Moulding of hollow moulded fibre products

Abstract

The present invention relates to methods and systems for moulding a hollow moulded fibre product from a fibre suspension, such as a fibre suspension comprising paper pulp. In one aspect, there is provided a method of moulding a hollow moulded fibre product from a fibre suspension. The method comprises at least partially filling a cavity of a mould with a pre-filling liquid to form a body of the pre-filling liquid in the cavity, the cavity being defined by one or more internal surfaces of the mould and the mould having a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould; and subsequently introducing a fibre suspension to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid.

1 . A moulding system for moulding a hollow moulded fibre product from a fibre suspension, the moulding system comprising:
 a mould comprising one or more internal surfaces that define a cavity, within which the hollow moulded fibre product is moulded in use, and a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould;   a fibre suspension supply system;   a pre-filling liquid supply system; and   a control system, configured to control the pre-filling liquid system and the fibre suspension supply system to:   at least partially fill the cavity with a pre-filling liquid from the pre-filling supply system to form a body of the pre-filling liquid in the cavity; and   subsequently introduce a fibre suspension from the fibre suspension supply system to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid.   
     
     
         2 . The moulding system of  claim 1 , wherein the control system is configured to:
 at least partially fill the cavity with the pre-filling liquid during a first time period;   introduce the fibre suspension into the at least partially filled cavity during a second time period; and   remove liquid from the cavity during a third time period.   
     
     
         3 . The moulding system of  claim 2 , wherein the second and third time periods overlap with each other and wherein the first time period does not overlap with the third time period. 
     
     
         4 . The moulding system of  claim 1 , wherein the mould comprises one or more of the following: an inlet into the cavity to receive the pre-filling liquid or the fibre suspension, and wherein the inlet is located above the cavity; a first inlet to receive the fibre suspension, wherein the first inlet is located above the cavity, and a second inlet to receive the pre-filling liquid, wherein the second inlet is located below the cavity. 
     
     
         5 . The moulding system of  claim 4 , wherein the cavity has an elongate shape with a said inlet located at one longitudinal end of the elongate shape. 
     
     
         6 . The moulding system of  claim 5 , wherein a major axis of the elongate shape of the cavity is vertically oriented. 
     
     
         7 . The moulding system of  claim 1 , further comprising a negative pressure source, and wherein the control system is configured to control the negative pressure source to apply a negative pressure to the exterior of the mould when controlling the fibre suspension system to introduce the fibre suspension to the at least partially filled cavity. 
     
     
         8 . The moulding system of  claim 1 , wherein the control system is configured to control the amount of fibre suspension introduced into the partially filed cavity using a flow rate of the fibre suspension into the partially filed cavity. 
     
     
         9 . The moulding system of  claim 1 , comprising a conduit network between the fibre suspension supply system and the cavity and between the pre-filling liquid supply system and the cavity, and wherein the control system is configured to control the pre-filling liquid supply system and the fibre suspension supply system to control the volume of pre-filing liquid in the cavity to be greater than a volume of air in the conduit network between the cavity and the fibre suspension system. 
     
     
         10 . The moulding system of  claim 9 , wherein the fibre suspension supply system comprises a fibre suspension valve coupled to the conduit network and the pre-filling liquid system comprise a pre-filling liquid valve coupled to the conduit network, the moulding system comprising a drain conduit system coupled to an exterior of the mould and having a drain valve coupled between the exterior of the mould and a drain outlet; the control system configured to:
 open the pre-filling liquid valve to allow the pre-filling liquid supply system to at least partially fill the cavity with the pre-filling liquid;   close the pre-filling liquid valve; and   open the drain valve and open the fibre suspension valve to allow fibre suspension to be introduced into the cavity and liquid to be removed from the cavity.   
     
     
         11 . A method of moulding a hollow moulded fibre product from a fibre suspension, the method comprising:
 at least partially filling a cavity of a mould with a pre-filling liquid to form a body of the pre-filling liquid in the cavity, the cavity being defined by one or more internal surfaces of the mould and the mould having a plurality of passageways that provide fluid communication between the cavity and an exterior of the mould; and   subsequently introducing a fibre suspension to the at least partially filled cavity, wherein at least some of the fibre suspension impacts the body of pre-filling liquid.   
     
     
         12 . The method of  claim 11 , comprising:
 at least partially filling the cavity with the pre-filling liquid during a first time period;   introducing the fibre suspension into the at least partially filled cavity during a second time period; and   removing liquid from the cavity during a third time period.   
     
     
         13 . The method of  claim 12 , wherein the second and third time periods overlap with each other and wherein the first time period does not overlap with the third time period. 
     
     
         14 . The method of  claim 11 , wherein each of the pre-filling liquid and the fibre suspension are received into the cavity via one of the following: an inlet which is located above the cavity; a first inlet to receive the fibre suspension, wherein the first inlet is located above the cavity, and a second inlet to receive the pre-filling liquid, wherein the second inlet is located below the cavity. 
     
     
         15 . The method of  claim 14 , wherein the cavity has an elongate shape and a major axis of the elongate shape of the cavity is vertically oriented. 
     
     
         16 . The method of  claim 11 , comprising using a flow rate of the fibre suspension into the partially filed cavity to control an amount of fibre suspension introduced into the partially filed cavity. 
     
     
         17 . The method of  claim 11 , comprising controlling the volume of pre-filling liquid in the cavity to be greater than a volume of air in a conduit network between the cavity and a fibre suspension system used to supply the fibre suspension for introducing into the cavity. 
     
     
         18 . A control system configured to cause a moulding system to perform the method of  claim 11 . 
     
     
         19 . A non-transitory storage medium storing machine-readable instructions that, when executed by a processor of a control system, cause the processor to control a moulding system to perform the method of  claim 11 . 
     
     
         20 . A receptacle manufacturing line comprising the moulding system of  claim 1  for moulding the hollow moulded fibre product and apparatus for performing at least one additional process on the hollow moulded fibre product to provide the receptacle.