Identifying fibres – burning test in Synthetic Fibres and Plastics – Class 8 Science Experiment

Chapter Name: Synthetic Fibres and Plastics

Activity Name: Identifying fibres – burning test in Synthetic Fibres and Plastics

Activity Description:

The experiment involves performing a burning test on various yarns to identify different types of fibres, including natural and synthetic ones.

Required Items:

1. Various yarn samples (wool, silk, cotton, rayon, nylon, acrylic, etc.)
2. Tweezers
3. Flame source (e.g., a candle or lighter)

Step by Step Procedure:

1. Unravel several warp and weft yarns from different fabrics.
2. Using tweezers, hold each yarn sample to the edge of the flame one by one.
3. Observe and note down the changes that occur during burning.
4. Pay attention to the smell, appearance, and behavior of the yarn while it burns.

Experiment Observations:

1. Yarn smelling like burning hair indicates wool or silk.
2. Yarn smelling like burning paper suggests cotton or rayon.
3. Yarn that melts in the flame indicates a synthetic fibre like nylon or acrylic.

Precautions:

1. Perform the burning test in a well-ventilated area or under a fume hood to avoid inhaling fumes.
2. Use tweezers to hold the yarn and keep a safe distance from the flame to prevent burns.
3. Have a fire extinguisher or water source nearby to deal with any accidental fires.
4. Handle the burning materials with care to avoid any mishaps.

Lesson Learnt from Experiment:

Through this experiment, students will learn how to distinguish between different types of fibres based on their burning characteristics. They will understand that natural fibres like wool and silk have distinct smells while burning, and synthetic fibres like nylon and acrylic melt when exposed to a flame.

This knowledge will help them identify the type of fibre used in various textiles and understand the properties of different fibres better.