The baled cork, as received, is our first consideration, for its bulk, being out of all proportion to its value, attracts the attention at once.
As in all business where the raw stock is conveyed from a distance and there is a possibility of delay in shipments, a large stock must necessarily be kept on hand, and this feature is very pronounced in and about a “cork factory.” Great piles appear in the open or within large sheds, covering much space, and sometimes in the factory itself.
This stock is carefully watched and care taken to keep it large enough to supply all needs for a long time as a shortage in raw material would not only mean no work, but the loss of business, due to the inability to supply first-grade material, for this is the prime factor, the various other grades being compelled to await a favorable market. Appended is a diagram that will give some idea of the utilization of corkwood.
The corkwood bale as received, measures as a general rule 2′ × 2′7″ × 4′ and is securely strapped with iron bands about one inch in width and a thickness of 1⁄16″ to 1⁄32″, and the weight depending upon the quality of corkwood ranging from 150 pounds to 200 pounds per bale.
[Sorting]
The first operation, that is, the first thing done with the corkwood, is the sorting. This is becoming more important as the uses of cork increase, as various grades can be used for so many particular things now, without the necessity of being called a by-product; but the principal divisions are: superfine, fine, common and coarse.
These of course are now extended to many classes, and is resulting in careful scrutiny of the shipments and stock, the sorter becoming an expert, and an increasing factor in the business. His knowledge not only including the grades of corkwood, but the uses to which the various grades may be put so that waste is avoided and the full value gotten out of all.
[Cork Stopper Making]
After the sorting, the slabs are placed in steam boxes and subjected to a steam bath, which it is claimed softens the material and also prepares it for the scraper, who cleans and removes the dirt and callous or “raspa” accumulated in its mountain home. This scraping is done either by hand or machine, the handwork being done with a short handle, curved bladed knife called a “doladera,” raspador or raspeta: a workman being able to scrape from two to three metric quintals of cork in a day, or ten hours. The scraper machine being a vertical steel shaft carrying several knives placed at a very slight helix and making about 1400 revolutions per minute and will scrape from ten to twelve metric quintals[35] per day or ten hours. Cutting the slabs into strips or fillets (tiras ó’rebanadas) is the next step. These strips, the width of which is equal to the length of the cork to be cut, as the cutting is done across and not with the grain, were formerly cut by hand with a knife having a flat surface and curved edge called “cuchilla de rebanar,” but now replaced by the circular knife, which operates the same as a rip-saw. From here the strips go to the stopper-makers’ punches or blocking machines. This machine has a rotating tubular die with sharpened edges of the diameter of the cork to be cut, made to revolve about two thousand revolutions per minute, the operator having a foot lever attachment which permits him to thrust the die through the strips of cork as he holds it against a resisting piece parallel with the operating plane of the die. Thus, he can punch out many thousands of corks a day, the noise of the punches being a very characteristic sound in all such establishments. The operator, of course, must use care to avoid defective spots in the bark, and also to cut the corks out as closely together as possible so as to reduce waste to a minimum. For it is here that the cork manufacturer seems to lay his particular lament. If he could but make his corks the sizes most in demand, ship them and thereby do a business that would clearly figure up the year’s work, and perhaps keep a surplus on hand for unexpected orders. But this he cannot do, for almost every cork he cuts there is enough waste material to make three or four smaller sizes, and this he fain would discard if it were not for the possible profit there is in it; and consequently in almost every cork factory will be found a large surplus stock of all sizes, and the owner anxiously hoping that some one will take them off his hands.
The stoppers which come from these machines are round with parallel sides. If tapered corks are desired, larger at the upper end than at the lower, the cylindrical or straight pieces must be passed through another machine which handles them deftly, holding them against the edge of another circular knife; seemingly motionless, the only outward indication of the speed with which the keen blade is revolving being a delicate shaving which curls upward for an instant, and then is drawn away by air suction to the waste bin, where this material is all collected and used in various, useful ways as will be shown later. In cutting the corks, although care is exercised, many will be imperfect and defective, and in order to utilize them they are cut into smaller sizes by men who sit at low tables and deftly handle the sharp-edged knife, which with one stroke reduces the cork to the size that it can fill, using a scale which is apparently standard with all cork dealers.