Shortly after joining I&J (Irvin & Johnson) in 1991, I was put in charge of their five Cape Town freezer stores. One of them, now Auckland Cold Store in Paarden Eiland, was an early South African example of the Woodmason’s design using SIPs insulated panels from Rudnev’s South African company. Without knowing any of this history, I am glad to say that I closed three of the brick and cork stores, moving the stock to Auckland Cold Store, which was until recently very much in operation. On the structural front, the US Forest Products laboratory conducted experiments in the 1930’s using skinned timber panels with paperboard/tar paper insulating cores to find an alternative way building houses using less wood. Building timber was seen as a scarce resource. An early example was visited and praised by Eleanor Roosevelt, showing just how much importance was attached to this initiative. Frank Lloyd Wright, the famous American architect, understood the structural strength of these panels, the two skins being compared to the flanges of a steel H beam and the filling being the web, and designed larger structures with minimal internal framework. He also passed the idea on to a student, Alden B Dow. Alden was a member of the Dow Chemical family and realized the advantages of using Dow’s trademark “Styrofoam” to replace the paper core. Styrofoam vastly improved the insulation and durability of SIPs or structural insulated panels, as they came to be known. Indeed, there is a continuing trend toward the use of SIPs in US residential house construction. On the structural front, the US Forest Products laboratory conducted experiments in the 1930’s using skinned timber panels with paperboard/tar paper insulating cores to find an alternative way building houses using less wood. Building timber was seen as a scarce resource. An early example was visited and praised by Eleanor Roosevelt, showing just how much importance was attached to this initiative. Frank Lloyd Wright, the famous American architect, understood the structural strength of these panels, the two skins being compared to the flanges of a steel H beam and the filling being the web, and designed larger structures with minimal internal framework. He also passed the idea on to a student, Alden B Dow. Alden was a member of the Dow Chemical family and realized the advantages of using Dow’s trademark “Styrofoam” to replace the paper core. Styrofoam vastly improved the insulation and durability of SIPs or structural insulated panels, as they came to be known. Indeed, there is a continuing trend toward the use of SIPs in US residential house construction. Hermann Staudinger, who later won the 1953 Nobel prize for chemistry, realized that Simon’s Styrene, a liquid, was actually a monomer which, with a bit of heat or free radical initiators, naturally “polymerized” into a hard rubber like substance, hence the name polystyrene. Styrene is now one of the basic building blocks in the all – pervasive plastics industry. Replacing storax with erethhylene and benzine, the German IG Farben company used industrially produced polystyrene during the early 1940’s to replace heavier zinc castings in many applications, but it was only in the 1954 that Dow Chemical and the Kopper company of Pittsburgh started producing “Styrofoam” and “Dylite” using Otis Ray McIntire’s process of mixing styrene and isobutylene under pressure. Otis Ray McIntire This “foamed” polystyrene was 30 times lighter than the original and 98% air while having structural strength and a low thermal conductivity. It is said McIntire discovered Styrofoam by accident while attempting to develop a flexible insulator for electrical cables as natural rubber was in short supply during the war. (1951) Examining pieces of Styrofoam by Dow Chemical Company So, by the late 1950’s SIPs were manufactured using Styrofoam/Dylite as the filler. The first known use of SIPs in cold storage construction occurred in Australia. During the late 1950’s, Australia was increasing its food exports, primarily mutton, beef and frozen vegetables and needed bigger, more efficient and acceptably sanitary cold stores to hold this frozen produce prior to export. Michael Rudnev, a Russian immigrant who had settled in Brisbane, was manufacturing SIPs panels for residential housing. During 1960, Rudnev with the assistance of CSIRO, (Commonwealth Scientific and Research Organisation), experimented on ways of sticking thin metal, plastic and other materials instead of wood on either side of Styrofoam. He presented his new product using steel skins at the Commonwealth Cold Storage Conference held near Brisbane in 1962, but most delegates thought that SIPs would never replace standard cold store construction methods using brick with internal cork layers. But Frank Vale, MD of Woodmasons, now part of the Swire Group, needed new cold store in Dandenong outside Melbourne. Vale quickly saw that Rudnev’s product could significantly reduce building costs, while giving his freezer chambers sufficient height and space for forklifts. Cork insulation was problematic as it couldn’t satisfy the requirements of the USDA 191 regulations for export Meat Plants or the Codex Alimentarius. Neither would the normal wood or OSB skinned SIPs. Rudnev’s metal skinned panels could be longer, possessed structural strength and had a high R value. The non-corrosive easily cleaned and bacteria resisting metal skins would satisfy the health requirements. FRANK VALE By the late 1960’s Woodmason’s Dandenong store design was being replicated globally as the old brick cold stores simply couldn’t compete. Michael Rudnev then opened SIPs businesses in other countries including South Africa, where he entered into partnership with Durban’s Southey company in 1971. Rudnev panels are still a brand to be reckoned with in the South African market. Shortly after joining I&J (Irvin & Johnson) in 1991, I was put in charge of their five Cape Town freezer stores. One of them, now Auckland Cold Store in Paarden Eiland, was an early South African example of the Woodmason’s design using SIPs insulated panels from Rudnev’s South African company. Without knowing any of this history, I am glad to say that I closed three of the brick and cork stores, moving the stock to Auckland Cold
