Apparatus and method for controlling moisture in the manufacture of glass fiber insulation

Abstract

Apparatus, systems and methods for monitoring and controlling the amount of moisture introduced into the forming hood area in the manufacture of mineral fiber insulation products. Moisture from coolant liquids, binder dispersions and binder diluents are all introduced deliberately into a forming hood; ambient moisture and water from combustion are additional sources. A series of global variable control valves, one for each fluid system; as well as individual variable control valves for each fiberizing unit are provided with associated meters. Sensors monitor fibrous pack conditions and ambient conditions and provide inputs to the valve control system. A specific 3-ring liquid dispensing system is also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U. S. provisional application Ser. No. 61 / 421,306, filed Dec. 9, 2010, the entire contents of which is incorporated herein by reference. Also incorporated herein in their entireties are U.S. provisional applications bearing Ser. Nos. 61 / 421,301, and 61 / 421,304, and 61 / 421,310, all filed Dec. 9, 2010.BACKGROUND[0002]This invention relates in general to insulation products made from mineral fibers such as fibrous glass and, in particular, to methods and apparatus for controlling product properties by monitoring and controlling moisture in a forming hood.[0003]Fibrous glass insulation products generally comprise randomly-oriented glass fibers bonded together by a cured thermosetting polymeric material. Molten streams of glass are drawn into fibers of random lengths and blown into a forming chamber or hood where they are randomly deposited as a pack onto a moving conveyor or chain. The fibers, while in tran...

AI Technical Summary

Benefits of technology

[0050]In yet another aspect the invention provides a method of improving the stiffness, vertical weight distribution or surface quality of a fiberglass insulation product, said method comprising;

[0053]curing the binder in the pack, wherein the fiberglass insulation product has at least one property selected from stiffness, vertical weight distribution or surface quality that is improved compared to a fiberglass insulation product manufactured in a process wherein the rate of binder delivery is constant at all fiberizing units.

[0060]In yet another aspect, the invention is directed to a method of reducing corrosion of downstream air components of a manufacturing process for making a fibrous product, the manufacturing process including attenuating molten material into fibers at a plurality of fiberizing units associated with a conveyor moving in a machine direction, and directing the fibers onto the conveyor to form a fibrous pack using negative pressure created by downstream air components including a suction fan; spraying the fibers with an atomized stream of formaldehyde-free curable binder dispersion; and curing the binder in the pack; the inventive method comprises:

Problems solved by technology

Vaporization or “flashing” of the binder dispersion in the forming hood is a significant problem for multiple reasons.

Environmental concern with binder emissions is a first problem, leading some state and federal regulatory agencies to prohibit the release of binder solids or vaporized gasses into the atmosphere.

Secondly, binder can accumulate on the equipment in the forming hood, including the chain, the side hoodwalls and downstream air ventilation equipment, causing higher costs for increased binder usage and for cleaning the binder from the equipment.

Finally, physical properties of the insulation pack may be adversely impacted by binder concentration and viscosity.

Binder and / or glass fibers that stick to hood walls can dislodge into the pack causing wet spots or splotches of higher density.

In addition, a product may not achieve a desired thickness prior to curing in the oven, and may not meet intended specifications for R-value.

This tends to minimize vaporization of the binder; however, the addition of coolant water causes other problems such as waste water control and wetter packs that require further energy to cure in the drying oven.

Images