Tetra Laval Holdings & Finance S.a.

Tetra Pak Holdings S.a.

Roby Teknik Aktiebolag

Lars Lofgren

Peter Frisk

Cecilia Svensson

A laminated material for the manufacture of packing containers with good gas and aroma barrier properties, and a method for the manufacture of the laminated material. The laminated material has a base layer (18) and a barrier layer (19) of inorganic material of a thickness of only 50-500 .ANG. serving as a gas and aroma barrier. The barrier layer (19) is applied to the base layer (18) by means of vacuum deposition and bonded to the base layer by means of at least one intermediate layer (22) of bonding agent. To facilitate the conversion of the material to packing containers the barrier layer (19) is omitted along such areas (17a and 17b) of the material which are intended to be folded against, and combined with, one another by heat-sealing during the manufacture of the said containers.

Method for the manufacture of laminated packing material with good gas

A packaging laminate for a package possessing superior gas and light barrier properties is disclosed, and a method of producing the packaging laminate. The packaging laminate includes a layer of a silicon oxide compound serving as gas barrier and a layer of metal serving as light barrier, these layers being deposited by vacuum deposition on each respective layer of plastic serving as carrier, and being permanently bonded to one another through an interjacent layer of adhesive for the formation of the packaging laminate. By regulating the thickness of the gas and light barrier layers independently of one another, an optional combination of gas and light barrier properties is made possible, whereby the packaging laminate may be more or less 'tailor made' for each type of product which is to be packed.

Packaging laminate possessing gas and light barrier properties, and a

A laminated material for the manufacture of packing containers with good gas barrier properties or parts for such containers. The material (1) comprises a barrier layer (8) consisting of a mixture of amorphous polyamide and ethylene-vinyl alcohol copolymer serving as a gas barrier.

Laminated material with gas barrier properties

A flexible, laminated material (10) for reforming into packages for contents of the type such as oxygen- and flavor-sensitive liquid foods, for example fruit juices. The material displays a carrier layer (11) of paper or paperboard and a preferably extruded layer (13) applied to one face of the carrier layer (corresponding to the inside of the finished package), this layer consisting of a mixture of polyethylene and ethylene vinyl alcohol copolymer. Since the barrier layer (13) thus includes both a polar (the ethylene vinyl alcohol copolymer) and a non-polar (polyethylene) component, the material possesses barrier properties against both polar and non-polar flavor components, at the same time as the material moreover displays tightness properties vis-a-vis oxygen.

Packaging material of laminate type

A laminated material for the manufacture of packing containers with good gas and aroma barrier properties and or parts for such containers, and a method for the manufacture of the laminated material (1). The laminated material (1) comprises a first partial laminate (1) comprising a carrier layer (2) of thermoplastics and a barrier layer (3) of inorganic material of 50-500 .ANG. thickness serving as a gas and aroma barrier and a second partial laminate (1b) comprising a carrier layer (4) and a barrier layer (5) of inorganic material of 50-500 .ANG. thickness serving as a gas and aroma barrier, these partial laminates being joined to one another by means of an intermediate layer (6) of bonding agent, their respective barrier layers facing inwards towards one another.

Laminated packing material with gas and aroma barrier properties

In the manufacture of packing containers by means of folding of laminate in the form of sheets or of a web of the type which comprises a relatively thick carrier layer (2) of paper or cardboard and a gas-tight, thin metal foil (5) the laminate is subjected to stresses which, particularly within folding regions comprising multiple material thicknesses, may be so strong that crack formations occur in the metal foils protecting against gas which are sensitive to tension, thus entailing the risk of the intended gas barrier characteristics of the packing container being impaired or wholly lost. To counteract this risk the packing laminate is provided with a layer (6) of ethylvinyl alcohol laminated between the metal foil (5) and the carrier layer (2) which for one thing is mechanically sufficiently durable to withstand the external stresses during the folding of the laminate, and for another has sufficiently good gas barrier properties to compensate for the loss in gas tightness which thus may arise if the integrity of the metal foil (5) is lost during the manufacture of the container. Preferably the laminate is provided also with a further layer (7) of a material permeable to moisture which is laminated between the ethylvinyl alcohol layer (6) and the carrier layer (2) and which is adapted to let through moisture which from the liquid-filled inside of the container might be able to penetrate into the ethylvinyl alcohol layer (5) through such crack formations in the metal foil (5). As a result the moisture content in the ethylvinyl alcohol layer (6) can be kept at a sufficiently low level so as not to have a negative effect on the gas barrier characteristics of the ethylvinyl alcohol layer (6) which otherwise diminish with increasing moisture content.

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Staffanstorp, Sweden

Lars Lofgren