Milk Powder And Cream From £150,000 Factory

Press, Volume XC, Issue 27369, 7 June 1954, Page 10

Milk Powder And Cream From £150,000 Factory

Another factory was added on Saturday to the growing list of those operating in the Christchurch area. It was a “milk balancing station,” where whole mill? surplus to the requirements of the city milk supply , will be treated. a \

Situated on the Main North road, just north of the Waimakariri river bridge, the factory belongs to the Canterbury Dairy Farmers’ Co-opera-tive Milk Supply Company. Production has begun scarcely a year since work on the bare section commenced.

Practically the only use for surplus milk before the construction of the balancing station was to separate it and sell the sweet cream. The new factory will produce not only sweet cream —which can be stored in refrigerated chambers on the premises—but also about 700 tons a year of dried skim milk.

The equipment is housed in a spacious building of concrete blocks, which was erected by the Fletcher Construction Company. The high stud of the single storey provides plenty of storage space and allows for the mezzanine floor where a single operator can watch several processes- at once.

The factory is situated on the highest piece of land along the road from the river to Kaiapoi; a reporter was told on Saturday that flood waters have never covered the section. As an added protection, the whole floor of the factory is raised an average of 3ft above ground level—though this is mainly- for convenience in handling. The platform on to which the cans are unloaded is the height of a truck deck. and . the processed milk and cream is loaded on to trucks further along the same platform. The manager’s residence, lawns and gardens, a sealed drive, and an ornamental fence are improvements to be. added to the site as time permits. The* company intends to make the surroundings of the factory as pleasant as possible, maintaining the tradition of Christchurch factories of providing attractive settings.

Mechanisation and speed in handling and processing are features of the factory. A staff of 10, including the manager (Mr M. Gale) and two women will probably be sufficient to handle all the operations carried out in the £150,000 station. One of the most .important factors of sucess in such a factory is the speed with which the whole milk is turned into cream and put into refrigerated storage and into milk powder, packed in specially-lined bags. The separating capacity of the station is 4400 gallons an hour, and although the skim milk cannot be handled at a comparable pace, huge storage vats keep milk cool till it can be processed. When a truck draws up at the loading platform <ttie vats are pushed on rollers across W tbe weigh pen, which can take up to 200 gallons of milk. Samples are taken herecx>f each batch of milk and tested in the adjoining laboratory, and the quantity of milk sent in by each supplier is recorded. A device constructed on the same principle as the glass-washing moving belts in modern hotel bars washes and sterilises the. .cans, which are returned to the platform or stored in a storeroom as required. The milk, when weighed, gushes

through a plughole into one of two 1000-gallon stainless steel tanks covered to prevent contamination. At this point the liquid disappears from sight until it emerges in processed form as sweet cream or milk powder. AU tanks, vats, pipes, valves and other equipment through which the milk passes is stainless steel with a mirror finish.

The tanks into which the weigh pan discharges are placed in a well which, with its gleaming metal fittings, and spotless tiled floor and walls, creates the atmosphere of a bathroom rather than a factory. • Pumped up to the mezzanine floor from these tanks, the (milk is separated in. four outsize separators, each with a capacity of 1100 gallons an hour. The milk first passes through a pre-heating plant, which raises the temperature—usually about 60 degrees Fahrenheit—to blood temperature. The pre-heating plant, which operates on the plate principle, is so designed that the “chill” imparted to the plates by the incoming whole milk is used to cool the separated skim milk, most of which must be stored until it passes through the next process. One man standing on the mezzanine floor can regulate by switches the flow of milk from the tanks in the well, the speed of the pre-heating plant and the speed of the separators. Pasteurised in tw6 250-gallon batch pasteurisers, the cream is quickly cooled, first by aerators and then—if for deep-freezing—by “blast” refrigerators. The cream is then stored in a storeroom lined with six inches of cork. Floors of refrigeration storerooms resting on the ground sometimes buckle and crack as the ground freezes, so the storerooms of the factory are raised well clear of the ground. There is enough storage space at the factory to hold £50,000 worth of frozen cream at one time. Skim Milk Treatment

.The treatment of the skim milk is rather more elaborate than that accorded the cream. Passing into another room through overhead pipes, the milk is kept in stainless steel vats until it can be handled by the “pre-con-centrator.” The function of this £l3OO piece of equipment is to evaporate some of the moisture before the final process, which reduces the jnilk to powder. Because a lower atmospheric pressure lowers the boiling point of any liquid, a partial vacuum is created in the pre-concentrator, with a consequent saving of fuel. The remaining moisture in the milk is expelled in the roller-driers, in which .steam is kept at a temperature of 512 degrees, and the “milk” comes off the rollers in a thin film, Bft wide. The maximum efficiency of the rollers is secured when they can be kept clear of steam, and an improvement invented by a New Zealand engineer, has been incorporated in the factory’s driers. It consists of a channel which collects the moisture from the rollers. The exhaust steam from the plant is returned, by an inverted funnel, and ft. flue, to the boiler, thus making a further saving of fuel.

The film of dried milk, which [ crumbles at a touch, is milled and r sifted before being bagged ready for , dispatch. The 801 b bags are of hessian, lined with polythene, which keeps the , product fresh and repels moisture.