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

    Ed. 2009.

    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.

    .

    Polymer Properties. Te Wiley Encyclopedia o Packaging echnology. 3rd

    Ed. 2009.

    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. .

    Rattray, om Source reduction - an endangered species? Resource Recycling. Nov. 1990.

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    esting, Product Fragility. Te Wiley Encyclopedia o Packaging echnology. 3rd Ed.

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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

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    Valves. Fresco.com. Fresco. Fresco, n.p. Web. n.d. 5 Feb. 2010. .

    Volokh, Alexander and Scarlett, Lynn. Is Recycling Good or Bad or Both? Consumers

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