Packaging Review
What are the 7 plastic recycling codes (labels)?
1. PETE 2. HDPE 3. V 4. LDPE 5. PP 6. PS 7. Other
How does the nature of the surface that is to be bonded affect the selection of the adhesive? Provide an example.
Depending on the nature of the substrate, certain adhesives must be coordinated with the surface properties to ensure it does not break loose. For example, kraft stock has long-fibrous, open, and porous surfaces that are nonabsorbent. High solids, high-viscosity adhesives would be the best choice
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.
Mechanically cutting/grinding the wood is the fastest and cheapest method, but it breaks the fibers and reduces their effective length. 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.
Describe the Injection Blow Molding (IBM) Process.
More control of material distribution, multiple cavitation, faster process (ideal for small bottles), parison retained on core pin and transfer to blow mold station, then air blows parison into final shape.
A production engineer is not happy with the strength of an adhesive bond, so he or she increases the amount of adhesive. To the engineer's surprise, the bond is even weaker. What has happened?
The adhesive has low cohesive strength, and its excess amount has reduced the tensile strength of the bond.
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.(a sketch of this process, properly labeled, is acceptable)
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.
How can the basic communication message be delivered to the viewer?
Through color, shape, text, and graphics.
What is differential tinplate?
Today, black plate is electrolytically tin-plated, allowing substantial reductions in the amount of tin used, as well as offering the ability to put different thicknesses of tin on either side of a steel sheet. The tin layer is extraordinarily thin, about 0.38 micrometers (0 .000015 in.). 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.
What are the two types of liner systems used for induction heat-seal innerseals?
Two types of liner systems: - Wax bond allow sealed liner to separate from pulp liner which remains in cap - Non-pulp liner completely attaches to container; cap remains unlined, i.e. dispensing closure
What is meant by "Extended Producer Responsibility"?
Typically, local or national governments are responsible for recycling collection, sorting and disposal costs. Extended producer responsibility means these recycling costs are passed on to the producer of the material being recycled.
Complete the following sentences:
a. As the molecular weight increases, melting point __________________. b. As the degree of branching increases, density ____________________. c. A plastic that has two monomers in its molecular structure is called a ___________________. d. A polymer in which the chains are highly ordered is said to be ________________________. e. A polymer in which the chain arrangement is essentially random is ___________________ . f. The stiffer HDPE is the one with a molecular weight that is ___________________________. a. increases. b. decreases. c. dimer. d. crystalline. e. amorphous. f. higher.
Define CLOSURE, and FINISH.
• Closure: A mechanical device that seals the contents within a container and can be removed to allow the contents to be dispensed • Finish: The part of a container that receives the closure
What are 2 thermoplastic closures? What are their differences?
• PP most commonly used - Easily formed - Colors well and is economical - Less viscoelastic deformation than PE - Higher use T∘ - Best living hinge properties • PE used where elongation and deformation is needed - Closures pressed rather than rotated - Snap on lids - Better cold resistance than PP
Name at least 3 different plastic properties that are considered when trying to choose what plastic to choose?
• Tensile strength: resist direct pull • Tear strength: resist tearing • Impact strength: resist direct shock • Heat-seal strength: resistant pealing • Coefficient of friction: static, dynamic • Haze and gloss • Water-vapor transmission: permeation resistance • Gas permeability: O_2, CO_2,N_2, flavors, and fragrances • Grease and oil barrier • Dimensional stability: thermal expansion • Environmental Stress Crack Resistance (ESCR): surface initiated cracks due to biaxial stresses in the presence of an external agent • Chemical Properties:
In printing, what is Bleed?
"Bleed" compensates for printing plate, substrate and cutting-die movement. The printed area on the paperboard carton blank "bleeds" or extends slightly beyond the cut or visible edges.
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.
In preparation for printing, what is Make Ready?
"Make Ready" is the process of preparing a press or off-line setup -Printing trials to adjust registration between print stations -Secondary print registration (silk screening) to primary press sheet -Secondary (procrss) Embossing or Hot Stamping registration to press sheet -Die cut registration to press sheet
Define: Sprue, Runner, Gate, Under Cut, Knock out Pins, Sink Marks.
"Sprue": main channel through which molten plastic flows into a mold "Runners": channels that distribute molten plastic to cavities "Gate": smell opening through which molten plastic enters the cavity "Under Cut": a configuration that prevents the straight opening of a mold "Knock out pins": move forward when mold opens to eject the parts from the core "Sink Marks": plastic shrinkage where wall thickness is uneven
Name the 6 Technical Functions of a package.
1. Contain 2. Measure 3. Protect 4. Dispense 5. Preserve 6. Transport
What are three cases of bond failure on paper and what does each case mean?
1. Fiber Tear — Failure is based on strength of the fibers in paper. 2. Adhesive Failure — Failure is based on insufficiency of the adhesive on the substrate. 3. Cohesive Failure — Failure is based on low internal strength of the adhesive.
What are the two main authorities that dictate Packaging Law and what are their roles?
1. Food and Drug Administration (FDA): Responsible for controlling the food safety and carries out both risk assessment and risk management. FDA's regulation on food packaging revolves mostly around a materials contact with the food based on exposure rather than its transportation. 2. Environmental Protection Agency (EPA): Main role is to regulate packaging for materials, drugs, and cosmetics. EPA also promotes government procurement of recycled products and issues guidelines to ensure that manufacturers do not make unfounded claims about the environmental benefits of their packaging in violation of federal laws.
What are the four subject matters that are encompassed by packaging law? Briefly describe them.
1. Labeling Law: laws and regulations dictating what goes on the label of the product, typically determined by the use for which the product is intended 2. Environmental Law: laws established by state and local governments to reduce the quantities of solid waste that they produce by targeting packaging 3. Structural Requirements: laws dictating structural requirements a package must have (such as tamper-evident structures), typically associated with product types 4. Intellectual Property Rights: laws encompassing patents, trademarks, copyrights, trade dress and trade secrets intended to protect intellectual property
Name the six ways of extending the natural shelf life of foods. For each method, briefly note the mechanisms by which the keeping quality of a food product is increased
1. Reducing Temperature: slows chemical activity and reduces/stops biological activity. This can be done in a freezer. 2. Thermal Processing: increasing heat kills/controls microorganism populations. This can be done using hot fill on sterile and sealed cans. 3. Water Reduction: removing moisture in order to control microorganism growth. This is done by drying the product. 4. Chemical Preservation: changing the pH levels of a product controls microorganism populations. This can be done by adding acids, carbon dioxide, curing/smoking and antioxidants. 5. Modified Atmosphere Packaging: Controlling the atmosphere a product is packaged in can control ripening processes as well as come microorganism growth. Such an example is vacuum packaging. 6. Irradiation: using irradiation kills harmful microorganisms. This can be done through ionization.
List 3 benefits of a sustainable package
1. depending on the materials use, sustainable packaging can save you money 2. It is good for the environment as it can reduce our carbon footprint and be recyclable 3. It can be safer as you're riding the package of toxins etc
Below what gauge does pinholing become a major concern? What is the concern?
7 Micrometers Suffer from pinholing - minute holes through the foil major pathway for gas penetration
What is a Life Cycle Assessment (LCA) and why is it conducted?
A life assessment is an analysis of the plotting of the complete material, energy, and process flow path from raw materials to the end of life for a particular product. It is conducted to identify opportunities for increasing the sustainability level
What is the Ellen MacArthur Foundation (EMF) definition of successful recycling?
A packaging or packaging component is recyclable if its successful post-consumer collection, sorting and recycling is proven to work in practice and at scale. "In practice and at scale" = 30% post-consumer recycling rate for at least 400 million inhabitants, or on markets where packaging is sold. Recyclable if over 95% of packaging by weight is recyclable - Minor components compatible with process
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 increasing 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 box board, add scores (creases) and other minor operations. A flexo folder gluer can print, slot, fold, glue and stack completed boxes for delivery. Some flexo machines even have rotary diecutting sections
Discuss the importance of a programmed parison.
A programmed parison controls the wall thickness in a narrow-waisted container. The extruder has a moving mandrel on a set program to help control wall thickness along the length of the bottle.
Why are most cartons designed to have a rectangular shape?
A rectangular shape makes packing and shipping of the container much easier.
What is the difference between addition and condensation polymerization?
Addition polymerization involves monomers adding onto themselves like links in a chain. Condensation polymerization occurs when two reactive monomers join together with the release of a molecule of water.
List three advantages and three disadvantages of Injection Blow Molding.
Advantages - no regrind generated, better material distribution, high precision neck finish Disadvantages - requires two mold sets, handleware is difficult, limited size containers
What are some of the advantages and disadvantages of using a glass container?
Advantages include, inert to most, does not alter the taste of food, good clarity, stable at high temperature to allow hot filling, and impermeability provides long term storage benefit against volatile loss Disadvantages include breakability, high density, and energy-intensive
How is Polyethylene Terephthalate (PET) made and what are its main properties?
An ester produced by reaction of organic acid with an organic baseEthylene glycol + Terephthalic acid -> PET. 249 C∘ is highest melting point of common packaging plastics, When injection, stretch blown, it has superior barrier properties. (biaxially blown) Can not be extruded; not enough melt strength to support an extruded parison. PETG is a copolymer with other glycol molecules; has good melt strength; can be extruded. Polyesters must be molded dry to prevent hydrolysis. 70% of PET is used for beverage bottles.
At what point in a package design program should distribution packaging be considered?
At the inception of a product's design.
Why is corrugated glue called starch?
Because the main ingredient in corrugated glue is FDA-approved food grade corn starch. Corn starch plus water makes glue that adheres the medium to the linerboard.
Why are many medical bottles molded from polypropylene rather than polyethylene?
Because they can be steam sterilized. Compared to HDPE, PP has better resistance to cold flow and reduced deformation at elevated temperatures. PP has a higher softening point, and therefore, is used where hot filling or other thermal expsure occurs. Medical supplies that will be steam-steralized often use PP.
How can boxes for fruit, vegetables, fish and chicken be kept from coming apart when wet?
Chemicals can be added to the starch to increase moisture or water resistance. Also, boxes can be wax coated or plastic coated inside and outside to help them hold together. Some box styles add to the ability to hold ice or wet product without the box corning apart
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 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.
What are the three main methods of making 2-piece metal cans?
Draw, Draw and Redraw (DRD), and Draw and Iron (D&I)
What purpose do dust flaps and glue flaps serve?
Dust flaps work to keep debris out of a package while glue flaps are used to fuse two areas of the package to complete its structure.
Why can't the same mold be used to shape all plastic materials?
Each plastic being molded has a unique expansion of coefficient and temperature at which the molding takes place. Using the same mold for different plastics would produce parts with slightly different dimensions.
Paper is made with different machines, each machine imparting certain characteristics.In most discussions, paper is referred to as corning from two types of papermaking machines. What are these machines, and what is the principal characteristic that indicates what kind of machine it came from?
Fourdrinier and Cylinder papermaking machines. Fourdrinier makes thinner paperboard and the Cylinder makes thicker paperboard and has definite layers.
Define the 3 types of Color Terminology.
Hue-Focus on colors position in the spectrum Value-grey ranging from black to white Saturation- Strength of color
"On a bottle finish, what are the I, T, E, H, and S dimensions? What are the corresponding dimensions on a closure?"
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 transfer bead or to intersection with bottle shoulder on beadless designs; S = the vertical distance from the top of the finish to the start of the thread. Corresponding dimensions are S, H, T and E.
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.
Induction heat-sealing heads have sealing coils powered by generators running at 5O to 500 kilohertz; 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.
Identify and define the three forms of food spoilage.
Internal Biological Deterioration: When changes happen within a product such as fruits ripening, vegetables respiring and myoglobin in meat reacting with oxygen External Biological Deterioration: when the food product is the host to mold, bacteria or yeast. Some microorganisms can be beneficial while others are deadly if grown on food Abiotic (non-biological) deterioration: Chemical, physical or environmental deterioration such as the reaction of oxygen iwth Vitamin C or oils and fats turning rancid
What coloring agents are used to make amber glass, emerald glass, and blue glass?
Iron and sulfur for amber glass, chrome oxide for emerald glass, and cobalt oxide for blue glass.
Identify these abbreviations and their Polymer grouping name?
LLDPE; HDPE; LDPE
What is the difference between MD and CD and what is the relationship between MD and tear, stiffness, and fold properties?
MD is known as machine direction, which is the direction of travel that a moving wire belt aligns fibers in. CD is the cross direction, which is the direction across (or perpendicular to) the fiber alignment. Fold endurance and stiffness is greater across MD and tear strength is higher across MD. (Recommend looking at the pictures on the bottom of page 174 and top of 175 from the textbook to help visualize this information).
What are the best three types of adhesives used when a board is expected to be exposed to moisture/water or high humidity for extended periods of time?
MRA - Moisture Resistant Adhesive: Includes low levels of resin and is the third best level of waterproofing adhesive. WRA - Water Resistant Adhesive: Might be chosen for applications where one expects exposure to high humidity, especially under heavy loads. This adhesive has the second-best level of waterproofing adhesive. WPA - Waterproof Adhesive: Includes very high levels of resin and is the highest level of waterproofing adhesive.
Many (commercial) packages are intended to be a point of sale package to the consumer. However, there are 3 main types of industrial packages which are meant for use by manufacturers. List 1 of the 3 types and explain what that package is used for.
Manufacturer to Manufacturer package - Used by separate manufacturers to ship usually raw goods in industrial quantities. Work in Progress (WIP) package - When a product is only partially finished (partially assembled), and manufacturer needs temporary package for those unfinished product before completing it. Manufacture to Retailer package - Package which is usually in the form of a shipping container with the intention of shipping to distributors or retailers in large quantity.
Which plastic would you use to make a clear presentation box for a gold watch? Why?
PS. (Polystyrene)Hard, clear, brittle Homopolymer (Crystal Styrene) (clarity not crystallinity), inexpensive and easily processed. Can be colored with transparent or opaque colorants. Dimensional stability, superior optics, good chemical resistance to food acids and alkalis, good printing characteristics. Poor resistance to many solvents
What is packaging?
Packaging is a coordinated system for preparing for functions that are both technical and marketing oriented such as transportation, distribution, storage, retailing and use. A package cannot exit without a product.
Packaging waste contributes how much to total residential waste?
Packaging waste contributes approximately 30% to total residential waste.
What is pad printing and how does it work?
Pad printing is a printing technique to decorate irregular shapes. The pad is first pressed against the plate and then it is pressed against the objects that is to be printed.
What is the difference between paper and paperboard?
Paper is less than 300 micrometers or 0.012-in and paperboard is more than 300 micrometers or 0.012-in. thick.
What are polymers? What are the two chemical classes for polymers and what are the differences? Name two things that determine the properties of a polymer.
Polymer is raw material for plastics. The two chemical classes are Thermoplastic and Thermoset. The Thermoplastic can join to each other in long chains and can be re-melted. For Thermoset, it cross linked chains in a 3 dimensional pattern and cannot be re-melted. Chemistry of the polymer molecule and size or molecular weight are two things that determine the properties of a polymer.
What are two benefits of using an HDPE plastic and name an application?
Possible Answers Part 1: Low cost, easy processing, good moisture barrier, flavor barrier properties, sturdy, can be translucent or opaque Possible Answers Part 2: milk jug, shampoo bottle, laundry detergent bottle, pipes, cover on cables or wires
How might you recognize whether a pouch was made on a VF/F/S machine or a HF/F/S machine?
Pouches made on a VF /F /S machine feature a seal across the pouch top and bottom and a vertical seal across the center of the back. Pouches made on HF /F /S machines are characterized by a three-sided edge seal.
Define primary package, secondary package, distribution/tertiary package and unit load.
Primary package: the first containment of a product. Directly holds the product. Secondary package: containment for the primary package. Tertiary package (shipper): contains the secondary package with the purpose to protect the product during distribution and provide for efficient handling Unit load: a number of tertiary packages assembled into a single unit for mass handling
What are some pros and cons of using cut and stacked labels?
Pro: Low cost handling of many inventory variables. Con: Risk of mixed labels
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 and Recover
Name and describe the three plastic thread styles.
Rounded style: Rounded profile L style: 30 degree angle on top and bottom of thread M style: Modified Buttress thread, 45 degree angle on top of thread, 10 degree angle on bottom of thread
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.
What is a slit lock?
Slit-lock closures incorporate small slits between the tuck flap and the top closure panel. When the carton is closed, the slits engage shoulders cut into the dust flaps, securely locking the flap into place.
What are the three principal constituents of glass?
Soda, lime, silica. Silica sand (silicone oxide) Limestone (calcium carbonate) Soda Ash (sodium carbonate)
One of the functions of packaging is to inform and sell. What are the 3 of the 6 legal requirements from the Fair Packaging and labeling Act, which are required on most labels of consumer products and describe why those 3 are important/significant.
Specific name of product - So a consumer knows that they are getting the exact product they are looking for and not some other generic version of that product. Generic Name - So a consumer knows what is inside the packaging if they do not recognize a brand name, or a product which does not have a brand name is still easily identifiable. Quantity contained - So a consumer does not have to guess or estimate the amount of product within packaging. Companies are forced to put exact amount of product in packaging that consumer pays for. Address of the responsible body - So a the company which produced a product can be legally traced to that product Net Weight - Same reasoning as quantity contained Legal name and address of manufacturer or distributor - same reasoning as address of responsible body.
Shock and vibration are typical distribution environment hazards. List six more.
Static compression, dynamic compression, piercing and puncturing, racking and deformation, elevated temp, reduced temp, low pressure, light, moisture/water, biohazards, time, contamination.
List the methods of creating a body seam on a three-piece steel can. What are the advantages and limitations of each?
Steel three-piece can bodies can be mechanically seamed, bonded with adhesive, welded or soldered. Mechanical side-seaming, or clinching, is 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 is the Box Makers Certificate?
The Box Makers Certificate is a stamp printed on the box that tells the end user and shipper-freight carrier that the box meets or exceeds requirements for the rules (tariffs) for that particular box. "Standard" BMCs exist for regular boxes and rectangular BMCs are for boxes that have special requirements. Some boxes, particularly hazardous material boxes, require special markings. These markings supercede or even replace the regular BMC. UN-marked boxes have very stringent regulations and penalties for failure to comply with regulations. Failure to comply with a standard BMC rule may result in a freight carrier refusing to accept a shipment
What does the DOT regulate?
The DOT regulates the packaging and transport of hazardous materials. These regulations vary based on the product shipped and the shipping method used. Normally, a hazardous material package is tested and certified that it complies with regulations. Once the complete package has been tested and certified, no changes can be made, except for variations allowed in the regulations
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.
Discuss the benefits and problems of postconsurner waste paper as a fiber source for papermaking.
The benefits of postconsumer waste paper as a fiber source are that it is plentiful and also reduces the cost of papermaking. However, every repulping process degrades and reduces the fiber length, and some extraneous contaminants may appear as bits of color, "grease spots" and "shiners" on the paperboard.
A manufacturer is having trouble printing on a paper because its rough surface. What does this say about the fibers used to make this paper?
The fibers are long which creates a rough surface
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
How many colors can the human eye see? What are they.
The human eye retina has receptors that are sensitive to RED, GREEN and BLUE. The brain interprets and blends these wavelengths to create the color spectrum we actually see.
What is the origin of the term "branding"?
The original term "branding" comes from a time when the manufacturer would use a blackened brush or hot branding iron to create identifying marks on a barrel or cask.
Describe the Flexographic printing process.
The printing plate has raised letters. A chambered 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.
Which metals are used to coat metal cans? What are the pros and cons of the metals?
The two metals used are tin and chrome. The benefit of using tin comes from the ability to be welded and the benefit of using chrome comes from it being more economical.
What are the differences between type 1, type 2 and type 3 glass? Where are they used?
These three glass types are used in the pharmaceutical industry for vials and ampules. 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.
Describe the difference between dry-bond laminating and wet-bond laminating.
Wet bonding requires that at least one substrate be porous enough to allow adhesive solvent or water to escape. Almost invariably, this substrate is paper. Adhesive is applied to one substrate, the two substrates are nipped together and the whole sent through an oven to set the adhesive. In dry bonding, adhesive is applied to the substrate and then dried of solvents. The resinous adhesive is either tacky or can be activated and set by heat. The second substrate is joined by a heated nip against the first to create the bond.
What is meant by the term "wettability," what does it indicate and why is it important?
Wettability refers to the surface energy of a substrate and indicates a high polarity that promotes bonding of the adhesive to the substrate. The formation of a chemical union is enabled in "clean" surfaces, free of contaminants, with intimate contact of the adhesive with as many high polarity sites as possible.
Name 2 of the first forms of brand names.
Yardleys, Schweppes, Perrier, Smith Brothers, Colgate
What advantage is gained by metallizing film?
does not need to be sealed, smother or dried decorative appeal significantly improved barrier properties to all gasses
Explain the two types of injection mold designs used to create threaded closures.
• Unscrewing Core - Threaded core must continue to top of the closure - Inserted liner can not be much wider than the "E" dimension; adhesive used to hold liner - Threads can be deep - Unscrewing lugs on perimeter of closure • Stripping Core - Material must have recoverable elongation - Threads 25 - 30% thinner - Liner retention ridges can be added; liner can rotate with closure since there is no adhesive - Ejection is simpler than unscrewing from core
