Why Do Crayons Melt?

Crayons may seem simple and fun, but there's a fascinating science behind why they melt. Understanding this phenomenon not only enlightens us about the materials they are made of but also touches upon their potential uses beyond coloring and drawing.

The Science Behind Crayon Melting

The pigments in crayons are what give them their vibrant colors. However, the nature of these pigments and the materials used to bind them together have a significant impact on how quickly a crayon melts. This is particularly evident in the different melting rates of various colors:

Black Crayons: Melting quickly due to their dark pigments. Darker colors absorb more heat, causing them to melt faster. This is why black crayons are often the first to melt when exposed to heat.

Yellow Crayons: Resist melting for a longer time as they contain light pigments. Light colors reflect more heat and absorb less, leading to a slower melting process.

This principle of heat absorption and reflection is why darker colors tend to melt faster and lighter colors tend to melt slower. It's a fundamental concept in both art and science.

The Composition of Crayons

Crayons are primarily made of petroleum wax, which melts at relatively low temperatures. This is an interesting dual-purpose property of crayons that might surprise many. Since crayon wax is similar to substances like paraffin and polyethylene, it shares many of the same characteristics in terms of melting points and properties.

Paraffin Wax: A component of most crayons, paraffin is a hydrocarbon obtained from petroleum. It is often used in candles and other wax products due to its low melting point. This characteristic makes it an excellent choice for crayons, as it allows the wax to remain solid and manageable at room temperature but melt quickly when heated.

Similiarty to Polyethylene: Polyethylene is a form of plastic made from the polymerization of ethylene. While it is synthesized from petroleum, it shares a similar melting point range with paraffin. This shared property is why crayons can be used as emergency candles in certain situations.

Crayons as Emergency Candles

In an emergency, where electrical lighting is unavailable, crayons can serve as natural candles using their waxy properties. While it sounds unconventional, the melting point of crayon wax is surprisingly close to the boiling point of water (100°C or 212°F).

This property allows crayons to be used for heating water or illuminating a small area. However, it is crucial to remember that melting crayons to make candles can produce toxic gases. Crayons are not designed for this purpose and do not produce clean, safe flames like traditional candles.

Using crayons in this manner involves significant risks, including smoke and fumes that contain harmful chemicals. It is essential to use them cautiously and only in emergencies when no other source of light is available.

Conclusion

In conclusion, understanding why crayons melt is a window into the fascinating world of materials science. From the pigments that determine the melting rates to the wax composition that makes them suitable for both art and emergency lighting, crayons offer a unique blend of functionality and fun.

Remember, while crayons can be repurposed as emergency candles, doing so carries risks. Ensure safety by following proper guidelines and using them only in emergencies.