US-12617173-B2 - Method for manufacturing three-dimensional products from a fiber-containing material using at least one forming tool and forming tool

US12617173B2US 12617173 B2US12617173 B2US 12617173B2US-12617173-B2

Abstract

A method for manufacturing three-dimensional products with at least one inclined product portion made of a fiber-containing material using at least one forming tool and a forming tool are described. Vibrations are introduced via a device and this results in an improved compression of fiber-containing material in the region of inclined portions.

Inventors

Josef Strasser

Assignees

KIEFEL GMBH

Dates

Publication Date: 20260505
Application Date: 20240613
Priority Date: 20230616

Claims (11)

1 . A method for manufacturing three-dimensional products with at least one inclined product portion made of fibers, using at least one forming tool, wherein the at least one forming tool has at least one first tool component with at least one cavity and at least one second tool component with at least one mold part corresponding to the at least one cavity, wherein the at least one mold part and the at least one cavity are movable relative to one another to form a mold cavity between corresponding surfaces of the at least one cavity and the at least one mold part, the method comprising: introducing the fibers into the at least one cavity of the at least one first tool component; closing the at least one forming tool by relative displacement of the at least one first tool component and the at least one second tool component; pressing the fibers within the mold cavity; and laterally moving the at least one first tool component and/or the at least one second tool component relative to a pressing direction during the pressing to introduce vibrations in the fibers.
2 . The method according to claim 1 , wherein the vibrations are introduced in the fibers perpendicular to the pressing direction.
3 . The method according to claim 1 , wherein the vibrations are introduced in the fibers in parallel to the pressing direction or in an optimized direction of action.
4 . The method according to claim 1 , wherein the vibrations are introduced in the fibers via the at least one mold part.
5 . The method according to claim 1 , wherein a frequency of the vibrations is modified during the pressing.
6 . The method according to claim 1 , wherein a duration of the vibrations and a duration of the pressing are different.
7 . The method according to claim 1 , wherein a pressure used for the pressing is modified during the pressing.
8 . The method according to claim 1 , wherein a frequency of the vibrations and/or a vibration duration are adapted to a pressure used for pressing.
9 . The method according to claim 1 , wherein laterally moving the at least one first tool component and/or the at least one second tool component relative to the pressing direction includes a linear or rotating movement.
10 . The method according to claim 1 , wherein the vibrations are introduced according to a product geometry specification of a product to be manufactured.
11 . A forming tool for manufacturing three-dimensional products with at least one inclined product portion from fibers, comprising at least one first tool component with at least one cavity and at least one second tool component with at least one mold part corresponding to the at least one cavity, wherein the at least one mold part and the at least one cavity operable to be moved relative to one another to form a mold cavity between corresponding surfaces of the at least one cavity and the at least one mold part, and are operable to be pressed to press the fibers that is configured to be inserted into the mold cavity, the forming tool further comprising a device for laterally moving the at least one first tool component and/or the at least one second tool component perpendicular to a pressing direction during the pressing to introduce vibrations in the fibers.

Description

PRIORITY CLAIM The present application claims priority under 35 U.S.C. § 119 to German Patent Application No. DE 10 2023 115 817.1, filed Jun. 16, 2023, the disclosure of which is incorporated by reference herein in its entirety. TECHNICAL FIELD Methods for manufacturing three-dimensional products with at least one inclined product portion made of a fiber-containing material using at least one forming tool, and a forming tool, are described. DESCRIPTION OF RELATED ART Products made from fiber-containing material can be used, for example, as packaging for food (e.g. bowls, capsules, boxes, lids, etc.) and consumer goods (e.g. electronic devices, etc.) as well as beverage containers. Furthermore, such products can also be used for everyday goods, such as disposable cutlery and tableware. Fiber-containing materials contain natural fibers or artificial fibers. Recently, fiber-containing material is increasingly used that has or is made of natural fibers that can be obtained, for example, from renewable raw materials or waste paper. BACKGROUND When molding products from a fiber-containing material, the fiber-containing material is pressed between the forming surfaces of a forming tool. During pressing, the products are heated and strongly compressed. In particular, during manufacturing of products from a fiber-containing material in a so-called “dry fiber” manufacturing process, where relatively dry fiber material is processed, difficulties arise for pressing at inclined portions of the products. Inclined product portions are inclined relative to a main axis in the pressing direction, usually the vertical axis, of a product. The term “dry fiber” is generally used when the moisture content of the fiber-containing material is between approximately 0.1 and 60 wt. %, preferably between 5 and 30 wt. %. The pressing force acts linearly and/or vertically via the forming tool halves in the direction of the product base, where the pressing force on the product walls decreases depending on the inclination. The steeper the product walls are compared to the product base, the lower the pressing force acting on the product walls. Due to the lower pressing force, poorer compression occurs, where the mechanical properties (e.g. strength) of the product to be manufactured are significantly worse than those of the product base. In addition, the surface properties of the product walls suffer. So far, attempts have been made to counteract the problem by using flexible tools with an inflatable inner tool (“balloon”). However, flexible tools have the disadvantage that the inflatable inner tool, which must be made of a flexible material, can provide significantly poorer heat transfer, so that the product properties on the surface, and in terms of mechanical properties, are worse than with products manufactured using fixed tools without flexible inner tools. SUMMARY Object In contrast thereto it is an object of the present disclosure to provide a solution for the manufacture of products from a fiber-containing material that eliminates the disadvantages of the prior art, where products can be produced with consistent quality and mechanical properties over the entire product geometry. In particular, it is an object to provide such a solution for fiber-containing material that is pressed in a so-called “dry fiber” processing. Solution The above-mentioned object is achieved by a method for manufacturing three-dimensional products with at least one inclined product portion, made of a fiber-containing material, using at least one forming tool, where the at least one forming tool has at least one first tool component with at least one cavity and at least one second tool component with at least one mold part corresponding to the at least one cavity, where the at least one mold part and the at least one cavity are movable relative to one another to form a mold cavity between corresponding surfaces of the at least one cavity and the at least one mold part, including the following steps: introducing a fiber-containing material into at least one cavity of at least one first tool component,closing the forming tool by means of a relative displacement of the at least one first tool component and the at least one second tool component,pressing the fiber-containing material within the mold cavity, andintroducing vibrations by moving the at least one first tool component and/or the at least one second tool component relative to the pressing direction during the pressing. By introducing vibrations relative (perpendicular, parallel or another optimal direction of action) to the pressing direction, the fiber-containing material is repeatedly moved between the inner and outer tool and thus “squeezed”, so that the fiber-containing material is compressed in the same way as it is within a portion on which the pressing force is able to act over the entire surface, such that the strength is also increased on inclined surfaces of a product and the surface propert