Moisture presents many issues for a door manufacturer and having a thorough understanding of what moisture can do to a door during and after the manufacturing process is essential. There are three factors concerning moisture that we must be aware of during the manufacturing process: dry air during the winter time, variations of moisture content of raw materials and the challenge of controlling the amount of moisture added during the manufacturing processes. All of these factors can test our abilities because wood expands and contracts as it gains and loses moisture and door components all do this at varying rates.
What happens when moisture is not controlled properly?
- Dry air causes the face of the top door in a stack to dry more quickly and contract more compared to the bottom face. The door will then cup upwards as it sits.
- Dry air causes veneer to curl up before it gets into the press. It will also be more likely to have open joints and splits.
- Excessive moisture can also be a problem as it is introduced into wood materials during the veneer slicing process and when pressed with steam injected particle board presses. This can cause veneer faces to shrink and then lead to warp, splits and open joints.
- Various core constructions will shrink at different rates and core that has high moisture content will continue to shrink after the stiles and rails have been applied.
What does Eggers do to control moisture during the manufacturing process?
- Both of our facilities have humidity control systems that keep the relative humidity between 38 and 42 percent during the winter months. This helps to prevent warping throughout the manufacturing process.
- Our purchasing, engineering and manufacturing teams are currently working with suppliers to establish tighter controls on incoming materials. Continuous improvements are also being made to our existing procedures to lessen these concerns.
- All loads are properly covered, especially on weekends.
What can you do after you receive our doors to maintain the high quality product you purchased?
- Monitor the environment in which the doors will be stored and hung. Doors should not be subjected to extreme heat and/or humidity.
- Relative humidity should not be less 25% or greater than 55%.
- Temperatures should not be less than 50 degrees F or greater than 90 degrees F.