3526 Chapter 28 



28-14 $1.0 MILLION— MANUFACTURE OF WOOD- 

 FOAM COMPOSITES" 



Wood-foam composites, xylofoam, are mixtures of specially comminuted 

 wood particles and foams, in which the foam is both bonding agent and binder, 

 (see sect. 24-24 and fig. 24-63 for discussion of properties and illustration of 

 products.) 



Briefly, the wood particles are produced primarily by cleavage action on 

 preferably green wood (fig. 18-285), screened for oversize and undersize, dried, 

 and reclassified by air into the size range dictated by the dimensions of the 

 product. A loose mat is formed on a moving belt. Manufacturing sequence is 

 then as follows: 



1 . The mat arrives from the former to the head end of a press at 60 feet/ 

 minute, riding on its backing material or release paper. 



2. Foaming resin is sprayed continuously over the top of the mat as it 

 moves forward. 



3 . The top facing material or release sheet is kissed to the mat as it passes 

 under a film control roll. 



4. The composite sandwich enters the press with foam on the rise. At this 

 point the xylofoam is carrying a cost of 15 cents/pound. Except for the 

 allocated cost of the pressing operation, most of the additional costs 

 are dictated by facing materials, further treatment of the products, and 

 density. 



5. With a belt press 60 feet long, and 4 feet wide, product emerges at a 

 rate of 60 feet per minute. Production rate therefore is (assuming no 

 down time) 240 square feet/minute or 1 15,200 square feet/8-hour day. 



Laboratory experience (no production experience is available) suggests that 

 this output may be profitably converted to three products. 



In the manufacture of an automobile, 20 to 50 square feet of headliners are 

 used for ceilings, package decks, glove compartments, and other interior struc- 

 tures. Usually covered with a fabric, plastic film, flocking, or paper, they form 

 the base for many of the decorative elements in a car. Key product data follow: 



Weight: 0.121 pound/square foot 

 Thickness: 0.150 inch 

 Density: 10 pounds/cubic foot 

 Sales price: $0.05/square foot 



Interior decorative panels, half-inch as well as quarter-inch thick, of rela- 

 tively light weight would find immediate use in mobile homes and recreational 

 vehicles where weight is a major problem. They would compete with lauan and 

 other plywoods, as well as pulp-based fiber products which are either heavy or 

 costly. Key product data follow: 



'Abstracted from Marra (1981). 



