Medical gown with fluid- and microorganism-impervious seam

Advances in Textiles Technology, Nov, 2008

A method of making a fluid-impervious seam in a multi-laminate medical fabric is disclosed by Allegiance Healthcare, a subsidiary of Cardinal Health. Such materials may be converted into contamination-resistant drapes or clothing.

The method, disclosed in various patents, including US Patent 7 390 376, is said to produce heat-sealed seams that exhibit fluid penetration-resistant characteristics similar to those of the base material.

According to the company of McGraw Park, Illinois, USA, the heat-sealing technique uses the differing properties and melting point ranges of each layer in the multi-laminate fabric--without the need for additional sealing methods, such as stitching or adhesives.

The fabric (10) includes at least two layers, each having different melting points. Moreover, one of the layers comprises a flexible, thermoplastic, fluid-impervious material. Two portions of the fabric are overlapped such that the innermost layers have a lower melting point (preferably 40[degrees]C or lower) relative to that of the fluid-impervious layer.

The fluid-impervious material (16) can be a film layer; for instance, a polyether-ester block copolymer, such as Arnitel from DSM, or an elastomeric copolyester, such as Hytrel from DuPont.

The other layer (12) can be a nonwoven, such as a spunmelt or carded polyolefin or a carded, spunlaced or spunmelt polyester. Examples of spunmelt polypropylene include those from BBA Nonwovens and First Quality Nonwovens.

The fabric can include a third layer (14), which may be the same material as the overlapped material or a different material, provided the melting point of this layer is at least the same or higher than that of the overlapping layer. If this third layer is made of a different material, carded or spunlaced wood pulp/polyester is suitable.

When applying the heat source to the overlapped multi-layered fabric, the sealing temperature is chosen so as to be greater than the melting point of the innermost layers, but less than that of the inner film.

Allegiance emphasizes that, when applying heat from the sealing process, it is important to only melt the nonwoven fabrics that are in contact with each other to obtain the impervious seal; the film must not melt, otherwise defects or leaks in the seal will occur.

Typically, the width of the seal to create the seam is 6.4-9.5 mm. Preferably, an impulse sealer is used, although ultrasonic welding techniques or a constant temperature sealing bar can be considered, the company explains.

For further information, see WO 2004/045368, US Patent 7 390 376, European Patent 1 594 690, Australian Patent 2003/290774, or contact: Joseph Palomo or Fernando Amaya, inventors, c/o Allegiance Corp, 1430 Waukegan Road, McGaw Park, IL 60085-6787, USA. Tel: 847-689-8410. http://www.cardinal.com/mps; or: Cardinal Health Inc, 7000 Cardinal Place, Dublin, OH 43017, USA. Tel: 614-757-5000. Fax: 614-757-8871. http://www.cardinal.com