CLEANING OF MILKING-MACHINES.

New Zealand Journal of Agriculture, Volume XXX, Issue 1, 20 January 1925, Page 8

CLEANING OF MILKING-MACHINES.

J. W. SMITH,

Dairy Instructor, Palmerston North

In the course of his visits to farms for assisting and instructing farmers in dairy-work the writer has found many and varied methods of cleaning milking-machines in vogue, and is satisfied that there is a laudable desire on the part of users to keep their machines in a clean condition, and to carry out the work in a way which will ensure the longest possible working-life of all parts, particularly the rubberware. In many cases more time is spent on the work of cleaning than is really necessary, the life of the rubbers is shorter than need be, and, in addition, too much faith is placed in the supposed merits of more or less costly commercial preparations for cleaning dairy appliances. Some cleansing-material is necessary to remove greasy deposits left by the milk, and no material will effect this more thoroughly or at a lower cost than a solution. of. soda. Either washing-soda or caustic soda may be used. Care and judgment must be exercised in using soda solution, for should any get .into the milk the effect is disastrous,: especially when the milk is for making, into cheese. Furthermore, damage may result to the machine or other apparatus to which a soda solution is applied if the latter is not promptly and completely removed after use. THE CAUSTIC-SODA-AND-BOILING-WATER METHOD. Of the many methods which have come within the writer’s experience he would direct special attention to the caustic-soda-and-boiling-water method, which a number of practical farmers have been using for about two seasons with excellent results .in respect to the sanitary condition of the . milk, the cleanliness of the machine, an extended life for the rubberware, and a considerable saving of time.

The writer has been demonstrating and recommending this method, for several months., and is confident as to its efficiency, provided it is carefully carried put,„.,„, ■ The quantity of boiling water required is small, but the water must be at boiling temperature—not merely hot or warm. The hot : water from the jacket of an oil or benzine engine is not ■ sufficiently high in temperature, and therefore its use is not recommended. The causticsoda solution must be well stirred • and thoroughly dissolved in the boiling water. • The solution will not spoil tinned ware, provided it is rinsed off immediately after use. Care must be taken to prevent the solution lodging in the milk-holding vat. - 'No scrapers or spiral

hair-brushes are necessary for cleaning the, inner surface of the rubbers, and scoring is thereby avoided. [The outside as well as the inside of the rubbers must be kept clean, otherwise their life is shortened. Rubbers after being cleaned should be laid out without bends or twists. To operate the method successfully it must be done immediately after milking. The time taken to complete the work need not exceed twenty minutes. The essentials required at the milking-shed are(i) a suitable plant for boiling water; (2) a stock of caustic soda; (3) an ample supply of clean water; (4) some scrubbing-brushes, large buckets, a suitable bath or tub, and a ball of horsehair. To operate the method the procedure is as follows : — (1.) Before milking' draw cold, water through all milk-tubes and the releaser, so as to prevent the adhesion of milk to the pipes, &c. (2.) Immediately after milking wash all dirt off the .'outside of the teat-cups and rubbers; then draw through each set of teat-cups

sufficient cold (or preferably warm) water to flush out the milk-system. When drawing the water through the set farthest from the releaser insert a ball of horsehair in the end of the milk-pipe, to cause it to travel through to the releaser with the water. (3.) Next draw through each set of teat-cups not less than 1 gallonof boiling water to which caustic soda has been added at the rate of not less than one to tablespoonfuls per 4 gallons of boiling water. Distribute the solution as evenly as possible through each set of teatcups. (4.) Immediately follow by flushing out the caustic-soda solution with 2 gallons of hot water or 1 gallon of boiling water for each

set of teat-cups. The flushing with boiling water helps to dry the rubbers and leaves the milk-system dry and sweet. (5.) Then remove or open the plug or flap from the releaser-pipe, to allow of free circulation of air. . V (6.) Next clean the vacuum-system in the same manner as the milk-system, by drawing through first the caustic-soda solution, and next the boiling water which has been circulated through the milksystem. Pay particular attention to the cleaning of the pipe connecting the' releaser to the vacuum-tank, by flooding the releaser to cause the water to travel through to the -vacuum-tank. . This is important. ' : ‘ ’ f ' ' ■ (7.) The engine can now be stopped. Disconnect the two long rubbers from downpipes and teat-cups, and hang in a clean airy place out of the sun. - -

(8.) Next disconnect the releaser, wash, rinse, and place in a clean, dry, sunny place ; then disconnect the top or bottom half of the vacuum-tank and treat in a similar manner. To ensure effective cleaning by . this method it is essential that it be carried out daily in the manner directed. The caustic-soda solution instantly removes the greasy coating left by the milk on the inner surface of the tubing, and the final flushing with boiling water ensures the removal of the caustic-soda solution. In a short time the inner surface of the rubbers, through the action of the caustic soda, will become coated with a hard glass-like surface. If, however, the method is not carried out daily in the manner directed the grease will penetrate into the rubber, and it will then be necessary to revert to the use of spiral brushes, which in turn will damage the inner surface, as indicated in the accompanying illustrations. The photographs are of rubbers which have been in actual use and subjected to different methods of cleaning. These serve to demonstrate the good results obtainable by the use of the caustic-soda-and-boiling-water method of cleaning.