Intro to Packaging Engineering Final Rutgers

How does an extruder for injection molding differ from an extrusion profile extruder?

An injection mold extruder must have a provision for ejecting a certain amount of melted material, while an extrusion profile extruder has a continuous flow of melted material.

What are the two main authorities/agencies that dictate Packaging Law?

Food and Drug Administration (FDA) and Environmental Protection Agency (EPA).

What is the molecular structural difference between HDPE, LDPE and LLDPE?

HDPE structures are linear chains, LDPE are highly branched chains LLDPE have short, branched chains

Describe the Gravure printing process

The graphics are engraved onto a gravure cylinder. The gravure cylinder passes through an ink fountain and is doctor bladed to remove the surface ink and leave the engraved wells filled with ink. The substrate passes between the gravure cylinder and an impression roll. Ink transfers from the gravure cylinder to the substrate.

Describe the Offset Lithographic printing process

The printing plate has oil receptive and water receptive areas. Water is applied to the plate and is absorbed by the water receptive areas. Oil based ink is applied to the plate and is held by the oil receptive area. The printing plate is compressed on to a rubber blanket and the ink transfers to the blanket cylinder. The substrate passes between the Blanket Cylinder and the Impression Cylinder; ink transfers to the substrate.

What is the difference between softwood and hardwood as a source of wood pulp for papermaking?

They have different fiber lengths and therefore different properties. Softwood has long fibers while hardwood has short fibers.

Glass containers are surface-coated at the glass plant. What function do these coatings serve?

To reduce the coefficient of friction and to help preserve the inherent strength of the glass by protecting the surface.

What are the differences between type 1, type 2 and type 3 glass?

Type 1- a borosilicate glass that has the most stringent extractable standard. Type 2- a soda-lime glass that has been treated in the annealing oven with sulfur to reduce alkalai solubility. Type 3- a conventional soda-lime glass that has been tested and shown to have a specified extractives level. Type 3 glass (without testing) is also used for most general purpose and cosmetic bottles

Shock and vibration are typical distribution environment hazards. List six more.

static compression, dynamic compression, piercing and puncture, racking and deformation, elevated temperature/reduced temperature, low pressure, light, moisture/water, biological hazards, time, contamination

What is the "flute" of a corrugated box? How are the flutes labeled?

"Flute" is the term that describes the wavy medium between the two faces of linerboard that make up corrugated. Flutes range from A, the thickest / tallest to E, the thinnest or even F or Micro, which have hardly any "wave" to them.

What are two of the first things shoppers want to know about a package when their eyes comes across a package on a market shelf? What third piece of information might the customer want to know to make a purchasing decision?

"What is this?" "What is it about this product that makes it better than others?" "Who guarantees that?"

White light is beamed onto a surface that (a) absorbs the blue wavelength. What color does the eye see? Also (b) absorbs the Red wavelength, and c) absorbs the Green wavelengths

(a) Yellow, (b) Cyan, c) Magena

List ten of the considerations you would take into account when designing a distribution package .

1) Product design (fragility); 2) the distribution environment;, 3) complementary primary and shipping containers; 4) ease of (package) assembly and disassembly; 5) multiple use and reuse; 6) compliance with legal and/or carrier requirements; 7) disposal of packaging waste material; 8) efficient materials handling. 9) dimensions for maximum efficiency; 10) the primary container could become the shipping container;

What are the advantages of injection blow molding, and for what specific applications and industries are these advantages particularly beneficial?

1) no generated regrind, 2) no secondary operations, 3) high-precision neck and finish, 4) more cavities for small bottles, 5) better material distribution 6) wide-mouth jars are easy to make.

Name 5 typical glass defects.

1. Heel Tap and Choked Necks: excessive glass thickness 2. Seed: contaminating grain or grit <1.5mm 3. Blister: bubble <1.5mm 4. Spike: glass protrusion inside the bottle 5. Stone: particle of unmelted material in the glass

What are the 7 plastic recycling families?

1: PETE, 2: HDPE, 3: V, 4: LDPE, 5: PP, 6: PS, 7: Other

What is the standard pallet size?

48 in x 40 in

Describe the Flexographic printing process

A chanbered doctorblade fountain applies ink to an engraved anilox roll. The doctor blade removes the ink from the surface leaving ink in the engraved wells of the anilox roll. The Anilox roller applies ink to the raised portions of the printing plate. The printing plate applies the ink to the substrate while it is compressed by the impression cylinder.

What are the purposes of a compound?

A compound is a vital can-end component that is applied around the perimeter curl. This compound acts as a caulk or sealant when the end is mated and double-seamed to the can body.

Which is easier to make, a fin seal or a lap seal? Why?

A fin-style vertical seal is easier to make because it brings together two inside heatseal-coated surfaces

To mold plastic into a useful shape, it must first be heated and softened. What is the name of the machine that does this? Describe the process.

A plasticating extruder-a barrel with rotating screw. As the screw drives the plastic pellets forward, an inceasing screw diameter causes the pellets to compress, heat, and melt.

What is the difference between a printerslotter and a flexo folder- gluer

A printer slotter can print onto the boxboard, add scores and other minor operations. A flexo folder gluer can print, slot, fold, glue, and stack completed boxes for delivery. Some flexo machine even have rotary die-cutting sections

Define the term "green washing".

A provider trying to look more environmentally preferable than it really is

What is at is a Color Key, and what is it used for?

A series of photographic transparencies of the color separations in generic color used to show how the color image will be assembled

What is a sink mark, and what might cause it?

A sink mark is the point where there is a substantial wall thickness change. This is caused by plastics' high expansion coefficients. This only occurs in injection molding

A total package design consists of two separate components. What are they, and what primary roles does each component play?

A structural component and a graphics component. The structural component's primary role is to fulfill the package's technical and physical requirements. The graphic component attracts and informs the consumer and motivates a purchase decision.

What is the difference between addition and condensation polymerization?

Addition polymerization: monomers adding onto themselves like links in a chain. Condensation polymerization: two reactive monomers join together with the release of a molecule of water.

What are the principal advantages and disadvantages of a set-up box?

Advantages: upscale image, many types of decoration possibilities and appearances, they make a convenient long-term storage unit and serve as a low-cost shipper. Disadvantages: boxes cannot be knocked down flat and empty boxes in storage occupy as much space as when they are full, not designed for high-speed manufacturing

What is annealing, and why is it necessary?

Annealing raises the temperature of a newly blown bottle and slowly cools it to room temperature. The process reduces the stresses in the container wall caused by inside to outside temperature variation

Why is corrugated glue called starch?

Because the main ingredient in corrugated glue is FDA-approved food grade corn starch.

What does "bleed" mean?

Bleed occurs when extending a printed area beyond the dieline to allow for press movement.

Can a box be made water-proof?

Boxes can be made moisture resistant and water resistant, but not fully waterproof

How are closure designated

By diameter and thread design; inside diameter in millimeters followed by an ISBT designation.

Describe the coextrusion process and explain its advantages, compared with alternate systems

Co-extrusion combines the outputs of two or more extruders so that a curtain of material exiting the extruder is actually multiple materials fused together. It is solventless, so there is no release of objectionable solvents

What is co-extrusion, and what advantages does co-extrusion offer?

Co-extrusion occurs when more than one extruder feeds material to a sheet to make layers into one sheet. This method is used to combine the performance advantages of different materials.

What is the difference between a cohesive failure and an adhesive failure?

Cohesive failure is indicative of low internal strength in the adhesive. Adhesive failure is indicative of a high internal strength of the adhesive that exceeds the interfacial bond of the adhesive to the substrate.

What is "Conditioning"?

Conditioning is the act of bringing a package, prior to testing, to a set of "standard conditions": 73°F ( + /- 1 degree) (23°C + /- 1 °C ) and % RH for 24 hours prior to testing.

A Life Cycle Assessment (LCA) is useful in the packaging industry for what purpose?

Creating a complete picture of material energy and process flow path, from raw materials to the end of life, for a particular product.

What is cullet, and why is it important to glass manufacturing?

Cullet is broken glass from rejected production and/or post-consumer recycled bottles. It is added to help improve melt rate and reduce energy cost

Name the four process colors:

Cyan, magenta, yellow and a key color (usually black)

Define demographics, and give three examples of demographic information. What are some sources of demographic information?

Demographics is numerical information about consumers in specific, easily quantifiable classifications. Examples are gender, age, education level, family size, ethnic background and religious beliefs. Demographic information can be obtained through the U.S . Census and surveys

What are we testing when we test the "dimensional change" in a plastic film, and when would it be important to know this value?

Dimensional stability, which is the capacity to retain original size/shape when exposed to environmental changes. Materials that shrink even slightly under heat will produce distorted packages of unreliable volume and with puckered heat-seal areas.

What is double gluing, and where would you specify it?

Double gluing is the gluing of both the inner closure panels and the outer closure panels to provide a complete sift-proof seal. It is specified for a product that requires sift proofing.

You want a transparent package with a high oxygen barrier. What two polymeric materials are candidates for adding barrier properties to the laminate structure? If the package did not need transparency, what other options might you consider?

EVOH and OPP. EVOH is used as a high-oxygen barrier. However, EVOH absorbs water and must be sandwiched between materials that will keep moisture away from it. Oriented polypropylene's (OPP) combination of excellent base properties at an economical cost make it one of the most popular materials for wraps and laminates having sparkling clarity. Foil and metallized film are other non-transparent options

Why can't the same mold be used to shape all plastic materials?

Each plastic has a unique coefficient of expansion and temperature at which the molding takes place. Using the same mold for different plastics would produce parts with slightly different dimensions.

Define ethnography, and explain the methodology in conducting a consumer study using ethnography.

Ethnography is the study of consumer buying habits. It is used to observe a consumer's buying preferences and interaction with the product.

List five factors to consider when selecting an adhesive for an application.

Five factors to consider when selecting an adhesive for an application are: the nature of the surfaces to be bonded, application methods, open time, temperatures of application and end-use, and chemical resistance.

How can you tell the difference between a can that was drawn and one that was drawn and ironed?

For a can that was drawn, the thickness of the finished can sidewall and bottom remain essentially the same as in the original blank. The bottom of a D&I can has the same thickness as the starting disk; however, the sidewalls are considerably reduced in thickness, and the metal area of the final can is greater than that of the initial disk.

What is "formation", and what qualities contribute to poor and good paper formation? What is the significance of formation to the paper user?

Formation is the evenness of the fiber distribution on the papermaking screen. The length of the fibers contributes to the formation on the screen. Poor formation can lead to uneven ink absorption or erratic adhesive bonding.

What does the First Moment of Truth describe?

Get and keep the attention of the shopper at the point of purchase.

What two packaging materials offer absolute barrier properties?

Glass and Metal

Define "distribution environment."

How will the product be handled? How will it be stored? How will it be transported? How high will it be stacked? What will the temperature and humidity range be? How many times will it be transferred and handled? What kind of pallets will be used? Will it be unitized or containerized?

On a bottle finish, what are the I, T, E, H, and S dimensions?

I= diameter at smallest opening inside finish; T =thread diameter measured across the threads; E = thread root diameter; H =top of finish to top of bead or to intersection with bottle shoulder on headless designs; S =the vertical distance from the top of the finish to the start of the thread.

What effect does stress have on the final orientation of the polymer?

If the polymer is under stress (stretching), then the polymer chains will straight and align with the direction of stress. If the polymer cools without external forces, the polymer orientation is random.

What are the advantages and disadvantages of a two-piece can?

Immediate advantages are reduced metal usage, improved appearance and the elimination of two possible leakage locations-Makers end and Side seam. However, while three-piece cans easily can be changed in length and diameter, two-piece cans require more elaborate tooling that is dedicated to one can size and shape.

What three metals can be formed by impact extrusion?

Impact extrusion forms ductile metals such as tin, lead or aluminum into seamless tubes (and cans and bottles).

Explain how an induction innerseal works. What container or closure body materials would interfere with the creation of a seal?

Induction heat-sealing heads have sealing coils powered by generators; they produce energy that couples with the aluminum foil that is part of the innerseal. The foil's temperature rises and transfers heat to the heat-seal coating, which then bonds with the container's land area. Rigid glass containers and metal closures do not change or deform under normal stress.

Parts made by injection molding have tighter tolerance ranges than parts made by extrusion blow molding or thermoforming. Why?

Injection molds are completely controlled by metal mold surfaces, giving the most dimensionally accurate part. Extrusion blow molding makes bottles so only the exterior surfaces are controlled by the mold. Thermoforming uses vacuum and has high draft angles to remove parts. Thermoformed parts cannot have undercuts or holes without an extra step after forming.

Describe the two biological spoilage mechanisms.

Internal biological deterioration, which occurs after food has been harvested. External biological deterioration, which is microorganisms on food (mold, yeast and bacteria).

What is the printing method for 3-piece can bodies?

Lithography is used when the can blank is decorated in the flat.

What are the advantages to a "trade secret"? Give one example of a trade secret.

Low cost. Gives value to things that are not patentable. Example: Coca-Cola soda recipe

Which thread style is preferred for plastic closures? Why?

M Style. 10 degree angle on the thread provides greater contact surface between bottle finish and closure thread.

What is differential tinplate?

Manufacturers identify differential tinplate, as to both the amount of tinplating and the side having the thicker tin content, by embossing an identifying pattern onto one side of the sheet. The heavier tin deposit goes to the inside of the container where greater protection is needed.

Cellulose fiber can be separated from the wood mass by several means. Name the two main methods, and lists the advantages and disadvantages of each method.

Mechanical Pulping: Mechanically cutting (grinding) the wood is the fastest and cheapest method, but it breaks the fibers and reduces their effective fiber length. Chemical Pulping: The least fiber damage occurs when chemicals are used to dissolve the natural lignin binders in wood, leaving the fiber bundles intact and undamaged, but it is expensive.

List the methods of creating a body seam on a three-piece steel can. What are the advantages and limitations of each?

Mechanical side-seaming: used for containers intended for dry product, where a hermetic seal is not important. Adhesive bonding is an attractive body-assembly method for applications where the can will not be subjected to thermal processing. Unlike welded cans, adhesive-bonded constructions can have full wraparound lithography. The welded seam line is about 30% thicker than the two base metal sheets. Cans shorter than 75 mm (3 in.) are too short to be welded individually, and are made by welding a body twice the required length and cutting it into two cans. Soldered food cans are no longer permitted in North America. Some soldering is still done for nonfood applications. All solders have eliminated lead content.

What are three tests associated with the regulations and requirements?

Mullen Test: determines the burst strength of a box, ECT determines the stacking strength. Cobb Test: determines the ability of boxes and boxboard to resist moisture and water absorption. Pin Adhesion Test: determines the quality of the corrugated board.

Most dairy tubs are injection molded from polypropylene except for ice cream. What material is ice cream tubs made of and why?

PE or a copolymer. PP is subject to cold fracture when frozen and therefore is unacceptable for ice cream tubs.

Define "packaging."

Packaging is a coordinated system of preparing goods for transport, distribution, storage, retailing and use.

What paper would you specify for an ice cream box?

Paper coated with either polyethylene or wax.

In thermoforming, cavity molds are preferred over plug molds. Why?

Plug molds have poor material distribution and limited draw. Cavity molds have better material distribution with the use of plug assist.

Loss of torque would be higher when a polypropylene closure is applied to a polyethylene bottle than if a polypropylene closure is applied to a polypropylene bottle. Explain why.

Polypropylene is less subject to viscoelastic deformation than polyethylene.

What are two significant factors attributed to the growth of the packaging industry?

Population growth in developing nations and growth of the middle classes in these regions.

Define primary package, secondary package and distribution/tertiary package.

Primary package is the first containment of product that directly holds the product. Secondary package is the containment for the primary package. Tertiary package is the containment with the foremost purposes of protecting the product during distribution and providing for efficient handling.

What three colors does the human eye detect?

Red, green and blue.

The four R's are used as the guiding principles for managing the waste problem. What are the four R's in the correct order?

Reduce, Reuse, Recycle, Recover

What is the difference between serif and san serif fonts, and which is more common in packaging?

Serifs are small, decorative extensions on letters. San serif fonts are more commonly used than serifs on packaging to improve legibility.

Name three methods of unitized load handling, and comment on the advantages and disadvantages of each.

Slip sheets are economical, take up little space and are light. However, the equipment is not universally available and is more expensive and is slower to operate. Pallets are universally adaptable to a variety of handling situations and locations. However, they are costly and take up space, and disposal can be difficult. Clamp trucks use no added materials, but the geometry and character of the load must be such that it can be squeezed between the truck's clamps

What are the three principal constituents of glass?

Soda, lime, silica.

What are the major applications of the following adhesive classes: starch, casein, and cold-seal adhesives? Why are they chosen for these applications?

Starch adhesives are used for corrugated boxes because of their low cost. Casein adhesives are used for refillable beverage bottles because of their resistance to cold water. Cold-seal adhesives are used for chocolate bar wrapping because it doesn't need to use heat and it's a high-speed application.

What is static coefficient of friction? What is the dynamic coefficient of friction?

Static COF- Force to get an object to move Dynamic COF -film's friction as it moves over a surface

List 3 methods of increasing the shipping stability of a palletized unit load.

Strapping, stretch-wrapping, high-friction inks/coatings and high-tack packing adhesives

List the most widely accepted definition of sustainability.

Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Explain the two theories of adhesion.

The Mechanical Adhesion Theory proposes that fluid adhesives mechanically interlock into the surface cavities of the substrate and they cannot be pulled away without destroying the surface of the substrate. The Specific Adhesion Theory is based on the bonding that takes place when regions of positive and negative charges are brought into intimate contact to mutually attract each other. The surface charges are expressed as polarity and occur at molecular distances.

Why is it difficult to print on natural kraft paper?

The fibrous nature (irregular surface) and color of natural kraft paper does not lend itself to fine printing. Ink transfer on an irregular surface is uneven and the color of the Kraft will distort the printing ink color

Discuss the impact of fiber length on paper properties.

The longer the fiber, the better the fiber entanglement and the stronger the resulting paper. However, long, course fibers produce a rougher surface texture. Printing is more dificult on a rough surface

Describe the purpose of laminates.

The purpose of laminates is to combine the best properties of protection, aesthetics, machine ability, and cost into a single structure

Describe a Regular Slotted Container (RSC). Why is it the most popular corrugated box?

The top and bottom flaps meet in the middle of the box. No special tooling (die cutters) are required. The box maker simply sets the cutters to the dimension of the box. There is very little waste in the box layout.

What causes loss of torque in a plastic closure application?

Thermoplastic closures on thermoplastic containers can suffer from considerable torque loss after closure application because of the viscoelastic flow (cold flow or creep) properties associated with the materials.

Polymers can be divided into two general chemical classes. What are they, and which is most commonly used in packaging? What is the difference in molecular structure that characterizes the two general polymer classes?

Thermoplastics are most commonly used in packaging. Thermoplastic polymer chains are free to pass over one another when heated. Thermoset polymer chains are cross-linked and interconnected so they can never come free of one another without destroying the material.

How does the manufacturing process for vials and ampules differ from the process for larger glass bottles?

They are made from preformed tubing stock rather than the blowing methods used for glass bottles. The container is cut and formed into shape without the use of a mold, so there are no visible parting lines.

Name four product characteristics that will have a major impact on board selection.

Weight, is product wet, is product greasy or oily, will the product tear or burst the package.

Where might we specify polyethylene as a closure material? Where might we specify polystyrene?

You might specify polyethylene for closures that require elongation or some deformation (snap-on tub lids). Polyethylene also might be specified when better cold resistance is needed. Polystyrene might be specified for closures that require press-fit bases that snap over an interference ridge on a container or that require a hard, glossy surface or complex designs; also, when a fast capping process is desired.

Packaging plays a vital role in modern society. Explain the significance of that role for: a) food products and b) massmanufactured durable goods.

a) Improves shelf life, offers better protection, reduces deterioration and protects products for transportation and distribution. b) Durable goods are a global business requiring packaging suitable for the broader distribution environment, including industrial, retail and home delivery.

Name the commodity packaging plastic that: a. Does not burn (self-extinguishes). b. Is used mostly for thermoforming. c. Is an exceptionally high all-around gas barrier. d. Is strongest and stiffest. e. Has the lowest melting point. f. Has the highest melting point. g. Is used most often for closures. h. Is used most often for detergent and oil bottles. i. Forms the best "live hinge." j. Is used for thermoformed film when packaging luncheon meat. k. Is lowest in cost. I. Is made into soda bottles. m. Is an exceptionally high oxygen barrier but is water soluble. n. Is an exceptionally high oxygen barrier. o. Is used for most hot-filled bottles. p. Would be used to make a squeezable bottle.

a. PVC. b. PVC. c. PVDC. d. PC. e. LDPE/LLDPE. f. PC. g. PP. h. HDPE. i. PP. j. PA (unoriented nylon 6). k. PE. I. PET. m. PVAL. n. PVDC. o. PP. p. LDPE