GB469882A - Improvements in moulding pulp or other fibrous material - Google Patents

Abstract

469,882. Moulding pulp. HAWLEY PRODUCTS, Ltd. (Hawley Products Co.) Jan. 2, 1936, No. 179. [Class 87 (ii)] In moulding articles from fibrous material such as wood pulp wherein a porous former 3 is dipped in a bath 1, pulp is deposited thereon by suction, and the pulp blank is compressed against the former by a yielding pressing die 21, the pressed pulp blank is applied to and further compressed between a contoured die 28 and a yielding member. The die 21 may be used as the yielding member. The forming die 3 is provided with holes 4 and is covered by a porous sheet 5 which may be wire fabric or have pores. A suction box 6 is clamped to the die 3 by lugs 7, 8. The box and die are lowered by means 11 on to a felting plate 12 normally held above the surface of the pulp in the bath 1 by springs 16. The plate 12 coacts with a shoulder on the die 3 and shapes the edge 20 of the article. Suction is applied through a pipe 10 placed low down in the box 6. When the pulp is deposited to a required thickness, the die 3 is raised from the bath and lowered on the yieldable die 21 which is mounted on a plate 22 provided with a shoulder 27 to engage the shoulder on the die 3. The pressure of the die 21 and the suction remove almost all the water. Pressure is introduced through the box 6 to transfer the pulp blank to the die 21. If drying is required, the blank can readily be removed from the die 21. For finishing, the blank is raised on the die 21 into contact with the rigid finishing die 28. A heating box 30 is clamped to the die 28 and the remaining water is removed and absorbed by a layer of porous material such as thin felt or other fibrous material or of metal links or mesh capable of contraction and expansion on the die 21. Before the final compression, the blank may be treated to produce rigidity or smoothness. The die 28 may be coated with beeswax to prevent sticking. Heat may be transmitted through the die. Where a hollow article, such as a head, is to be moulded, the mould is formed in two sections providing a forming die enclosed by a suction chamber. The yieldable die is in the form of an inflatable rubber tube or bag which is introduced into the mould through a narrow inlet and inflated therein. The finishing die is similar to the forming die, being in two sections adapted to close around the moulded blank and inflated tube. Specification 468,622 is referred to.