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Hardwood Record — Veneer & Panel Section 



January 10, 1917 



MEDFORD VENEER CO. 



MEDFORD, WISCONSIN 

 Specialists in- — ^ 



High-Grade, Rotary-Cut 

 BIRCH VENEERS 



Northern Grown Woods ] 

 Modern Equipment ! 

 Experienced Workmen J 



I Soft Textured ipd 

 = 1 Higfa-Grade Venciers 



i 



I Smoothly and Accurately 

 Cut— f-ScientifieaUj: Dried 



Also manufacturers of 



SINGLE -PLY 



various sizes and 

 Ash, Basswood, 



VENEERS jn, 



thicknesses from 



Elm and Maple 



Drying by Machinery 



The veneer inaiiufacturiiig aud using trades liave been rather 

 slow, as a general proposition, to come around to the idea of 

 using mechanical methods of drying. Some sort of air drying 

 system, more or less crude, but based on the fundamental idea 

 of circulating warm air through the stock, is usually found, and 

 these methods have produced reasonably good results. They have 

 dried the stock, but they have not turned out the veneers in a 

 flat condition, nor have they been able to maintain unifoimity 

 of jiroduction, for the reason that varying conditions of the 

 atmosphere have affected the rate at which elimination of moisture 

 has been possible. 



It has been interesting to observe how the present activity in 

 the veneer business, due largely to the big rush which is on in 

 the furniture trade, has resulted in manufacturers turning toward 

 mechanical dr_ying methods as a means of speeding up their output. 

 The mechanical system has air-drying beat a long ways, not only 

 in uniformity, which is a bigl advantage in itself, but in the rate 

 at which the stock can be turned out; and when a concern finds 

 itself unable to keep up with orders, help of this kind looks 

 mighty good. 



Two instances are known where veneer drj'ing equipment has 

 been installed recently. In one plant two machines have been 

 used right along, and the third was installed because the manu- 

 facturer knew how much it could help to stimulate production. 

 In the other plant, the old-time systems had been used for years, 

 and the arguments of manufacturers of mechanical dryers had 

 never been availing. With orders coming in rapidly and diflSculty 

 being experienced in keeping up with them, however, the concern 

 turned in the direction of mechanical methods, determined to try 

 ihom out and see whether the benefits would equal promises. And 

 without much doubt this is what is happening in a lot of other 

 places. 



Some Important Points in Selecting and Operat- 

 ing Veneer Presses 



Tlic laying of veneered panels requires considerable experience, as 

 tliere are so many things to interfere with the making of a first class 

 1 anel. There is considerable difference of opinion in regard to the 

 amount of pressure necessary to do this work. A great deal of stock 

 is spoiled on account of having received an insufficient amount of 

 [uessure. However, very little stock is damaged by applying too much 

 pressure. Any damage resulting from an over-pressure is easily 

 detected, while damage from too little pressure may not become 

 a]iparent until the panel has been made up and finished. The only 

 damage from over-pressure is in crushing the cores where a soft wood 

 is used. 



There are a great many grades of work being put up at the present 

 lime. This work ranges from the first-class panel ma<le up for fine 

 furniture and interior finish to the cheap three and five-ply panels used 

 in building jiacking boxes and cases. The amount of pressure required 

 to do good work depends largely upon the class of work that is being 

 u:ade. The finer the work the better it is necessary to prepare the 

 surfaces. Nicely prepared panels do not require quite so much pressure 

 as the rough ones. It is well to use all the pressure that can safely be 

 ai)plied without crushing or distorting the cores. 



For large panels very heavy presses are required, but some manu- 

 facturers are tempted to install a lighter jiress than is necessary to 

 ilo good work. Some very good veneer work may be accomplished 

 \\here the surfaces are nicely prepared with 100 pounds pressure per 

 sc|uaie inch on the panels, but it is an unusual occurrence. For the 

 coarse panels used in packing boxes and cases, about 200 jiounds per 

 square inch is advisable in order to bring the surfaces closely together 

 and to force out all of the air and surplus glue. For ordinary work 

 l.")0 pounds pressure per square inch is a safe pressure to obtain good 

 work. Cores of most any kind of wood will stand up under this 

 jiressure, and the pressure is sufficient to bring the surfaces firmly 

 together and to prevent the pocketing of the glue. 



Veneering should be done as rapidly as possible, especially where 

 high-grade work is being done. In this case the veneers are very thin 

 ami the cores heavy. When the veneer is placed on the core, the wet 

 glue i)cnetrates very quickly on account of the thinness of the face 

 stock, and it immediately begins to swell. Being heavy the core is not 

 jienetrated so quickly and, of course, it docs not swell so rapidly as 

 the veneer. When the pressure is applied there is no chance for the 

 veneer to contract, as it dries. The pressure is held on the package 

 until the ]ianels are perfectly dry. If the panels go from the press 

 room to the finishing department and are finished quickly the checking 

 quite froi|uently does not take ]dace until after the varnish has been 

 applied. This causes the checking of the panel, which is frequently 

 laid to the finishing department instead of the press. The checking 

 may be overcome: First, by applying sufficient pressure; second, by 

 applying it quickly before the veneer or the core has a chance to swell ; 

 third, by a])plying the pressure uniformly the same on each scjuare 

 inch of the package. 



The glue manufacturers quite frequently have to answer for defects 

 in panels that are caused by too little pressure being applied when the 

 veneer was laid. Immediately on finding defective panels caused by too 

 little pressure the blame is laid at the door of the glue manufacturer 

 because this is the easiest thing to do. Th(' veneer manufacturer 

 does not think to look into his pressure methods. If he would, he 

 would probably find that the press manufacturer has furnished him 

 with a jiress unsuitcd for his work and with too little juessurc. There 

 are a great many secret processes for making glue used on veneers to 

 some extent in this country. These originate mostly in Germany and 

 requires presses with hot plates. This process is quite different from 

 the regular jirocess of laying veneers and rf<iuires different treatment. 



By Frank B, McMillln, general manager and sccrctiirj' of the Il.vdraulic 

 Press Manufacturing Company, Mount Gllcad, 0, 



All Three of Ui Will Be Benefited if You Mention HARDWOOD RECORD 



