Q
The Manufacturing Process of road signs
A
The Manufacturing Process of road signs
The production of signs can involve many different processes, depending on whether the
Road Sign retroreflective sheeting uses a heat-sensitive or pressure-sensitive adhesive and whether silk-screening, etching, or other coloring processes are used. Many traffic signs, however, undergo the following process using heat-sensitive adhesives.

Cutting the blank

1 The sign blank is cut, usually from a sheet of steel or aluminum, by a metal shear machine or a band saw. Corners are rounded using the rounding-selection mode on a punch machine. Holes for mounting the sign are punched or drilled.

Checking the blanks


Degreasing the blanks
3 The blank surface is wiped with mineral spirits or naphtha to remove greasy fingerprints. The surface is dried with a clean, lint-free cloth before the solution evaporates. The blank is then degreased by immersion in a bath of trichloroethylene or percholorethylene vapor. Certain alkaline solutions can be used instead of the vapors in the bath. A water rinse afterward is not necessary
Cutting the retroreflective sheets
4 Using scissors, razor blades, a knife, or a paper cutter, individual background retroreflective sheets are cut by hand. Multiple sheets, on the other hand, are cut using a band saw. In this process, the shape of the sign is traced on to a 0.125-inch (3.2 mm) wallboard. This wallboard is laid on top of about 50 sheets, secured and nailed to a hardboard cutting base. The band saw follows the pattern and cuts the sheets.
5 Letters and symbols are punched out from white or black retroreflective sheeting either by hand or by using a "clicker" press. Up to 29 sheets can be placed in the press at once; cutting dies, which function much like cookie-dough cutters, are placed in the machine to produce the desired characters.
Applying sheet to sign blank
6 The adhesive liner on the back of the background sheeting is removed in one motion, and the sheeting is applied to the dry blank surface. The sign is cranked through a large squeeze-roller applicator to remove air bubbles trapped between the sheeting and the blank. Edges are then trimmed.
Heating the sign
7 The sign is placed in a heat lamp vacuum applicator for one minute, removed, and allowed to cool before the sign copy and border are placed on the sign. The squeezeroller applicator or a hand roller is used over the copy to eliminate air bubbles. The sign is then covered with a plastic slipsheet and placed in the heat lamp vacuum applicator for another minute.

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