a substance that has a
molecular structure consisting chiefly or entirely
of a large number of similar units bonded together,
e.g., many synthetic organic materials used as
plastics and resins.
There are close to 2 million metric tons
of super absorbent polymers made annually in the world. Most of
this volume is used in the personal care markets and in finished goods
such as disposable baby diapers, feminine care, and adult incontinence
Only a very small portion of this total volume is used in the
Our purpose is to identify the best SAPs for these markets and make them
available on an ongoing basis in these specialty applications.
WGc does this by offering a broad array
of granular superabsorbent polymers
that encompass the most up-to-date
These polymers may differ in manufacturing process, chemical make-up,
particle size and shape, absorption speed, retention, gel strength and
The information presented below gives a general overview about the two
basic methods used for making superabsorbent polymers and how the
processes will affect the different performance aspects of our products.
General Overview of Superabsorbent Polymer
A polymer is a substance made up of many (“poly”) repeating units
The subunits of a polymer are called monomers.
Superabsorbent polymers are made by connecting monomer units together
make a long polymer chain that carries an ionic charge (usually positive
or negative… like the opposite ends of a magnet) along the chain itself.
Acrylic acid, and its neutralized form, sodium polyacrylate, are the
However, there are SAPs made with two monomers – acrylic acid and
These products are called copolymers.
During the manufacturing process, the long polymer
chains are linked together
a three-dimensional structure using specially designed cross linking
This special polymer structure allows super absorbents to chemically
absorb and retain water-based fluids.
This important feature is what sets super absorbents apart from other
absorbent products – water based fluids cannot be “squeezed out,” nor
will they “leak out”
of the polymer, as the fluid is chemically bonded within the structure.
Super absorbents can be made in two ways: through
Inverse Suspension Polymerization or via Continuous Gel Polymerization.
There are advantages to both systems.
The physical characteristics and performance parameters of polymers are
controlled through the manufacturing process, although occasionally
post-treatment additives are used to alter or affect certain desirable
Inverse Suspension Polymerization:
In this process, SAPs are produced in batches in large reactors that
particles that are perfect spheres.
Under a microscope, these materials will look like bunches of grapes.
Due to their very high surface-to-volume ratio, these SAPs have
exceptional absorption speeds and capacities.
They are also very low dust products.
Such as our Premium Super absorbent snow polymer,
G-70 (Texas Snow©
Continuous Gel Polymerization:
Using this method, SAPs are polymerized on long “poly-belts” that yield
mats of polymer that are then chopped to the correct particle size
and oven dried.
These materials will look like shards of glass under a microscope.
Due to their irregular shape, the absorption speeds and overall
of these polymers are lower than those that are perfect
the overall gel strength (or performance against
pressure) of these products
is typically higher than their inverse
Our copolymer products,
41K and 42K Polymers, are made with Continuous Gel