Designing for Movement: How Linear Thermal Expansion Impacts Signage Performance

From the plant floor to final installation, signage components experience a wide range of environmental conditions. Designing for linear thermal expansion allows us to proactively manage those variables, ensuring consistent quality, structural integrity, and visual performance no matter where a program is produced or installed. 

There are four main points to consider while using this equation. 

1. Initial length - This is the length of the part when it is cut on the machinery. 

2. Change in temperature is the difference between the temperature when the part is cut and the temperature at either the high or low extreme.  

3. While designing part lengths for repeat order programs it is important to consider that the initial part length must be determined by considering when the part is cut. A plant could be 90 or 100 degrees in the summer or as low as 40 degrees or even colder in some plants during the winter. 

4. Regional weather history is also very relevant. The extreme temperatures to use in the change of temperature variable could be vastly different.  As an example, the maximum low temperature in a northern state could be near or below zero while the maximum high temperature might be around 90 degrees. Contrast that to extreme southern latitudes where you might have the maximum low nearer to 20 and the maximum high as much as 120. 

The practice used at Principle considers all the above factors. Two specific conditions are used to determine initial part length based on both the summer and winter plant temperatures and the change in temperature is determined on where a program is likely to be installed. Using the calculated worst-case expansion or contraction we can determine the proper clearances in the metal framing to allow for all thermal movements of the plastic components without causing light leaks or buckling.