What is Fill Power?

What is Fill Power?

According to American standards, Fill Power refers to the value that represents the volume in cubic inches occupied by one ounce (28.34 grams) of down under specific conditions. For example, if one ounce of down occupies a space of 500 cubic inches, it is referred to as having a Fill Power of 500.

Fill Power is one of the most important indicators of down quality, reflecting warmth, elasticity, and comfort in down products. Under the same fill weight, higher Fill Power results in a thicker layer of still air that can be trapped by down products. Air is a poor conductor of heat, and a stationary layer of air does not allow heat loss through convection. Therefore, there is a linear relationship between Fill Power and the warmth of down products.

However, Fill Power is not only about volume (Fill), but also about resilience (Power). When down products are compressed and then released, good Fill Power indicates rapid recovery to their original state. The main contributor to Fill Power is down, while feathers and other impurities have minimal impact.

In general, higher down content leads to higher Fill Power, better down quality results in higher Fill Power, and less damage to down contributes to higher Fill Power. Therefore, Fill Power can measure the quality of down.

A Brief History of Fill Power

The history of down as an insulation material dates back to 1892, but the concept of Fill Power did not exist at that time. As more down products appeared in the market and comparisons between products became more common, the term "LOFT" (thickness) was often used to describe down products. Higher LOFT indicated greater warmth.

Reaching Fill Powers of 650 or even 700 was considered a milestone because it marked the maturity of the Fill Power concept. By the 1980s, the term Fill Power gained popularity, although its usage was not completely standardized. However, it was widely recognized that a Fill Power of 700 indicated extremely high-quality down.

Factors Affecting Fill Power

The increase in Fill Power over the years has been relatively slow. It reached 725 in the 1990s and remained around 800 by the year 2000. However, today's Fill Powers of 900 have emerged rapidly in a short period. The source of down has not changed significantly over the years, and there have been no major breakthroughs in bird breeding for down quality. So, why has Fill Power suddenly advanced so quickly?

The length of time geese and ducks are raised affects the size of their down clusters, leading to higher Fill Power. However, two additional factors are essential for further increasing Fill Power:

  1. Advancements in down processing techniques: Down needs to undergo processes such as sorting, washing, and drying before being used in pillows and duvets. These processes are crucial for enhancing Fill Power.
  1. Changes in Fill Power standards: More precise categorization of down and feathers has allowed for greater potential improvements in Fill Power.

Why Is Peterhanun's Down So High in Fill Power?

Our down is sourced from premium production areas worldwide:

Currently, the recognized premium origins for down include the 24° North Latitude World Gold Down Belt and the 45° North Latitude World Golden Down Belt. These regions provide ideal breeding conditions, resulting in large and dense down clusters with strong insulation properties.

Unique processing techniques:

Every down cluster goes through 11 processing steps, including raw material preparation, dust removal, initial washing, thorough washing, dehydration, high-temperature sterilization (at 120°C), cooling, further dust removal, sorting, iron removal, stacking, and inspection. Only when down meets the quality standards can it be used to fill pillows and comforters.

Hand selection:

Our workers carefully select down clusters with a diameter exceeding 4.1 cm from the raw materials while removing small impurities such as feathers and fine fibers, ensuring that genuine down constitutes over 95%. Despite being time-consuming and labor-intensive, this is the secret to achieving high Fill Power.

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