Stora Enso Oyj

Lappeenrannan-lahden Teknillinen Yliopisto Lut

Sami Matthews

Jari Räsänen

Kimmo Nevalainen

Outi Kylliäinen

Panu Tanninen

Mari Hiltunen

Juha Varis

Henry Lindell

Marko Kasurinen

Mikko Rikkonen

Jari Selesvuo

Juha Turku

Outi Kyllianen

Ville Leminen

The invention relates to a method and an apparatus for deep-drawing a tray () from fiber-based sheet material (), such as polymer coated board. The apparatus comprises a female moulding tool (), which comprises a cavity () for forming the tray bottom outwardly, 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 clamps () 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 () 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 () may be positioned behind the plunger plate (), to adjust its position in relation to the cavity () of the female moulding tool (). The cavity may have a separate bottom plate () and spacer plates () 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.

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

The invention relates to a method and an apparatus for deep-drawing a tray () from a blank of sheet material (). The blank is provided with score lines, which determine the location of wrinkles formed in the process. The apparatus comprises a female moulding tool (), which comprises a cavity () for forming the tray bottom outwardly, a male moulding tool (), which comprises a plunger () for forming the tray bottom inwardly, the plunger being movable with respect to the cavity for forming the tray, and clamps () 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 () from the sheet material leeway is pro-vided for free forming so that wrinkling of the tray side walls is achieved in a controlled manner. Spacer plates () may be positioned behind the plunger (), to adjust its position in relation to the cavity () of the female moulding tool (). The cavity may have a separate bottom plate () and spacer plates () therebelow, 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.

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Lappeenranta, Finland

Sami Matthews