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7/29/2019 Determining the Optimal Material for Coffee Packaging- Oxygen Tra
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Determining the Optimal Material for Coffee Packaging
Oxygen Transmission Rates and Ink Abrasion Resistance
A Senior ProjectPresented to
The Faculty of the Graphic Communication Department
California Polytechnic State University, San Luis Obispo
In Partial Fulfllment
of the Requirements for the Degree
Bachelor of Science
by
Laura Kiyoi
June, 2010
Laura Kiyoi 2010
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Table o Contents
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Chapter 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Chapter 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Chapter 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Works Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
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Abstract:Like many packages, coee packaging must attract consumers or purchase. In addition, coee
packaging has the specic requirements o keeping its contents resh. Tis study attempted to
determine the optimal material or coee packaging under the subjects o ink abrasion resistance
or printed graphics and content reshness. Te materials that were chosen to compare were
Aluminum (Al), low density polyethylene (LDPE,) polyethylene terephthalate (PE,) polyvinyl
chloride (PVC), nylon and polystyrene (PS.) o determine which material was the best or ink
abrasion resistance, ink rub tests were perormed. Also, oxygen transmission rates (OR) were
gathered to determine which material would best keep oxygen rom getting into the packageso the coee would stay resh or longer. Aer tests were perormed, PE was ound to best
optimize ink abrasion resistance and content reshness. Tis study provides material specic
inormation to describe the potential o using one type o material or coee packaging instead
o a multilaminate material. However, urther research is needed to see how using one material
instead o the currently used multilaminates would benet manuacturers.
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Chapter 1
What makes coee taste bitter? Tere are several aspects that could play into ones coee
not being o the best quality such as the beans that are harvested, package transportation, coee
making machinery and the technique o the barista. One subject that plays a role in aspects o
coee traveling to the consumer is coee packaging. Tis study addresses coee packaging and its
role to preserve the reshness o coee as well as attract the consumer with graphics. Te researchquestion o this study is: What is the best coee packaging material based on its ability to keep
the contents resh and hold graphics to attract the consumer? Tis question will be addressed by
discussing the topics o material oxygen transmission rates (OR) and resistance to ink abrasion.
Te purpose o this study is to determine the coee package material that best optimizes content
reshness and ink abrasion resistance.
o rst address the purpose o this study, the requirements o coee must be known.
Coee needs packaging that has barrier properties that keep oxygen (O2) out to preserve the
reshness o coee. Companies use several materials such as aluminum, paper, polyethylene andother multi-laminates as materials to preserve the coee. In addition to a type o main substrate,
the package needs to have a one-way vent that allows carbon dioxide (CO2) to leave the package
rom the roasted coee but does not allow O2
into the package.
In addition to the quality o the coee, the package must also attract the consumer with
graphics. Coee is an extremely consumer-driven product. Even i a package preserves the quality
o the coee beans, there is no purpose unless the consumer takes it o o the shel and purchases
it. Tereore, the material that is used or coee packages must be able to hold ink even through
transportation where the ink rom the graphics may be rubbed o.
Not only does the package need to attract the consumer, but it also must have strength
or shipping and handling. Te package would be worthless i it broke when put in secondary
packaging such as regular slotted containers (RSCs), palletized and shipped. Any quality-
preserving properties o the package would be eliminated i the package breaks and lets O2
in.
Te package has to be durable enough to handle rough handling and shock in transport without
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Chapter 2
Since coee is the package contents, the package needs to have a one-way vent to let out
gases produced rom the coee out while keeping oxygen (O2) out that could damage the quality
o the coee beans. Since coee is a highly consumer-driven product, graphics are also needed to
attract the consumer. Tis study attempts to determine the best material or coee packaging to
maximize content reshness and ink abrasion resistance. o decipher the best material or coee
packaging in both o these areas, common materials used in coee packaging were researched and
tested. Common materials used today or coee packages are aluminum, low density polyethylene
(LDPE), polyethylene terephthalate (PE), polypropylene (PP) and paper. Aluminum, LDPE and
PE were chosen to compare and contrast. Polyvinyl chloride (PVC), nylon and polystyrene (PS)
were also tested to compare.
Cofee Package Requirements: Letting Carbon Dioxide Out
Beore one ocuses on the materials o coee packaging, the particular packaging
requirements or coee as the package contents must be recognized. Coee is particularly dicultto package because it needs to allow carbon dioxide (CO
2) out while keeping oxygen (O
2) out.
According to an article in theJournal o Food Engineeringtitled Te Diusion Kinetics o
Carbon Dioxide in Fresh Roasted and Ground Coee, coee has certain package requirements
because o the CO2
that is produced when the beans are roasted. Te journal wrote that,
Although some carbon dioxide is released during roasting and upon grinding, some is trapped
and slowly released creating a packaging problem (Anderson et al. 71). Te issue with coee
bean packaging is that the package will explode or billow i it does not have the ability to release
the CO2. Tis article also stated that darker roasted coee beans contain more CO2 than lighterroasts. Tis is because darker roasts require more time to roast and more roasting creates more
CO2
(Anderson et al. 71). Tereore, level o roasting should be taken into consideration by the
packager.
Another aspect that must be addressed when calculating CO2
emission is whether or
not coee is ground or kept as a whole bean when packaged. According to the Wiley Packaging
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echnology Encyclopedia o 2009, CO2
content is around 1000 cm3/lb when the bean is roasted
but not ground. When the bean is ground, about hal o the CO2
is released(Vacuum-Bag Coee
Packaging). Tereore, whole roasted coee beans have a higher need or venting than ground
beans.
Cofee Package Content Freshness: Low Oxygen Permeability
In addition to letting CO2
out, coee packaging must also keep O2
rom permeating the
packaging and making the contents lose quality(Brody and Marsh 1256). Even though one can
wait or the coee to degas beore packaging, this takes a twenty-our hour period, where O2
can compromise the quality o the coee (Fres-co). Application o Weibull Hazard Analysis to
the Determination o the Shel Lie o Roasted and Ground Coee was a study that involved
consumer testing to determine the shel lie o coee taking into account exposure to O2
(Carbella
and Labuza 275). Te shel lie or the product ended when 50 percent o the tested consumers
said that the coee was unacceptable (Carbella and Labuza 273). Te ndings o the study showed
that or every 24 hours that coee was in room temperature; there was a decrease in shel lie o
ten percent due to exposure to O2
(Anderson. 1).
o address this issue o O2
permeation, the oxygen transmission rates (OR) o common
coee packaging materials was researched. For this study OR is dened as amount o O2that can
get through a given amount o area with pressure within a certain time rame.
Tese are some issues that the packager needs to be aware o when manuacturing coee
packaging. A type o one-way vent is usually used to reduce CO2
and keep coee rom being
damaged.
Cofee Printing Package Graphics or the Consumer
Even aer achieving high quality coee in a low OR packaging material, one must also
make sure that the substrate is printable or graphics that will attract the consumer. Te bottom
line is whether or not the consumer purchases the product.Data on the ink adherence o LDPE, PE, nylon, aluminum, PS and PVC were included
aer ink rub tests were perormed. However, this study also provides inormation on what the
coee packaging industry is doing currently or printing aesthetic graphics or the coee-drinking
consumer.
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PJs Coee o New Orleans shows an example o this with converging packaging material
knowledge with graphics knowledge. Tey used Sonoco as their packaging vendor who created
a new matte-nished, three-ply oil-based bags that eature the sophisticated imagery o New
Orleans (Package Design). Te printing was done with Sonocos rotogravure press capable o
using seven colors with a matt nish. Te matt nish gave a warmer look to the package thatattracting the coee-drinker:
Te soer nish minimizes the glare that oen occurs in fexible coee packaging. As a
result, the detail o the photos is emphasized, imparting a sense o nostalgia and refecting
the sophisticated favor consumers expect o New Orleans roasted coee (Package
Design).
PJs Coee did an excellent job o achieving printability rom a sustainable standpoint in terms o
reduction o materials. Te multi-laminate o the packaging material is made up o polyester and
oil while the seal is made rom polyethylene. When compared to a our ply laminate package,
this three-ply package achieves a reduction in material by 10 percent. It also uses 15 percent less
energy in production and 10 percent less carbon emissions (Package Design).
Sonocos PJs Coffee Packaging
(Package Design)
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One can see there are multiple aspects o coee packaging with the added concern or
maintaining the reshness o the coee. Knowing the quality o print on the dierent materials
this study covers allows manuacturers to include graphics that can attract the consumer. In
addition ink adherence or graphics, one must also keep the quality o the coee at the oreront
o knowledge when designing coee packaging.
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Chapter 3
Although there are several important aspects to packaging such as durability,
sustainability and graphics, coee packaging in particular has the additional requirement o
preserving the quality o coee that consumers demand. Although there are many aspects to
packaging, this study ocuses on the subject o substrates that preserve the reshness o coee
through low O2
permeation. Tis study also compares material to see which is the most capable
o holding graphics that can attract the consumer. Te purpose o this study is to determine the
coee packaging material that will best optimize content reshness and resistance to ink rub-o.
Tere are many types o lm materials that are used or coee packaging. However,
the specic materials that this study addresses are polyethylene terephthalate (PE), polyvinyl
chloride (PVC,) aluminum (Al), polystyrene (PS,) low density polyethylene (LDPE) and nylon.
Tese lms were chosen upon availability in Caliornia Polytechnic State University, San Luis
Obispos (Cal Poly) Industrial echnologys Plastics Lab. Current coee packages are usually
composed o a combination o materials in a multilaminate material. However, to see the basic
physical characteristics o coee packaging, each material was analyzed separately or the purpose
o this study. Te purpose o this study is to distinguish the best coee packaging material to
optimize content reshness and ink abrasion resistance.
o determine the best coee packaging material, the scientic method o research was
conducted as dened in Dr. Harvey Levensons book titled, Some Ideas about Doing Research in
Graphic Communication.
Te scientic method is a method where one addresses the problem through perorming
experiments instead o relying on previously known inormation. Te scientic method is broken
up into several stages:Identiy and dene the problem1)
Formulate a hypothesis2)
Collect, organize and analyze data3)
Formulate conclusions (Levenson, 19).4)
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Tis method is appropriate when needing to address specic issues that may not be available in
past, published data through historical research (Levenson, 19).
Using the scientic method, rub tests were perormed on LDPE, PE, Al, Nylon, PVC and
PS in the Inks and Substrates Lab at Cal Poly. Each material was corona treated to create a surace
tension on the substrate to aid the inks adherence to each material. Aer this, a fexographic hand
prooer was used to print on each material with brown water-based ink. o determine how much
ink was rubbed o, three ink density readings on dierent locations o the materials were taken
beore and aer testing each material. Te testing was done on an ink rub tester where the printed
substrate was taped to a our-pound block. Tis block rubbed back and orth across a material
o the same type that was not printed on. For example, a piece o printed PE lm was rubbed
against a non-printed PE lm. Each material rubbed back and orth a hundred times at a cycle
time o orty-two rubs per minute. Tese tests helped point to the best perorming material or
ink adherence.
Secondly, oxygen transmission rates (OR) were gathered rom Nippon, Gohsei, a
Japanese company that specializes in polymers, adhesives and gas barrier lms. Tis company
provided ORs o LDPE, PE, Al, Nylon, PVC and PS (Nippon).
Trough gathering data rom Nippon Gohsei and rub testing several materials, this study
was able to provide inormation that pointed to the highest perormance coee packaging that
optimized content reshness and ink adhesion.
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Chapter 4
Te purpose o this study is to determine the best material or coee packaging to
optimize the reshness o its contents and its ability to hold graphics to attract the consumer. o
do this, the materials o PE, PVC, Al, PS, LDPE and Nylon were studied and compared with rub
tests and oxygen transmission rate (OR) ndings.
Ink rub testing was perormed in the ink and substrates lab on the ink rub tester at
Caliornia Polytechnic State University in San Luis Obispo. Te testing was done ace to ace
using the 4 lb block. Te machine rubbed this block back and orth on the same type o material
or a 100 strokes. One could observe that certain materials had more ink loss than others aer the
rub tests. For example, PVC appeared to have the most ink loss out o all six materials. However,
or the purpose o this study, density readings were chosen as the means o comparison between
materials or ink abrasion resistance. o do this, three ink density readings were taken beore and
aer each rub test. Tree readings were taken at dierent locations o the materials to account
or the possible ink lay down dierences across materials rom the fexographic hand prooer.
Density readings beore rub tests were perormed are shown in the table below:
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As one can see, there are dierences o ink density across each material. Tis study
acknowledges that in materials such as PVC, these dierences are signicant. PVC had a density
in one location that was as low as 0.8 while in another location it had a density reading o 1.56,
which gives it a density dierence o 0.76. o account or these dierences in ink lay-down, three
readings were taken beore and aer rub tests and the readings were averaged.
Tree density readings were also taken aer rub tests were perormed and are provided
below:
Tese readings were averaged and then divided by the averaged densities that were taken
beore rub testing. Tis number was then subtracted rom one to determine the percent o ink lost
or each material. Te results are shown below. One should note that lower numbers are better
than higher numbers here because higher numbers represent more ink loss.
As one can see, the material that lost the most ink due to abrasion was PVC (also
conrmed by eye) and the material that lost the least amount o ink was PS.
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Oxygen Transmission Rates
Freshness o coee is equally important as the graphics outside o the coee package.
Published oxygen transmission rates o materials were used to determine which lm would be
best or coee packaging. Tis study uses oxygen transmission rates o materials to determine
which substrate will perorm the best to optimize content reshness as well as ink abrasion
resistance. Tis study denes oxygen transmission rate (OR) as the amount o O2that can get
through with pressure through a given amount o area and time.
Research was perormed using Nippon Gohsei data. Te ollowing inormation was
collected rom this company as shown below:
Tis graph depicts oxygen transmission rates in units o cc x mil/m2 x day x atm, atm
being an amount o pressure equaling 101,325 Pa. Lower OR numbers mean that the material
lets in less O2. Given this inormation, one can see that PS and LDPE cannot compete with the
other lower materials when it comes to protecting the coee rom the damages o O2. Tereore,
a more detailed graph is provided that compares PE, PVC, AL and Nylon and excludes PS and
LDPE:
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Aluminum as shown above, serves as a complete O2barrier; however, this is only the case
when the material is in perect condition. Because aluminum is usually used in fexible packages
in the orm o a lm that is less than 1.0 mil, it is rarely perect. Aluminum oil that is 1.0 mil or
less usually has pin holes that increase the materials OR (SPMC). However, using aluminum
in addition to other layers has been proven to decrease OR in comparison to not using analuminum layer even with this pinhole eect (Murray). As stated earlier, AL can act as a complete
barrier when in perect condition; however, pinholes and tears are common in this material
substantially lowering the materials barrier properties. With tears, Al can have an OR that is
even higher than LDPE. Tereore, the variety o materials narrowed urther, ocusing exclusively
on PE, PVC, and Nylon. Out o these three material PE scored as the best deense against
oxygen with an OR o 3.5 cc x mil/m2 x day x atm.
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Highest Perormance Material that Optimizes Content Freshness and Ink Abrasion
Resistance
Aer gathering the data above, the materials were compared to see which was the best
material to optimize content reshness and ink abrasion resistance. Te study ound that PE was
the optimal choice. Tis included both OR and percent ink lost as shown in the table below:
o best show this data, a graph is provided:
Even though, PS and LDPE had low amounts o ink loss rom the rub tests, the material ORs
are too high to be considered or the purpose o this study. Similarly, although PVCs OR seems
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competitive with Nylon and PE, its loss o ink rom the rub tests is too high to compare with the
OR o PE and Nylon. Since lower bars mean lower OR and less ink loss, one can see that the
two materials that were compared the most were Nylon and PE.
PE alls lower than Nylon with ink loss and OR; thereore, PE was determined to be
the material that best optimized content reshness and resistance to ink abrasion.
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Chapter 5
As one can see, coee is a particularly challenging product to package. Not only does the
manuacturer need to pay attention to strength o materials and graphics to attract the consumer,
but he or she must also ocus on preserving the reshness o coee that consumers demand. o
tackle these subjects, this study ocused on content reshness with OR and graphics or coee
packaging with ink abrasion resistance.
Trough these two ocuses o research and testing, this study ound that PE was the
optimal single material or content reshness and ink abrasion resistance with nylon as a close
second.
As one can see, this study researched individual materials, not multilaminates. Te
reason that multilaminates are used is to decrease ORs by having multiple layers o material
and thereore extra barrier properties. Usually in the coee packaging industry, multilaminates
are used where one material is reverse printed on and adhered to the rest o the multilaminate
material. In this case, ink rub resistance is not as applicable.
However, this study provided material specic ink abrasion resistance and OR data. Byproviding this inormation, one can examine the potential o using one type o material instead o
a multilaminate. Manuacturers can use this inormation to see how individual materials would
perorm without having to reverse print and adhere to another material. Further research is
needed to determine the specics on how this can benet coee package manuacturing.
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Works Cited
Anderson, B.A, Shimoni, R Liardon, and .P Labuza. Te Diusion Kinetics o Carbon Dioxide
in Fresh Roasted and Ground Coee. Journal o Food Engineering, 59.1 (2003): 71. .
Barrier Polymers. Te Wiley Encyclopedia o Packaging echnology. 3rd
Ed. 2009.
Cardelli, C. and Labuza, .P., 2001. Application o Weibull Hazard Analysis to the
Determination o the Shel Lie o Roasted and Ground Coee. Lebensmittel Wissenschafundechnologies 34, pp. 273278.
De Monte,, Michele; Padoano, Elio and Pozzetto, Dario. Alternative Coee Packaging:
An Analysis From a Lie Cycle Point o View. Journal o Food Engineering 2005 vol: 66 iss: 4 pg:
405. .
Film, Oriented Polyester. Te Wiley Encyclopedia o Packaging echnology. 3rd Ed.
2009.
Film, Oriented Polyester: Barrier. Te Wiley Encyclopedia o Packaging echnology. 3rd
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Foil, Aluminum. Te Wiley Encyclopedia o Packaging echnology. 3rd Ed. 2009. p. 475.
Levenson, Harvey. Some Ideas about Doing Research in Graphic Communication. 2001. p 19-27.
Nippon Gohsei. OR o Various Film Samples. Soarnol. 12 Feb 2008. .
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Nylon. Te Wiley Encyclopedia o Packaging echnology. 3rd Ed. 2009. p. 475.
Nylon Sheets.Nylon Sheets - Cast & Extruded.3 March 2010. .
Package Design. PJs Coee Converts to Sonocos Leaner and Greener Coee Bag. 28 Oct. 2009.
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Polymer Properties. Te Wiley Encyclopedia o Packaging echnology. 3rd
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Polypropylene. Te Wiley Encyclopedia o Packaging echnology. 3rd Ed. 2009. p. 475
Salomone, Roberta. Lie Cycle Assessment Applied to Coee Production: Investigating
Environmental Impacts to Aid Decision Making or Improvements at Company Level. April 29
2003. .
Schewe Phillip and Stein, Ben. Producing Oriented Polymers.American Institute o Physics. 7March 1991. .
Sirivatanapa, Dr. Somjate. Packaging o Processed Beverages. .
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Te Evolution o Vacuum Packaging. vanderstahl, n.p. Web. n.d. 5 Feb. 2010.
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Vacuum-Bag Coee Packaging. Te Wiley Encyclopedia o Packaging echnology. 3rd
Ed. 2009.
Valves. Fresco.com. Fresco. Fresco, n.p. Web. n.d. 5 Feb. 2010. .
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