Container construction for powdered material

Abstract

Furthermore, a method of manufacturing a package for a powdered material is disclosed, comprising sliding the tub in the sleeve, such that at least the peripheral wall of the tub is enclosed by the sleeve, whereby the sleeve supports the tub and the tub and sleeve form a container for the powdered material.

1 . A method of packaging a powdered nutritional product under high-care conditions, the method comprising, in a high-care zone having an over-pressure with respect to atmospheric pressure and a filtered atmosphere:
 providing a thermoformed tub having a base and a peripheral wall with a top edge;   filling the tub with the powdered nutritional product;   providing a membrane for separating the powdered material from the environment; and   sealing the membrane to the peripheral wall of the tub,   
       the method further comprising transferring the filled and sealed tub from the high-care zone to a low-care zone and in the low care zone:
 providing a sleeve of carton material, 
 enclosing the peripheral wall of the tub with the sleeve, whereby the sleeve supports the tub and the tub and sleeve form a composite container for the powdered material. 
 
     
     
         2 . The method of  claim 1 , further comprising providing a lid assembly, comprising a peripheral rim defining a wide access opening and a lid, hingedly attached to the rim for reclosing the access opening and connecting the peripheral rim of the lid assembly over the top edge of the tub. 
     
     
         3 . The method of  claim 2 , wherein the lid assembly is connected to the tub in the high-care zone. 
     
     
         4 . The method of  claim 2 , wherein the lid assembly is connected to the tub in the low-care zone. 
     
     
         5 . The method of  claim 1 , wherein the over-pressure in the high-care zone is between 5 Pa and 30 Pa. 
     
     
         6 . The method of  claim 1 , wherein a temperature in the high-care zone is between 19° C. and 23° C. and a humidity is between 35% RH and 50% RH. 
     
     
         7 . The method of  claim 1 , wherein the atmosphere within the high-care zone is filtered with a HEPA filter of H10 or higher according to EN 1822:2009. 
     
     
         8 . The method of  claim 1 , further comprising checking the tub and the membrane with a vision system for imperfections or foreign bodies prior to filling. 
     
     
         9 . The method of  claim 1 , wherein filling takes place in a low-oxygen atmosphere. 
     
     
         10 . The method of  claim 9 , further comprising flushing with nitrogen or carbon dioxide before and during the filling procedure and prior to applying the membrane. 
     
     
         11 . The method of  claim 1 , wherein the tub comprises an outwardly extending flange at the top edge and the membrane is connected across the flange. 
     
     
         12 . The method of  claim 11 , wherein the membrane comprises a weakened tear line defining an opening region, and a pull tab. 
     
     
         13 . The method of  claim 12 , wherein the tear line further defines a peripheral region, permanently connected to the flange. 
     
     
         14 . The method of  claim 1 , wherein the peripheral wall of the tub comprises a laminate comprising polypropylene and including a barrier layer having reduced oxygen transmission. 
     
     
         15 . The method of  claim 14 , wherein the barrier layer comprises EVOH. 
     
     
         16 . The method of  claim 1 , wherein the peripheral wall of the tub has a thickness of between 0.15 and 0.40 mm and the sleeve has a weight of 100 g/m2 to 300 g/m2. 
     
     
         17 . The method of  claim 1 , wherein the powdered nutritional product is infant milk formula. 
     
     
         18 . The method of  claim 17 , further comprising providing a scoop within the package, wherein the scoop is placed onto the membrane within the low-care zone. 
     
     
         19 . A package, manufactured according to the method of  claim 1 . 
     
     
         20 . A package of powdered nutritional product manufactured under high-care conditions, the package comprising:
 a thermoformed tub for receiving the nutritional product, the tub having a base and a peripheral wall of polymeric material with a top edge, the peripheral wall being provided with a barrier layer having reduced oxygen transmission;   a quantity of powdered nutritional product within the tub, the product being flushed with nitrogen or carbon-dioxide, whereby substantially no oxygen is present;   a membrane, hermetically sealing the powdered nutritional product within the tub from the environment;   an outer carton sleeve enclosing and engaging the peripheral wall and base of the tub around its complete periphery; and   a lid assembly comprising a peripheral rim for connection over the top edge of the peripheral wall of the tub and defining a wide access opening and a lid, hingedly attached to the rim for reclosing the access opening.