Before describing in detail the processes involved in paint making and color grinding, it is well to consider briefly the general arrangement of the plant, the necessary machinery, apparatus, storage and facilities for handling the raw material and requirements for shipping the finished products.
The writer is well aware, that much will depend upon the capital that is available and the size and capacity of the plant, and whether it is contemplated building a new factory, where all conditions can be planned and controlled from the very start, or whether an old factory must be used with machinery in operation, that is still too good for the scrap heap, or where conditions of site will not permit desirable or modern arrangements, yet it is possible to point out ideas from which the paint manufacturer may approximate plans to improve upon existing conditions.
It may be well to state right here, that true economy will often consign to the scrap heap a mill, mixer or other apparatus, that might be still used for years, but at the expense of yield in production, quantitatively and qualitatively. By working with antiquated apparatus, it is difficult to compete with those owning modern equipped plants and it has been asserted by those who have made efficiency a study, that more paint and other factories have failed, because of the use of antiquated machinery and systems or processes, than from any other cause.
In selecting a site for a plant, the first consideration, of course, should be facilities for transportation with opportunity to introduce railroad sidings, if the size of the output warrants such, or at least close proximity to shipping terminals, because cartage is quite an item of expense.
As to the factory building or buildings, the arrangements should be such, that really only the storing of the raw material should require any amount of power, while the progress of the material during the process of manufacture should be accomplished by gravity. Hence, wherever a factory building is of sufficient height, it should be so substantial that the heavy raw material can be stored on the top floor and the mixing with the vehicles should be done there or on an intermediate or half floor immediately beneath, while the mills are stationed on the floor next to the storage and mixing floor, and the pastes may be fed directly into the hoppers of the grinding mills without further handling.
Of course, this can apply only to factories having a large output of staple goods, because it would not be very economical to clean large mixers and mills very frequently to permit changing from one color to another.
Whenever possible, when the output of the mills is to be used as the base for liquid paints, it should be chuted right into the liquid paint mixer, which should be so arranged, that when the product is ready to be filled into containers, such as barrels, kegs, kits or cans, the liquid mixer can be raised to convenient height from the floor, and the containers filled without using intermediate filling cans, thus preventing waste.
If a floor still below this is at hand, the final handling, such as closing packages, labeling, marking and shipping can be done conveniently here, or if the filling has been done on the ground floor, then ample room should be provided for doing this work. In paint factories, where much of the output is for supplying jobbers and dealers, quite a large stock of colors in oil and ready mixed liquid paints must necessarily be kept on hand at certain seasons of the year and the storage space for these goods should be so located, as to make the least amount of handling and rehandling necessary.
One very important item of expense in paint factories is fire insurance, as insurance men consider this business as extra hazardous. For this reason, and in order to obtain as low a rate as possible and to save waste and labor in transportation, the vehicles, such as oils, turpentine, benzine and any other solvents, that may be used in sufficient quantity, should be stored, if possible, in metal tanks in fire proof sheds outside the factory and piped to the mixing floors into smaller storage tanks, in quantities sufficient only for a day's requirements. This can be accomplished by the use of compressed air, centrifugal pump or similar means. Wherever these liquids are brought to a factory in tank cars, the storage tanks should be placed low enough, that the material may be discharged into them from the tank car without the use of pressure. Another item of economy is the use of measuring pumps on the mixing floor, wherever practicable.
Many large concerns make their own barrels, tin cans and packing cases, but where cases are purchased in large quantities, such as car load lots, economy can be practised by using conveyors for unloading these as well as for large size tin cans.
We will not dwell on what style of packages, tin cans, etc., are best or most economical to use for shipping, as that will depend largely upon the pleasure of the trade, but in order to prevent errors in labeling, marking, etc., it is a matter or precaution to use a stamp on all containers, which plainly shows to the initiated by letters or figures, as the case may be, the contents of package. While this does not absolutely prevent errors at all times, it is the best system of marking yet devised. When storing away goods in cases, that are to be shipped later on, it is best to have them dated and so stored that the oldest stock is moved first. The same applies to tin cans stored in bins, the latter to be so arranged that the oldest stock must necessarily move first and the person in charge should see, that the help follow that rule. No one has any adequate idea what waste there is in a factory, when this rule is not followed as the trouble is mostly discovered only after the goods have been on the dealer's shelf for a long time and the disgruntled customer returns an opened tin that contains old fatty paint or color that has become hard. There cannot be too much system in this respect or care exercised, the help as a rule being indifferent to or ignorant of the trouble caused. A system, that is not followed up to the letter is worse than none at all. This applies also to the system of keeping records of formulas of mixings and grindings.
The formulas given to the men at the mixers or mills should be collected by the man in charge of the floor as soon as a batch has been made and any changes noted that it may have been necessary to make. This precaution does not necessarily imply a suspicion of the honesty of the help, but will prevent errors and permit a true record to be kept in the factory office of all transactions.
If anyone however has any idea that a correct tally can be made between the material used and the material produced, he makes a very serious mistake and he will find quite a leakage that cannot entirely be accounted for by evaporation during the milling or mixing process. The salary paid to the clerk or clerks necessary to superintend the weighing and measuring in a factory of some size would cost considerably more than any leakage that can be figured in the long run. When, as is often the case, illiterate labor has to be made use of, some intelligent person must needs be on the floor to look after the weighing and point out the material required. As a further means of identifying the materials, it would be well to follow the method of a very prominent paint manufacturer not many miles from New York City, who used to number his dry white material like this: "Lead No. 0", "Lead No. 1", "Lead No. 2", and so on; Dry white lead being "No. 0"; French zinc, "No. 1"; American zinc, "No. 2"; and barytes, No. 3; whiting, No. 4; while his liquids were designated as oil; raw linseed being "Oil No. 0"; boiled linseed, "Oil No. 1"; refined linseed, "Oil No. 2"; while color grinder's Japan was simply "black oil." The names for white pigments as barytes, whiting, gypsum, clay, asbestine, talc, etc., do not mean anything to the kind of labor referred to. Other details will be found in the body of this volume under proper headings.