Draft
Course Outline
See also: Alternate Course Outline
1/21/02
Related links:
- http://disappearingpackage.com/
- The Weird, Underappreciated World Of Plastic Packaging (NPR)
- Molded Pulp Video
- The Invention of the Cardboard Box
- Dear Packaging, I hate you (Bolt Blog)
- Design of Aluminum Beverage Cans
- Kraft has recalled some American cheese singles after reports of customers choking on plastic wrapping (time.com)
Dual nature of packaging: Technical V. Marketing (psychogrphics).
History of packagin.
Leather, skins, leaves, etc.
buckets, clay
2500 BC glass, core wound glas.
Greeks had labels
Egyptinas had location stamps
Industrial revolution, movement to non-self supporting societies, adaptation of bulk systems. (barrels) wrapped product in paper, lead to advertiaing on paper.
By-products, re-use
EG. Cotton
1. Fibers
2. Linters (cellulose)
3. Cottonseed oil
4. Husk, soil abatement, animal feed filler
Centralized processing.
1856 – first cellulose baed plastic
1907 – Phenyl… Bakelite
1911 – Cat cellophane
Environmental Issues.
1. Reduce
2. Reuse
3. Recycle
4. Recover
CHAPTER 2
Primary – individual use – can beverage – single can
Secondary – Sales grouping – 12 pk
Distribution – Tray – 24 pk case
Shipping – Group for loading – unit load (pallet)
Physical form
solid/liquid
rigid/compliant
Nature of product
Phase
Stability (flavor, reactivity, pH)
Functions
Preserve and Protect
1. Internal, biological deterioration (fruit respiration)
2. External Biological deterioration. (Bacteria, etc) many are eliminated by heat, etc, product and package must be compatable with treatment method. Sometimes package is sterilized diffferent than product sometimes.
Five kinds of organisms that affect food (pathogens). Did not list.
4 Ways to control bacterial/ microbe growth.
1. Temperature
2. Moisture control
3. pH (acidity)
4. Nutrient deprivation.
(1-3 are most economical)
6 Ways to extend shelf life.
1. Reduce temperatuer (frozen foods, meat, dariry)
2. Thermal Processing (canned goods, jelly, soup etc.)
3. Water reduction (potato chips)
4. Chemical preservation (CO2 – natural microbe killer, benzoic acid, citric acid, salt, 02 absorbers built into films.
5. Modified atmosphere (O2 Elimination, CO2 elimination)
6. Irradiation. Cobalt 60, does not make product radioactive, changes chemical structure, not GRAS generally regarded as safe. Other levels are FDA approved, Medically steral.
post break
A. Reduced temperature
bacteria and molds stop developming -8C, (18F)
Chemcial and Microorganism activty stops -18C (0F)
Peak Ice Crystal formation 0to -5C (32 to 23F)
B. Thermal treatment depends:
which Micro organsim is to be reduced.
pH acidity
Physical Nature
Heat Tolerance of item
Container type dimensions. Heat conductivity, affects temperature treatment times.
C. Water reduction (again). Salt and sugar both absorb moisture, used as dessicants.
Modified atmospheres (MAP) also (CAP) continually applied packaging (at warehouse) bannanas put in hydrogen to get them yellow on an entire container.
TRANSPORT FUNCTION
protect from shock, vibration, impact, contaminants. Must understand distribution chain. SHIP TESTS are one example.
INFORM and SELL
Product name, manufacturing, other legal info. Food has another level, ingredients, batch and lot, nutritioin. DEMOGRAPHICS and PSYCHOGRAPHICS. Demo: who do you want to sell to.
Psych: how do they react. shape size color, type, icons, illustrations all have an impact. Example: how people respond to colors. Same crackers, in red and yellow box. Different responses. Perceived difference.
Graphic design. People categories.
Laisse fair (18%)
Mature moderates (17%)
3 squares (meals) (21%)
FatPHobics
Trend Trackers (22%)
5 different groups, 5 ways to sell to them. Different featrues and approaches for differnt groups. This is a driver for requests to the engineer.
Purchase Intent – different appraoches.
1. Durable good (car, TV).
2. Impulse item.
3. Staple item (detergent, flour)
Use and application
features your package will use because of the way it is used. Mc donalds changed coffee package. (?)
presentation. Mail order, vs. department store
Brand identity.
To Develop a brand name with national recognition takes upwards of $50 million dollars. Colors, perception and control during printing process. Color carries majority of the identity. Print quality is important.SHAPE value impressions from dimensions. Diameter v. Length. L/D ratio. 1 to 2, 1 to 1 boxy, square, longer is more interesting. TEXTURE. TONE, use of lines. Horizontal = calm, Vertical = Dignified, Diagonal = vitality, Curved = Grace.
DONT DO TO ANSWER DESIRE:
1. Pizza flavored product, wanted checkerboard along short side of box. Showed the least inaccuracy. Misregestrations, scoring, etc. Help yourself up front. Get better appearance, with more slop.
Packaging Week 2
1/28/03
Key things to remember:
Graphics and design, how it matches with the demographics and psychographics. Psychographics are how the package strikes a person, overall appeal, differentiation from other products. For example, generic cola packaging has changed to be more like major brands. As differentiation becomes less, one will change to try to lead.
Demographics are characteristics of the people who by the product.
Review of the different consumer types. In USA, each take a fifth. Shifts in world market.
USE FEATURES (review)
Dispensing or measuring agent. Some brands of laundry detergent have drainback feature. Reclose features, such as on cheese, twist-on caps, etc. Are reclose features.
Warning labels.
SIZING AND POSITIONING OF A PACKAGE.
One function is to protect through the distribution process. Eg. Wal mart has specifications on merchandising. Color of tags, opening devices, etc. these have to be adapted to, and integrated in.
BRAND NAMES
$50 Million dollars to get recognition. Probably really 2 to 3 times that much. “tastes great..less filling”
COLOR, SHAPE, ICONS, SYMBOLS.
Eg. pringles icon. Mustache man.
COLOR, UNITY, TYPE, FONTS
—-END REVIEW FROM LAST WEEK—
PRINTING (CH4)
OBJECTIVE:
to present image consistently over a large number of units. (upward of 20 * 25* 25 million) Variation between packages is BAD. Color used to dictate color. If red turns to orange, does that mean cheese flavor?
IMAGE AND NON IMAGE
Three technologies for mass production. Contrasted with decorating like gold foil transfer, etc.
1) Flexographic
2) Lithographic
3) Gravure
Goal of printing is to get image and colors put onto package.
Electromagnetic Spectrum:
AM…TV… Red…..violet… UV..gamma
>>>>power>>>
<<<wavelength<<<
Some people interchange red and green. Color blindness.
Sensitivity of human eye.
Black is absence of color.
White is all color.
Human eye can detect around 1million color differences.
Dupicating consistently is the challenge.
Black: no stimulus.
White: all receptors equallly activated.
Two things to help graphics to be presented:
1) additive synthesis
Combining of light.
2) subtractive synthesis
Taking light away (absence)
Taking out blue and yellow, see red light. To formulate inks, must work within these two principles.
COLOR
The true colors used in printing are
CYAN (bluegreen), MAGENTA (redblue), YELLOW
Usually a fourth color (TRUE BLACK) is added black is the KEY color.
CMYK
WHITE
Paper quality. Paper is not pure white. Fibers have natural chemicals that absorb light. To get pure whiteness, bleach , etc. 85 brightness paper has coating on it to reflect light.
COLOR TERMINOLOGY
Hue, Chroma, Value
HUE: Position in the spectrum that has a name. Red, blue, violet.
VALUE: Greyscale indication of lightness or darkness. If we have two colors on a greyscale, light blue, light purple with equal value, when converted to black and white, would not be able to tell the difference.
CHROMA: (saturation) How strongly colored is the thing. The higher the number, the more color. Chroma values.
Reflectivity: aluminum is often used. Also lacquers, varnish.
Coatings: reduce abrasion, smearing, high gloss, low gloss.
VALUE AND CHROMA are important in “Tinting” or making lighter start with light, or “Toning” start with black, dark. making darker.
PURE MAGNESIUM DIOXIDE.
Is used for color matching. It is 100 brightness. Brightness of paper is matched against this standard.
Most inks are transparent, and absorb and reflect color. if you dont have a light baes, will look dull. Brighter background or substrate is critical to end result.
COLOR PERCEPTION
Is subjective. Some factors influencing perception:
1) Observer.
2) Lighting. Flourescent light is green.
Industry standard for illumination is a 5000 degree K light (noon sun color).
3) Nature of the object itself. Texture diffusivity, reflectivity.
INSTRUMENTS FOR MEASURING COLOR
Colorometer, and densitometer.
ARTWORK
three kinds:
1) line art
Black and white, or solid colors.
2) half tone: use of patterns to create a scale of saturation. Dots. From 50-60 up to 200 dpi.
3)process printing: plates with CMYK. Book page 82.
Usually, Line art on a case, one plate without critical registration. [ Often, surface of packages is coated with clay, titanium oxide, to allow smoother surface for finer printing.]
Standard resolution is about 150 DPI.
Registration is critical.
BLEEDOVER: when someone prints beyond the borders to improve effect. printing beyond borders so when it is folded, assembled, will look complete. To help with repeat and alignment.
REGISTRATION STARS:
To help printer align the different colors.
GREYBALANCE CHARTS:
Similar to CMYK chart, but black and white.
SEPARATION:
When artwork is split into CMYK. For example, the red separation is the magenta field.
MOIRE
optical illusion of swirls, when dots align themselves.
industry standard to set dot lines, skewing is called MOIRE pattern. everybody puts each CMYK component at a certain angle.
Yel: 0 deg. Skew.
Mag: -15 deg.
Cya: 15 deg.
PANTONE
matching system: a scale system to assign numerical values to a color. PMS number.
PROOFING
Getting a sample of the art before running thousands.
Four approaches
1) Iris proof.
Inkjet printer applies to substrate. Only gives idea of color PMS# with line art..
2) Fuji
Also called “match print” laminated sheets.
3) Chromalin
Color separated plates, powdered ink stick to it. Overlaid to get print. Not as good as fuji.
5) Color Keys
Uses solid substrate. Not laminated. Shows press operator how each individual color should look.
TRAP
A phenomenon where inks can overlap. Without enough trap, lines appear between colors.
LITHO: 100 micrometers
FLEXO: 350 micro.
GRAVURE: 175 micro.
REFERENCE SAMPLES
Keep reference samples to compare other runs. For example if you run 2 Millioin cases, only order what you want, for each order, need samples.??
SIX FEATURES COMMON TO ALL PRESSES
1) Material feed system.
2) Ink reservoirs. Sometimes called a “fountain.”
3) Metering system.
4) Configuration system (Plates/Cylinders, etc.)
5) Transfer point.
6) “Drying” method. Elimination of solvent that carries ink.
FLEXO
Web (roll) or sheet fed. Some roll feed, sheet stack. Some applications require web, such as envelope making machines, etc. Some webs come with registration marks printed on. There is a limit on the number of impression you can get out of flexo. Plates are rubber, pick up ink from anilox roll, iink is transferred to lands on the plate. Can be a 2-up, 4, or 8-up.
Can get 500k to less than 1Million. Flexo plates are photo-etched onto rubber surface new plates can be made in about 36 hours. Gives ink on the high spots. Topographical process? Biggest users are corrugated at 60dpi resoluton, usu. One color.
LITHO
Oil based, water as a rider. Originally wax on stone. Wax repelled water, uses a much thicker ink. gives a finer product than Flex. 130-150DPI is average accuracy. Offset is most common. Used for can labels, etc. A trick, the substrate will see both water and oil based substances. Not used for plastic printing. almost always on paper. Not extremely accurate, but allows good looking labels at good cost. Usu 24 hour cure.
GRAVURE
Uses hardened roll with mechanical properties etched into the surface. Works in a negative method. Cavities hold the ink much like an ingraving. Depth of the cavity increases the ammmount of ink held in. See p. 419. Substrate is pressed onto roll. Can get really high quality graphics. Takes several weeks to get plates. Can do small print. NOTE can get up to 10million impression out of a plate.
4.3, 4.4, 4.5
Compares pros and cons of the types of presses.
4.7
Compares configurations.
4.8
Inks and thicknesses.
SCREEN PRINTING
“silkscreening” fill pours in screen, squeegee ink through the screen that has been masked. Usu. For object hard to print on.
EMBOSSING.
HEAT TRANSFER
image is in the transfer media. Usually used in plastics.
ALUMINUM
used as a moisture barrier, when using metal, changes the drying dynamics. Usually minimize extra bleed because metalized is expensive.
INKS
4 components
1) pigments – source of the color.
2) vehicle – binding component binds particles together and to the surface.
3) solvent – now mostly water, sometimes alcohol, sometimes MEK. Are the carrier, goes away as cures.
4) additives.antifoaming, wetting,
CURING
Four methods for ink curing/solidifying
1) evaporation of solvent
2) absorbtion of solvent
3) oxidation of solvent
4) other chemical reactions.
HEAVY METALS
reds and oranges that are bright, often have trace elements of lead, mercury, etc. Mostly not used today, but need to know to avoid. Recyclability issue as well. Lots of reds have mercury in them.
SOY INKS
Packaging Week 3
Review of last week. Humans can sense millions of colors.
Trap – inkdots overlap each other. Different types of printing have different ammounts of trap possible. Average trap is:
Flexo – .004
Litho – .014
Gravure – .007
This helps compensate for inaccuracies of printing registration.
Viscosity:
Flexo – water like
Litho – paste like – usually oil-based
Gravure – in between, middle viscosity
Material:
Flexo – Corrugated, low quality platic
Litho – paperboard
Gravure – Plastics
Print Quality:
Litho – Smooth edges
Flexo – Haloing
Gravure – sharp sawtooth
See also number of impressions
And initial cost (last week)
Specialty Processes
MEATLIZED INKS
METALIZED SUBSTRATES
EMBOSSING
GLOW IN THE DARK
TEMPERATURE SENSITIVE INKS
SCRATCH OFF (GAME PIECES)
SCRATCH AND SNIFF
MOISTURE SENSITIVE
many standard equipment can print with these. Lots are expensive.
Bleed/bleedover – going beyond the borders so when folded, “seam” wont show.
***PAPER***
What is paper: a fiber matirx matted or felted into a sheet. Consistent thickness.
FIBER: sources are many.
*Recycled Linen from rags, Cotton
*Bagasse (sugar cane, palm)
*Cotton
*Straw
*Wood fiber (cellulose) #1 in developed world. Most from planned and managed forrests.
TYPES:
*Heavy paper stocks
Paperboard
Boxboard
Cardboard
Cartonboard
All are used synonomously, according to different companies, etc.
ISO distinctions:
PAPERBOARD >250g/m^2 (51#/1000SQFT)US STD. By thickness
300 micometers or .012″
(Measured in density or thickness.)
also see weight / 3000 sq ft. For fine papers business. like for a printer is weight per 3000 sqft.
FOUR THINGS TO KNOW ABOUT A PAPER.
1) fiber (grown) – source. Wood? Cotton? Hardwood? Northern, souther hardwood? All relate to strength and properties, fiber length etc.
2) Preparation (fiber reduced/ harvested)- how was fiber extracted? Many processes change properties of the paper. Impacs fiber legnth, etc The longer the fiber, the better to “tangle” newsprint has short fibers. Easy to tear, etc. Fiber is chopped. Recycling, beating refibrilation shortens fibers.
Fiber length affects tensile strength, tear, folding characteristics.
*pure mechanical
*pure chemical
*combination
Usually a very acidic or alkaline environment. Today most are alkaline, helps with bleaching process, acid reacts with lignin with light to yellow paper. Dissolve rosins and bleach (with chlorine or Hydrogen Peroxide. H2o2) most today, uses HP. Water sometimes has a turbidity that can affect pulp machine. Seasonal variation. Changes in turbidity of the water.
3) Paper machine used. (mat formation). See book for 3 styles of paper machines.
*four gernier? Lays stock down in a slice. Stock lays down on screen, become a “felt.” Some are up to 160″ wide to 300″ wide machines. Almost 10 yards wide. Used for papers from tissue to crepe. Limited ability to pull free water out (limits thickness)
*Cylinder Machine. Rotating screen drum. Some have 6 to 8 cylinders. Used for thicker papers (can de-water between stages). Can make laminates with different properties in different layers.
*Twin Wire. Effective in removing water. Difficult to control variability between wires.
Common to all:
Wire
Felt
4) Additives and treatments. Such as bleaching.
*additives (usually coatings) primarily to improve surface of paper. Adhesives, “clays”, starch (as a moisture control). When you change the absorbtion properties of the paper, it is usually defined as “Sizing”.
Hard size = repellent
Soft size = absorbant
“clays” not always pure, refined clays. used to increase brightness, to fill voids. Treatment “Calendering” or “polishing”. Polishing is done by passing through 2 highly polished rolls. Calendering: squishing the fibers enormously. Tissue paper calendered at 30# per linear inch to 80# per linear inch. Some writing grade papers, 500 to 600# per linear inch. Rolls have to be designed for crown, journal loading, and control deflection on the roll. Super calendering required for 200dpi.
TESTING
Folding test
Newsprint 15x
Printer 30x
Craft 100-200X
Currency 1000+
WET STOCK DENSITY
Bundles of fibers are hydrophilic. A high density stock for paper towels, for example 2% fiber. Two grams of fiber to 100 grams of water. Takes a huge ammount of water to make paper.
Some pumps can handle up to 7% stock. Most run 2% or so.
Paper leaving the “dry” end of the machine still has 35-55% density.
WOOD COMPONENTS
*Cellulose – what we want out of it. About 50% of a piece of wood.
*Lignin – a natural adhesive that binds fibers together.
*Carbohydrates –
*Mis. Rosin, and other.
Most cellulose grown in warm climate, grows rapidly. Souther pine, loblolly, black pine, other long needle pines. Have lots of resins, used for turpentine, and other uses.
KRAFT – From german word meaning “strength”
RECYLCING
Fiber length, gives better properties. Recycling reduces quality, fiber length. Newsprint can be recycled about 5-8x.
Insolubles (inks, etc.) foreign particles “stickies” make discontinuity in paper.
Recycle loops sometimes have to be “dumped”
TREES
5.1 table
Sources, Fiber lengths,
[move to machines]
Movement of wire in formation process relative wire to fiber. Fibers lay down in the machine direction. Called the “MD” or Machine direction. compare with CD or Cross direction. Properties are rated MD or CD. Forward Grenier has MD to CD ratio of 2:1.
Cylinder machine 4:1.
FORMATION
Term used to describe how consistently and evenly the fibers are deposited. Esp important with cartons and cases. Should indicate machine direction on prints.
PROBLEMS TO WATCH OUT FOR
*using untreated paper on a litho. will come off on litho system.
*Calendering changes paper “sizing”.
TYPES OF PAPERS AND PAPERBOARD
Hard sized (grease proof)
Soft sized (books, etc)
AUVIOR DUPOIS UNITS
Caliper points in thousands of inches
in paperboards
0.001″ = 1point
20 point board = .020″ thick
Container board Units
Weight/1000Sq Ft.
Also called the basis weight. Such as 60pound paper = 60 Lbs/1000sq ft.
Fine paper units
Weight/500 sheet ream.
Roughly equivalent to weight/3000 sq. Ft.
***CARTONS***
paperboard, not corrugated.
See diagram with names of carton parts. Machine direction in circumference, hoop stress direction ( from panel to panel).
REAR PANEL
LEFT SIDE PANEL
FRONT PANEL (PRINCIPLE DISPLAY PANEL)
RIGHT SIDE PANEL
INNER CLOSURE PANEL
DUST FLAP
OUTER CLOSER PANEL
GLUE FLAP
WORKING CREASE
when carton is glued, width and length describe opening, depth describes the height. Must understand whether product will be loaded horizontally or vertically. Some products are put in as powder. Must have “dust flaps” to prevent powder from coming out.
TUCK FLAPS
friction lock, no glue.
SLIT LOCK
Like a tuck flap, but has slits to grab. Toothpaste box has a slip lock.
TONGUE LOCK
Tab that slides in. Like toy boxes.
EDGE LOCK
ZIP-LOCK
breaks away to expose tuck flap.
HEIMS LOCK
corners pre-glued, locks bottom.
PACKAGING 021103
Recycling. Cellulose Fibers degrade until they are so fine they escape the felt.
Different types of trees have different size and shape of cellulose fiber (different cell structure). Cotton has very long fibers. Currency has high cotton content.
Paper machines (review) forward gernier. Weir keeps constant pressure by keeping headbox at a given level. Has a limited water removal.
Middle, can lay down fiber in layers
Twin-wire machine. Allows removal of water from web in two directions. Can dry in a shorter distance.
See list of 16-17 characterization tests for thickness, basis weight, etc. ASTM standards and TAPPI (technical assoc. Of pulp and paper industry). Pulp and paper is interchangable (a commodity) must make money being low-cost producers. $/ton. TAPPI journals have lots of information.
Read about paper characterizations.
PAPER –
Hgroscopic: will take up and release moisture. Each cell is a tube for water to be stored in. Is a problem usually when you try to build structures out of it (as in boxes, cartons). Done through laminating with other papers, foils, poly, etc. Drying/moisture (like bi-metal with thermal, so is bi-material with moisture) can affect shape. or corrugating.
Hygroexpansive: relates to expansion overall accordign to the the ammount of moisture. (1% growth @ 1 meter = 1mm)
Viscoelasticity: sensitive to the rate of application. A test of rupture (mullin burst test) changes according to rate. Apparent property. Important in its relation to “fiber set,” “distortion,” “creep.” tendency to relax over time. Tensile strengths can change over time. For example, the longer a carton is laid flat, the harder it is to open.
23deg C at 50% RH.
Standard testing environment.
(from dry side up; add moisture.)
PAPERBOARD AND CARTONS
Cutoff paper to liner: 250 g/m^2
Most cartons are made out of paperboard.
Styles of folding cartons. 3 categories.
1) tube style
2) trays
3) setup boxes.
4) Tubs/ trays/liquid resistant
Most are types 1 or 2 (80-80%).
Tube style: well suited for high production filling up to 600 per minute. Milk cartons are of this style.
Tray style: usually heavily clay coated. Donut box. 6pack box.
Setup box: empty, they take up the same space as when they are full. Some perfume boxes. Paper DVD box[?] usually reusable.
Another classification:
Tubs/trays/liquid resistant boxes.
Ice cream tubs, Trays for microwave meals, these are more specific to the product than the generic nature of the other three.
Carton Features:
See diagram of working crease and overlap joint in book. Open flat, the side you tear is the overlap joint, the others are working creases.
Design considerations for a carton.
1) product itself
2) retailing – how is it presented to the consumer.
3) produciton – is it run on an automatic machine, etc.
4) consumer needs – slot tab retuck features, etc.
5) other considerations – distribution requirements, etc.
See book.
1) is it self contained
2) single, repeated entry
3) security feature?
4) is product heavy
5) do contents come out/ separate.
6) operation itself, automated flap tucking
7) does it get filled vert or horiz.
8) how it is sold, how it sits on shelf
9) requirments of the manufacturer/supplier.
Carton Layouts
Usually cartons are seen from the outside surface. But, always ask whether diagram is printed side or die layout side.
Creases. Creasing dies and cutting dies. When you fold a joint down, crease is pushed in opposite direction. (clean line down) excess fiber goes to the inside. Problems can come in on creasing operation because it is a middle ground between moving and breaking fibers.
Dust Panels.
Full overlap, sift proof.
Partial overlap, save fiber, just overlap enough to glue.
Glue flap dimensions are pretty standard, determined by carton manufacturer (5/8, 3/4, other).
Slit lock, edge lock, tongue lock, zip-lock, gusseted.
Tube cartons
Standard beverage carton (milk carton). Folded to be liquid tight.
Fifth panel for pegboard display.
Himes lock – automatically closes bottom when opened.
123 lock – uses geometry to stay closed.
TRAYS
Donut box. Brightwood box.
Garment box – beers tray.
Click-lock (pinch lock) don’t need glue to hold together.
Setup boxes
Cigar box (flap cover), Book Hinge cover, tube and slide (match box).
ratio of tabs etc.for high speed filling.
Inserts etc. Use of flaps to hold things in place.
inserts that book together, etc.
CORRUGATED FIBERBOARD.
see back of p.2 notes.
early 1900’s was to compete with boxes and barrels.
Railroad use – UFC uniform freight classification.
Trucks and other – NMFC nationan motor freight classification.
Boxes had different shipping costs because had different handling costs. All carriers had defining performance standards for replacement of standardized wood boxes.
MULLEN BURST TEST – pressure it takes to rupture a piece of paper. Has been the same procedure till 1991. In ’91, edge-crush test began to be used for qualification. Crush the fluting of columns. The flat crush test approximates the mullen test.
REGULAR SLOTTED CONTAINER.
(RSC).
COMPONENTS
Single wall board -> corrugations are called the medium, others are liner and facing.
Single wall – uses same liner paper on both sides. Now can have unbalanced structure. Usually medium is a lower grade than the liners.
Double wall (and Triple wall). Three liners and two media.
Additives used to prevent damage from water. Adhesive is taylored for the application.
Takeup factor – how much the corrugations (media) takes up.
natural kraft replaced with bleached craft. next step up from unbleached is moddled white (also oyster board). Next step up is Preprint. Liner is printed before applied to corrugated.
Next step ups is fancier preprint.
Flute sizes and grade. B,C,E, and others?
Corrugated structure reporting: start with outer ply and work your way in.
eg: 35, 26B, 35. This is balanced board.
Score wheels. 3 point score.
Switch from Mullen to edge crush, quick formulas to calculate performance of box.
If box is within book ratios, use mckee to calculate:
Box Compression Strength:
Approx = 5.87 * edge crush test * sqrt(box perimiter * thickness)
Packaging Week 5
Test will be the first hour of class.
Open book, open notes.
See notes on homework (not on test).
Corrugation, continued.
comes out of machine with one side faced (usually).
Can lay up several layers up to triple wall. Usually for appliances and industrial products.
MEDIUM is the middle ply, the corrugated piece. Can be any material you want, usually the least expensive you can afford. Since it is not seen.
SPECIFYING BOARD
Go from the Outside-In. eg, 35/28/32 board has 35# paper on outside, 28# medium, and 32# paper on the product side.
FINGERS
Are not used to make corrugated any more. Used to hold paper into corrugation die. Would wipe away glue, and leave weak area on edges. Now they use air pressure (vacuum) to hold paper in. Changed in the ’60s.
TESTING CORRUGATE
Two codes standardization.
1) UFC => Uniform Freight Classification.
2) NMFC => National Motor Freight Classification.
Two ways to test
MULLIN BURST – looked at paper and corrugate performance. Burst through a die, against flutes. Force outward, not as a stack. Uses a loaded bladder to puncture material.
EDGEWISE COMPRESSION TEST – or EDGE CRUSH TEST (same).
Makes more sense for stacking, actual use in real life.
FLAT CRUSH TEST
Not as critical. Simply compresses corrugations.
***McKEE FORMULA***
Rule of thumb for estimating box compression strength.
Box compression strength
BCS = 5.87 * ECT * sqrt(Box perimeter * Thicknkss)
ECT = edge crush test [kN/m]
BP in [m]
T in [m]
only applicable for RSC regular slotted container. No dividers, no handles, etc.
Only applicable when perimeter to depth ratio
2L+2W/Height </= 7.
FLUTE GRADES
A – most coarse. Original not available
C – less media, used instead of A.
B
E
F – fine fluted
FLUTES PER METER
A, 100-120
C, 120-140
B, 145-165
E, 280-310
F, 380
TAKEUP FACTOR
A, 1.54
C, 1.42
B, 1.32
E, 1.27
KNOCK DOWN FLAT (KDF)
Mode. Once the carton has been cut, has a manufacturer’s seam to hold together.
WRAPAROUND
Glue joint is not sealed until product is loaded. Usu has glue joint on the outside. Usu high speed conversion machinery uses this kind. Has extra thickness on one side that can make it harder to handle, sides are not exactly symmetrical.
See table 15-6
3 KINDS OF CORRUGATE DESIGN
1) RSC – regular slotted case. Slits, cuts, and scores are usually all straight lines. Can be set up with simple scoring wheels and dies.
2) DIE CUT – anything irregular. Tabs, hang tabs, irregular profile, etc. Curves, angles, cutouts. Tab locks.
3) BLISS BOX – an assembled box that basically allows for internal supports or protection of internal parts. Same style as produce is shipped in. Triangluar structures in corners, has internal features for protection. Used for display cases. Requires specialty machines, requires extra work.
LENGTH, WIDTH, DEPTH
Main dimension is the length, largest dim.
Depth is filling depth, perp to opening.
Length and width are open side dimensions.
LxWxD
See drawing.
SCORING
the score determines how the fold pattern workds. Score to score dimenison need to allow for part of the material thickness.
Running with the flutes are easier to get consistent. Double score for those that will be repeatedly opened. Machinery problems come from alignment and scoring.
FLEXIBLE PACKAGING
FLEXIBLE LAMINATES
Laminate (noun) a combined structure. 2 or more materials that form a single structure. Properties equal sub components. Eg. Structural, puncture, abrasion resistance, Performance, how it seals, how it runs on a machine, barrier.
Can combine structure, performance, and barrier, and aesthetic properties.
Foil is the only way to get metallic sheen onto a package. Metal laminate (foil). can be made with a window to see soup mix, etc.
FOIL
aluminum see chapter 14. Bauxite => aluminum oxide => aluminum.
4kg — 2kg — [8kw] — 1kg.
recycle
Almunim reclaim — [.05 * 8kw].
aluminum has good strength and weight properties, sometimes easier to handle.
rolled aluminum is foil under <= 152.4 micrometers. (.006″ or less).
O Temper, easily workable, easily shaped.
Work hardening – hardness increases as material is worked. Becomes harder to work. Can reverse by annealing. Metal temper is designated by rockwell hardness. FOILS use a Rockwell 30T scale. Evaluate ability to process thin films of metal.
ALUMINUM
two ways of making foils
1) ingot process. Furnace melts product, forms and ingot, and is usu. rolled, and annealed. Not the most efficient. Usu. to make structural shapes.
2) continuous system. Takes metal hot from furnace, and works while at an elevated temperature. Can process down to foil more quickly. Usually for food processes, etc. (used for composite packages, etc.)
ROLLING
continually rolling and pulling.
See diagram fig II
Foil thickness tolerances (household foil thickness is .0007).
At < .001, two sheets run together – shiny side, dull side.
Aluminum foil has good barrier properties. Can varnish, shellac to make it look like gold, copper, etc.
Coatings under .001 usually don’t affect properties of substrate. Table
14-2. Some of the common coating
aluminum is not tolerant of strong bases.
Decorating and printing. Light reflectance will make printed images hard to see unless they are very large. Embossing can help that sometimes.
foil in packaging can be .0005 or thinner. Usu gold foil or other.
Some limitations for foils
Aluminum is a great gas and moisture barrier when in good shape. Usu. Pure foil is combined with another barrier to cover PINHOLES.
Flex Cracking also introduces gaps.
Laminates help overcome some of these.
Performance is dictated flat, never folded.
METALIZING
Vacuum chamber, 84″ in diameter. 2.1 meters long. Unwind roll, chill roll over ceramic “boat” where wire is vaporized. Fig III
Extremely thin layers can be applied.
can be done to paper, but usu only for graphics, paper too porous for it to change properties much.
Packaging Week 7
3/4/03
Laminates and their components.
Stacking elements to get combination of qualities.
#1 thing to increase barrier properties is metallizing usually with Aluminum. Al is vaporized and deposited on film. A batch process.
Household Al is .0007 inches thick. Under .001, Al is pressed two sheets at a time. This is why there is a shinny and dull side.
Al forms an oxide layer that is corrosion resistant, but not in strong alkaline environment.
Horizontal form fill sealing machine. Seals three sides, fourth is fold of material.
Powder filling is very fast.
Vertical form fill. For larger bulkier applications. Cheeze-its, cereal. Usu. Have an integrated boxer.
HFFS – Horiz. Form fill seal 1000/min
VFFS – vert form fi
Vert has two seal options, Fin seal – one side coating for sealing. Lap seal – must have coating on inside and outside. if coating expense is high, will use fin seal.
Multilane – multiple pouches are made simultaneous, Multilane has two rolls that come together. Seals all four sides. Intermittent control. Slow. 50/min. rotation has to start and stop repeatedtly.
Most all need eye-mark. To align product graphics with material.
GMP good manufacturing practice – not sterile, but good enough for food product. lotions, shampoos, etc.
One system not in text.
**FLOW WRAPPING**
A hybrid between the above units
A combination of a vertical and horizontal mode. Typcically run in horizontal mode, folds and makes a fin seal, as film is sealed, 500-600/min for candy bar wrappers.
All three (hor, ver, flo)can have the same treatments, vacuum, etc.
Many coatings are product and machine specific. Coatings can be printed on with gravere process that change barrier and other properties.
glue coating, antistatic.
Extrusion bonding. Bonding two layers of substrate with an adhesive. Usually extrude is hi temp. One application is the parrison for blow molding bottles. advantage is that it gives good clarity.
3or4 methods of bonding.
Bonding Methods:
Difference is whether or not materials need to have any porosity. For the carrier to be eliminated through the web.
Wet Bond, Dry Bond.
Wet must have a porous media.
Dry must be dry before the time the two substrates are brought together.
In dry bond, carrier must not be trapped in between layers. Solvent odor possible.
Barrier properties, refers to moisture and oxygen transmission. Sometimes other gasses, such as coffee and CO2 outgassing.
Ordering by suppliers, varies with suppliers.
Sealing – wax, DuPont Surlyn, and others, which to use depends on many factors; speed of machine, sealing properties. Pressure limits, time limits, and temperature. Most adjustments on machines is the temperature set point.
Sealability –
