contact technical support

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Issue: Steam blisters
Possible Causes:

• ‍Excessive spread | Recommendation: Reduce adhesive spread
• ‍High moisture content | Recommendation: 6%-8% moisture content recommended
• ‍High press temperature | Recommendation: Reduce temperature

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Issue: Warpage of panels
Possible Causes:

• ‍Excessive spread | Recommendation: Reduce adhesive spread
• ‍Unequal spread | Recommendation: Make sure that top and bottom spread are equal
• ‍High moisture content | Recommendation: 6%-8% moisture content recommended
• ‍Unbalanced construction | Recommendation: Check grain orientation
• ‍High press temperature | Recommendation: Reduce platen temperature

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Issue: Checking of Veneer
Possible Causes:

• ‍Moisture content of the veneer and substrate are not equal | Recommendation: Select well-manufactured, tight-cut veneer, keep face veneer within 6% at time of pressing; core components and cross band materials should be held at about the same moisture content as the face veneer; keep assembly time to a minimum.