Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Light barrier properties of paperboard, packages and plastic caps in packages

Tu, Cam-Minh LU and Apt, André (2013) MTT920 20131
Packaging Logistics
Abstract (Swedish)
Examensarbetet inleddes den 15:e januari 2013 på Tetra Pak packaging solutions AB i Lund.
Mjölk är en produkt, som är särskilt ljuskänslig. För att skydda mjölk från ljus, kan dess förpackning innehålla aluminiumfolie. Det laminerade aluminiumfoliet ger en utmärkt ljusbarriär, men är dyrt och är inte ett förnybart material. För att kunna ta bort eller ersätta aluminiumfoliet och samtidigt inte förlora för mycket av förpackningens ljusbarriär är det viktigt att få kunskap om ljusbarriäregenskaper för andra material än aluminiumfolie.
I det här examensarbetet har fokus legat kring ljusbarriärer för material, som kan användas för okylda mjölkförpackningar. För okyld mjölk får inte ljustransmissionen (andel ljus, som penetrerar ett föremål)... (More)
Examensarbetet inleddes den 15:e januari 2013 på Tetra Pak packaging solutions AB i Lund.
Mjölk är en produkt, som är särskilt ljuskänslig. För att skydda mjölk från ljus, kan dess förpackning innehålla aluminiumfolie. Det laminerade aluminiumfoliet ger en utmärkt ljusbarriär, men är dyrt och är inte ett förnybart material. För att kunna ta bort eller ersätta aluminiumfoliet och samtidigt inte förlora för mycket av förpackningens ljusbarriär är det viktigt att få kunskap om ljusbarriäregenskaper för andra material än aluminiumfolie.
I det här examensarbetet har fokus legat kring ljusbarriärer för material, som kan användas för okylda mjölkförpackningar. För okyld mjölk får inte ljustransmissionen (andel ljus, som penetrerar ett föremål) överskrida 0.1%.
Två olika slags spektrofotometrar fanns tillgängliga för ljusbarriärmätningarna. En av maskinerna var en dubbelstråle spektrofotometer, som användes för att mäta plana prov. Den andra var en kupol spektrofotometer, som användes för att mäta tredimensionella strukturer.
Undersökningarna av papprena för 1 liters förpackningarna visade att de skyddade mot ljus med våglängder som gav upphov till bismaksreaktioner med Riboflavin (220-275,410-475 nm). Men transmissionen i våglängdsintervallet 650-700 nm var över 0.1%. Dessa våglängder ger upphov till bismaksreaktioner med porfyriner och chloriner.
Plastkorkarna på förpackningarna utgör en bråkdel av förpackningens totala area. Men ljusbarriären hos hela förpackningen kan försvagas på grund av plastkorken, vilket är anledningen till varför den har undersökts.
Ljusbarriären hos papper, plastkorkar och förpackningar från marknaden undersöktes.
Papper som användes för en liters mjölkförpackningar hade mindre än 0.1 % transmission för våglängder upp till 500 nm.
Fysikaliska egenskaper, som tjocklek påverkar ljusbarriären. De olika lagren i kartongen bidrar olika mycket till ljusbarriären.
Pigmentet i plastkorkar påverkar ljusbarriären. Den bruna korken från Tetra Pak och den blå kommersiella korken hade tillräckligt bra barriär mot bismaksreaktioner med Riboflavin, kloriner och porfyriner.
Tryckfärgen förbättrar ljusbarriären på papper. Detta kan användas som ett alternativt sätt att förbättra ljusbarriären i papper. (Less)
Abstract
The thesis started 15th January in 2013 at Tetra Pak Packaging Solutions AB in Lund.
Milk is a product that is particularly sensitive to light. In order to protect milk from light, its package can have aluminium foil. The laminated aluminium foil provides an excellent light barrier but is expensive and not a renewable material. To be able to remove the aluminium foil and not lose too much of the package´s light barrier it is important to obtain knowledge in light barrier properties of other packaging materials than aluminium foil. Aluminium also provides a barrier against other components that may harm the milk, for example moist and oxygen, however this report will only focus on light barrier.
The light barrier for ambient stored milk... (More)
The thesis started 15th January in 2013 at Tetra Pak Packaging Solutions AB in Lund.
Milk is a product that is particularly sensitive to light. In order to protect milk from light, its package can have aluminium foil. The laminated aluminium foil provides an excellent light barrier but is expensive and not a renewable material. To be able to remove the aluminium foil and not lose too much of the package´s light barrier it is important to obtain knowledge in light barrier properties of other packaging materials than aluminium foil. Aluminium also provides a barrier against other components that may harm the milk, for example moist and oxygen, however this report will only focus on light barrier.
The light barrier for ambient stored milk has been the focus during the thesis. Most of the light barrier is located in the paperboard for milk packages. For milk stored at ambient temperature, the light transmission (light that penetrates a sample) should not exceed 0.1%.
Two different kind spectrophotometers were available for the light barrier measurements. One of the machines was U-3010 spectrophotometer which is a dual beam spectrophotometer that were used to measure flat samples. The other spectrophotometer was a dome spectrophotometer that was designed to measure on three dimensional structures.
The investigation of paperboards for 1 litre packages showed that they had protection against light of wavelengths that induced off flavour reactions with Riboflavin (220-375, 410-475 nm). But the transmission for light within the range 650-700 nm was above 0.1%. Those wavelengths induce off flavour reactions with porphyrins and chlorins.
The plastic caps on packages are a rather small part of the total package in term of area. But the light barrier of the total package could be lacking due to the plastic caps which is why they have been investigated.
The light barrier properties of paperboard, plastic caps and packages available in the market were investigated.
The paperboards used for 1 litre milk packages have less than 0.1% light transmission for wavelengths up to 500 nm. This means that they give enough protection against light that induce off-flavour reactions with riboflavin, but may still be subjected to light induced off-flavour reactions with porphyrins and chlorins.
Physical properties such as grammage and thickness affect the light barrier in paperboard, because the thicker a sample, the lower the light transmission according to Lambert-Beer’s law. Some layers in the paperboard contribute more to the light barrier than others, due to different chemical composition.
The pigment in the plastic caps affects the light barrier. The brown plastic cap supplied by Tetra Pak and one blue cap available in the market had sufficient light barrier against off-flavour reactions with Riboflavin and also had low transmittance for the wavelengths where chlorins and porphyrins cause off flavour reactions.
The printing on paperboard improved the light barrier and transforming the paperboard into a package by creasing and then folding didn’t result in a weakened the light barrier. This means that the light barrier of a paperboard still remains or has improved after being transformed into a package. (Less)
Please use this url to cite or link to this publication:
author
Tu, Cam-Minh LU and Apt, André
supervisor
organization
alternative title
Ljusbarriär hos kartong, förpackningar och plastkorkar
course
MTT920 20131
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
4175246
date added to LUP
2014-01-07 13:48:58
date last changed
2014-01-07 13:48:58
@misc{4175246,
  abstract     = {The thesis started 15th January in 2013 at Tetra Pak Packaging Solutions AB in Lund.
Milk is a product that is particularly sensitive to light. In order to protect milk from light, its package can have aluminium foil. The laminated aluminium foil provides an excellent light barrier but is expensive and not a renewable material. To be able to remove the aluminium foil and not lose too much of the package´s light barrier it is important to obtain knowledge in light barrier properties of other packaging materials than aluminium foil. Aluminium also provides a barrier against other components that may harm the milk, for example moist and oxygen, however this report will only focus on light barrier.
The light barrier for ambient stored milk has been the focus during the thesis. Most of the light barrier is located in the paperboard for milk packages. For milk stored at ambient temperature, the light transmission (light that penetrates a sample) should not exceed 0.1%.
Two different kind spectrophotometers were available for the light barrier measurements. One of the machines was U-3010 spectrophotometer which is a dual beam spectrophotometer that were used to measure flat samples. The other spectrophotometer was a dome spectrophotometer that was designed to measure on three dimensional structures.
The investigation of paperboards for 1 litre packages showed that they had protection against light of wavelengths that induced off flavour reactions with Riboflavin (220-375, 410-475 nm). But the transmission for light within the range 650-700 nm was above 0.1%. Those wavelengths induce off flavour reactions with porphyrins and chlorins.
The plastic caps on packages are a rather small part of the total package in term of area. But the light barrier of the total package could be lacking due to the plastic caps which is why they have been investigated. 
The light barrier properties of paperboard, plastic caps and packages available in the market were investigated.
The paperboards used for 1 litre milk packages have less than 0.1% light transmission for wavelengths up to 500 nm. This means that they give enough protection against light that induce off-flavour reactions with riboflavin, but may still be subjected to light induced off-flavour reactions with porphyrins and chlorins.
Physical properties such as grammage and thickness affect the light barrier in paperboard, because the thicker a sample, the lower the light transmission according to Lambert-Beer’s law. Some layers in the paperboard contribute more to the light barrier than others, due to different chemical composition.
The pigment in the plastic caps affects the light barrier. The brown plastic cap supplied by Tetra Pak and one blue cap available in the market had sufficient light barrier against off-flavour reactions with Riboflavin and also had low transmittance for the wavelengths where chlorins and porphyrins cause off flavour reactions.
The printing on paperboard improved the light barrier and transforming the paperboard into a package by creasing and then folding didn’t result in a weakened the light barrier. This means that the light barrier of a paperboard still remains or has improved after being transformed into a package.},
  author       = {Tu, Cam-Minh and Apt, André},
  language     = {eng},
  note         = {Student Paper},
  title        = {Light barrier properties of paperboard, packages and plastic caps in packages},
  year         = {2013},
}