Down Cleanliness
Down cleanliness is a quality indicator that evaluates the amount of dust, oils, and organic matter remaining in down and feathers using measures such as transmittance and oxygen number.
Contents6 sections
Definition and Evaluation Methods
Down cleanliness is an indicator used to check how little dirt and washing residue remain in down after washing and drying. It does not directly indicate thermal insulation, but it is a quality control item related to the hygiene, odor, and comfort of down products.
Typical evaluations include transmittance and oxygen number. Transmittance is an evaluation of how clear the liquid extracted from the down is; in general, the higher the value, the cleaner it is considered. Oxygen number is an evaluation of the amount of easily oxidized organic matter in the extract, and in general, the lower the value, the cleaner it is considered.
Applicable Parts and Role
Cleanliness is applied to down and feathers used as filling in down jackets, coats, bedding, and other products. It is not a trim used in a specific part of the product, but an item for checking the quality of the down raw material itself that is filled into the product.
Using clean down helps suppress unpleasant odors caused by residual matter and maintain comfort during wear. However, odor perception varies by person, and product odor cannot be judged only by cleanliness.
Materials and Types
The down involved is waterfowl down and feathers. Down is insulating plumage with barbs spreading outward, while feathers have a shaft. Depending on the type of raw material, blend ratio, and washing process, the management method and evaluation values for cleanliness differ.
Cleanliness is a separate evaluation from down content and fill power. Down content indicates the proportion of down in the filling material, and fill power indicates the loft of the down. Even if these are high, cleanliness may not be sufficient, so they are checked separately according to the application.
How to Choose and Points to Confirm
When planning or procuring down products, confirm cleanliness together with down content, fill power, fill weight, and the downproof performance of the shell fabric. Even when lightweightness and insulation are prioritized, it is important to clearly specify the raw material test details, including cleanliness, in the specification sheet.
Because transmittance and oxygen number are based on different measurement principles, do not judge overall cleanliness from only one value. Also, since test methods and acceptance criteria may differ by trading partner, sales region, and product application, match the adopted standard and the conditions on the test report in advance.
- Check the down content and fill power of the filled down as separate items.
- Require the shell fabric to have downproof performance to prevent down leakage.
- Confirm whether the results are from the same lot, including the sampling method.
- Also confirm performance and odor after washing or cleaning in product testing.
Differences from Similar Terms
Transmittance is one of the test items used to evaluate cleanliness, and it is not synonymous with down cleanliness itself. A good transmittance result indicates that the extracted liquid has little turbidity.
Oxygen number is also a test item related to cleanliness, but it is an indicator for checking the state of organic matter contained in the extract. Fill power indicates loft, and down content indicates the blend ratio, so they evaluate different aspects from cleanliness.
Frequently Asked Questions
If down cleanliness is high, does that mean thermal insulation is also high?
Cleanliness is an indicator of how little dirt and organic matter remain in the down, and it does not directly indicate thermal insulation. Thermal insulation is mainly affected by fill weight, down content, fill power, and the product structure. Cleanliness is checked separately as a quality factor for comfort and hygiene.
Which should be checked first, transmittance or oxygen number?
Since the two measure different things, they should generally be checked together. Transmittance relates to the clarity of the extracted liquid, while oxygen number relates to the state of residual organic matter. It is important to align the test method and acceptance criteria according to the application, sales region, and specifications with the trading partner.
