Standard Detergent for
By Diana A. Wyman
Although the latest revision of several AATCC laundering test methods and procedures defines standard laundering conditions for traditional top-loading machines, many labs also have high-efficiency (HE) washing machines. AATCC offers a standard detergent specifically formulated for use in HE washers.
Order AATCC HE Detergent
One of the most visible features of high-efficiency detergents is that they produce less foam or bubbles than traditional detergents. Excess foam interferes with cleaning and, especially, rinsing. Residue build-up in test specimens, ballast, and even the washing machine can lead to inconsistent test results and damage to the washer.
The AATCC HE detergent formula was recently adjusted to produce even less foam, although all active ingredients and performance remain the same. As a standard detergent, the target is to match the performance of mid-tier consumer detergents. Because textile testing typically involves little or no soil and a very small load size, the 50-mL dose of AATCC HE detergent produces even less foam than comparable consumer detergents. It is still important to ensure specimens are thoroughly rinsed before testing.
While traditional detergents should never be used in HE washers, HE detergents can be used in traditional washers. AATCC Laboratory Procedure (LP) 1-2018, Home Laundering: Machine Washing, includes instructions for use of both traditional powder detergent and HE liquid detergent in the Alternate Laundering Procedure for traditional top-loading washing machines. The test report should clearly indicate which detergent was used.
An interesting side note is that the same amount of HE detergent will actually produce more foam in an HE washer than in a traditional washer.
AATCC HE detergent contains no optical brighteners. For colorfastness testing, the optical brighteners present in most consumer detergents can interfere with specimen evaluation. Optical brighteners, also referred to as fluorescent whitening agents (FWAs), absorb light in the ultraviolet (invisible) region of the electromagnetic spectrum, and re-emit it in the blue (visible) region. A white surface treated with an optical brightener emits more visible light than shines on it, making it appear brighter. The blue light emitted by the brightener effectively neutralizes pale yellow or cream colors to make the substrate appear cleaner, or more “white.”
AATCC standard reference detergents without optical brightener (WOB) let you assess color change due to the test procedure, without the added influence of brighteners. This makes it easier to determine whether a particular dye or process is suitable for your product. Brighteners do not affect any other textile properties or the detergent’s cleaning performance.
AATCC recently published LP1 to provide complete laundering specifications and procedures for traditional top-loading washers, HE top-loading washers, and HE front-loading washers. This document replaces Monograph 6.
Order AATCC LP1, Home Laundering: Machine Washing
The “standard” conditions for LP1 and related test methods use a traditional top-loading washer, but several “alternate” options are available for HE washers.
HE washing machines come in both front- and top-loading formats. The HE designation is based on water and energy use, not which way the door opens. Non-HE washers are referred to as “traditional” and are almost exclusively top-loading in the US. Typically, a traditional top-load washer has a tall agitator; an HE top-loader has a lower impeller; however, there are a variety of designs. Here too, the efficiency is more important than the appearance. If the sticker says HE, it probably is, no matter how tall the central insert happens to be. High efficiency is good news for your utility bills and the environment, but comes with some precautions for textile testing.
HE washers are designed to hold a larger load than traditional washers. This is important for standardized textile testing because most test methods call for a 1.8-kg (4-lb) load—smaller than a normal consumer load. The prescribed 50-mL dose of AATCC HE detergent is based on this load size, but a full dose of consumer detergent may be too much.
A consistent load size is very important for testing. Because the standard 1.8-kg load is on the small end of the scale, a load up to twice as heavy may use the same minimal level of water (exact load-to-water ratios vary by model). More fabric in the same amount of water means more potential for fabric-to-fabric abrasion, which can lead to variation in test results. Once you get beyond the minimum threshold, HE washers are designed to adjust the water level based on the load size. This means an additional variable in your test, particularly if you are using multiple machines with different ratios.
One of the energy-saving features of HE washers is the high spin speed, removing excess water and leaving less work for the dryer. The high spin speeds, combined with low water levels, and long cycle times are prone to cause tangling. This is not good for your home laundry, but can be particularly problematic for dimensional change, skew, and smoothness testing. Tangled and twisted fabric can become stretched or distorted, resulting in incorrect or inconsistent test results.
There is still some debate about the relative effects of agitation in different machine types. Advocates of HE machines note that traditional machines rely on fabric-to-fabric abrasion for some of their cleaning power while HE machines rely more on detergent chemistry. The agitator is another source of abrasion in traditional washing machines. On the other hand, low water levels and longer cycle times for HE machines can also lead to significant abrasion.
Efficient use of water and energy may cost you time. As noted above, cycle times for HE washers are longer than for traditional washers, particularly the spin segment. Most traditional machines specified in LP1 have a spin time of 5-6 minutes. HE spin times can range from 5 to 18 minutes for a normal cycle, though they are shorter for the delicate cycle. (The average wash time listed for both traditional and HE top-load machines in LP1 is about 11 minutes.) The wider range in HE spin times is due to technology that determines when excess water is sufficiently extracted. It’s another “smart” feature that can add variability to your testing.
Standard detergent is an important part of correctly and consistently evaluating textile performance, durability, and quality.
Dictionary definitions of the word “standard” hit on several points relevant to standard detergent. AATCC standard detergents are widely used, well-established, and of permanent value as suggested by the Merriam-Webster definition. They are also, as the Oxford definition states, accepted as average.
The recipes for AATCC detergents are the same lot-to-lot. Standard detergent offers permanent value by eliminating concerns about the impact of new formulas, scents, or additives on your results. Using standard detergent throughout your supply chain means one less variable to consider when comparing test data.
Normal and Average
AATCC standard reference detergents are formulated to have the performance of an “average” consumer detergent. This means the results you see in the lab are likely to match the results an end-product consumer sees at home. This reduces the number of false passes from using a high-end detergent in the lab. During the development process AATCC detergents are tested alongside comparable mid-level consumer detergents for performance in dimensional change, color change, color staining, stain release, and general appearance.