PAPER ENVELOPES, BAGS, ETC. 



737 



which dried the fresh gum before the circuit 

 was completed. In the latest machines the 

 envelopes are delivered in packs of twenty-five 

 on a table in front of an attendant, who has 

 only to fix a paper band around each package. 

 A step in advance are the self-feeding at- 

 tachments which enable the attendant to lay a 

 pile of blanks upon the table and let the ma- 

 chine feed itself. This necessitates the lifting 

 of the blanks one by one. It is effected some- 

 times by the gammers which, attached to arms, 

 descend upon the pile of blanks. The top 

 blank adheres to them and is picked up, car- 

 ried forward and disengaged from the gummers. 

 by the descent of the plunger. A still more 

 ingenious device is to raise the blank by air- 

 suction. In Fig. 4, A is a pile of blanks, and 



FIG. 4. 



B is a rubber tube leading to a small suction- 

 pump, actuated at proper intervals by the mo- 

 tion of an attachment. At the end of the tube 

 is a small metal fixture, E, indicated by dotted 

 lines adjusted so that it rests lightly upon the 

 upper envelope blank, and is slightly raised as 

 soon as the air in the tube is exhausted. To 

 this fixture the top blank adheres a*nd is raised 

 as indicated enough for a carrier, C, to run for- 

 ward under it, detach it wholly from the pile 

 and deliver it the air-suction being at this 

 instant released to the rollers under the form, 

 D, which in turn carry it forward to the fold- 

 ing arrangements already described. 



The manufacture of paper bags is closely al- 

 lied to that of envelopes, but the machinery 

 for making them is of comparatively recent in- 

 vention, and differs from envelope machinery 

 in many particulars. The bags are made of all 

 sizes, from a few inches square up to the capac- 

 ity of a flour-barrel, and are used in enormous 

 quantities by retailers of all sorts of goods. As 

 in the case of envelopes they were at first made 

 by hand, but machinery was soon devised to 

 meet the increasing demand. The paper is first 

 cut to the desired size and laid upon a sloping 

 table, whence it is carried by rollers under an 

 iron slab of the exact width of the intended 

 bag, the principle being the same as that indi- 

 cated at D, Fig. 4, in the envelope machinery. 

 It moves at a rapid rate until its forward cor- 

 ners encounter two bent plates of smooth iron 

 something like plowshares, one of them on 

 either side of the slab. These first raise the 

 corners and forward edges of the moving sheet, 

 then cause them to bend inward until the edges 

 of the sheet overlap and adhere to one another, 

 having been already gummed. The bag is now 

 VOL. xxvi. i7 A 



technically called a tube that is, it is a bag 

 without a bottom. "While in this condition it 

 usually receives whatever label or other printed 

 matter it is designed to bear, and is then sent 

 to a special machine which with wonderful ra- 

 pidity cuts two slits at the bottom of the tube, 

 gums the edges, folds the corners over, and in 

 an instant turns out the complete paper bag 

 with one end closed in such a way that, when 

 filled with flour or meal or an j suitable article 

 of commerce, it will permit the bag to assume 

 a nearly cylindrical form without any weak 

 angles at the bottom where it would be likely 

 to tear when subjected to a strain from within. 



The manufacture of paper and cardboard 

 boxes for fancy packages of confectionary, for 

 all the smaller varieties of goods sold by re- 

 tailers, is enormous. These boxes are fre- 

 quently of a complicated pattern, but the in- 

 genuity of manufacturers has devised a species 

 of die that at one motion cuts and creases a 

 piece of cardboard so that it is ready to be 

 folded and packed for shipment. This species 

 of goods merits description, since it involves 

 an exceedingly nice degree of mechanical skill. 

 Usually, designs more or less elaborate are 

 wanted on each of the exterior surfaces of the 

 box. As the simplest box must have at least 

 four sides and a top and bottom, it is evident 

 that a good deal of planning is necessary. The 

 printing, usually from a lithographer's stone, 

 is done on the uncut sheet of cardboard with 

 due regard to economy of material. Next a 

 die is made on a stout slab of wood, corre- 

 sponding in size with the sheet of cardboard. 

 When it is remembered that several boxes are 

 to be cut out at once, that some angles must 

 be creased and others cut, and that the whole 

 must register to a hair's breadth, the difficulty 

 of the mechanical problem can be appreciated. 

 The die is made by setting firmly in the wooden 

 slab a system of knives and creasers, which 

 project about one quarter of an inch above the 

 surface of the wood. The die is set on edge, 

 and held firmly in position in a frame, while 

 another frame, similar in size, carries the card- 

 board, and for a moment presses the whole 

 sheet against the die. Then the movable frame 

 falls back, the sheet of cardboard is removed, 

 and the operation is repeated. A very ingen- 

 ious device in this connection should not be 

 overlooked. Of course, when the knives push 

 through the cardboard they have a tendency 

 to retain it when the pressure is removed. To 

 prevent this, the whole surface of the die is 

 studded with little bent strips of cardboard 

 fastened to the wooden slab so that each gently 

 resists being pressed down flat agninst the 

 slab, and their combined effort is sufficient to 

 free the cardboard from the knives as soon as 

 th$ positive pressure is removed. 



The variety of shapes in which boxes and 

 envelopes are made is only equaled by the in- 

 finite diversities of individual tnste, and the 

 insatiable desire for something new even in 

 such a simple thing as the wrapper for a paper 



