JP2009516094A5 - - Google Patents

Claims (9)

A gypsum-based sound absorbing board having a solidified gypsum core disposed between two substantially parallel cover sheets,
The solidified gypsum core is about 75 wt% to about 90 wt% stucco based on the total weight of the core formulation, about 0 to about 15 wt% perlite based on the total weight of the core formulation, and the total of the core formulation and about 2 wt% to about 12 wt% of the paper fibers by weight and it has been prepared from the formulations of cores having a total weight basis from about 0.5% to about 5% by weight starch in the core formulation sound absorbing board characterized by and having a number of sound absorbing perforations through the cover sheet extends in the set gypsum core. The core formulation, said core and stucco about 80 wt% to about 85% by weight based on the weight of the formulation, perlite from about 5% to about 8% by weight based on the weight of the core formulation If the paper fiber weight basis from about 6% to about 10% by weight of the core formulation, the starch weight basis about 0.5% to about 2% by weight of the core formulation The sound-absorbing board according to claim 1. The sound absorbing board according to claim 1 or 2 , wherein the pearlite has a density of about 3.0 pcf to about 5.0 pcf. The sound-absorbing device according to any one of claims 1 to 3, further comprising a cover sheet having a cover and a back cover, wherein the perforation extends through the cover and reaches the solidified gypsum core but does not penetrate the solidified gypsum core. Board . The sound absorbing board according to claim 4, wherein the cover has a pattern that creates a textured appearance when viewed at a distance. The perforations have a diameter of about 0.062 inches and have a diameter of 1800 feet (929 cm). ² The sound-absorbing board according to any one of claims 1 to 5, wherein there are about 1800 per unit. The board is about 0.54 inches thick and the perforations are about 1/4 to about 1/2 inches deep (about 0.64 cm to about 1.27 cm). The sound absorbing board according to any one of 1 to 6. 8. A sound absorbing board according to any preceding claim, wherein the pearlite in the core formulation is present in a weight ratio of pearlite to paper fiber of about 1: 1.1 to about 1: 2. A method of making a sound-absorbing board based on gypsum,
(A) based on water, stucco in an amount of about 75 wt% to about 90 wt% based on total solids weight, pearlite in an amount up to about 15 wt% based on total solids weight, and based on total solids weight Mixing a slurry comprising paper fibers in an amount of about 2 wt% to about 12 wt% and starch in an amount of about 0.5 wt% to about 5 wt% based on total solids weight;
(B) adding a soap foam having a density of about 10 pcf to the slurry;
(C) depositing the slurry on a first cover sheet;
(D) maintaining the slurry under conditions sufficient for the stucco to form a solidified gypsum core;
(E) installing a second cover sheet on the solidified gypsum core to form a sound absorbing board;
(F) drying the formed board to a constant weight to produce a dried board having a density of up to about 20 pcf;
(G) cutting the dried board;
(H) The cover sheet of the dried board with pins having a pin count of about 1800 per 929 cm 2 and a pin diameter of about 1.57 mm so that perforations extend through the solidified gypsum core but do not penetrate. Piercing one of the methods.