Module 4

Question 1

is typically defined as a nonmetallic construction material, which is able to bond substrates together by surface adhesion and internal cohesion

Answer 1

adhesive

Question 2

categories of classifying adhesives

Answer 2

solidification method
polymer base type
chemical base
solvent type
application category

Question 3

refers to a protein-based bonding substance obtained from animal hooves, bones, and skins

Answer 3

glue

Question 4

modern formulations of glue are derived from

Answer 4

natural polymers such as starch or are based on synthetic polymer classes

Question 5

a more technically correct term compared to gluing

Answer 5

adhesive bonding

Question 6

refers to the attraction or bond of one material to another

Answer 6

adhesion

Question 7

refers to the internal attraction or bond of a material’s molecules

Answer 7

cohesion

Question 8

___ of an adhesive is related to its molecular polarity and determines how well it is attracted to a substrate surface

Answer 8

surface tension

Question 9

affect machinability, how the adhesive flows out over the substrate & level of adhesive penetration into the substrate

Answer 9

viscosity

Question 10

expresses as a percentage, refers to the actual amount of material left to form a bond after all solvents and carrier liquids have been removed

Answer 10

solids content or nonvolatile content

Question 11

can be regarded as a pigmented adhesive

Answer 11

ink

Question 12

adhesive bonds are the result of three phenomena:

Answer 12

mechanical bonds, micro-mechanical adhesion, and intermolecular interaction

Question 13

proposes that fluid adhesive flows into tiny surface irregularities

Answer 13

mechanical adhesion theory

Question 14

what happens to when the adhesive solidifies in mechanical adhesion theory

Answer 14

adhesive mechanically locks into the surface cavities and can no longer be pulled away without destroying the surface

Question 15

theory that explains paper or wood bonding

Answer 15

mechanical adhesion theory

Question 16

theory explaining glass, metal, and plastic bonding

Answer 16

specific adhesion theory

Question 17

proposes that bonding takes place when minute regions of positive and negative charge are brought into intimate enough contact that they mutually attract one another

Answer 17

specific adhesion theory

Question 18

the surface charges in the surface adhesion theory are primarily a result of

Answer 18

dipole interaction, hydrogen bonding, and Van der Waals’ forces

Question 19

passes the substrate through a gas flame that has been adjusted to have excess air

Answer 19

flame treatment

Question 20

surface of materials with low polarity can be increased by

Answer 20

chemically altering the surface using flame treatments, corona discharge, or chemical treatment

Question 21

creates a similar highly reactive atmosphere (ozone) using a high-frequency, high-voltage charge to ionize the air in contact with the plastic

Answer 21

corona discharge

Question 22

plastic films are usually treated with __________ since the application of direct flame would harm most films

Answer 22

corona discharge

Question 23

flame or corona treatment: somewhat more durable

Answer 23

flame treatment

Question 24

to achieve good bonding, the dyne level of a surface should be about ______

Answer 24

10 dynes/cm higher than the surface tension of the wetting liquid

Question 25

dyne level of a surface to ensure adequate bonding of the adhesive material

Answer 25

37 dynes/cm or higher

Question 26

surface tension can be measured by

Answer 26

measuring contact angle of a drop if distilled water with the test surface

Question 27

it has been established that an adhesive must be:

Answer 27

1. polar to form chemical bonds with the substrate 2. fluid so it can flow out and make intimate contact with (wet out) the substrate

Question 28

solidification method: loss of water.

Answer 28

water-borne

Question 29

common examples of water-borne adhesive

Answer 29

starch, dextrin, and casein

Question 30

a special category of water-borne adhesives are the emulsion types typified by _______, usually a _________.

Answer 30

"white glue" usually a polyvinyl acetate emulsion

Question 31

solidification method: loss of solvent

Answer 31

solvent-based

Question 32

solidification method: loss of heat

Answer 32

hot melts

Question 33

do not need a diluent or solvent that is removed during solidification

Answer 33

hot melts

Question 34

are usually based on liquid pre-polymers or special monomers that can be polymerized to a solid after application

Answer 34

reactive adhesives

Question 35

example of reactive adhesives

Answer 35

epoxies & polyesters

Question 36

various ways of initiating chemical reactions

Answer 36

mixing of two components or a component and a catalyst, atmospheric oxygen, atmospheric moisture, heat, or UV radiation

Question 37

these types of adhesives take a special position as they don't show a defined solidification process in physical or chemical hardening terms

Answer 37

pressure sensitive

Question 38

a liquid physical mixture (suspension) of powdered thermoplastic (polyvinyl chloride or acrylic) polymer and plasticizer(s)

Answer 38

plastisol

Question 39

is a naturally occurring vegetable polymer usually extracted from the seeds, pitch, and roots of corn, grains, or potatoes.

Answer 39

starch

Question 40

is the largest single starch-based adhesive application

Answer 40

corrugated board manufacture

Question 41

generally are roasted or converted starches which have been cleaved by acids and heat to create shorter molecules

Answer 41

dextrin

Question 42

have high tackiness, high solids, fair to good adhesion and are fast-drying

Answer 42

dextrin adhesives

Question 43

___ treatment of starch produces jelly gums

Answer 43

alkaline

Question 44

are derived from the phosphoprotein in acidified milk

Answer 44

casein adhesives

Question 45

have a unique property of having good cold-water resistance but of being rapidly hydrolyzed in aqueous caustic solutions

Answer 45

casein adhesives

Question 46

a collagen derivative, very tacky, protein-based glue used occasionally for set-up boxes and tube winding

Answer 46

animal glue

Question 47

are based on polymers such as polyvinyl acetates, acrylates, and maleates, which in themselves are not water soluble

Answer 47

synthetic emulsion adhesives

Question 48

is the most common base resin used in formulating hot-melt adhesives

Answer 48

ethylene-vinyl acetate

Question 49

is important for viscosity control and adjustment of open time and set speed

Answer 49

wax

Question 50

improve hot tack and viscosity of the formulation

Answer 50

tackifier

Question 51

are often used to characterize hot melts

Answer 51

ring & ball (R&B) softening points

Question 52

is the temperature at which the hot melt softens enough for a metal ball of a specified size and mass to drop through it

Answer 52

R&B softening point

Question 53

hot melts come in a variety of solid shapes:

Answer 53

slats, pillows, wafers, chips are the most common terms

Question 54

these adhesives are used most often by converters in coating and laminating operations, particularly with plastic substrates

Answer 54

lacquer adhesives

Question 55

are applied and immediately oven-dried to leave a pressure-sensitive surface to which the next laminate component is nipped

Answer 55

laminating lacquers

Question 56

are mostly based on one of two elastomeric polymer classes:

Answer 56

acrylics and rubber/resin blends

Question 57

means that the adhesive has a greater tendency to stick to itself rather than to other surfaces

Answer 57

co-adhesive

Question 58

a type of co adhesive usually based on natural rubber latex

Answer 58

cold-seal adhesives

Question 59

are similar to pressure-sensitive adhesive

Answer 59

co-adhesive or cold-seal adhesive

Question 60

were originally developed for bonding plastic-based chocolate bar wraps, where chocolate's low melting point precludes heat sealing

Answer 60

cold seals

Question 61

take the finished laminate supplied to them by the laminating company and convert it into a bag, pouch, wrap, or other type of package for their liquid or dry product

Answer 61

flexible laminating adhesives

Question 62

used to bond two or more continuous webs together to form a laminate which is used by packagers to form packages for their products

Answer 62

flexible laminating adhesive