Method for processing planar material webs made of a fiber-containing material

Abstract

A method for processing planar material webs made of a fiber-containing material is disclosed. The planar material webs are fed as material web portions or endless material web, for the production of three-dimensional products. Before a material web is pressed for shaping, the material web is preformed three-dimensionally by deforming the material web in at least one direction substantially without stretching or compressing.

Claims

1. A method for processing planar material webs made of a fiber-containing material, wherein the planar material webs are fed as material web portions or endless material webs for a production of three-dimensional products, wherein, prior to pressing a planar material web for shaping, the planar material web is preformed three-dimensionally by deforming the planar material web in at least one direction substantially without stretching or compressing in a region of a three-dimensional product.

2. The method according to claim 1, wherein the planar material web is substantially freely movable during the three-dimensional preforming.

3. The method according to claim 1, wherein the planar material web is pushed together laterally on a surface.

4. The method according to claim 1, wherein at least one region of the planar material web is selectively fixed in terms of position and/or orientation with respect to a geometry of the three-dimensional product to be produced during the three-dimensional preforming.

5. The method according to claim 1, wherein at least one region of the planar material web is selectively severed with respect to a geometry of the three-dimensional product to be produced prior to and/or during the three-dimensional preforming.

6. The method according to claim 1, wherein at least one region of the planar material web is selectively moistened and/or subjected to additivation with respect to a geometry of the three-dimensional product to be produced prior to the three-dimensional preforming.

7. The method according to claim 1, wherein three-dimensional preforming takes place in at least two preforming steps.

8. The method according to claim 1, wherein a three-dimensional deformation of a plurality of portions of the planar material web for a corresponding plurality of products takes place simultaneously and the portions are decoupled from one another such that an individual three-dimensional deformation of the portions is carried out, wherein no mutual influence of the portions due to the respective three-dimensional deformation occurs.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] In the drawings:

[0029] FIG. 1 depicts schematic representations of a procedure for preforming a material web made of a fiber-containing material, according to some embodiments.

[0030] FIG. 2 depicts schematic representations of a procedure for preforming a material web made of a fiber-containing material, according to some embodiments.

[0031] FIG. 3 depicts schematic representations of a preformed material web, according to some embodiments.

[0032] FIG. 4 depicts a schematic representation of a fiber forming facility for producing three-dimensional products from a fiber-containing material, according to some embodiments.

DETAILED DESCRIPTION

[0033] Various embodiments of the technical teaching described herein are shown below with reference to the figures. Identical reference signs are used in the figure description for identical components, parts and processes. Components, parts and processes that are not essential to the technical teachings disclosed herein or that are obvious to a person skilled in the art are not explicitly reproduced. Features specified in the singular also include the plural unless explicitly stated otherwise. This applies in particular to statements such as a or one.

[0034] FIG. 1 shows schematic representations of a procedure for preforming a material web made of a fiber-containing material.

[0035] FIG. 1a) schematically shows a material web portion 200 made of a paper-like material web, which includes a fiber-containing material (e.g., natural fibers) and may have additives. As with normal paper, the height of the material web portion 200 is relatively low. In other embodiments, it may be higher than in the case of normal paper. The material of the material web portion 200 has a relatively low moisture content of 6-10 wt. %.

[0036] FIG. 1b) shows the material web portion 200 during a preforming step, where here, as indicated by the arrows, the material web portion 200 is deformed laterally and/or from below so that a material accumulation results in the center. There, the material web portion 200 forms a projection 210. It should be noted that the planar extent decreases because the material of the material web portion 200 is pushed into the center. Substantially no stretching of the material occurs, so that the material web portion 200 does not tear or otherwise become damaged. Preforming can be carried out using auxiliary means and/or a forming tool.

[0037] FIG. 1c) shows the material web portion 200 during a final forming step, where the preformed region 213 of the material web portion 200 is pressed under high pressure (specific surface pressure 100 to 5,000 N/cm.sup.2) and high temperatures (20 to 250 C.), where steep side walls 214 can be produced from a paper-like material without damaging the material due to the large forming depth.

[0038] FIG. 2 shows schematic representations of a procedure for preforming a material web made of a fiber-containing material. Here, a material web portion 200 is fed to a forming tool 140 that has a plurality of cavities 144. Depending on the design, the cavities 144 can either have the final shape of a product to be produced or a preformed preform. In case of the latter, the material can be pressed completely against a corresponding surface, where a stretching of the material that would otherwise occur in the prior art can be compensated for by the fact that the material can be pulled laterally into the cavity 144 from the outside so that despite the deformation, the material itself is not stretched. In particular, this ensures that the material is displaced in certain regions instead of being stretched. The material of the material web portion 200 is thus substantially freely movable.

[0039] In a subsequent step (FIG. 2b), the material web portion 200 is pressed downward via preforming punches 146. In addition, cutting devices 148 can be used that sever the regions of the material web portion 200 associated with the cavities 144 between the cavities 144 so that the material can slide into the cavities 144 during preforming without mutual interference.

[0040] As shown in FIG. 2c, additionally or alternatively, at least in the regions shown in the example between the cavities 144, the material web portion 200 can be clamped or fixed in order to avoid mutual interference. In further embodiments, clamping can be carried out in combination with severing. In further embodiments, the material of the material web portion 200 can also be fixed in the region of the bottom surface of a cavity 144 via the preforming punches 146 in order to sufficiently preform a bottom 212 for a product and to prevent material from being pulled from the region of the bottom in the direction of the side wall portions.

[0041] After preforming, the preformed portions are pressed into final products in the cavities 144 between the tool halves 142 and 149, as shown in FIG. 2d.

[0042] In further embodiments, a selective moistening of regions of the material web portion 200 can additionally take place prior to preforming in order to support or facilitate the preforming.

[0043] FIG. 3 shows schematic representations of a preformed material web. FIG. 3a shows an already preformed material web portion 200 having a trough 217 in the center and a preformed ring 216 surrounding the trough 217.

[0044] FIG. 3b shows a section through the material web portion 200 of FIG. 3a with the formation of the preformed regions and the final shape after pressing (dashed line). Preforming can be carried out using two halves of the forming tool, which press the material web portion 200 against corresponding forming surfaces without substantial stretching occurring. An appropriate tool design can allow material to slide into a cavity.

[0045] By preforming, the paper-like material can easily be brought into its final shape in a subsequent pressing step, as shown by the dashed line representing (final formed) edge 218, since the material is or has to be only slightly deformed and thus stretched between the orientation and shaping by preforming and the final shape. This allows complex geometries and large forming depths to be achieved in paper-like materials without damage or complex treatments.

[0046] FIG. 4 shows a schematic representation of a fiber forming facility 100 for producing three-dimensional products from a fiber-containing material. For this purpose, individual material web portions 200 or a material web can be fed from a roll or another feeding device, as shown in FIG. 4.

[0047] The fiber forming facility 100 can be used to produce products that are biodegradable and can themselves be used again as a starting material for the production of three-dimensional product made of a fiber-containing material and can be composted because they can generally be completely decomposed and do not contain any harmful, environmentally hazardous substances. The products can be designed, for example, as cups, lids, bowls, capsules, plates and other molded and/or packaging parts (e.g., as holding/support structures for electronic or other devices).

[0048] In the illustrated embodiment, the fiber forming facility 100 has a feeder. As schematically indicated, the feeder can also have a transport device that serves to transport a material web or web portions. The transport device can be designed in a variety of ways. The material web passes through a pretreatment chamber (e.g., climate chamber 402) and is subjected to pretreatment (e.g., inline pretreatment 404). During pretreatment, properties of the material web are selectively influenced in a product-specific manner in order to support or allow a directly subsequent preforming and/or shaping. Subsequently pre-cutting 406 can take place. This is followed by preforming and optional pretreatment 408. Afterwards, an intermediate treatment 410 can take place. This is followed by final shaping 412. Subsequently the finished products can be separated from the remaining material using a punch (e.g., punching 414) and then fed to a stacking and/or automation station (416).

[0049] The material web can be fed continuously or intermittently via the feeding device. In the example shown, the pretreatment and shaping take place during a feed pause. To ensure continuous unwinding of the material web, devices for length compensation can be provided, as are known, for example, from thermoforming systems for plastics films. The fiber forming facility 100 may have further stations and devices. For example, a supply of fiber-containing material can be provided.

[0050] The pretreatment chamber (e.g., climate chamber 402) can include a housing that surrounds the space in which the pretreatment takes place. The pretreatment chamber has a passage on the inlet and outlet sides, which can be closed in other embodiments. This allows the space within the pretreatment chamber to be substantially sealed or decoupled from its surroundings so that, at least temporarily, other conditions (temperature, moisture, pressure) can prevail within the pretreatment chamber.

[0051] Optional post-processing of the produced products can include, for example, printing, dyeing, filling, stacking, etc.

[0052] For controlling the production steps and the pretreatment, the fiber forming facility 100 also has at least one controller that, in further embodiments, is connected to at least one monitoring device (e.g., camera, sensors, etc.) in order to adjust and regulate the preforming, the moistening of regions of the fiber-containing material and the pretreatment.

[0053] In addition, the surface finish and properties of the product to be produced can be substantially influenced and improved in a two-stage forming or pressing process. For example, after a first forming step, the entire product can be moistened again or pressed again at a different pressure and/or temperature.

[0054] Until now, the forming of planar material webs made of a fiber-containing material, such as dry paper (cardboard, special paper, airlaid, compressed airlaid, nonwoven) made of natural fibers has been limited by the stretchability (2-10%) and/or the material flow into the form geometry (formation of folds or tears). As a result, only simple product geometries (false bowls or plates) were previously possible for products made from such materials.

[0055] Instead of using or providing very complex, expensive papers or process preparations of one or more paper layers for higher degrees of forming, the technical teaching described herein involves a material accumulation of the required material in special geometric regions in at least one process step in order to ultimately achieve high degrees of deforming at this point in the product (e.g., undercut, sharp radius, rib on the inside, etc.).

[0056] To realize preforming in multi-cavity tools, a corresponding system having pre-cutting and hold-down devices can be combined with the preforming and final forming devices such that the material flow can be controlled and monitored in a targeted manner. This also prevents the cavities from influencing one another. In further embodiments, this process can be supported and simplified by means of targeted moisture (moist paper or spraying of water shortly before forming) and heat input (hot tool). This means that the product range can be significantly increased with available papers (see above), for example to produce SipLids, lids with a tight fit, plates, trays or clam shells with segments, steep (<15) draft angles and small radii on the bottom (<10 mm). Furthermore, the deep drawing rates can be significantly increased (>20 mm).

LIST OF REFERENCE SIGNS

[0057] 100 Fiber forming facility [0058] 140 Forming tool [0059] 142 Tool half [0060] 144 Cavity [0061] 146 Preforming punch [0062] 148 Cutting device [0063] 149 Tool half [0064] 200 Material web portion [0065] 210 Projection [0066] 212 Bottom [0067] 213 Preformed region [0068] 214 (Final formed) side wall [0069] 216 Preformed ring [0070] 217 (Preformed) trough [0071] 218 (Final formed) edge [0072] 402 Climate Chamber [0073] 404 Inline pretreatment [0074] 406 Pre-cutting [0075] 408 Preforming+Pretreatment [0076] 410 Intermediate-treatment [0077] 412 Final shaping [0078] 414 Punching [0079] 416 Stacking/Automation