Method and apparatus for deep-drawing a tray from sheet material

Patent metadata

Field	Value
Publication number	US-2016288445-A1
Application number	US-201415034365-A
Country	US
Kind code	A1
Filing date	Oct 17, 2014
Priority date	Nov 4, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

The invention relates to a method and an apparatus for deep-drawing a tray ( 1 ) from fiber-based sheet material ( 2 ), such as polymer coated board. The apparatus comprises a female moulding tool ( 3 ), which comprises a cavity ( 7 ) for forming the tray bottom outwardly, a male moulding tool ( 4 ), which comprises a plunger plate ( 11 ) for forming the tray bottom inwardly, the plunger plate being movable with respect to the cavity for forming the tray, and clamps ( 6, 15 ) with an interface for holding the sheet material and forming a tray rim flange. According to the invention by laterally distancing at least one of the moulding tools ( 3, 4 ) from the sheet material leeway is provided for free forming of the tray side walls while wrinkling or tearing of the same is avoided. Spacer plates ( 13 ) may be positioned behind the plunger plate ( 11 ), to adjust its position in relation to the cavity ( 7 ) of the female moulding tool ( 3 ). The cavity may have a separate bottom plate ( 8 ) and spacer plates ( 9 ) there below, or screw means may be provided for adjusting the distance of the bottom of the cavity from the clamp interface and thereby varying the depth of the tray.

First claim

1 . A method of deep-drawing a tray from fiber-based sheet material, characterized in that the method comprises the steps of:
(i) bringing the sheet material between a female moulding tool, which comprises a cavity for forming the tray bottom outwardly, and a male moulding tool, which comprises a plunger plate for forming the tray bottom inwardly, (ii) clamping the sheet material along the circumference of the female and male moulding tools by clamping means, to hold the material during the deep-drawing step, (iii) moving the plunger plate with respect to the cavity for forming the tray, and (iv) wherein the moulding tools are arranged so that between the cavity bottom and the clamp interface at least one of the male and female moulding tools is laterally distanced from the sheet material to allow free forming of unwrinkled side walls for the tray.

2 . The method of claim 1 , wherein the male moulding tool is distanced from the sheet material so as to leave free open space inside of the tray side wall being formed.

3 . The method of claim 2 , wherein both the male and the female moulding tools are distanced from the sheet material so as to leave free open space to both sides of the tray side wall being formed.

4 . The method of claim 1 , wherein the distance between the cavity bottom and the clamp interface is adjusted to correspond to a selected depth of the tray.

5 . The method of claim 4 , wherein the vertical position of the cavity bottom is adjusted by means of at least one screw connecting the cavity bottom to a clamp on the underside of the tray rim flange.

6 . The method of claim 4 , wherein the male moulding tool has a plunger plate for forming the tray bottom inwardly, and spacer plates are inserted to adjust the vertical position of the plunger plate.

7 . The method of claim 6 , wherein said spacer plates are laterally distanced from the sheet material to leave free space inside of the tray side wall being formed.

8 . The method of claim 6 , wherein the female moulding tool has a cavity bottom plate, the vertical position of which is adjusted by means of spacer plates.

9 . The method of claim 1 , wherein unscored and/or uncreased sheet material is formed into trays having unwrinkled side walls and rim flanges.

10 . An apparatus for deep-drawing a tray, comprising
(i) a female moulding tool, which comprises a cavity for forming the tray bottom outwardly, (ii) a male moulding tool, which comprises a plunger plate for forming the tray bottom inwardly, the plunger plate being movable with respect to the cavity for forming the tray, and (iii) clamps with an interface for holding the sheet material and forming a tray rim flange, wherein within a vertical span between the cavity bottom and the clamp interface the male and female moulding tools are laterally distanced from each other to allow free forming of the side wall of the tray.

11 . The apparatus of claim 10 , wherein the female moulding tool at least one screw is provided to connect the cavity bottom to a clamp on the underside of the tray rim flange.

12 . The apparatus of claim 10 , wherein the female moulding tool has a cavity bottom plate, and spacer plates ( 9 ) are provided for adjusting the vertical position of said bottom plate.

13 . The apparatus of claim 10 , wherein the male moulding tool has a plunger plate for forming the tray bottom inwardly, and spacer plates have been provided for adjusting the vertical position of the plunger plate.

14 . The apparatus of claim 13 , wherein the spacer plates are laterally distanced from the sheet material so as to leave free space inside of the tray side wall being formed.

15 . (canceled)

Assignees

• Stora Enso Oyj

Inventors

• Räsänen Jari
• Lindell Henry
• Nevalainen Kimmo
• Tanninen Panu
• Matthews Sami
• Hiltunen Mari
• Kylliainen Outi

Classifications

• B65D1/26 Primary

  Thin-walled containers, e.g. formed by deep-drawing operations {(B65D1/165 takes precedence)} · CPC title

• B31F1/0077 Primary

  Shaping by methods analogous to moulding, e.g. deep drawing techniques · CPC title

• B29C51/30

  Moulds · CPC title

• B29K2105/256

  Sheets, plates, blanks or films · CPC title

• B31F1/00

  Mechanical deformation without removing material, e.g. in combination with laminating · CPC title