Corrugation Factor

The Corrugation Factor calculator computes the ratio to use on computations to account for corrugated material.

INSTRUCTIONS:  Choose units and enter the following:

• (W) Width
• (SL) String Length

Corrugation Factor (CF): The calculator returns ratio as a real number (no units).

The Math / Science

Surface area can be a simple length times width calculation, but what if one of the dimensions is not smooth?  This is found in corrugated material.  To account for this, this calculator has a corrugation factor that is applied to the length and width dimensions to account for corrugation. 

Corrugation refers to the process of shaping a material into a series of parallel ridges and grooves. This is commonly seen in corrugated materials, such as cardboard or metal sheets. The purpose of corrugation is often to add strength and rigidity to the material while maintaining flexibility. In the case of corrugated cardboard, for example, the corrugated structure provides strength and helps the material withstand pressure and impacts. Corrugated metal sheets are used in roofing and packaging for similar reasons.

To calculate the Corrugation Factor, do the following:

1. Measure the Linear Width which is (W) in the diagram above, for any length of the corrugation.
2. Use a string, and lay it on top of the same length, letting is fall into all the recesses as much as possible.
3. Mark the end of the string to match the end of the Width.
4. Pull the string straight (taunt) and measure how much longer it is than the Width.

The formula for the Corrugation Factor is:

CF = SL / W

where:

• CF = Corrugation Factor
• SL = String Length
• W = Linear Width

Squared Corrugation

In the following example, the String Length is the sum of the segments.

SL = (A + B + C + D) + (A + B + C + D) + (A + B + C + D) + (A + B + C + D)

or 

SL = 4 * (A + B + C + D)

This is important in computing the surface area of a corrugated surface.

Curved Corrugation

A simple, but effective method to compute the String Length is to lay a string over a section of the corrugated material.

The profile of a curved corrugated surface is shown below.  The dotted lines represent a string laid over the width of the material.  When the string is pulled taunt, it can be measured as the String Length in this equation.

Shout Out

Special thanks to Travis Barnett from Wyoming Insulation and his math teacher cousin Brad for the inspiration for this calculator.