Patent GB-191300571-A (GB)
Title: Improvements in the Manufacture of Glue.
Inventor: HEIDE HENRY CONRAD
IPC: C09H3/00
Filed: 1913-01-08
Granted: 1913-10-09
Abstract: 571. Heide, H. C., [Perkins Glue Co.]. Jan. 8. [Addition to 24,692/11.] Starch-.In the process described in the parent Specification, for making a wood-glue substitute from starchy materials, according to which starch flour is treated with caustic soda or potash, without any preliminary treatment of the starch, particular strengths of the caustic alkali solution are selected and the times occupied in adding these solutions to the starch material are modified. Modifications of treatment are used for different starches and flours used, those obtained from corn, wheat, potato, and sago palm being suitable, but particularly those of the cassava plant sold as high-grade cassava flour. In examples: (1) 250 1b. of this flour, air-dried, is thoroughly stirred with about 300 lb. of water, and, when the mixture is complete. about 450 lb. additional water is added rapidly and the whole thoroughly stirred for at least half an hour, or better, stirring longer or allowing the batch to stand over night and then stirring up again. To the milk so prepared is added, with extreme slowness, about 25 lb. of caustic soda, about 96 per cent pure, or an equivalent quantity of caustic potash, dissolved in 50 to 75 lb. of water. If more water is used, the proportion in the original mixture should he reduced. (2) The same flour mixed with 2-73 times its weight of water at about 140‹ F. is slowly treated with the same solution of caustic soda, the alkali being 2 per cent of the weight of the starch, and the temperature being maintained or, preferably, raised to 150 or 160‹ F. (3) Raw potato starch is mixed with 2-7 times its weight of water, as in the first example, and 10 per cent of caustic soda is added similarly in about ten hours with continuous stirring. (4) Raw cassava starch, best quality, is mixed with 2-7 times its weight in water and similarly stirred, 5 per cent of caustic soda is added similarly in about half an hour, with subsequent continuous stirring for one hour. A. further 5 per cent of alkali is then added, with subsequent stirring for half an hour. (5) In general, any suitable starch or flour is mixed to a milk with from 2 to 4 times its weight of water, according to the density of the glue desired, and heated to 130‹ F. so gradually that it is not tumefied, and is then treated, with constant stirring, with about 4 per cent of its weight of caustic soda, 96 per cent pure, dissolved in about three times its weight of water. The addition of the soda is continued to such a point that the batch assumes a white creamy consistency, with but little tendency to agglutinate in transparent masses of considerable size. The stirring is then continued for one-half to three-quarters of an hour and the same soda solution is added to bring its total amount up to 7 to 10 per cent; the batch is then further stirred, allowed to stand an hour or two and finally stirred again before being applied warm. The use of a raised temperature during manufacture gives rise to more fluid 'glues' and permits the use of smaller quantities of caustic alkali which may be added more rapidly. A method of determining the desired end-point of the alkali treatment is described.