T H E J O C R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
AW., 19x9
facturer whose white sample gave up about I mg. of antimony. Another blue sample was from a company which furnished white ware without and gray ware wlth antimony. Four samples from one company, I.blue, I white, and 2 gray, failed t o give any test for,antimony. TABLE II-NUMBER
OF SAMPLES LOSING DIFFERENT AMOUNTS O B ANTISOLUTIONS OF ACETICAND TARTARIC ACIDS None 0.5 mg. 1.0 mg. 2.0 mg. Total White ware.. , . . 9 6 12 5 32 Gray ware.. 4 3 5 3 15 Blue ware , 4 0 0 0 4
MoiiIy
TO
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In general, as much antimony was dissolved from gray ware as from white. A white-coated cup which was made without tin oxide for use in these studies gave up less antimony than a number of the other white and gray vessels. The highest three values were obtained from gray vessels. The results show t h a t enamel ware can be bought, in white and gray, which is free from antimony. LEAD
Lead was dissolved from the ware of only one manufacturer. Vessels treated with different amounts of acetic acid gave up from 2 t o 9 mg. of lead. The freedom from lead shows the desire of practically all manufacturers to keep their product free from such a well-known dangerous poison. E F F E C T O F T E M P E R A T U R E CHANGES
Although no effort was made t o test the resistance of the different vessels t o changes in temperature, a number of the samples failed to hold their coating during the tests. Most of the tests with boiling acetic acid were made by placing the vessels over a Bunsen burner flame after the vessels had been filled with a cold solution of acid. I n some cases the enamel cracked as soon as the flame was applied; in a few instances large pieces of enamel chipped off a t once. I n some other cases the coating seemed t o be sound until the vessel was removed from the flame, when pieces of the enamel chipped off the inside of the vessel. I n one case a dipper was removed from the flame, and placed o n a tilt: table top a t room temperature. Large pieces of enamel came off the inside a t once. I t is evident t h a t considerable differences exist in the ability of the vessels t o withstand sudden changes in temperature. Hardly any of the vessels which lost large quantities of enamel received any more harsh treatment t h a n an ordinary cooking vessel must receive. SUMMARY
Acid tests were made on 61 samples of enamel ware from 26 different American manufacturers. These included white, gray, and blue cups, bowls, and pans. The test most used was made by boiling 500 cc. of 4 per cent acetic acid in the vessel for hr. Some tests were made with I per cent tartaric acid. About half the samples of white and gray ware suffered no loss of glaze on treatment with 4 per cent acetic acid, while nearly all the blue ware was badly affected by 2 per cent acid. The amounts of material dissolved corresponded to the loss of glaze. Seventeen samples from 9 manufacturers gave no antimony. There was no great difference between
7 59
the white and gray ware in the amounts obtained from the 34 vessels which gave from 0 . 5 t o 2 . o mg. of antimony. Lead was found in ware from only one manufact ur er . Pieces of enamel chipped off several vessels under heat treatment no more severe than might be received by any cooking vessel. BUREAUO F CHEMISTRY
u. s.DEPARTMENT O F AGRICULTURE WASHINGTON, D. C.
CHANGES IN OILS UPON STORAGE B y HENRYA. GARDNER Received March 15, 1919
I n various papers’ the writer has called attention t o the storage changes t h a t may take place in oils when ground with pigments. For instance, when paints made with pure raw linseed oil having a certain iodine number are stored for long periods of time, subsequent analysis may show t h a t the oil has a lower iodine number than t h a t called for by the specifications upon which the paints were made. Reactions t h a t are responsible for such changes are of course greatly stimulated a t high temperatures. As a result of some investigations t h a t have just been completed, it would appear t h a t similar but less marked changes may take place in pure oils without the presence of pigments, and t h a t such changes will depend t o a very great extent upon the method of storing and certain other factors. During the early part of 1911 the writer secured a quantity of a number of commercial oils for use in experimental paints t h a t were t o be exposed t o the weather t o determine the efficiency of various oil mixtures as paint ingredients. After the painting tests were made, samples of the pure oils were placed in pint glass bottles having ground glass stoppers. The bottles were well filled, an air space above the oil of more t h a n one inch not being allowed in any instance. The oils were placed upon a shelf in the laboratory where they were exposed t o indirect light and t o ordinary room temperature (in the summer not over 10.5’ F., and in the winter not less than 35’ F.). I n November 1914portions of the oils were removed from the bottles and examined as a check against the original determinations. Air was, of course, admitted during this procedure. During September 1916 the oils were again examined, further quantities being removed for this purpose. The bottles were again placed upon the shelf and allowed t o remain there until March 1919,when further quantities &ere removed for examination. The results obtained on these samples are given in Table I. I n Table I1 are shown the results on a series of oils obtained during 1914 and kept under similar conditions t o those shown in Table I, the analyses being made in September 1916,and in March 1919. 1 “The Effect of Pigments upon the Constants of Linseed Oil,” J . Frank. Inst., 1912, 415-423; ”Changes Occurring in Oils and Paste Paints, Due to Autohydrolysis of the Glycerides,” I b i d . , 1914, 533-540, “A Study of Some Curious Painting Phenomena,” I b i d . , 1916, 681-695.
760
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
TABLE 1-1911-1919 OILTESTS~ Analyses were made when oils were first obtained and again a t three later periods as shown below. Refrac. Sp. Gr. Iodine Sapon. Acid Index a t 60' F. No. No. No. No. at 6 0 ° F . 1 Linseed Oil March 1911.. 0.931 186.0 188.0 2.0 November 1914.. 0.933 185.4 189.6 2.8 1:4867 September 1916. 0.936 190.2 3.3 1.4798 February 1919.. 0.943 l8i:l 192.3 4.8 1.4870 2 Soy Bean Oil March 1911.. 0.924 129.0 189.0 2.3 November 1914.. 0.925 130.2 193.1 4.7 1:4813 September 1916... 0,937 122.0 192.1 7.0 1.4733 February 1919 0.939 121.7 193.4 7.8 1.4721 3 Menhaden Oil March 1911. 0.932 158.0 187 0 3.9 November 1914.. 0.934 156.3 193:7 16.1 1:4850 September 1916... 0.938 191 4 19.2 1.4768 February 1919.. .. 0.940 156:9 191:s 21.3 1.4838 4 Tung Oil March 1911. 0.944 166.0 183.0 3 8 0.946 161.5 190.3 5:7 1:5650 November 1914.. September 1916.. 0.944 158.6 188.7 5.6 1.5138 February 1919.. 0.948 141.12 191.6 6.0 1.5024 Perilla Oil March 1911.. 180.0 188.0 2.0 0.94 0.94 November 1914.. 172.0 195.4 7.4 114i74 193 3 14.8 1.4767 0.939 September 1916. 0.941 February 1919.. lis19 192:l 10.5 1.4817 Perilla Oil (Specia1)s March 1911 . . . . . . 0.94 192 0 189.0 3.2 0.981 November 1914.. 123:8 219.4 20.8 114678 1.000 September 1916. 122.4 220.9 31.2 1.4840 February 1919.. 7 Heavy-bodjed Linseed Oil March 1911 . . .... 0.968 133.0 189.0 2.8 0.992 130.5 200.0 6.3 1:4466 November 1914.. 124.4 206.3 9.0 1.4876 September 1916... February 1919.. 133.5 192.2 11.1 1.4892 8 Lithographic Linseed Oil March 1911 0.97 102.0 199.0 2.7 November 1914.. 0.96 103.4 150.9 13.4 114978 September 1916. 0.974 108.5 137.7 15.2 1.4890 100.2 131.5 18.3 1.499 February 1919.. 9 Whale oil 148.0 191.0 9.2 March 19 11 0.924 138.2 191.2 17.4 1:4820 November 1914.. 0.926 September 1916 ... February 1919.. 01929 136:9 19j:3 20.2 1:4?93 10 Boiled Linseed Oil March 1911 . . 0.941 170,0 172.0 188,0 187.0 3 2.1 7 1:4i95 November 1914.. 0.943 September 19 16.. 1?2:7 193:7 10.9 1:4890 February 1919.. 0:948 1 A11 of the determinations were made a t 60' F except in t h e case of tung oil which had become so viscous by February l 9 i 9 t h a t a temperature of 60- C. was required for the determination of its refractive index. I n determining the iodine numbers of the oils, Hanus solution was used in every case except for the tung oil, in which case Hubl solution was used 2 Hubl a t 60" C. 8 This is a special grade of bleached oil which has become highly viscous, possibly through oxidation, as result of exposure t o air for long period.
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I n Tables 111, IV and V are given the results on special oils, the history of which is given in each table. Previous t o the examination of the oils in March 1919 a record was made of the approximate contents of each bottle so t h a t some information might be on record as t o the amount of air space above the oil and the appearance of the oil. This record is given in Table VI. I t will be noted from a study of the tables t h a t the ageing of nearly every oil causes a drop in the iodine number, which is accompanied by a rise in the specific gravity, saponification number, and acid number. T w o special exceptions t o the rise in saponification num%er are shown by Oils 8 and 13. It is probable t h a t the highly over-oxidized condition of Oil 8 may be held responsible for the results shown. I n the case of Oil 13, the low result may be due t o the condition of t h e oil, a considerable amount of material having precipitated out. This precipitate was of a highly acid character and consequently may have been the means of lowering the acid value of the clear oil. Special attention is directed t o the rapid increase
Vol.
11,
No. 8
TABLE 11-1914-1919 OIL TESTS Analyses were made when oils were first obtained and again a t two later periods as shown below. Refrac. Sp. G r Iodine Sapon. Acid Index No. at 60°F. No. No. No. a t 60OF. 11 Corn Oil November 1914 0.921 124.8 4.1 1.4800 190.1 September 1916... 0.924 121.3 191.1 4.6 1.4707 February 1919 0.926 127.2 5.3 1.4742 191.4 12 Cottonseed o i l November 1914 0.920 111.7 0.9 1.4781 194.3 September 1916. 0.924 110.6 1.4 1.4681 192.9 February 1919 0.925 109.4 193.0 0.82 1.4718 13 Rosin Oil (Low Grade 4 t h Run)l November 1914 ... 0.964 68.9 35.5 32.4 September 1916 0.964 66.0 36 6 31 6 February 1919 0.965 64.4 2216 17:9 1.'5202 14 Treated Tung Oil2 November 1914... 0.882 56.4 101.3 7.7 1.4764 0.884 53.2 103.2 8.0 1.4660 September 1916. February 1919.. 15 Lumbang Oil November 1914... 0.927 162.0 1.0 1.4789 189.0 September 1916 0.926 164.0 188.9 1.9 1.4748 February 1919 0.927 161.2 2.4 1.4749 189.4 16 Sunflower Oil November 1914 0.924 124.6 189.3 7.5 1.4796 September 1916... 0.923 122.2 9.0 1.4712 190.2 February 1919 0.922 130.1 194.2 8.2 1.4747 17 Hempseed Oil November 1914... 0.927 149.4 191.1 3.9 1.4822 September 1916 0.930 146.1 5.0 1.4745 191.0 February 1919 0.930 151.3 4.9 1.4777 191.8 18 Shark Oil 0.910 November 1914 132.8 5.2 1.4815 158.9 September 1916. 0.915 127.4 6.2 1.4722 163.3 February 1919 0.918 121.4 8.9 1.4749 168.9 19 Sardine Oil November 1914 0.919 134.6 177.3 10.4 1.4800 September 1916... 0.962 91.4 180.2 31.1 1.4755 February 1919.. 76.5 188.7 1.4787 1 Considerable matter of highly acid character settled out during 1917. 2 Heat treated with driers and thinned with mineral spirits; as used in the liquid portion of interior flat paints.
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in acid number shown by Oils 3, 9 and 19 (fish oils). It would appear t h a t marine animal oils are very susceptible t o changes which develop considerable- percentages of free f a t t y acid. The- subsequent drop in the acid number of Oil 19 may have been caused by the precipitation of matter during 19x7. TABLE I11 A. S. T. M. AMERICAN-GROWN TUNGOILS Iodine Sapon. Acid Refrac. No. Sp. Gr. No. No. No. Index 201 Oil No. 3 A 0.9 Dec. 1914 167.4 190.0 0.6 1.56424 Mar. 1919 168.6 193.6 211 Oil No. 4 A Dec. 1914... 168.5 189.6 0.6 Mar. 1919 . . . . . . . . . . . 163.3 194.8 0.5 1.50374 A. S T. M. TUNGOILS 222 Oil No. 1 B Commercial 3.8 1.5195 Dec. 1913 0.9395 168.7 192.1 Mar. 1919 (inglass) 0.939 169.4 193.4 2.1 1.5177 Mar. 1919 (in tin)s, 0.945 160.6 192.9 2.0 1.5178 238 Oil No. 2 B American Tallahassee Dec. 1913 0.939 169.5 191.0 0.9 1.52104 Mar. 1919 166.9 193.0 0.6 1.5037 1 Oils 20 and 21 were crushed by the Bureau of Chemistry from two lots of tung nuts grown during 1914 in Leon County, Florida. For d a t a on character of nuts percentage of oil contained therein, evaluation of kernels etc see repo;t of Subcommittee I11 of Committee D-1 on Testing of'Paidi Vehicles, Proc. Am. SOC.Testing Materials, 1915, 21 1. 2 Oil 22 was a portion of a sample submitted t o the American Society for Testing Materials by L. P. Nemzek as representing a large commercial shipment of imported oil t h a t had proved satisfactory in making paints and varnishes. 8 Oil 23 was crushed by the Bureau of Chemistry from nuts grown in China and obtained through the Agricultural Explorer of the Bureau of Plant Industry. For data on character of nuts, percentage of oil contained therein, evaluation of kernels, etc., see report of Subcommittee I11 of Committee D-I, on Testing of Paint Vehicles, Proc. Am, SOL.Testing Materials, 1914, 237. 4 Because of condition of oil, 60' C. required for determination of refractive index. 6 Oil in can streaked with fungus growth.
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On Oils I , 3 and 5 t h e September 1916 iodine numbers have been omitted, since they had been recorded a s being lower t h a n is shown in the 1919 examination. This result not being in accord with the progressive decrease in iodine number, would lead t o
A N D ENGINEERING CHEMISTRY the concIusion t h a t some error was made in these determinations rather t h a n t o the assumption t h a t the iodine number of an oil may drop and then increase. Special attention should be focused on the rather moderate changes in constants shown b y corn oil, cottonseed oil, lumbang oil, sunflower oil, and hempseed oil (Nos. 1 1 , 1 2 , 1 5 , 16 and 17: respectively). These oils were all received in excellent condition and were perfectly clear and apparently free from moisture. These factors may have had much t o do with their keeping properties.
24
RAW LINSEEDOIL Untreated and Sterilized Iodine Sapon. Sp. Gr. No. No. Original Oil Not Sterilized Examined 1911 Original Oil Not Sterilized Examined Nov. 1911 Original Oil Not Sterilized Examined Feb. 1919 Original Oil Sterilized Nov. 1914' Examined Feb. 1919
Acid No.
Refrac. Index
0.931
186.0
188.0
2.0
,.
0.933
185.4
189.6
2.8
1 .4867
0.943
182.1
192.3
4.8
1.4831
0.935
181.5
191.8
0.9
1.4816
RAW MENHADEN OIL Untreated and Sterilized 25
Original Oil Not Sterilized Examined 1911 Original Oil Not Sterilized Examined Nov. 1914 Original Oil Not Sterilized Examined Feb. 1919 Original Oil Sterilized Nov. 19141 Examined Feb. 1919 1 Heated t o 105' C.
place in oil upon standing are due very largely t o autohydrolysis caused by the presence of either moisture or, in some instances, f at-splitting enzymes. Whenever oil is heated t o a temperature of 105' C. for a sufficient period of time t o remove the moisture, and then filtered, a moisture-free, clear and sterile oil will result. Such oil will apparently keep for a long period of time without showing any marked changes. TABLEVI-APPEaRANCE
O F OILS I N CONTAINBRS I N TO ANALYSIS
MARCH1919,
PREVIOUS
0%
No.
TABLEIV
No.
7 61
0.932
158.0
187.0
3.9
..
0.934
156.3
193.7
16.1
1 ,4850
0.940
156.9
191.5
21.3
1.4802
0.938
156.2
190.1
5.1
1 .4802
Most interesting results were obtained with Oils a n d . 2 1 (American-grown tung oils). These oils have shown but very moderate changes in acid value, although both developed rather high saponification numbers, and Oil 2 1 showed a substantial decrease in iodine number. A comparison of t h e value of glass and tin for storage purposes is shown in t h e cases of Oils 2 2 and 23. It seems rather curious t h a t the oil stored in tins should have shown more change t h a n t h a t stored in glass. This may possibly be due t o the action of t h e fungus growth t h a t was in 1919 observed t o be present in the tinned sample. Similar action on the same oil in t h e glass bottled sample may have been inhibited by t h e action of light. 20
TABLB V-MISCELLANEOUS TESTS Analyses made after allowing oils to remain in glass bottles for nearly three years. No determinations were made a t start of test. Iodine Sapon. Acid Refrac. NO. Sp. Gr. No. No. No. Index 3.5 1.4696 87.1 192.4 26 Peanut Oil. . . . . . . . . 0.916 133.2 194.3 7.4 1.4767 27 Poppy Seed Oil.. . . 0.931 152.1 186.4 3.8 1.4791 28 Alfalfa Seed 011 . . . 0.926 0.8 1.4995 153.5 190.1 29 Tung oil^,., 0.937 Very heavy, granular deposit settled out, streaked 1 Source unknown. with fungus growth.
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I n Table I V some data is given on the effect of sterilization of linseed and menhaden oils by heat treatment. The rapid rise in acid value shown by t h e unsterilized sample of menhaden oil, and t h e very moderate rise in acid value shown b y the sterilized oil would indicate t h a t properly treated oils may be made more or less immune from changes of a n undesirable nature. I n the writer's opinion the changes t h a t take
Very slight sediment Vwy clear 3/4 White sediment a t bottom. Globular-like oxidation a t surface 4 =/3 full Completely solidified to white mass, crystalline a t surface 5 1/3 full Very clear 6 '/a full Highly viscous. Clear 7 Q/s full Clear. Slight film a t surface 3 / 4 full 8 Highly viscous 3/4 full 9 White sediment a t bottom. Globular-like oxidation a t surface 10 ' / 2 full Clear ' / 2 full 11 Slight white sediment a t bottom. Clear 12 '/4 full Heavy white sediment a t bottom. Clear 2,'s full 13 Dark sediment 2/3 full 14 Clear. Film a t surface 2/3 full 15 Very clear 16 '/3 full Very clear I / 3 full 17 Very clear '/a full 18 Dark sediment a t bottom 19 l/sfull Dark sediment a t bottom 20 3/4 full Lower third of oil completely solidified to white mass. Upper part clear 21 '/s full Completely solidified t o white mass Clear. I n can 9/10 full. Clear, but sllght fungus 3/a full 22 streaks 23 */a full Completely solidified to milk-white mass Very clear '/a full 24 Very clear 25 '/a full 26 S/4 full Clear 27 full Lower third of oil black mass with white specks throughout and a blanket of milk-white granules a t top The precipitated foots and curious form of oxidation products a t the surface of the fish oils was of a distinctive nature. The solidification of the tung oils t o a white, granular mass is characteristic of these oils when exposed to light for long periods. This condition makes necessary the determination of refractive index a t 60' C. The matter, settled out from the corn and cottonseed oils, was very flocculent and white. 1
'/4
2 3
3/4
full full full
There was unfortunately no analytical data originally obtained on the samples of oils shown in Table V, b u t a t the end of nearly three years' storage the constants would indicate t h a t but slight changes have taken place in t h e oils, with t h e exception of tung oil. This sample was from a n unknown source and may have been adulterated. THEINSTITUT@ OF INDUSTRIAL RESEARCH WASHINGTON, D. C.
WIRE CLOTH AND ITS ADAPTABILITY TO THE CHEMICAL INDUSTRY By ALVIN ALLEN CAMPBELL Received June 11, 1919
Under t h e heading of wire cloth there may be numbered over ten thousand different meshes, sizes, and grades. The term wire cloth even t o the mind of large users is hardly appreciated t o its full extent. The wire cloth industry was started in Scotland many years ago, and t h e first plant in t h e United States was started a t Belleville, N. J., some I O O years ago,
