VIT 118 – Fabric Drape Tester

Testing Method

Fabric Drape Definition
Fabric drape refers to how a fabric forms and hangs under its own gravity. It plays an important role in the fabric’s visual appearance and aesthetic comfort. Draping represents the degree of droop and the shape of the fabric, which are key factors in determining the fabric’s visual appeal. Fabrics like Poe knit fabrics tend to have poor drape, while materials such as curtains have excellent drape properties. The fabric drape tester helps in selecting the appropriate fabrics with suitable drape characteristics.

Drape Test Principle
To test drape, a circular fabric specimen is placed on a supporting disk. A perpendicular light source is directed at the fabric, and the projection of the sample is captured. The percentage of the projected area relative to the original area is calculated using image processing methods.

Drape Index
There are three common parameters for evaluating fabric drape:

1. Drape Shape: Refers to the number and size of twists in the fabric.
2. Drape Degree: Describes the drooping extent of the fabric’s free edges.
3. Drape Coefficient (F): Refers to the ratio of the projected area to the original area of the fabric. A lower drape coefficient indicates better drape.

Sample Preparation

1. Ensure the sample is conditioned in standard atmospheric humidity.
2. Sample Diameter Selection:
   • For a clamping disc diameter of 12 cm, use samples with a 24 cm diameter.
   • For a clamping disc diameter of 18 cm, start with a 30 cm diameter sample and calculate the drape coefficient.
     • If the drape coefficient is less than 30%, use a 24 cm diameter sample.
     • If the drape coefficient is between 30% and 85%, use a 30 cm diameter sample.
     • If the drape coefficient is greater than 85%, use a 36 cm diameter sample.
3. Take at least three samples for each fabric, testing both the front and back sides.

What is Drape Testing?
The Fabric Drape Tester measures the drape coefficient of fabric, which is influenced by factors such as weight, stiffness, thickness, and rigidity. Different fabrics exhibit varying drape characteristics. The tester provides precise calculations for the drape properties, offering a consistent, reproducible way to assess fabric drape.