Mineral fiber insulation having thermoplastic polymer binder and method of making the same

Abstract

A method of forming a fibrous insulation product includes forming at least one fibrous veil including first fibers and blowing a non-aqueous, formaldehyde-free, thermoplastic binder in powder, liquid or fibrous form into said veil during said forming step to form a mixture of the binder and the first fibers. When in fibrous form, the binder fibers have average length of less than or equal to about 15 mm. The mixture is collected on the forming belt and formed into an insulation batt, board or molding media.

Description

FIELD OF THE INVENTION[0001]The present invention relates generally to mineral fiber insulation products and methods of making the same.BACKGROUND OF THE INVENTION[0002]Batt insulation is commonly manufactured by fiberizing mineral fibers from a molten mineral bath (e.g., molten glass) by forcing them through a spinner rotating at a high number of revolutions per minute. The fine fibers are then contacted by a pressurized hot gas to draw the fibers to a useable diameter and length. The fibers are typically sprayed with an organic material, such as a phenol / formaldehyde binder. The fibers are then collected and distributed on a conveyor to form a mat. The resin is then cured in a curing oven. The mat is then sliced into lengthwise strips having desired widths and chopped into individual batts. In some cases, a facing material, such as Kraft paper coated with a bituminous material or other vapor retarder, is added to the mat prior to the cutting step.[0003]Often, the organic material ...

AI Technical Summary

Benefits of technology

[0012]The manufacturing system and method avoids or substantially reduces contamination and other problems associated with phenolic resins by using a non-aqueous, formaldehyde-free thermoplastic polymer binder to bind the insulation fibers. Use of a non-aqueous solution lessens the storage area needed for the binder and generally provides a simpler, cleaner, more efficient process. Further, the final insulation product is formaldehyde-free, or substantially free.

Problems solved by technology

One of the problems with applying aqueous organic binders to cylindrical veils of mineral fibers is that a portion of the binder tends to evaporate prior to contact between the liquid binder drop and a mineral fiber in the veil.

This evaporated binder material becomes a contaminant in the exhaust air stream of the process and must be cleaned, adding significant expense to the manufacturing process.

Further, the binder material on the mineral fibers tends to be sticky and necessitates extensive cleaning of the fiber collection apparatus in order to avoid the formation of product defects.

Another problem associated with the application of the thermosetting phenolic binder material is that a curing process is required.

Typical problems associated with curing include operational costs associated with the curing oven, the cost of handling pollution issues, degree of cure problems and product integrity problems.

However, because these acrylic binders are applied in aqueous form, they are difficult to use since a low PH is required for storage and application, at least when compared with binders in dry form.

It is very difficult to obtain uniformly blended mats of glass and organic fibers using this system.

As with the system of the '584 patent, it is very difficult to obtain uniformly blended mats of glass and organic fibers using this system.

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