How duct tape is made


How Duct Tape is made:

Duct tape is a cloth tape coated with a poly-ethylene resin on one side and very sticky rubber-based adhesive on the other. The fabric backing gives duct tape strength yet allows it to be easily torn.

Consumers have found a broad range of uses for this popular product. It can be used for household repair jobs, and in car maintenance.

Snow mobilers have even been known to apply duct tape to their noses to thwart frost-bite and sunburn. The Duct Tape Book describes how to use duct tape to make aprons and trampoline covers.

Raw Materials:

Cotton mesh: Cotton mesh forms the backbone of duct tape. It provides tensile strength and allows the tape to be tom in both directions. Cloth that has a tighter weave and higher thread count is of a higher quality, provides greater strength, and gives a cleaner tear. A premium quality tape can have a thread count of 44 x 28 threads per square inch. Tape made with this fabric is more expensive. The cotton fabric is called a "web" when it is spread across the coating machinery.




Polyethylene coating: The cotton fabric is coated with polyethylene, a plastic material that protects it from moisture and abrasion. This plastic coating is flexible and allows the tape to adhere better to irregular surfaces.

The polyethylene is melted and applied to the fabric in a preliminary coating operation. The coated fabric is then stored on rolls until the manufacturer is ready to apply the adhesive.

Adhesive compound: Adhesive itself is formulated with rubber compounds that ensure long-term bonding. Adhesive is applied to the substrate in a much thicker coating than those used on cellophane or masking tapes. This too serves to increase the adhesive properties of the tape.

The Manufacturing Process:

Adhesive compounding: The rubber-based adhesive used in duct tape is prepared in a multi-step process. In the first step the adhesive is compounded in a mixer known as a Branbury-type mixer consisting of a stainless steel tank equipped with a steam jacket to heat the compound and a high torque mixer. The rubber compounds are introduced in pellet form, then heated and mixed until they are melted and homogenous.

Other ingredients are added to the blend tank. These include tackifying agents, viscosity modifiers, antioxidants, and other adjuncts. The final mixture is thick but smooth enough to be pumped to a holding tank connected to the coating equipment.




Packaging operations: In this final stage the rolls of duct tape are packaged for sale. They are typically shrink wrapped, either singularly or in packages of two or three. These packages are then boxed and marketed for shipping.

Depending on the manufacturer, the steps described above can be combined through automation into fewer steps. Permacell uses a self-contained apparatus which mixes, heats, and fastens the adhesive onto the backing. This method allows the glue to be prepared without pollution-causing solvents.

Quality Control: Adhesive strength and cohesive strength. Standardized stainless steel plate, and then measuring the force required to rip it off. The plate is then examined to determine how much, adhesive residue is left behind. The adhesive coating itself is monitored to evaluate how well it sticks to its backing. Adhesive leaves a residue is known as creeping, crazing, oozing and bleeding.

Companies may measure the duct tape's breaking point. Others evaluate the "scrunch" sound of the tape as it unwinds because consumers believe a noisy rip off the roll is a sign of strength.

Other tests are designed to measure quick stick. By shooting ping-pong balls at tape strips with the sticky side up to measure how far they roll before they are stopped by the tape.


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