Cellulose insulation is made from recycled paper/cardboard. Newspapers, Magazines and now shipping boxes find their end-of-life as cellulose. Because cellulose is based on recycled materials, it needs to go through a thorough process to remove junk.
Recycling and Conversion to Insulation
When newspapers and magazines are brought to the cellulose factories, they are filled with garbage. Some people bring their newspapers in plastic bags. Magazines have staples which need to be removed. Cardboard boxes require a separate process to break down the heavy board. The glue, used to hold the cellulose together, needs to be broken down. For this reason, cellulose manufacturers of various companies develop unique systems to make the recycled materials as clean as possible. Some do a better job than others.
The Components of Cellulose
Because cellulose has a variety of materials, these materials are sorted and ground down. This material is either boiled in water or processed dry. Chemicals are added to make the cellulose flame-resistant. Lately, most companies are using boric acid. Ammonium sulfate is used by manufacturers as well. Even a combination of boric acid and ammonium sulfate.
The Different Methods for Applying Cellulose
Loose-fill in attics and dense pack in walls: The most common cellulose on the market is designed for loose-fill in attics. Dense pack cellulose is usually the same product as the loose fill material. Some manufacturers grind the cellulose differently for dense pack.
Stabilized Cellulose: When using an internal wetting system or wall spray system (with water), starch is added to the cellulose to make it stick in the walls and to allow water to keep the cellulose from settling.
Pest-control Cellulose: Boric acid is well-known for use in the pest control industry. Extra boric acid is added to the cellulose for these products.
Commercial Glue Cellulose: Cellulose can be glued-in-place. This is typically used for commercial applications where cellulose is sprayed to a 4-6″ depth to help with thermal as well as sound control.
Fireproofing Cellulose: This cellulose is used for fireproofing. There are different levels of fireproofing depending on the mix of either gypsum, Portland cement and even other cement products.