Section 1091 2022.docx

Plywood sign panels shall not be used with Type A retroreflective sheeting.

SECTION 1091. SIGN FACE, SIGN LEGEND, AND SUPPLEMENTAL PANELS

1091.01 Sign Face Material Requirements. The sign face material shall be in accordance with the Department's Fabrication of Highway Signs Policy.

The sheeting for the background, legend, border, shields, and symbols shall be provided by the same manufacturer.

1091.02 Sign Legend and Supplemental Panel Material Requirements. The sign legend and supplemental panel material shall be in accordance with the Department's Fabrication of Highway Signs Policy and the Illinois Manual for Uniform Traffic Control Devices.

Signs shall be fabricated such that the material for the background, legend, border, shields, and symbols are applied in the preferred orientation for the maximum retroreflectivity per the manufacturer's recommendation. When using Type ZZ retroreflective sheeting, the nesting of legend, border, shields, or symbols will not be permitted.

Letters and numerals used shall be according to the standard alphabets for highway signs (available from the Federal Highway Administration) of the series indicated in the design details for the sign.

The finished letters, numerals, symbols, panels, and borders shall show careful workmanship and be clean cut, sharp, and have essentially a plane surface.

(a) If demountable copy is specified, each demountable legend unit and supplemental panel shall be supplied with mounting holes and shall be secured to the sign face with aluminum dome head rivets with aluminum mandrels and may not be held in place, even temporarily, using any type of adhesive that would damage the sign face, legend unit, or border when removed at a later date. All rivets shall be color matched to the legend or supplemental panel being installed.

(b) Direct Applied Legend. All direct applied sign legend and borders shall be affixed to clean, dust-free sign panels in a manner specified by the legend manufacturer. The legend and border shall be cut neatly at any intersecting panel edge.

Direct applied retroreflective sheeting and nonreflective sheeting used for legend and border shall be according to Article 1091.03.

The sheeting may be manufactured with a thin aluminum layer between the sheeting and the precoated adhesive.

(c) Flat Frames. The retroreflective sheeting and nonreflective sheeting used on flat frames for legend and border shall be according to Article 1091.03.

Art. 1091.03 Sign Face, Sign Legend, and Supplemental Panels

Sign Face, Sign Legend, and Supplemental Panels Art. 1091.02

Flat frames shall be 0.032 in. (0.8 mm) aluminum according to ASTM B 209, Alloy 3003-H 14. The frames shall be properly degreased and etched and treated with a light, tight, amorphous chromate type coating before any sheeting is applied.

(d) Supplemental Panels. All supplemental panels shall consist of 0.080 in. (2 mm) sheet aluminum according to Article 1090.02 with reflective sheeting applied according to Article 1091.03.

1091.03 Retroreflective and Nonreflective Sheeting and Translucent Overlay Films. The retroreflective sheeting shall serve as the reflectorized background for sign messages and as cutout legends and symbols applied to the reflectorized background. Nonreflective sheeting shall be used as material for cutout legends and symbols applied to the reflectorized background. Translucent overlay films may be used to provide color to white retroreflective sheeting. Messages may be applied in opaque black or transparent colors.

All material furnished under this specification shall have been manufactured within 18 months of the delivery date. All material used to fabricate individual signs shall be supplied by the same manufacturer.

(a) Retroreflective Sheeting Properties. Retroreflective sheeting shall consist of a flexible, colored, prismatic, or glass lens elements adhered to a synthetic resin, encapsulated by a flexible, transparent plastic having a smooth outer surface. Only suppliers whose products have been tested and approved in the Department's periodic Sheeting Study will be eligible to supply material. All individual batches and or lots of material shall be tested and approved by the Department. The Department reserves the right to sample, and test delivered materials according to ASTM D 4956.

(1) Adhesive. The sheeting shall have a Class 1, pre-coated, pressure sensitive adhesive according to ASTM D 4956. The adhesive shall have a protective liner that is easily removed when tested according to ASTM D 4956. The adhesive shall be capable of being applied to new or refurbished aluminum and reflectorized backgrounds without additional adhesive.

(2) Color. The sheeting shall be uniform in color and devoid of streaks throughout the length of each roll. The color shall conform to the latest appropriate standard color tolerance chart issued by the U.S. Department of Transportation, Federal Highway Administration and to the daytime and nighttime color requirements of ASTM D 4956. Sheeting used for side-by-side overlay applications shall have a Hunter Lab Delta E of less than 3.

(3) Coefficient of Retroreflection. When tested according to ASTM E 810, with averaging, the sheeting shall have a minimum coefficient of retroreflection as shown in the following tables. The brightness of the sheeting when totally wet shall be a minimum of 90 percent of the values shown when tested according to the standard rainfall test specified in Section 7.10.1 of AASHTO M 268-84.

Type A Sheeting Minimum Coefficient of Retroreflection candelas/footcandle/sq ft (candelas/lux/sq m) of material Type A Observation Angle (deg.)

Entrance Angle (deg.)

Type AA Sheeting Minimum Coefficient of Retroreflection Candelas/footcandle/sq ft (candelas/lux/sq m) of material

Type AA (Average of O and 90 degree rotation) Observation Angle (deg.)

Entrance Angle (deg.)

Type AA (45 degree rotation) Observation Angle (deg.)

Entrance Angle (deg.)

Type AP Sheeting

Type AP (Average of O and 90 degree rotation) Observation Angle (deg.)

Entrance Angle (deg.)

White

Yellow

Red

Green

Blue

Brown

FO

Art. 1091.03

Art. 1091.03

Type ZZ Sheeting

Type ZZ (Average of O and 90 degree rotation) Observation Angle (deg.)

Entrance Angle (deg.)

(4) Durability. When processed and applied, the sheeting shall be weather resistant. Accelerated laboratory weathering will be used for provisional qualification of sheeting before the results from accelerated outdoor weathering are available. When they become available, the results from outdoor weathering take precedence over the results from laboratory-accelerated weathering tests.

Accelerated weathering testing will be performed for 1000 hours (300 hours for orange/FO) according to ASTM G 151. The testing cycle will consist of 8 hours of light at 140 °F (60 °C), followed by 4 hours of condensation at 104 °F (40 °C). Following accelerated weathering, the sheeting shall exhibit a minimum of 80 percent of its initial minimum coefficient of retroreflection as listed in the previous tables. The sheeting shall exhibit a Hunter Lab Delta E of 5 or less when compared to the original.

Outdoor weathering will entail an annual evaluation of material placed in an outdoor rack with a 45 degree angle and a southern sun exposure. The sheeting will be evaluated for five years. Following weathering, the test specimens will be cleaned by immersing them in a five percent hydrochloric acid solution for 45 seconds, then rinsed with water and blotted dry with a soft, clean cloth. Following cleaning, the applied sheeting shall show no appreciable discoloration, cracking, streaking, crazing, blistering, or dimensional change. The sheeting shall exhibit a Hunter Lab Delta E of 5 or less when compared to the original.

(5) Shrinkage. When tested according to ASTM D 4956, the sheeting shall not shrink in any dimension more than 1/32 in. (0.8 mm) in ten minutes and not more than 1/8 in. (3 mm) in 24 hours.

(6) Workability. The sheeting shall show no cracking, scaling, pitting, blistering, edge lifting, inter-film splitting, curling, or discoloration when processed and applied using mutually acceptable processing and application procedures.

(7) Adhesive Bond. The sheeting shall form a durable bond to smooth, corrosion-resistant, and weather-resistant surfaces and adhere securely when tested according to ASTM D 4956.

(8) Positionability. Sheeting, with ASTM D 4956 Class 3 adhesive, used for manufacturing cutout legends and borders shall provide sufficient positionability during the fabrication process to permit removal and reapplication without damage to either the legend or sign background and shall have a plastic liner suitable for use on bed cutting machines. Thereafter, all other adhesive and bond requirements contained in the specification shall apply.

Positionablility shall be verified by cutting 4 in. (100 mm) letters E, I, K, M, S, W, and Y out of the positionable material. The letters shall then be applied to a sheeted aluminum blank using a single pass of a 2-lb (0.90-kg) roller. The letters shall sit for five minutes and then a putty knife shall be used to lift a corner. The thumb and fore finger shall be used to slowly pull the lifted corner to lift letters away from the sheeted aluminum. The letters shall not tear or distort when removed.

(9) Thickness. The thickness of the sheeting without the protective liner shall be less than or equal to 0.015 in. (0.4 mm), or 0.025 in. (0.6 mm) for prismatic material.

(10) Processing. The sheeting shall permit cutting and color processing according to the sheeting manufacturer's specifications at temperatures of 60 to 100 °F (15 to 38 °C) and within a relative humidity range of 20 to 80 percent. The sheeting shall be heat resistant and permit forced curing without staining the applied or unapplied sheeting at temperatures recommended by the manufacturer. The sheeting shall be solvent resistant and capable of being cleaned with VM&P naptha, mineral spirits, and turpentine.

Transparent color and opaque black inks shall be single component and low odor. The inks shall dry within eight hours and not require clear coating. After color processing on white sheeting, the sheeting shall show no appreciable discoloration, cracking, streaking, crazing, blistering, or dimensional change when tested for durability (4). The ink on the weathered, prepared panel shall exhibit a Hunter Lab Delta E of 5 or less when compared to the original.

Transparent color electronic cutting films shall be acrylic. After application to white sheeting, the films shall show no appreciable discoloration, cracking, streaking, crazing, blistering, or dimensional change when tested for durability (4). The films on the weathered, prepared panel shall exhibit a Hunter Lab Delta E of 5 or less when compared to the original.

Transparent colors screened, or transparent acrylic electronic cutting films, on white sheeting, shall meet the minimum initial coefficient of retroreflection values of the 0.2 degree observation angle, -4.0 degree entrance angle values as listed in the previous tables for the color being applied. After durability testing, the colors shall retain a minimum 80 percent of the initial coefficient of retroreflection.

(11) Identification. The sheeting shall have a distinctive overall pattern in the sheeting unique to the manufacturer. If material orientation is required for optimum retroreflectivity, permanent orientation marks shall be incorporated into the face of the sheeting. Neither the overall pattern nor the orientation marks shall interfere with the retroreflectivity of the sheeting.

(12) Packaging. Both ends of each box shall be clearly labeled with the sheeting type, color, adhesive type, manufacturer's lot number, date of manufacture, and supplier's name. Safety Data Sheets and technical bulletins for all materials shall be furnished with each shipment.

(b) Nonreflective Sheeting Properties. Nonreflective sheeting shall consist of a flexible, pigmented cast vinyl film having a smooth, flat outer surface and shall meet the following requirements. The Department reserves the right to sample and test delivered materials according to ASTM D 4956.

(1) Adhesive. The sheeting shall have a Class 1, pre-coated, pressure sensitive adhesive according to ASTM D 4956. The adhesive shall have a protective liner that is easily removed when tested according to ASTM D 4956. The adhesive shall be capable of being applied to new or refurbished aluminum and reflectorized backgrounds without additional adhesive.

(2) Color. The sheeting shall be uniform in color and devoid of streaks throughout the length of each roll.

(3) Gloss. The sheeting shall exhibit a minimum 85 degree gloss-meter rating of 40 when tested according to ASTM D 523.

(4) Durability. Applied sheeting that has been vertically exposed to the elements for seven years shall show no appreciable discoloration, cracking, crazing, blistering, delamination, or loss of adhesion. A slight amount of chalking is permitted but the sheeting shall not support fungus growth.

(5) Testing. Test panels shall be prepared by applying the sheeting to 6 1/2 x 6 1/2 in. (165 x 165 mm) pieces of aluminum according to the manufacturer's specifications. The edges of the panel shall be trimmed evenly and aged 48 hours at 70 to 90 °F (21 to 32 °C). Shrinkage and immersion testing shall be as follows.

a. Shrinkage. The sheeting shall not shrink more then 1/64 in. (0.4 mm) from any panel edge when subjected to a temperature of 150 °F (66 °C) for 48 hours and shall be sufficiently heat resistant to retain adhesion after one week at 150 °F (66 °C).

b. Immersion Testing. The sheeting shall show no appreciable decrease in adhesion, color, or general appearance when examined one hour after being immersed to a depth of 2 or 3 in. (50 or 75 mm) in the following solutions at 70 to 90 °F (21 to 32 °C) for specified times.

Reference Fuel (M I L-F-8799A) (15 parts xylol and 85 parts mineral spirits by weight)

(6) Adhesive Bond: The sheeting shall form a durable bond to smooth, corrosion-resistant, and weather-resistant surfaces and adhere securely when tested according to ASTM D 4956.

(7) Thickness. The thickness of the sheeting without the protective liner shall be a maximum of0.005 in. (0.13 mm).

(8) Cutting. Material used on bed cutting machines shall have a smooth plastic liner.

(9) Packaging. Both ends of each box shall be clearly labeled with the sheeting type, color, adhesive type, manufacturer's lot number, date of manufacture, and supplier's name. Safety Data Sheets and technical bulletins for all materials shall be furnished with each shipment.

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