Innovative farmers of the Midwest, in the early 1900s, are the inventors of the insulation blowing machine. They already had equipment that moved material (silage) into their silos. The dense, moist feed had to move quickly to fill silos a hundred feet in the air. When the need to insulate homes rose, these innovative farmers invented blower which moved cellulose insulation into the attics as well as walls of the homes. Unfortunately, a picture of the earliest insulation machines does not exist. However, we do know from a patent filed in 1940 that he earliest machines were loosely based on the silage blowers. Insulation was passed through a chamber where vanes, tipped with a flexible material (not sure what that material was), would introduce the material to a stream of air. These material tipped vanes would prevent the material/air from blowing back up into the hopper. The 1940 patent by Patterson, introduced a number of improvements (and not so good changes) to the original idea.
Patterson’s Machine
Patterson’s Auger mechanism
Patterson’s “Insulation Blowing Machine,” 1940
Patterson made important contributions to insulation machine equipment. He modified the hoppers that he called a “chute.” He was critical of the material tipped vanes because the material was short-lived. Patterson did away with the airlock concept. Instead of relying on the sealing action of the flexible material, Patterson developed a screw-feeding mechanism which compacted the cellulose, preventing the air from backing up into the hopper.
Patterson’s Picker
When the material was compacted, this slug then needed to be broken by fingers (he called a “picker”) that could be adjusted to break the material into large or small particles. So we have two initial concepts for insulation machine design.
The original machines incorporated an airlock and Patterson introduced a picker to break up the material. We also see two problems to overcome with machines designed to blow material. The first problem is preventing the air stream from flowing back into the machine instead of driving the material out of the machine. Also, another complication was how to prevent the material from plugging the machines. Patterson’s picker solved that issue.
Wedebrock’s “Blowing Machine for Insulation and the Like,” 1945
Sideview cutaway of Wedebrock’s Blowing Machine
Within 5 years, Wedebrock, of Johns-Mansville introduced some major improvements. In fact, most insulation machines look alot like Wedebrock’s machine today. It appears by comments in this patent that up until 1945, blowing insulation was concerned with the actual function of blowing and not concerned with efficiency and coverage. Wedebrock improved earlier designs by incorporating Patterson’s auger and adding a rotating breaker bar with arms to condition the material inside the hopper.
These breaker arms are used in nearly all machines today, with one exception– Cool Machines (more on that below). Proper blowing of insulation involves breaking the material into small chunks that are fluffed to provide a consistent flow of material and even distribution in the attic spaces. Wedebrock’s stated goal was to provide a “steadier discharge” and “uniform coverage.”
Closeup of Auger System in Wedebrock’s Blower
The hopper improved Patterson’s “chute.” A larger hopper with one vertical wall and one slanted wall helped with the consistent feeding of the screw below. This larger hopper and breaker arms now allowed the machines to handle all known materials: cellulose, rock, slag and glass.
Still, the airlock concept was abandoned. To prevent blow-back into the hopper, Wedebrock designed a “Y” tube which narrowed to very close proximity to the screw and it was slanted to follow the direction of the air. Again, the idea was to use the material compacted in the screw with the advantage of a “Y” connection.
Elements of insulation machines that have survived since the original machines
Now that you have seen the differences between the original machines, Patterson’s and Wedebrock’s you may recognize some common elements in today’s machines.
Today’s machines have large hoppers that match the footprint of the entire machine in size.
Rotating arms to break up material in the hopper
Patterson’s picker element is incorporated in some machines.
The screw auger is common.
Fortunately, the airlock concept was brought back with some major improvements.
Learning from history and innovating for the future
Insulation machines find their origins in farm equipment. It is the goal of farm equipment to basically accomplish one task–move alot of grain. When blowing mineral fibers, attention to the following is critical:
Eliminating hopper blow-back. Losing air back into the hopper is a nuisance and means that proper PSIs are not being achieved for dense packing. It also means that your production rates drop significantly. Improvements to the airlock design overcome the original disadvantages. Airlock seals, made of heavy-duty rhino hide rubber will give you hundreds of hours of operation between changes. With the Cool Machine brand, you are able to easily change these seals with removable airlocks.
Conditioning the material properly for bridging-free, clog-free operation and uniform coverage. You cannot dump a compacted bale of material into a hopper and expect a screw-type mechanism, alone, to properly condition material. Nearly every manufacturer today incorporates the Wedebrock-style of rotating breaker arms. These breaker arms actually create a bridging problem in the hopper. Cool Machines has taken the auger concept and incorporated it BEFORE the airlock. The augers push the material into high-speed shredders THEN introduced into the airlock providing the most uniform and clog-free operation of other machines on the market today.
Providing high PSI for proper dense packing. The airlock is critical to produce 3.5 and above PSI pressure for proper dense packing. As an insulation contractor, you are well-aware that low PSI means your material will, over-time, sag. The airlock with heavy-duty seals will give you appropriate PSI.
What about the rotating arms? Aren’t they necessary to properly condition the material? Actually, the rotating arms in the hopper is a bad idea. First, concern for the safety of the operator. It is never a good idea to put spinning arms just inches away from the operator’s hands. Second, the rotating arms create bridging issues. When bales are thrown into the hopper, these arms have the common problem of pushing material back up. They prevent the material from dropping to the bottom of the machine. Yes. Nearly every manufacturer uses them. Once you try a Cool Machine, you will see that much of the industry is still stuck in the 1940s.