Best Ironing Practices

The principal damage to sheets is overheating during drying and with some heated roller ironing. If poly/cotton blend sheets are overheated, thermal contraction shrinkage and even fusion of polyester fibers occurs. Polyester fibers contract significantly when heated above 360ºF in a relaxed state. Contraction increases rapidly as fiber temperature increases beyond the 360ºF threshold. The progressive contraction will occur with repetitive excessive heating. Overheating cotton sheets weakens the fiber and causes it to become brittle. It is recommended that fabric ironing temperature should not exceed 300 F. Important commercial laundry operators understand that fabric temperature is the most important aspect when processing sheets. Heated mangle or roller press-type ironers are most common in commercial laundry. Hot oil or thermal ironers are sometimes operated at temperatures over 420˚F. Electric ironers can reach similar temperatures. Steam-heated ironers generally operate in the range of 320-360 F. A rationale for such high ironing temperatures is to provide a large temperature differential above the boiling point of water, 212˚F, thereby increasing the drying time and iron production. The danger is that the temperature of the bedding fabric rises rapidly once completely dried. The specific heat or energy required for heating polyester fiber is very low. Therefore, the temperature of the polyester in a blend sheet virtually jumps to the temperature of the ironer surface when the fabric is dried. Excessive iron temperatures can lead to excessive fabric temperatures and permanently damage products. The solution to thermal shrinkage and fiber fusion in blended sheets using heated mangle/roller ironers is apparent…don’t over-heat sheets…and do not allow fabric temperatures to exceed 300ºF at any time. Controlled ironing temperature and conditions will also provide ancillary benefits such as reduced energy cost, reduced static generation, and improved ambient working temperature, increasing the life of the sheets.