Rush possesses the characteristics of having high absorbency when first laid down and of being able to adapt to changes in humidity. It has a superior humidity control function that allows it to release moisture into the room when the air is dry. When rush is laid down in a tatami room, it is able to store approximately 1.8L of moisture.
The inside of rush is a structure of overlapping hexagons similar to that of a beehive, and between its fibers there are nodes that create many small rooms. The surface area of the inside is breathed in by the rush, which has a broad sponge-like shape, thus absorbing nitrogen dioxide (NO2) and formaldehyde.
By absorbing nitrogen dioxide, a leading contributor to air pollution that adversely affects human health, the rush helps purify the air.
Antibiotic activity has been discovered in the elements of rush against pathogens such as pathogen E‐Coli O‐157 and salmonella. Applications of rush to food products and medicines have been researched and interest in its effects is increasing.
Rush absorbs many chemical materials that cause offensive odor. It provides a pleasant air environment by restraining odors such as ・sweat odor ・pet odor ・toilet odor and ・cigarette odor.
The “rush sheets” that have been used since long ago are a functional bedding that effectively use the sweat and moisture absorbing function of rush. Compared to cotton, rush removes approximately three times the amount of sweat that you sweat while sleeping. Also, in cases where you are using a hada-buton (a thin and soft futon blanket) the rush prevents moisture from accumulating in the futon, thus allowing you to get a good night’s sleep.
The fragrance of rush relaxes both Japanese people and people all over the world; it is a natural fragrance created by a process called mudding used only for rush, and it is a traditional fragrance that is a foundation of Japanese culture. It has a calming effect similar to that of taking a walk in the forest and its naturally gentle fragrance relieves our exhausted minds and bodies. The perfume elements only found in the fragrance of rush emanating from new tatami matting have an “aromatherapeutic effect” that refreshes and relaxes both mind and body.
Air has the characteristic of not transmitting heat well. Because the rush cross section of tatami matting adds to a sponge shape the straw shape provided by the straw of the tatami floor, the inside of each contains lots of air. The incalculable amount of air stored in this tatami helps insulate and retain heat, thus cooling the room during summer and heating it in winter.
The cross-section of rush (the “wick”) has a sponge-like structure that contains lots of air. Tatami mats have a superior resilience that have a natural barrier-free function that gently absorbs shocks even when they fall over. They are also said to be effective in nurturing a sense of balance in young children. Furthermore, this air cushion functions to absorb sound in and soundproof the room.