Gypsum Gray Back

Four plys of 100% recycled brown fiber make the Gray Back grade. This backing paper fits perfectly with the Gypsum Cream Face paper to produce a quality wallboard construction that can be used in all applications. It is available in 38# and 42# per thousand square feet (MSF). Contact or Customer Service Department for any available variations of this.

All Republic Paperboard products can be customized to fit your needs! Contact our sales team and we’ll be happy to work with you to create the product that meets your exact specifications. Contact Us Today

GENERAL SPECIFICATIONS

Critical PropertiesUOMMinTargetMaxTest MethodMethod Comments
Basis Weight lbs/msf -2.0 as ordered +2.0 ABB Scanner
Moisture weight % 7.5 9.00 10.5 ABB Scanner
Porosity sec/100cc Grade Dependent Autoline Gurley; 5-min 300°F cure
Face Cobb g/100cm^2 0.30 0.80 1.50 T-441 10-min 250°F cure; 3-min 120°F water
Bond Cobb g/100cm^2 0.50 0.70 1.2 T-441 10-min 250°F cure; 3-min 120°F water
ZDT psi -20 BW dependent* ----- T-541 Uncured
MD Tensile lbs/in -10 BW dependent* ----- Autoline 5-min 300°F cure
CD Tensile lbs/in -4 BW dependent* ----- Autoline 5-min 300°F cure
Smoothness Sheffield SU 350 Autoline 5-min 300°F cure
Coefficient of Friction degrees Grade Dependent T-815 Uncured; test 3x, record 3rd value
Expansion 180 sec % -0.30 BW dependent* +.30 CD Wet Uncured; 10” strip

*BW Dependent Targets:

BW38/424854
MD Tensile 83 90 95
CD Tensile 28 32 35
ZDT 80 75 73
Expansion 1.15 1.0 0.80

Additional Requirements:

Surface Quality – Paper shall be uniform in appearance and formation. Examples of defects include, but are not limited to: orange peel, discoloration, tiger striping, streaking, spotting (dirty face), fuzzing, fish hooks, cockles, excessive wire, felt, press roll, or other marking.

Flatness – Paper shall lie flat - free of cockles, edge warp, curling, and grooves.

Holes – Paper shall be reasonably free from holes (no repetitive MD holes). Holes smaller than 3" may be patched (no more than 2 per roll).

Roll Quality – Rolls shall be tightly wound. No telescoping. No wrinkles. No crushed or damaged cores. Splices shall be clearly marked. No splices 1" from the top. Core diameter: 4".

Physical Damage – Paper shall be free from physical defects including, but not limited to tears, edge nicks, excess moisture.

Packaging – Rolls shall be packaged to prevent damage during transport (ex: plastic wrapped). Rolls shall be marked to indicate bond side and labeled with roll number, basis weight, MD & CD tensile strength, top & bond cobb, and porosity.