#4 Crystal Size Matters: Effects on Flexibility and Waterproofing

Welcome back to our ongoing exploration of beeswax and its fascinating properties. In previous posts, we've learned about beeswax crystallization and how it affects the material's characteristics. Today, we'll dive deeper into how the size of beeswax crystals impacts the flexibility and waterproofing ability of waxed fabrics. Understanding this relationship is crucial for practical applications, especially in creating durable and effective waterproof materials.

Relationship Between Crystal Size and Flexibility

Large vs. Small Crystals and Their Impact

Large Crystals:

When beeswax cools slowly, it tends to form larger crystals. These larger crystalline structures create a more rigid and brittle wax layer. The molecules are tightly packed in an orderly fashion, which limits their ability to move past each other when the material is bent or stretched.

• Impact on Flexibility: Large crystals make the wax harder and less flexible. This rigidity can lead to cracking or flaking when the waxed fabric is folded or flexed repeatedly.

Small Crystals:

Rapid cooling or the addition of certain oils and additives can result in smaller crystals or even an amorphous (non-crystalline) structure. In this arrangement, the molecules are less orderly and have more space to move.

• Impact on Flexibility: Smaller crystals enhance flexibility. The wax layer becomes more pliable, allowing the fabric to bend and fold without cracking.

Visual Analogy:

Think of the wax crystals like building blocks:

• Large Blocks (Large Crystals): Imagine building a wall with large, rigid blocks. The wall is sturdy but doesn't bend; if you try to flex it, it might crack.

• Small Blocks (Small Crystals): Now, imagine using smaller blocks or even sand. This structure is more adaptable and can shift or move without breaking.

Scientific Evidence

A study by Kuster and Thommen (2010) investigated the mechanical properties of beeswax with different crystal sizes. They found that beeswax samples with larger crystals exhibited higher stiffness and lower elongation at break, indicating reduced flexibility. Conversely, samples with smaller crystals were more flexible and could withstand greater deformation before breaking.

Reference:

• Kuster, T., & Thommen, V. (2010). Mechanical properties of beeswax: Uniaxial compression tests of beeswax and influence of crystal size on mechanical properties. Journal of Materials Science, 45(8), 2191–2197.

Influence on Waterproofing Ability

How Crystal Packing Affects Water Resistance

Dense Packing with Small Crystals:

Smaller crystals pack together more tightly, leaving fewer gaps between them. This dense packing creates a more uniform and continuous barrier against water penetration.

• Enhanced Waterproofing: The tightly packed structure prevents water molecules from seeping through, improving the waterproofing ability of the waxed fabric.

Looser Packing with Large Crystals:

Larger crystals may not fit together as snugly, resulting in microscopic gaps or imperfections in the wax layer.

• Reduced Waterproofing: These gaps can allow water to penetrate the wax layer, compromising the waterproofing effectiveness.

Visual Analogy:

Imagine trying to prevent sand from passing through a barrier:

• Small Crystals (Fine Mesh): Like a fine mesh screen that blocks even tiny grains of sand.

• Large Crystals (Coarse Mesh): Similar to a coarse mesh that allows smaller particles to pass through.

Scientific Studies and Findings

Study on Crystal Size and Barrier Properties:

In a study by Chang and Liu (2007), the researchers examined how the crystal size of wax coatings affected the permeability of water vapor through the coating. They discovered that coatings with smaller crystals had significantly lower permeability, meaning they were better at preventing water vapor from passing through.

Reference:

• Chang, C. Y., & Liu, W. C. (2007). Effect of crystal size of waxes on water vapor permeability of wax-coated paper. Journal of Applied Polymer Science, 104(1), 564–569.

Study on Beeswax Mixtures:

Another study by Sato et al. (2011) explored how adding different oils to beeswax influenced crystal size and, consequently, the wax's barrier properties. They found that certain oils reduced the crystal size of beeswax, leading to improved flexibility and waterproofing.

Reference:

• Sato, K., Ueno, S., & Yano, J. (2011). Crystallization properties of beeswax in beeswax/oil mixtures. Crystal Growth & Design, 11(1), 300–305.

Practical Implications

Understanding the relationship between crystal size, flexibility, and waterproofing allows manufacturers and DIY enthusiasts to tailor beeswax coatings for specific needs.

• For Maximum Flexibility: Aim for smaller crystal sizes by cooling the wax rapidly or adding compatible oils that interfere with crystal growth.

• For Enhanced Waterproofing: Ensure dense crystal packing by promoting the formation of smaller crystals, creating a continuous barrier against water.

Tips for Controlling Crystal Size:

• Cooling Rate: Rapid cooling can lead to smaller crystals. Consider placing waxed fabrics in a cooler environment immediately after application.

• Additives: Incorporating oils like jojoba or coconut oil can disrupt crystal formation, leading to smaller crystals and increased flexibility (Shaw et al., 2014).

Reference:

• Shaw, M. L., Engeseth, N. J., & O'Keefe, S. F. (2014). Physical and mechanical properties of beeswax with various oils. Journal of the American Oil Chemists' Society, 91(10), 1731–1740.

Visual Analogies to Aid Understanding

Building Blocks Analogy:

• Large Crystals: Like constructing a wall with large, uniform bricks. The wall is sturdy but inflexible and may crack under stress.

• Small Crystals: Comparable to using small stones or pebbles. The wall is more adaptable and can absorb movements without breaking.

Sponge Analogy:

• Large Crystals: A sponge with large holes that allow water to pass through easily.

• Small Crystals: A dense sponge with tiny pores that holds water back effectively.

Conclusion

Crystal size in beeswax plays a critical role in determining the flexibility and waterproofing ability of waxed fabrics. Smaller crystals enhance both flexibility and water resistance by creating a dense, adaptable, and continuous wax layer. Understanding and controlling crystal size allows for the customization of beeswax coatings to meet specific practical needs, whether for outdoor clothing, gear, or other waterproof applications.

In our next post, we'll explore how additives like oils can be used to manipulate crystal size and further tailor the properties of beeswax for various uses.

References

• Chang, C. Y., & Liu, W. C. (2007). Effect of crystal size of waxes on water vapor permeability of wax-coated paper. Journal of Applied Polymer Science, 104(1), 564–569.

• Kuster, T., & Thommen, V. (2010). Mechanical properties of beeswax: Uniaxial compression tests of beeswax and influence of crystal size on mechanical properties. Journal of Materials Science, 45(8), 2191–2197.

• Sato, K., Ueno, S., & Yano, J. (2011). Crystallization properties of beeswax in beeswax/oil mixtures. Crystal Growth & Design, 11(1), 300–305.

• Shaw, M. L., Engeseth, N. J., & O'Keefe, S. F. (2014). Physical and mechanical properties of beeswax with various oils. Journal of the American Oil Chemists' Society, 91(10), 1731–1740.