Duct Tape
Duct tape is a vinyl, fabric-reinforced multi-purpose
adhesive. Because it is waterproof and
has a very strong adhesive that can be ripped without scissors, duct tape has
become an everyday household item and is used anywhere applicable-the home, the
workplace, for automobiles, etc. Originally
it was designed for use in air ducts, but consumers soon found many different
household uses for it. Duct tape
generally comes in either black or silver, but a few companies produce a
variety of colors. It is composed of
three layers. The first is a resilient
plastic called polyethylene, followed by fabric mesh which makes up the middle
layer, and a rubber-based adhesive on the bottom.
Duct tape is produced in very large quantities on a set of
rollers. The adhesive is composed of
rubber, resin and calcium carbonate and is made in a heated mixer. Tackifying agents, viscosity modifiers and
antioxidants are added to the rubber compound.
The adhesive and fabric are then combined using coating equipment. The fabric is put onto a roller mill, which
consists of 2 hollow rollers made of stainless steel that rotates at a set
speed. The adhesive is heated up and fed
into a small space between the 2 rollers, which forms a thin, even sheet of
across the surface of the rollers. The
cloth is then fed into the coating machine and runs against the roller with the
adhesive, coating one side of it. After
the coating process, the tape is then unspooled, where the large rolls are
unwound, cut into smaller sizes and then respooled onto smaller cardboard cores
in a process referred to as slitting.
The tape is then packaged (usually shrink-wrapped) and ready for sale.