Pa′per-mold′ing ma-chine′.
One in which paper-pulp is molded to the form required, the
shape being afterward dried.
The object is then finished by sizing, varnishing, painting, or what not, according to its purpose.
Brown and
Macintosh, English patent 14,131 of 1852, describes a mode of making paper and articles of paper in hollow molds or frames with permeable surfaces, and within which a partial vacuum is obtained.
The mold has preferably a covering of felt, upon which the fiber is deposited while the water passes through, and this felt is removed from the
former with its deposited paper envelope.
See also American patent of French and
Frost, 1856;
Brown and
Smith, 1851;
Hatfield, 1862.
Fig. 3533 illustrates the principle of action.
A
former of the shape required — in this case a rectangular lamp-shade — is made of wire-gauze
C stiffened with internal strengthening plates.
The figure shows a mold
B with a hollow handle, connecting by a flexible tube with an air-pump.
The pulp is collected upon the foraminous surface, through which the water passes as the air is exhausted from the interior of the
former. The sheet of pulp is discharged by the internal pressure of air, the pump being worked as a compressor.
The fiber of slightly felted pulp is received from the
former by a felt cap which fits upon the film, and is from it transferred to a block on which it is dried.
The machine just described depends upon an exhausting air-pump to draw water through the meshes of the wire-gauze which detains the fiber of the pulp, and the thickness of the film of pulp will depend upon the thickness of the pulp and the rapidity and duration of the stream of water passing the wiregauze.
The compression system, in which a quantity of pulp is driven through the meshes of a former on whose surface the fiber collects, has also been repeatedly tried.
A third plan is that in which a displacing plunger descends into a molding-former and drives out the water, compacting the pulp against the sides of the
former.
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Knight's paper-molding apparatus |
Fig. 3534 is a machine for pressing and compacting the molded article.
The rigid, perforated frame, with the article formed in paper-pulp upon it, is removed and placed beneath a die which expresses the water from the pulp.
In another machine, the blanks are made from paper-pulp in shape suitable for forming boxes, etc. The creases made in the blanks facilitate the bending into form, and the notches in the corners obviate the
[
1626]
necessity of cutting into shape.
See also
Kimball's patent, 1868.
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Press for articles of molded pulp |
In
Smith's machine, 1868, the paper-pulp box is made by the sudden descent of a plunger into a perforated mold, which has a permanent perforated lining and removable bottom.
The plunger is constructed to automatically admit air beneath its lower end just previous to its withdrawal from the cavity of the completed box or other hollow article.
The bottom drops to discharge the molded box.
Leclere's machine, December 8, 1868, is designed for the formation of hollow paper articles from paperpulp, and operates by employing over a pervious former a column of thin pulp, which in hight several times exceeds the hight of the article to be made.
The pulp is condensed on the former and the water expelled therefrom against the atmospheric pressure by covering the pulp-covered
former with a close vessel, and admitting air under pressure within the
former. The paper is removed from the cap which received it from the former, and transferred to a receiving block by covering the block with the cap and admitting an air-blast into the latter.
