Neoprene is a modern miracle! There
is no other fabric with all these qualities: it stretches, it's
waterproof, it can be stitched or glued, it comes in a multitude of
colors, it provides an insulating layer in wet environments, it's
abrasion resistant and it is relatively inexpensive.
Neoprene was first discovered by
none other than Jacques Cousteau. His pioneering efforts after WWII
created a material suitable for diving in the frigid depths of the
ocean. This initial material is quite different from what we use today
but the technology to produce it is similar.
Neoprene is Made
Neoprene is often referred to as
'rubber' but it is actually plastic. It begins as a powder called
polychloroprene. To this base are added other ingredients that provide
elasticity, foaming agents, cell size, color, adhesion, bulk, plus
other properties. This mixture is made into a dough which is put into
a heat press. Under pressure and heat, the mixture squishes out to
make a sheet about 90" x 53". Sheet size varies according to the
manufacturer and type of neoprene being produced. Jacques Cousteau's
original method is still being used by a company called Rub Tex in
California, which also produces car door moldings for GM.
The final product is a foam block
about 2" thick. The top and bottom of the block will be either smooth
skin or textured. The sheet is then cut horizontally to produce sheets
anywhere from 1mm to 8mm thick. The top and the bottom sheets end up
as N1S (nylon one side), seen on many styles of wetsuits (if you look
closely at N1S you will see the aluminum mold release dust sparkle).
The middle layers get laminated with a variety of fabrics, most
commonly stretch nylon. These fabric covered sheets are called N2S
(nylon two sides). To streamline the sewing and cutting production you
will often see bright colors on one side and black or navy on the
other of N2S sheets.
N1S or 'skin' neoprene has the
benefit of being the most stretchy, softest and warmest when wet. The
drawback to N1S is that it does not wear well (both abrasion and seam
integrity) and comes in limited colors. N2S has the benefit of being
very durable, comes in many colors and stitches well. The disadvantage
of N2S is reduced stretch, less functional as the outer fabric stays
wet, and can be more expensive. You will often see N1S used in the
body core panels of wetsuits with N2S in the seat, knees and arm
Immersion suits are typically
constructed with one of two typical seam types: blind stitched
or Mauser/flat lock.
Blind stitched seams have the
advantage of being totally waterproof, very stretchy and invisible
from the outside when stitched on the inside. These seams are glued
first, creating a waterproof product. The blind stitch is best done on
the nylon side and is often used with N1S. The stitch can be easily
unraveled in one direction. If you break a stitch, use a drop of Super
Glue to anchor the thread where it exits the material. The biggest
drawback to a blind stitch is that it requires a highly skilled
operator to not allow the needle to penetrate too deeply through the
The Mauser, or flat lock, seam is
the most durable seam used in neoprene garment manufacturing. The
advantage to Mausering is that often an exterior fabric tape is used.
The stitches are embedded in the tape protecting them from abrasion.
The seam will stretch with the fabric and will not unravel if broken.
This seam will usually outlast the material. Gluing makes the sewing
easier and faster but it cannot be glued and still be strong. Other
than the cost of the machinery and high skill level of the operator,
the only other drawback is that there are forty stitch holes per inch.
Immersion suits are a technical
product and as a result utilize more than one seam type to provide for
optimum comfort and durability. Also used are processes like
seam welding, heat tape application for waterproofing or RF welding
for the installation of dry zippers.
How Neoprene Works
Neoprene works best if it fits snug
enough for you to breath comfortably and tight enough to restrict
water flowing through the suit. By trapping the water in the suit,
your body warms it up. Neoprene is comprised of many small bubbles.
This trapped air is the insulating factor.