Compression-moulded tray and method of producing a fibre tray

Abstract

A compression-moulded tray of fibre material, said tray being formed of fibre material in a compression method, from a suspension of mechanical pulp of cellulose. The formed tray has been formed by press-drying using heat to a dry content of 80-95%, preferably 90-95%, and the fibre material of the formed tray has a density in the order of 400-650 kg/m3. The inside of the tray is provided with a protective barrier.

1 . A compression-moulded tray of fibre material, said tray having an opening ( 3 ), an inside ( 5 ) and an outside ( 6 ), wherein the tray in a compression method is formed from a suspension of a fibre material of cellulose comprising at least 75% virgin fibre-based mechanical pulp from the group CMP, CTMP, cTMP, HTCTMP and mixtures thereof, and in that the formed tray has been formed by press-drying using heat to a dry content of 80-95%, preferably 90-95%, in that the fibre material of the formed tray has a density in the order of 400-650 kg/m3, and in that the tray on its inside is coated with a protective barrier. 
     
     
         2 . The tray according to  claim 1 , wherein said cellulose pulp comprises at least 75% CTMP. 
     
     
         3 . The tray according to  claim 1  or  claim 2 , wherein said protective barrier is constituted by an emulsion-based barrier that has been polymerised to a film by the addition of an initiator, or has dried to a film, on the tray. 
     
     
         4 . The tray according to  claim 1 , wherein said protective barrier is constituted by a film ( 7 ) of PET, PA, PP, PE, PBT, EVOH or combinations thereof. 
     
     
         5 . The tray according to  claim 1 , wherein said film ( 7 ) or protective barrier has been heat-laminated onto the formed tray. 
     
     
         6 . The tray according to  claim 5 , wherein said film ( 7 ) is black. 
     
     
         7 . The tray according to  claim 5 , wherein said film ( 7 ) is transparent. 
     
     
         8 . The tray according  claim 1 , wherein said tray has a smooth surface structure without any protruding fibres. 
     
     
         9 . The tray according to  claim 1 , wherein the fibre material of the tray has been treated with a hydrophobing agent. 
     
     
         10 . The tray according to  claim 9 , wherein the hydrophobing agent is selected from AKD (alkyl ketene dimer) and ASA (alkyl succinic anhydride). 
     
     
         11 . The tray according to  claim 1 , wherein said tray has a planar bottom ( 1 ) and side walls ( 2 ) that are straight to said bottom. 
     
     
         12 . The tray according to  claim 11 , wherein the opening ( 3 ) of the tray is surrounded by an outwardly extending and with said bottom parallel and completely smooth rim ( 4 ). 
     
     
         13 . A method of producing a fibre tray, comprising the steps of:
 a. forming a fibre tray by dewatering an aqueous suspension of cellulose from 1 to 15% in the forming section comprising at least 75% virgin fibre-based mechanical pulp from the group, CMP, CTMP, cTMP, HTCTMP and mixtures thereof using a dewatering tray;   b. press-drying the formed tray to a dry content of 80-95% and a density of 400-650 kg/m3; and   c. coating the dried fibre material with a protective barrier.   
     
     
         14 . The method according to  claim 13 , wherein said press-drying is performed at 250-280° C. 
     
     
         15 . The method according to  claim 13  or  claim 14 , wherein said protective barrier is applied by coating a surface of the formed fibre material with a plastic emulsion that is polymerised to a film by the addition of an initiator, or dries to a film, on the tray. 
     
     
         16 . The tray according to  claim 13 , wherein said protective barrier is constituted by a film of PET, PA, PP, PE, PBT, EVOH or combinations thereof. 
     
     
         17 . The method according to  claim 13 , wherein said film or protective barrier is secured to the formed tray by heat-lamination. 
     
     
         18 . The method according to  claim 13 , wherein the tray is formed from a suspension of fibre material having a pH between 6 and 8.5, preferably between 7 and 8. 
     
     
         19 . A method of laminating a film or a protective barrier on a fibre material comprising at least 75% virgin fibre-based mechanical pulp from the group CMP, CTMP, cTMP, HTCTMP and mixtures thereof fibre, comprising the steps of
 a. press-drying the fibre material to a dry content of 80-95% and a density of 400-650 kg/m3;   b. applying said film or protective barrier on said fibre material; and   c. laminating said film or protective on said fibre material.   
     
     
         20 . The method according to  claim 19 , wherein said protective barrier is applied by coating a surface of the formed fibre material with a plastic emulsion that is polymerised to a film by the addition of an initiator, or dries to a film, on the tray. 
     
     
         21 . The method according to  claim 19  or  claim 20 , wherein said film or protective barrier is secured to the formed tray by heat-lamination. 
     
     
         22 . The method of according to  claim 19 , wherein the applied film is PA, PP, PE, PBT, EVOH, APET, or combinations thereof. 
     
     
         23 . The method of according to  claim 19 , wherein the applied film is a film exhibiting increased E-modulus when stretched.