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CN-116901314-B - Mould for manufacturing moulded fibre products

CN116901314BCN 116901314 BCN116901314 BCN 116901314BCN-116901314-B

Abstract

The present invention relates to a mould for manufacturing moulded fibre products. The mould (11) comprises a porous product surface (23) made by additive manufacturing. The product surface (23) is arranged as a double layer structure (40) comprising two layers (41, 42). Between the two layers (41, 42) there is a cavity (43), wherein the first layer (41) has a porosity from the cavity (43) to the product surface (23). The second layer (42) has perforations isolated from the cavity (43) and extends from the product surface (23) through the bilayer structure (40).

Inventors

  • H. Truff
  • K. Vinio

Assignees

  • 维美德技术有限公司

Dates

Publication Date
20260505
Application Date
20230419
Priority Date
20220419

Claims (16)

  1. 1. A mould for manufacturing a moulded fibre product, the mould (11) comprising a porous product surface (23) made by additive manufacturing, characterized in that the product surface (23) is arranged as a double layer structure (40) comprising a first layer (41) and a second layer (42) between which layers there is a cavity (43), wherein the first layer (41) has porous properties from the cavity (43) to the product surface (23) and the second layer (42) has perforations isolated from the cavity (43) and extends from the product surface (23) through the double layer structure (40).
  2. 2. The mold according to claim 1, characterized in that the bilayer structure (40) has a thickness of 4-10 mm.
  3. 3. The mould according to claim 1 or 2, characterized in that the first layer (41) and the second layer (42) have a thickness of 0.2-2 mm.
  4. 4. A mould according to claim 1 or 2, characterized in that the first layer (41) has a randomly manufactured porosity.
  5. 5. A mould according to claim 3, characterized in that the first layer (41) has a randomly manufactured porosity.
  6. 6. The mould according to claim 1 or 2, characterized in that the perforations of the second layer (42) consist of 3D printed tubes (44), which tubes (44) extend from the product surface (23) through the bilayer structure (40).
  7. 7. The die of claim 6, wherein the mouth diameter of the tube (44) is 0.1-2 mm.
  8. 8. A mould according to claim 1 or 2, characterized in that the mould (11) is a uniform 3D print.
  9. 9. Mould according to claim 1 or 2, characterized in that the double-layer structure (40) is arranged to be detachably fixed to the skin (24) of the base structure (25).
  10. 10. A mould according to claim 9, characterized in that said base structure (25) is of a different material than said skin (24).
  11. 11. A mould according to claim 1 or 2, characterized in that the cavity (43) has an inlet (45) included inside the mould (11).
  12. 12. A mould according to claim 11, characterized in that the inlet (45) is preceded by a fluid distribution chamber (46) arranged inside the mould (11).
  13. 13. A mould according to claim 1 or 2, characterized in that inside the mould (11) there is a second cavity (48), one side of which is defined by the double layer structure (40).
  14. 14. A mould according to claim 13, characterized in that an outlet (33) is present at the second cavity (48).
  15. 15. A mould according to claim 1 or 2, characterized in that the properties of the first layer (41) are different in different parts of the product surface (23).
  16. 16. A mould according to claim 1 or 2, characterized in that the properties of the second layer (42) are different in different parts of the product surface (23).

Description

Mould for manufacturing moulded fibre products Technical Field The present invention relates to a mould for manufacturing moulded fibre products, the mould comprising a porous product surface made by additive manufacturing. Background European patent No. EP3237680 discloses a mould produced in an additive manufacturing process, such as a 3D printing process. Such additive manufacturing processes may include selectively sintering powdered materials having particles with an average size of 1-50 microns, preferably 5-30 microns. On the other hand, powder particle sizes of 40-45 microns are common. During the sintering process, the powdery material is completely melted by the energy addition of the laser beam. In the additive manufacturing process, the walls of the mould are provided with several small through holes to achieve dense perforations for infiltration. Thus, the tool wall portion has voids provided by a plurality of channels extending through the tool wall portion from the surface to the back of the product. Traditionally, it is laborious to manufacture the mould by machining from a solid piece of raw material. On the other hand, machining of complex structures is not possible. Furthermore, the through holes of the product surface may be too large, which may cause clogging. The surface of the product provided with the additional metal mesh leaves marks on the surface of the product. These marks may remain despite the hot pressing. Cleaning the mould is also laborious. The product surface roughens the final molded fiber product and is only suitable for low quality products due to marks. Moreover, the above known mould is usually only used for fibre suspensions or slurries of fibre slurries, wherein the mould is immersed in the fibre slurry and after that the fibre product is sucked from the aqueous suspension to the surface of the mould or injected with excess water through the channels. Disclosure of Invention The object of the present application is to provide a new mould for the manufacture of moulded fibre products, which mould is more versatile than before and which is also easier and faster to manufacture. Features of the mould according to the application are set out below. The characteristics of the mold can be easily changed to achieve new porous structures and some combinations. In the present application, porous means a minute gap through which liquid, air or vapor can pass via various undefined routes, unlike perforations or holes as defined channels from one surface to the other. In addition, the manufacturing time of the mold is shorter, thereby saving the cost. In addition, the mold has good strength even though the shape of the mold may be complicated. Moreover, the mold is easy to clean. Moreover, product changes can be accomplished faster, more easily, and at lower manufacturing costs than before. It is a further object of the present application to provide a new and efficient way to manufacture a mould for additive manufacturing of moulded fibre products. With the new mould the process time is short and high pressures can be used. At the same time, the idle time is short because the maintenance of the mold is quick and easy. Drawings The invention will now be described in detail with reference to the drawings, which illustrate some embodiments of the invention, wherein Fig. 1 shows a top view of a mould for shaping a moulded fibre product according to the invention; FIG. 2a shows a side view of a pair of molds according to the invention; FIG. 2b shows an enlarged view of a portion of FIG. 2 a; FIG. 3 shows a cross-sectional view of a portion of a mold according to the present invention; fig. 4a shows a side of a mould according to the invention, with parts separated in a cross-section; FIG. 4b shows the mold of FIG. 4a, wherein the parts are connected; FIG. 5a shows a split of FIG. 4 a; FIG. 5b shows the connection portion of FIG. 4 b; Fig. 6 shows a pair of molds for hot pressing. Detailed Description Molded fiber products, also known as MFPs, are made from cellulose fibers. For example, such products are disposable cups or plates. The cellulose fibers are first dispersed in water, then formed, assisted (drained, drain) and dried. One particular way of manufacturing molded fiber products is thermoforming. After forming, the product is compressed using high temperature and high pressure, which in combination discharge and evaporate the water and moisture in the product. Advantageously, the raw material is foamed before shaping, since, as will be described later, the mould according to the invention is perfectly suited for foaming, in particular in thermoforming. Thus, oven drying is not required and high quality, thin walled products can be prepared after manufacture. The dimensional accuracy and rigidity are good, and the surface of the product is smooth. Both shaping and pressing require a pair of mold tools consisting of one positive (male) mold tool and one negative (female) mol