Spray-applied cellulose insulation and method

Abstract

A spray-on cellulose insulation and method of application is described herein. The insulation comprises cellulose and an adhesive having gelling properties during application, preferably polyvinyl alcohol. The cellulose includes an additive that triggers gelling of the adhesive upon application to the cellulose. The cellulose preferably also includes a crosslinker for the adhesive. The additive and the crosslinker may be the same, which means the crosslinker is sufficiently alkaline to also trigger the gelling of the adhesive upon application of the adhesive to the cellulose. The gelling of the adhesive allows a reduction in the level of moisture added to the cellulose fibres to below 20%, resulting in an insulation with rapid drying times, reduced risk for fungal growth, lower applied densities and a total moisture content below 30% on an oven dry basis.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to building insulation. More particularly, the present invention relates to spray-applied fibre based insulation, most specifically spray-applied cellulose fibre insulation. BACKGROUND OF THE INVENTION [0002] Sprayed cellulose building insulation is generally made from recycled paper or paperboard stock modified with chemical additives. It can be applied to open surfaces or cavities that will be enclosed later. Cellulose insulation is an alternative to commonly used fibreglass insulation in the form of batts or loose fill. Because of the loose nature of the insulation material, sprayed cellulose fibre insulation can be applied to a wide range of areas, including attics, walls, floors or any other voids or hard-to-reach crevices where batt insulation is not easily applied. It forms a uniform covering throughout the cavity and forms a superior air seal around electrical boxes, wiring, pipes and framing members. To r...

AI Technical Summary

Benefits of technology

The present invention provides a spray-applied cellulose insulation that has acceptable integrity and wet strength for application to upstanding surfaces such as walls. The cellulose insulation has a moisture content of less than 30% on an oven dry weight basis. The invention also provides an adhesive system for use in spray-applied cellulose fibre insulation, including an aqueous adhesive resin and an additive that triggers gelling of the adhesive resin upon admixture with the additive. The adhesive resin can be polyvinyl alcohol or a mixture thereof with other adhesive resins such as polyvinyl acetate. The invention also provides a method for insulating an upstanding surface by applying the spray-applied cellulose insulation to the surface and triggering gelling of the adhesive resin upon application of the cellulose fibres to the surface. The invention further provides a cellulose insulation product including cellulose fibres for spray-application to an upstanding surface, the cellulose fibres having been treated with an additive for triggering gelling of the adhesive resin upon admixture therewith. The invention also provides an adhesive system for use in spray-applied cellulose fibre insulation, including an aqueous adhesive resin and an additive that triggers gelling of the adhesive resin upon admixture with the additive.

Problems solved by technology

Although the potential for gelling of certain adhesives during storage was previously observed as disclosed in the prior art (see U.S. Pat. No. 5,684,068), this effect was considered undesirable and was prevented in the prior art insulation application methods by the addition of an acidic medium to the cellulose fibres.