The basis for most cotton goods is starch which is also used largely for sizing wool although gelatin is also used considerably for wool . In addition there are oil sizes consisting of linseed oil which is caused to oxidase these certainly give warped which find considerable use in the weaving of rayon and especially nylon as they are emulsions they are easily removed if properly prepared . Finally there are adventitious aids to weaving such as the wax rods used by weavers for rubbing difficult warps these are frequently plain paraffin waxen extraordinary thing to use when wax rods containing emulsifying agents are available at almost the same price.
The diastolic ferments convert starch into dextrin and maltose. The action is conditioned by the following factors (a)temperature of action (b) time of action (c) P H value of the solution (d) presence of other substances.
Diastase begins to be destroyed at 65 deg. C . and decomposition is rapid at 70 deg. C . There are certain products of bacterial origin claimed to be resistant to higher temperatures but their efficiency is greatly reduced. The optimum action of all type seems to be obtained at about 60 deg. C. In commercial diastolic the enzyme is found accompanied by a natural protective agent which may be carbohydrate in character :This agent is present only on diastoforsof vegetable origin and the bacterial types are more stable after a certain amount of designing has been accomplished . Stability to temperatures near 70 deg. C . should always be tested because lack of stability may cause waste under practical conditions careless workmen may put the diasto for into cold water and heat up with an open steam pipe instead of getting the bath to the required temperature before adding the malt or the temperature of the bath may be allowed to rise above 65 deg.C.
The time of action is related to the concentration. A certain weight of starch mey be removed quickly by a high concentration of diastase or more slowly by a lower concentration . In determining the amount to be used the cost of maly must ne nalanced against the cost of time usually maly will be found the cheaper of the two .
Malt extracts are very sensitive to P H even a small deviation from P H 7 having very noticeable effects 1/10 oz . of soda ash or one tenth pint of H C I per 100 gallons is sufficient to have a noticeable effect.
operation of a given product should therefore be known and works conditions examined to ensure that the range is not exceeded. Bacterial enzymes are much less sensitive to alkali than vegetable enzymes and it is possible with the former to design in a soap scouring bath free from alkali at the cost of using a decidedly higher concentration than would be required neutral.
