630 



THE INDIA RUBBER WORLD 



[August 1, 1919. 



inch, 14 ply. Bone dry 



and, at 6 per cent regain, 49.34 ounces. 



Moisture, per cent 5.28 



Average tensile strength, pounds 204 381 



8.22 

 491 



The straight line plots in Figure 

 increase 



Fig. 2 — Rate of Increase in 

 Tensile Strength with Re- 

 lation TO Weight of Fabric. 



show that the strength 

 n every case is fairly 

 uniform and at the rates indi- 

 cated in Table I. 



The plot of Figure 2 shows 

 the rate of increase in relation 

 to the weight of the fabric. Any 

 expression or formula, therefore, 

 to be used to correct apparent 

 strengths for the moisture pres- 

 ent must embody the weight of 

 the fabric. The rate of increase 

 in streng^th runs by approxi- 

 mately a straight line from 2.69 

 per cent for 1.54-ounce fabrics to 

 17.12 per cent for 49.34-ounce 

 duck. The rate of this increase 

 is very nearly 0.37 per cent per 

 ounce of fabric weight. 



Therefore, there is for every 

 weight of fabric a "correction 

 rate" equal to 0.37 multiplied by 

 its ordinary weight in ounces per 

 square yard. For the fabrics 

 given above this will be as shown 

 in Table 11. 



to correct any cotton fabric for moisture present and 



Moisture R<3>in, percent cf Dry Weight. 

 Fig. 3. Tensile Strength of Fabrics Corrected for Moisture. 



bring it to a condition of 6^ per cent standard regain, would 

 require the use of a formula such as: 



Tensile Strength Corrected to Standard Moisture Regain of 6J^ per cent = 

 Tensile Strength from Machine Reading X [100 + (Rate X 6.5)) 



If tlie above formula be applied to all the preceding tests 

 the plot of Figure 3 will be the result. This indicates a fair 

 degree of uniformity in the results whatever the moisture con- 

 tent may be. 



STEAM HOSE FOR CAR HEATING. 



AT THE RECENT MEETING of the American Society for Testing 

 Materials at Atlantic City, a paper on steam hose for 

 car heating was presented by H. J. Force. The author describes 

 briefly a method of manufacture for steam hose which will 

 neither contract nor expand in service. He said : 



When made from duck alone, steam hose has been 

 found to contract to such an extent in service that in 

 some cases it becomes uncoupled when passing around 

 a short curve. 



Again, the failure of steam hose in many cases has 

 been traced directly to the excessive expansion which 

 takes place after the hose has been in service for some 

 time. This expansion frequently results in the hose 

 blowing off from the coupling, requiring the use of a 

 special clamp to hold the hose on the coupling. 



After making a series of tests, it was decided to build 



a hose of duck with a heavy friction, and then one or 



more layers of braiding, if made from duck alone, hose 



will expand excessively. It is impracticable to make it 



from braiding alone, but with a combination of duck and 



braiding a very satisfactory grade of steam hose can be 



produced which will show no contraction in length and 



no expansion in diameter under the most severe service 



conditions. 



Four constructions of hose were tested, each, however, with 



two plies of braiding over the duck plies with intervening rubber 



layers for anchoring the braiding. All hose was steamed to 



bursting, ten hours a day at 60 pounds pressure. Under this 



test one series of hose showed an average life in eight samples 



of 960 hours, the minimum being 700 and maximum 1,535 hours. 



In this series the number of plies of duck was increased from 



two to three, and this apparently had the effect of nearly 



doubling the life of the hose. 



The detailed construction was as follows : Tube, regular 

 specification steam hose 5/32-inch thick : 3 ply, 23 ounces per 

 square yard with heavy coat of special steam-resisting friction ; 

 first ply of gum to anchor braiding, 1/16-inch thick, regular 

 specification, steam-resisting; first ply of braiding, number 8/3 

 yarn in 5 by 5 strands ; second ply of gum to anchor braiding, 

 1/32-inch thick, regular specification, steam-resisting; second 

 ply of braiding same as the first ply; outside cover, 1/32-inch 

 thick, regular specification, steam-resisting. 

 The author concludes : 



1. That steam hose should be made of a composition 

 of duck and braid. 



2. That machine-made tubes should not be used, and 

 that tubing of three-ply calender should in every case be 

 used in hose to be subjected to any considerable tem- 

 perature. 



100 + (Rate 



Actual Regaii 



: Test) 



J. P. DEVINE CO. PLANT ADDITIONS. 



Increased business during the past four years has compelled 

 the J. P. Devine Co., manufacturer of vacuum-drying and evapo- 

 rating apparatus and chemical apparatus, to build several addi- 

 tions to its great plant at Buffalo, New York. One of these, 

 constructed of steel and brick with the most improved light and 

 ventilating system, 30 by 100 feet, and just completed, houses the 

 vacuum-pump assembly department; another, 90 by 100 feet, of 

 the same material and general plan, in course of construction, 

 enlarges the general assembling department. The foundations 

 have been laid and the steel construction is proceeding for a third 

 addition, a new foundry, 90 by 225 feet, equipped throughout with 

 new machinery, giving greatly increased facilities for casting 

 large commercial tmits. The total investment represented in these 

 plant additions when fully equipped will amount to $200,000. 



