Varnishing of Fiber-based Closures
(2023) MTTM01 20231Packaging Logistics
- Abstract
- This research aims to investigate water-based varnishes and technologies to coat fiber-based closures to attain water barrier properties. To ensure recyclability the repulpability of coated and uncoated lids is tested. The research approach is exploratory. The investigation begins with the application of varnishes using a spray gun, brush, and dip coating followed by spraying equipment from Spraying Systems.
Nine varnishes are tested in the research. Based on the chosen minimum criteria to select the varnish, the primary objective is to analyze which of the varnishes show the following results 1) lower amount of dry coat weight(g/m2) (2) long penetration time (min) (3) high contact angle (°). The appearance (color, texture, and homogenous... (More) - This research aims to investigate water-based varnishes and technologies to coat fiber-based closures to attain water barrier properties. To ensure recyclability the repulpability of coated and uncoated lids is tested. The research approach is exploratory. The investigation begins with the application of varnishes using a spray gun, brush, and dip coating followed by spraying equipment from Spraying Systems.
Nine varnishes are tested in the research. Based on the chosen minimum criteria to select the varnish, the primary objective is to analyze which of the varnishes show the following results 1) lower amount of dry coat weight(g/m2) (2) long penetration time (min) (3) high contact angle (°). The appearance (color, texture, and homogenous coating) of the coated lid is evaluated through visual observation. Hydrophobicity is evaluated through water contact angle measurements using a goniometer, penetration time and visual observation. The repulpability trials of the uncoated lid and coated (selected varnish) material is tested using the lab equipment at Karlstad University.
The results show that closures coated with varnish 6 and 8 meet the minimum requirement; have a good visual appearance in terms of color and texture, high contact angle and relatively long penetration time. Repulpability results show that lids coated with varnish 6 are recyclable. Spray coating technology appears to be a potential process for implementation, although up-scaling is yet to be evaluated. (Less) - Popular Abstract
- Every product we see in the market these days is packaged in some material, for instance, plastic, glass, metal, paper, etc. Once the product is used, the packaging material ends up as waste. Research says that out of the many wastes that end up in the ocean, beverage containers made of plastic are the most dumped waste. Due to this, marine pollution has been a growing concern since plastics take centuries to degrade and affect the natural habitat of the oceans. As a result, regulations are being implemented to reduce the usage of single-use plastics.
BOC is a Swedish start-up that is producing fiber-based closures to reduce plastic. Fiber-based products are gaining importance due to their biodegradability, high recycling rate, and they... (More) - Every product we see in the market these days is packaged in some material, for instance, plastic, glass, metal, paper, etc. Once the product is used, the packaging material ends up as waste. Research says that out of the many wastes that end up in the ocean, beverage containers made of plastic are the most dumped waste. Due to this, marine pollution has been a growing concern since plastics take centuries to degrade and affect the natural habitat of the oceans. As a result, regulations are being implemented to reduce the usage of single-use plastics.
BOC is a Swedish start-up that is producing fiber-based closures to reduce plastic. Fiber-based products are gaining importance due to their biodegradability, high recycling rate, and they cause lesser environmental impact compared to plastics and metals in terms of carbon emission. However, one disadvantage of fiber-based material is their porous structure. We might have come across some paper bags for example, they readily absorb water and are used in products that do not need to be stored for very long.
To make the fiber-based materials suitable for longer shelf-life products, water-resistant property is required. This can be attained by coating them with a material that is hydrophobic (water-repellent). The materials used for coating are called varnishes and the process to apply on closures is called varnishing or coating.
This project aims to help BOC in investigating the type and amount of varnish, and coating processes for fiber-based closures. The chosen minimum criteria to select the varnish is the varnish that displays the following results.
(a) lower amount of coat weight so that it is economical,
(b) high contact angle measurements (angle between the liquid and coated lid), a higher contact angle implies water repellency, and
(c) long penetration time (the lasting duration of the liquid on the lid).
Since we want the closures to be recyclable, the coated closures need to be repulpable. If the repulpability yield is 70% and above, it indicates the product is recyclable.
We have tested nine different water-based varnishes from different suppliers and three coating technologies, spray, brush, and dip coating.
In conclusion, V6 and V8 showed the best performance by meeting the minimum criteria. The selected varnishes are food-grade and recommended for water-barrier-demanding food products. The repulpability yield of the coated lids ensured that varnish 6 coated lids are recyclable. Spray coating technology appeared to be the most suitable because it was easy to handle and attained lower coat weights.
Lastly, one interesting further recommendation would be to investigate the ocean biodegradability of the coated closures. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9125680
- author
- Sunil David, Nisha LU
- supervisor
- organization
- course
- MTTM01 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Varnishing, fiber-based closures, water-based spray coating, packaging, repulpability
- language
- English
- id
- 9125680
- date added to LUP
- 2023-06-22 10:10:52
- date last changed
- 2023-06-22 12:54:53
@misc{9125680,
abstract = {{This research aims to investigate water-based varnishes and technologies to coat fiber-based closures to attain water barrier properties. To ensure recyclability the repulpability of coated and uncoated lids is tested. The research approach is exploratory. The investigation begins with the application of varnishes using a spray gun, brush, and dip coating followed by spraying equipment from Spraying Systems.
Nine varnishes are tested in the research. Based on the chosen minimum criteria to select the varnish, the primary objective is to analyze which of the varnishes show the following results 1) lower amount of dry coat weight(g/m2) (2) long penetration time (min) (3) high contact angle (°). The appearance (color, texture, and homogenous coating) of the coated lid is evaluated through visual observation. Hydrophobicity is evaluated through water contact angle measurements using a goniometer, penetration time and visual observation. The repulpability trials of the uncoated lid and coated (selected varnish) material is tested using the lab equipment at Karlstad University.
The results show that closures coated with varnish 6 and 8 meet the minimum requirement; have a good visual appearance in terms of color and texture, high contact angle and relatively long penetration time. Repulpability results show that lids coated with varnish 6 are recyclable. Spray coating technology appears to be a potential process for implementation, although up-scaling is yet to be evaluated.}},
author = {{Sunil David, Nisha}},
language = {{eng}},
note = {{Student Paper}},
title = {{Varnishing of Fiber-based Closures}},
year = {{2023}},
}