Sewing and Fabrication Flashcards
6 steps common to all sewing project designs
determine use of project select fabric/webbing determine seam requirements determine closure/connector measure create templates
Seam classes
- SS-superimposed seam
- LS- Lap seam
- BS- binding seam
- FS- flat seam
The first resource for fabric design is the…..
aviation life support systems manual
COMDTINST M13520.1
selvage edge
edge of cloth tape, webbing, or fabric and is
woven in such a way as to prevent unraveling.
CGTO PG-85-00-310-A 8-1
warp thread
filler thread
A. threads that run parallel to the selvage edge. The
warp threads form the framework for the material and support most
of the strain during the weaving process.
B.threads that run perpendicular to the warp threads
and selvage edge.
CGTO PG-85-00-310-A 8-1
Bias seam
Seams made on the 45° angle to the filler threads, warp threads and
the selvage edge are said to be made on the bias. Bias construction
will provide more elasticity and strength, and will reduce the effect
tears have on the integrity of the material.
CGTO PG-85-00-310-A 8-1
What are the 4 seam classes
- Superimposed Seam (SS)
- Lap Seam (LS)
- Binding Seam (BS)
- Flat Seam (FS)
CGTO PG-85-00-310-A 8-6
Superimposed seam types
SS
Two types of Superimposed seams are Ssa-1 and SSc-2
a. The SSa-1 seam is a simplified method of joining two or more
pieces of material. The following example shows a Ssa-1 (one
row of stitching).
b. The SSc-2 seam, as seen below, is formed by superimposing two
plies of material, turning the edges of both plies a specific
distance to the inside, and seaming through both turned edges a
specified distance from the edges.
CGTO PG-85-00-310-A 8-6
Lap seam LSa-2, LSb-2, LSc-2, LSd-2
The lap seam is formed by lapping the plies of material, and seaming
with one or more rows of stitches. The standard seam for connecting fabric panels. There are four types of lap seams.
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a. Overlapping two or more plies of material, and seaming with two
or more rows of stitches as seen below forms the LSa-2.
b. Turning the edge of one ply of the material under itself and
lapping it on top of another ply and seaming with two or more
rows of stitches as seen below forms the LSb-2.
c. Turning the edges of both plies under and lapping them, then
seaming with two rows of stitches as seen below forms the LSc-2.
d. The LSd-2 seam, as seen below (step 2), is formed by placing one
ply on top of another. The top is placed a specified distance from
the edge to be sewed, then seamed with one row of stitches
Binding seam-BSa-2
The BSa-2 binding seam, show below, is formed by folding a binding
strip over the edge of one or more plies of material and seaming the
binding strip to the material with one or more rows of stitches.
CGTO PG-85-00-310-A 8-9
Flat seam- FS
The flat seam is formed by seaming the abutting edges of material
together, as seen below, in such a manner that the stitches extend
across and cover, or tend to cover, the edges of the plies of material
joined.
CGTO PG-85-00-310-A 8-9
2 seam classes for stitching
- Ornamental (OS)
- Edge Finishing (EF)
CGTO PG-85-00-310-A 8-9
Ornamental stitching
OS
The ornamental stitching, like the OSa-3 below, is formed when a
series of stitches are embodied in material, either in a straight line, a
curve, or following a design for ornamental purposes.
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Edge finishing-EF
The edge finishing stitching is used to prevent the raw edges of the
material from unraveling and can be sewn by one of three ways:
The EFa-1, EFb-2 has the edge of the material folded back one or
more times and then sewn together with one or more stitches.
CGTO PG-85-00-310-A 8-10
Seam specification
301-SSa-1
301-SSa-1 Stitch Class- 301 Class of Seam- SS Type of Class- a Row of stitches- 1
CGTO PG-85-00-310-A 8-10