Permanent press
Encyclopedia
A permanent press is a characteristic of fabric
that has been chemically processed to resist wrinkle
s and hold its shape. Alternative terms include wrinkle resistant, wash and wear, no-iron,
durable press, and easy care. This treatment has a lasting effect on the fabric.
. Starting in the 1940's a series of urea-formaldehyde
derivatives were introduced. Technical issues overcome included yellowing, odor, and the tendency of some agents to accelerate the degradation of fabrics by bleach
es. The technology advanced especially rapidly in the early 1990s.
In older washing machines, the permanent press setting sprays moisture during the spin cycle to maintain the moisture content of the permanent press fabrics above a certain specified limit to reduce wrinkling.
Most older clothes dryer
s feature an automatic permanent press setting, which puts clothes through a cool-down cycle at the end of the normal heated drying cycle. Modern dryers tend to include this as a standard feature.
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...
that has been chemically processed to resist wrinkle
Wrinkle
A wrinkle is a fold, ridge or crease in the skin. Skin wrinkles typically appear as a result of aging processes such as glycation or, temporarily, as the result of prolonged immersion in water. Wrinkling in the skin is caused by habitual facial expressions, aging, sun damage, smoking, poor...
s and hold its shape. Alternative terms include wrinkle resistant, wash and wear, no-iron,
durable press, and easy care. This treatment has a lasting effect on the fabric.
Chemistry
The crosslinking agents that result in the permanent press finish are often derivatives of urea. A popular agent is DMDHEU, dimethylol dihydroxyethyleneurea.History
Advances in producing permanent press fabrics involved a series of agents that crosslink the cellulose-based fibers that comprise most clothing. Initial agents included formaldehydeFormaldehyde
Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
. Starting in the 1940's a series of urea-formaldehyde
Urea-formaldehyde
Urea-formaldehyde, also known as urea-methanal, named so for its common synthesis pathway and overall structure, is a non-transparent thermosetting resin or plastic, made from urea and formaldehyde heated in the presence of a mild base such as ammonia or pyridine...
derivatives were introduced. Technical issues overcome included yellowing, odor, and the tendency of some agents to accelerate the degradation of fabrics by bleach
Bleach
Bleach refers to a number of chemicals that remove color, whiten, or disinfect, often via oxidation. Common chemical bleaches include household chlorine bleach , lye, oxygen bleach , and bleaching powder...
es. The technology advanced especially rapidly in the early 1990s.
In older washing machines, the permanent press setting sprays moisture during the spin cycle to maintain the moisture content of the permanent press fabrics above a certain specified limit to reduce wrinkling.
Most older clothes dryer
Clothes dryer
A clothes dryer or tumble dryer is a household appliance that is used to remove moisture from a load of clothing and other textiles, generally shortly after they are cleaned in a washing machine....
s feature an automatic permanent press setting, which puts clothes through a cool-down cycle at the end of the normal heated drying cycle. Modern dryers tend to include this as a standard feature.