GB708393A - Pulp molding dies - Google Patents

Abstract

708,393. Pulp moulding dies. MAPES CONSOLIDATED MANUFACTURING CO. May 2, 1952 [Jan. 17, 1952], No. 11126/52. Class 87 (2) A die for forming moulded pulp articles comprises a rigid body forming part of a moulding surface and provided with water drainage passages, a wire screening in contact with and overlying the moulding surface area of the die body, one or more outstanding rigid die members rigidly secured to the die body and constituting the remainder of the moulding surface, wire screening in contact with and overlying the moulding surface area of the outstanding die members and a sealing member between each die member and the wire screen overlying the die body. The die body 10 is flat, thinner round its margin 11, and with recesses 14, 16 in its upper surface, holes passing through the body in the centres of the recesses 16. Laterally spaced slots 13 in the body 10 provide for water drainage. The outstanding rigid die members 22 have bosses 24 that fit in the recesses 14, Fig. 9, and through the holes therein members 26 pass and are threaded into the members 22 to retain them, each having a drainage passage 28 opening into the screwdriver slot. The members 22 are frustroconical in shape with cup-shaped depressions 23 forming ridges in which there are series of recesses 31, Fig. 10, water drainage passages 30 being provided. The wire screening 17 in contact with the flat body 10 is held down at the margin by a frame 18, and may comprise a sheet of fine mesh overlying a sheet of coarse mesh. The members 22 have preformed wire mesh coverings 32 fitting their outside contour, the margins of the coverings being bent under the edges of the members to hold them down. The sealing member between each die member 22 and the wire screen 17 is a ring 35 with a flange which prevents the edge of the covering 32 -from spreading out when the member 22 is clamped down. The top flange edge of the ring 35 leaves a recess in the moulded pulp article which forms a relief space 43 to allow articles of slightly varying sizes to be stacked without jamming, Fig. 15. The recesses 31 in the ridges of the members 22 are to form strengthening cross-ribs in the moulded articles, and they must be suitably proportioned, as explained in the Specification, if the pulp is to thicken for that purpose instead of following the contour of the screen with uniform thickness. The die structure illustrated is designed to produce an egg flat, as partly shown in Fig. 8, in which the egg seats project from a slightly raised surface with shallow recesses between them.