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AVA

Four-hoop winding of the outer skin of a glass fibre house

Housing system based on filament winding

'HOMESPUN' may take on an entirely new meaning if a new housing system developed in the United States gets widely accepted.

The system, by which houses are spun out of filaments like a silkworm's cocoon, was produced as the result of an inquiry ordered by the US Defence Department into how the costs of mili- tary family housing could be reduced.

Among organisations invited to submit proposals were the University of Michigan and Aerojet-General Cor- poration. Both were interested in investigating the potential of the same technology, so they decided that a joint proposal should be submitted by the university's Architectural Research Laboratory and Aerojet's Structural Projects Division.

Their joint proposal was one of three selected by the Defence Depart- ment for the awarding of contracts. The other two successful bidders were General Electric Co. and Carl Koch and Associates, architects, in associa- tion with Kaiser Industries, National Gypsum Co. and Battelle Memorial Institute.

The University-Aerojet proposal suggested filament winding - a process derived from the aerospace programme for the manufacture of reinforced plas- tics structures as the basis for de- velopment of a new building system for family housing.

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Three-unit idea includes a garage

A report on the system has been prepared by Professor Stephen C.A. Paraskevopoulos, professor of architec- ture and director of the project.

The process is similar to the spin- ning of a cocoon. Continuous glass- fibre filaments are coated with a bind- ing resin and deposited on a forming surface called a mandrel. The mandrel rotates at a programmed speed to permit the impregnated glass-fibre filaments to be wound around its sur- face according to a preset pattern. After the desired quantity of material has been deposited on the mardrel it is fully cured and separated from the mandrel.

A variety of shapes can be obtained through the filament winding process, ranging from rectangular to spherical, which makes possible a series of in- teresting dwelling designs.

A rectangular tubular shape, open at each end, was chosen to serve ini- tially as the basic structural unit. Such units can easily be produced and com- bined for housing and community planning purposes in terms of both single-family and multi-family units.

Structural analysis, cost analysis and long-term performance analysis have resulted in the design of a mono- coque tube of sandwich construction. The tube has outer and inner filament- wound skins and a core of lower densi- ty material that provides both struc- tural stiffness and insulation.

A variety of core material was investigated and polyurethane, with a density of 3 to 4 lb. per cu. ft., was selected for the initial production of units.

Fabrication of the shell thus con- sists of three processes. First the inner skin of filament is spun on to the

Far East BUILDER, May 1970

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