A garment is constructed by forming panels of first and second matching layers of two new and useful polyester fabrics sewn together along their edges. The composite panels are sewn together in such a fashion as to create a garment that will provide an effective barrier to dirt and dust particles.

BACKGROUND OF THE INVENTION 
The Present invention relates to improvements in the construction of an 
electrostatic cleanroom and method for assembly of the parts thereof. 
In the manufacture of many products incorporating today's new technologies, 
it is necessary and essential to prevent contamination by dirt and dust 
particles commonly found on the clothing of those assembling or testing 
the products. During the manufacturing stage of certain types of highly 
sensitive products if dirt and dust particles come to rest on the surfaces 
of these products the product will begin to develop a higher and higher 
rate of failure to the point of being completely destroyed and made 
useless due directly to unwanted dust and dirt particles being deposited 
thereon. Enabling cleanroom workers to operate in a clean environment 
without contaminating the products with dust and dirt particles is a major 
concern in many fields requiring cleanroom manufacturing and testing. With 
the development of newer and more sensitive technologies the risk of 
contamination by smaller and smaller particles becomes even greater. 
To date many attempts have been made to develop a garment which will 
prevent this type of contamination during the manufacturing process of the 
highly sensitive products of this current age. Currently known are 
different types of cleanroom garments. The current cleanroom garment 
technology attempts to cure the dust and dirt permeation problem through 
the use of single layered garments. Due to the technical inability to 
weave densely enough the threads of the fabrics used in these garments to 
prevent the permeation of the microscopic dirt and dust particles that 
will contaminate today's new products this technology can not supply the 
proper barrier to dust and dirt particles which will normally contaminate 
the surfaces of the products. This method of solving the problem has 
currently outlived its effectiveness and usefulness. 
What is not known and is unique to the current invention is a cleanroom 
garment which is made of two electrostatic dissipative (ESD) fabric layers 
each impermeable to a certain microscopic size of dust and dirt which in 
turn are sewn together in such a new and useful manner to create a garment 
that prevents the permeation of dust and dirt particles larger that 0.02 
microns. 
What all of the present cleanroom garments lack and what is desirable to 
have is a cleanroom garment that can provide an effective barrier to dust 
and dirt particles as small as 0.02 microns. This longstanding but 
heretofore unfulfilled need is now fulfilled by the invention disclosed 
hereinafter. 
SUMMARY OF THE INVENTION 
The present invention relates generally to a coverall garment intended for 
use in cleanroom manufacturing environments to prevent the outward 
permeation of dirt and dust particles found on the surfaces of the normal 
outerwear of cleanroom personnel. These particles if left uncovered will 
become dislodged from the clothing of the cleanroom personnel and then 
become airborne and eventually settle onto the surfaces of the products 
being manufactured. These dust and dirt particles can cause serious damage 
to the products being manufactured. 
In the present invention the fabrics used are electrostatic dissipative 
(ESD) fabrics that are pattern-cut and sewn together in patterned panels. 
The pattern panels are then sewn together, or assembled, into a finished 
coverall. The seams and panel joinings are especially designed to prevent 
permeation of particles larger than 0.02 microns. 
The novelty of the present invention is that for the first time a cleanroom 
garment can be produced which prevents the permeation of dirt and dust 
particles thereby protecting the particle-sensitive product being 
manufactured. 
Full details of the present invention are set forth in the following 
description and in the accompanying drawings.

Similar reference numerals refer to similar parts throughout the several 
views of the drawings. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The cleanroom garment, generally depicted by the numeral 10 in FIG. 1, is 
constructed as shown in FIGS. 2-4. In accordance with the present 
invention, the garment comprises a plurality of shaped panels, each having 
an outer layer 12 of polyester, electrostatic dissipative (ESD) fabric and 
an inner layer 14 of polyester, ESD fabric. The outer layer 12 of fabric 
is preferably a material called "Selguard IV" and the inner layer 14 of 
fabric is preferably a material called "Selguard 110." Both materials are 
manufactured by Teijin, Ltd. of Osaka, Japan. However, other, similar 
materials may be used instead. 
Selguard IV is a fabric made of 100% polyester. The twill style weaving of 
the electro-conductive yarn utilized has a warp spacing of 0.5 mm and a 
weft spacing of 0.5 mm. The twill weaving produces a warp density of 159 
threads/in and a weft density of 120 threads/in. Selguard IV prevents 
filtration of particles larger than 0.3 microns. Selguard IV is light 
weight, weighing 120 g/m.sup.2. Selguard 110 is also 100% polyester. The 
weaving structure is plain. The warp spacing and weft spacing are the same 
as the Selguard IV, namely, 0.5 mm and 0.5 mm, respectively. The plain 
weaving of the Selguard 110 produces a warp density of 91 threads/in and a 
weft density of 83 threads/in. Selguard 110 prevents filtration of 
particles larger than 0.3 microns. Selguard 110 has a weight of 58 
gr/m.sup.2. 
Selguard IV is the trade name of Teijin, Ltd., Osaka Japan, for its ultra 
high performance fabric designed specifically for Class 10; and Class 1 
Cleanrooms--when used as an outer garment with Selguard 110 as an 
undergarment. Smaller, more densely spaced pores in this fabric block 
sub-micron particles but-pass adequate air and moisture to allow the 
operator comfort. Selguard IV fabric is composed of polyester filament 
yarns--75 denier warp threads/100 denier filling threads (weft) woven in a 
twill pattern with a density of 159 warp threads/inch and 120 filling 
(weft) threads/inch, incorporating electro conductive carbon yarn of 0.5 
mm, both warpwise and fillingwise in a 5 mm grid pattern woven into the 
fabric. This results in surface resistivity (ohm/sq) of the warp 
5.8.times.10.sup.5, filling (weft) 9.2.times.10.sup.5 and Particle 
Filtration Efficiency of 85 @ 0.3.mu., 88 @ 0.5.mu.. Selguard 110 is the 
trade name of Teijin, Ltd., for its unique plain wave undergarment fabric 
of electro conductive carbon yarns and 75 denier filament polyester warp 
threads and 75 denier filament polyester filling (weft) threads with a 
density of 91 warp threads and 83 filling (weft) threads to reduce the 
particle density within the outer garment shell. 
The integral joining of the Selguard IV and the Selguard 110 as one apparel 
unit to form a bilayered cleanroom garment ensures a nonporous 
construction. When these two fabrics are sewn together the unit more 
effectively blocks particulate contamination of the cleanroom environment 
than a single layer or two separate garments. 
Thus, according to the present invention, the outer and inner layers 12 and 
14 of fabric are each cut into separate pieces (i.e. sleeves, fronts, 
backs, etc.), which make up a defined shaped and structured part 16, of a 
finished garment 10. These parts 16 are then sewn together along the 
appropriate seams 18 to form separate patterned panels of integrated parts 
having an outer layer 12 of Selguard IV and an inner layer 14 of Selguard 
110. The Selguard IV and Selguard 110 panels are merrowed together, as 
seen in FIGS. 3 and 4, to provide an overlapping closure 20. When the 
Selguard IV and the Selguard 110 are merrowed together the particle 
filtration drops to particles as small as 0.2 microns. 
After the panels are completed the panels are sewn together at seams as the 
finished coverall 10 shown in the Figures. The seams sewn by merrowing are 
also especially designed to decrease the particle filtration. The finished 
garment will be provided with snaps or elastic necks and cuffs to snugly 
fit the cleanroom personnel. 
It shall be noted that all of the above description and accompanying 
drawings of the invention are to be considered illustrative and are not to 
be considered in the limiting sense. 
It is also understood that the following claims are intended to cover all 
of the generic and specific embodiments and features of the invention 
herein described.