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`Declaration of Robert A. Iezzi, Ph.D.
`APPENDIX C-2
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`
`117
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`13¢ .
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`ADHESlON AND
`
`SOLVENT BONDING
`
`8.6. Temin
`
`20 Rainbow Pond Drive, Walpole, MA 0208?
`
`Industrial practice often re uires that plastic parts he afiixed to other plastics or to nonplastic
`
`{hate-rials. 5f the methods availalile to engineers wlio must malée inilgements relative to {He
`most suitable assembly technique, adhesive bonding must be seriously considered.
`Adhesive bondin of
`lame substrates is she’
`a common mode ; even greater imi-
`lization can be expected with the increasing availability of improved adhesives. Currently.
`adhesives compete with welding. fusion, and mechanical fastening. However, adhesive bond-
`ing ofier special advantages. Not least among them is the opportunity of weight savings
`compared with metal fasteners. It is of sgecial aggeal in the automotive industry, where
`vehicle lightweighting is crucial.
`
`1 17.1 ADVANTAGES
`
`The use of adhesives may indeed be the only sensible route in some instances. The reasons
`are as follows:
`
`$l’<
`
`3»)
`
`1. The ability to attach materials that are impractical to bond in other ways. It is obvious
`that screws or bolts are not suitable for paper, glass or other brittle materials, thin
`films, fibers, and foams. Moreover, the shage of the sugsiratg may render mechanical
`fastening diflicult or impossible.
`The ability to join dissimilar materials. Significant differences in thermal coefiicient
` l fastening. Thermal fusion is also disqualified
`for unlike polymers. Adhesive bonding of dissimilar materials often yields composites
`with
`t
`COIHEOIIGII .
`
`3. Uniform distribution of stress. In a simple bonded overlap, any load applied to this
`joint is distributed evenly over the entire bonded area as if the material were oontim
`nous. In terms of stress vectors in both tensile stress (away from the bond) and shear
`stress (across the bond}, all of the adhesive contributes to opposing the stress. In
`contrast the holes required for rivets, nails, screws or bolts are stress ooncentrators
`or focal points that contribute to failure. Adhesive bonded assemblies generally can
`resist shock. vibralional and fatigue failure better than mechanically attached assem-
`blies. This often means that adhesive-bonded members can be thinner in cross-section
`
`and lighter in weight.
`
`1 643
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`Declaration of Robert A. Iezzl, Ph.D.
`APPENDIX C-3
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`Exhibit1017
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`1642
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`ADHESXON AND SOLVENT BONDING
`
`21. Reduction in joint weight. This feature is partially related to the better performance
`possible with lighter weight parts because of the elimination of stress concentration
`points. Reduction in weight is possible because adhesivos are generally of low spcciiic
`gravity, and agglied grefere:ntiailv in thin layers. In many joints the forces of adhesion
`exceed the cohesive strength of the adherends.
`5. Environmental protection. Although usually more important in mctal—to-metal join-
`ing, the continuous contact between surfaces made by adhesives seals out corrosive
`or harmful agents. Both gases and lig uicls can be excluded lav the adhesivg,
`6. Resistance to vibration. Elastomeric adhesives resist the fatigue and subsequent failure
`that is brought on by repeated dcfonnations. in general the more flexible the adhesive,
`the greater the resistance to strain occurring in the adhercnds.
`7. Smoother surfaces. Adhesive bonding, like thermal bonding, eliminates such impen
`factions as rivet-point dimpling, surface spots or projecting portions of drsviccs that
`are common with mechanical fastening. This rccluces finishing costs and makes possible
`more cstlictic and more functional product design.
`
`117.2 BASED FlEQUi$lTES
`
`All adhesives must be liquids, or at least capahlc of some degree of flow. A primary
`requirement for good adhesion is that the adhesive and adhercnti surfaces must be in close
`contact, since the attractive forces that promote adhesion vary as the inverse sixth power
`of the intermolecular distances. To get substrates close enough to effect a good bond, their
`surface rouglmosses must be made to correspond. In essence, the adhesive must be a fluid‘
`because the solid adherend is never smooth in a microscogtc sen
`. For solza polymerst this
`means that the adhesive must be melted or dissolved in a suitable solvent before application.
`The adhesive must also be sufiicicmly mobile to quickly penetrate holes and depressions
`in the solid surface. If voids are left when the adhesive solidifies, the joint will be weak.
`Finally.
`the adhesive must solidify to provide sufficient strength to resist unbonding
`stresses. (Pressure—sensitivc adhesives, of course‘ do not solidify: their function it best
`described in terms of tficir vxscoelastu: properties). solidification occurs either through twan-
`oration of a solvent or through chemical reaction (polymerization), frequently called curing.
`Drying or curing converts the fluid material to a solid. which can be either rigid or clamo-
`mcnc.
`
`Wettino of the solid surface re uircs the selection of an adhesive that is suitable in terms
`,
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`owever, it is often necessary to a tcrthe surface of the aclhcrend to malte
`it receptive to adhesives.
`
`1 ‘S 7.3 TYPES
`
`Thar: are "five basic physical tvges of adhesives: curable liguids. solvent cements, hot melts,
`aqueous, an pressure—sensitive. The curable. liquids undergo a chemical reaction or poly-
`merization to attain a nonfluid condition. Often these consist of two gatts, each of which
`is stable by itself but when mixed together undergo 2: chemical reaction. Solvent cements
`are simply dilute solutions of fully reacted adlrcsivcs that solidify by loss of solvent. I-lo:
`melts are 100% solids that become liquids on heating above their melting or softening points;
`they are applied hot and solidify on cooling.
`Aqueous adhesives dissolved or dispersal in water may either simply dry to the proper
`physical form or undergo a reaction when the water is removed. Solv.ent~activatecl adhesives
`are deposited at the bond line in solid form and rcwet with solvent just before making the
`
`Declaration of Robert A. lezzi, Ph.D.
`APPENDIX C-4
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`117.4 LIMITATIONS
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`1 643
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`assembly. As with all solvent-borne adhesives, better joints are formed with porous substrates
`that permit a faster evaporation of solvent.
`Pres9ure—scnsitive aéhesives do not change form or harden but behave as high-viscosity
`fluids which, because of an increase modulus as the shear or deformation rate is increased,
`can be easily removed from the substrate. Pressurosensitives are frequently used as tom-
`porary anchorage for components that must be repositioned.
`Another way of looking at adhesives is in terms of their chemical composition. Table
`117.1 lists in a Sim listic sense the more common 11 sical and chem“
`t
`(the actual
`chemistry of each is more complex and beyond the scope of this chapter). In addition to
`
`
`unlisted additional compositions that fall in each catezor . there are man mixtures or blcn s
`0 two or more c emical t
`55, called hvlzwrids. Table .1 17.2 lists common adhesives and their
`
`Tiffiical properties.
`
`or
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`1 1 7.4 LlMiTATIC*!\¥S
`
`A koy disadvantage of adhesive bonding is the need for fixtures or clamps in many such
`operations. Another is the slowness, relative to mechanical fastening or fusion welding, of
`adhesive bonding. Other disatlvamages include the following:
`
`Limited Shelf Life. Adhesives that depend on a curing reaction and are mixed beforehand,
`have a. relatively short pot or storage mix. Some other adhesives must be carefully stored
`
`X TABLE 117.1. Adhesives Classified by Type
`Types Examplcs.
`
`
`
`Curable liquids
`(one or twoazomponcnt)
`Solvent cements
`(includcs watcr)
`
`Piryxiczzl
`Epoxies, urethanes.
`acrylics. siliccmes
`Acrylics. elastomers.
`vinyls. ccllulosics,
`urcthaacs
`
`Hot melts
`(10098 solids)
`Aqueous
`(includes dispersions)
`
`Pressure scnsirive
`
`Polyamides. EVA,
`polyesters, urcthanes
`PVA. epoxiesysilioones,
`amiraoplastics, rubbers.
`phenolics
`'Doub!e—faced rapes
`Ci1c'.>m'caI
`
`Anaerobic
`Contact
`Cyanoacryiazc
`Emulsions
`
`Ho: melt
`
`Solvent-oascd
`{Ccmcrus)
`
`Z8/iethacryiatcs
`Rubber
`Methyl, ethyl esters
`PVA. FVC, rubber. EVA,
`acrylic, chloroprene
`Polyurexhane. polyasnide,
`EVA, polyester
`Acrylic. chloroprene,
`nitrilc, nitrocellulose
`phenolic. PU rubber,
`vinyl
`Egsoxy, PU. silicone,
`polyamides
`Room temperature cure
`Acrylic. cyanoacrylatc.
`
`epoxy‘. PU
`
`High temperature use
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`Declaration of Robert A. Iezzi, Ph.D.
`APPENDIX C-5
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`Exhibit 1017
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`age 125
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`1644
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`Armsstow mo SOLVENT raomrmzo
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`TABLE 117.2. Common Aclhasives
`
`Adhesive
`
`Acrylic
`Phenolic
`Epoxy
`
`Modified polyolcfm
`Mortal cement
`Polyurethane
`Pressure-sensitive
`Emulsions (vinyl, acrylic,
`rubber)
`Sealants
`
`White glues
`
`Properties
`
`Room temperature cure
`Most require hcztt
`Broad range of
`properties
`Hot melts
`Resin in solvent
`Broad range
`Mostly in tape form
`No solvent
`
`Caulking {l:rutyls,
`silicones)
`P‘/A dispersion
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`‘
`
`‘
`»
`N
`
`in order to avoid premature reaction. Addltional.ly, two-part adhesives have :3 working life
`that depends on their rate of reaction; the faster the cure, the shorter the pot life. For this
`reason it may be desirable to use dispensing machines that blend the two components
`immediately prior to application. In general, if rapid cure under ambient conditions is *
`required, care must be taken not to pre~mix large quantities of the two components.
`
`Need for Surfaco Preparation. Surface contamination of plastics can prevent the necessary
`intimate Contact between adhesive and adhcrcncl. For example, low molecular weight sub- ‘
`stances can bloom to the surface, as can certain additives, creating a “film” that defeats the
`purpose of the adhesive.
`
`Solvent Retention. Where solvents are used, or where 3 product of the curing reaction is
`volatile, there is always the danger that failure to dry the adhesive adequately can cause 1
`bubbles or voids. These imperfections can seriously weaken the glue line, since they function
`as stress concentrators that prevent intimate and complete contact of the two surfaces.
`
`Temperature Limitations. At elevated temperatures, polymeric adhesives become: tznstablc
`and will degrade. some adhesives also become brittle and inelfective at low temperatures.
`Thus, temperature considerations are important in adhesive selection, and could in fact
`alfcct the decision as to whether adhesive bonding is suitable for a particular application.
`
`Material Limitations. A primary disadvantage of adhesive bonding {excepting pressure-
`sonsitives) or welding is the inability to disassemble the parts for repair or inspection.
`
`117.5 SELEGTWN FACTORS
`
`9?’
`
`Determinatfion of the relative merits of a particular adhesive, involves a number of factors:
`need for a primer, amount of surface preparation, cure time, fixture time, need for heating,
`aafieszve vrsoosity, cost, and properties of the cured adhesive.
`Some of these considerations relate to the cost of the operation. Elimination of surface
`preparation and the need for a grime: can be imgortam factors in selecting an adhesive. If
`cure time or consequent fixture time is excessive, the resulting time delays may mitigate
`against an otherwise useful adhesive. If heating is necessary (either to effect complete curt:
`or to reduce the time for reaction or solvent evaporation) an additional cost is involved.
`However, most adhesive operations require realtively low capital costs.
`
`Declaration of Robert A. lezzi, Ph.D.
`APPENDIX C-6
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`Exhibit 1017 ‘ Tage 126
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`ms SURFACE PREPARATION
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`1645
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`Other selection factors relate to the nature of properties of an adhesive. Viscosity must
`be suitablc———eithcr low enough so ensure good wetting of the adhcrend or high enough to
`prevent rurvolf on vertical surfaces. Further, the modulus of the cured or dried adhesive is
`a factor in terms of the flexibility or resistance to deformation required for the bond line.
`In turn, these Considerations depend on the nature of the plastic and the anticipated use-
`lifc stresses or extent of strains.
`
`A most critical factor in selection, of course, is adhesion to this Elastic. Not all adhesives
`will function satisfactorilz with all Elastic surfaces; even within classes of adhesives or Elaslics,
`
`individual members differ in behavior.
`Consideration of environmental resistance depends on tho desired use life for the bonded
`assembly. For instance, water resistance obviously is required if the assembly is intended
`for outdoor exposure. Pheriolics, cpoxics, and acrylics are examplcs of adhesives that weather
`well. Similarly, the part may have to be exposed to oils or solvents and an adhesive should
`be chosen with that in mind. Also, certain rubber-based adhesives are contraindicated if
`long use life is contemplated, since polymers with unsaturated backbones undergo an oxi-
`dativc degradation with time, which is accelerated by heat or light.
`
`117.6 SURFACE PREPARAWON
`
`Improved adhesion can be obtained when the surface of a plastic part is prepared correctly.
`The adhesive mus! wet, 2; read and
`netrate me too
`surface of the adher M1
`Cleanliness is a basic requirement in order for the adhesion to make intimate Contact
`with the substrates to be bonded. Surface preparation entails both obiaining a clean surface
`and, if necessary, altering the surface tension of the substrates to corresgond to the surface
`tension of the adhesive:
`Roughening of the plastic surface provides an increased area for bonding and strengthens
`the joint against shear forces. Accordingly, instructions for surface preparation usually entail
`both cleaning and abrading the surface. The extent of surface preparation required for a
`particular bond depends on the physical rcquircments for the assembled part; more extensive
`preparation is indicated in instances where extreme in—use stress will be placed on the joint.
`Thus surface preparation may consist of one or more of the following: solvent cleaning;
`abracling and solvent cleaning; chemical treatment (to alter surface energetics).
`
`Solvent Cleaning. For many operations, particularly where the joint will not be subjeclccl
`to severe in-use stresses, cleaning the surface may require only a wipe with a suitable solvcnt
`or detergent solution. Difierent solvents are recommended for wiping various plastic surfaces.
`The choice of solvent is clictatcd by the solubility properties of the plastic. For example,
`most common solvents other than alcohols severely attack polystyrene, whereas, nylons are
`resistant to this same solvents. As a generalization? crystalline polymers are less likely to be
`attacked by common solvents.
`Often, parts are solvent cleaned by more elaborate procedures, such as vapor dcgreasing,
`ultrasonic vapor degreasing, or immersion in a series of cleaning agents, which tend to give
`cleaner surfaces than wiping with cloth or paper. Commonly used solvents are halogenated
`to minimize flammability concerns. They include methylene chloride, perchloroctliylenc and
`similar materials Table 117.3.
`
`Abradlng and Solvent Cleaning. In the simplest case, plastic components can be wiped
`with a solvent, abraded with emery cloth and than wiped again to ensure removal of all
`debris. The plastic surface is not changed chemically but is altered physically; because. some
`of the plastic may be removed the roug,lie.ned surface now offers the possibility of mechanical
`interlocking Table 117.3.
`
`_,.
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`Declaration of Robert A. lezzi, Ph.D.
`APPENDIX C-7
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`Wavelock
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`Exhibit 1017 l Page 127
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`1646
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`.taDl~£iiSlO-N Am: SOLVENT BONDING
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`TABLE 117.3. Plastic Surface Cleaning’
` Plastic Method
`
`
`Acrylics
`Aminoplasls
`Ceiiulosics
`Epoxy
`fluorocarbon
`Nylon
`
`Poly'arni.t:le
`
`Wipe with methanol
`Scrub (detergent), scour, rinse
`Wipe with alcohol. scour
`Degrease (acetone, MI-SK.)
`Sodium (solubilizecl), acetorr: wash
`Phenol (£25/E> aqueous); 1:1 r.esorci-
`nol—ethano1
`
`Solvent‘-clean (acetone, MEX},
`scrub
`
`%
`
`oxidize (chromzrte or radiation)
`Polyolclln
`Wipe with alcohol
`Polystyrene
`Wipe with acetone or MEK
`Polyurethane
`Scrape. scrub with toluene (immerse
`Rubbers l_NBR,
`in acid)
`SBR. NBR, Nco-
`prone)
`Reinforced plastics Wipe with MEK
`
`"Most surfaces {except those chemically allcred) are preferably abraded
`or roughened.
`
`1
`3
`
`Chemical Treatment. Where optimum adhesion is required, chemical treatment of surfaces
`may be required. For low energy plastics, such as polyolefins and fiuorocarbons, the chemical
`nature of the plastic surface must almost always be altered in order to give a more polar
`(ltiglzervenergyl surface.
`Chemical alterations can be drastic in the case of the low energy plastics. For instance,
`chromic. oxidation involves using a liquid used to remove organic contaminants from glass-
`ware. It is hazardous to use. and proper safeguards must be exercised. Similarly the do
`fiuorinating solution (utilizing a form of sodium) is dangerous and requires expertise in
`disposal.
`To avoid the problem of hazardous chemicals, sheets of lluorocarhons can be purchased
`already chemically modified.
`An alternative approach to activating plastic surfaces that does not require. the use of
`hazardous fluids is radiation treatment. Such treatment renders polyolefins more amenable
`to oclltesive bonding. Other techniques for enhancing adhesion of plastics include flaming
`and plasma treatments‘ Detailed instructions on surface preparation for plastics are available
`in the literature.
`
`1117 SOi..VENT CEMENTWG
`
`A variation of adhesive bonding, solvent cementing is particularly useful for noncrystalline
`thermoplastics. Crystalline polymers generally do not dissolve in ordinary solvents at room
`temperature.
`Solvent cementing depends on active solvents to soften and swell the plastic surfaces;
`after assembly and evaporation of the solvent, a monolithic clear joint is obtained. Individual
`solvents are seldom used; a combination of solvents is a more common way to attain the
`properties desired. Solvents frequently contain some dissolved polymer (of the same type
`as that to be bonded}. to aid in gap filling and to speed up drying. With cements thickened
`with dissolved polymer, it may be necessary to mask the area around the joint to facilitate
`removal of excess cement squeezed from the bond line by clamping pressure.
`Masking has general application in solvent cementing when the parts to be assembled
`are soaked in the solvent as a preliminary to adhesion. Cellophane tape rather than masking
`
`Declaration of Robert A. Iezzi, Ph.D.
`APPENDIX C-8
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`Wavelock
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`Exhibit 1017 l Page 128
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`Page129
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`ll7.S PREFERRED ADHESYVES
`
`1547
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`paper, is preferred. Parts can also be masked using commercially available masking com-
`pounds based on animal glues or gelatins. The masking compounds are applied hot and
`carefully stripped away for application of the solvent cement.
`Another method used in joining is capillary action. Fine wires are used as shims. and
`the adhesive applied from a dropper or needle. After capillary action has adequately spread
`the cement, the wires are removed.
`Table 117.4 gives some examples of bonding with solvents or solvent cements. The plastics
`listed are not necessarily always bonded this way, however. For example, ABS can be readily
`joined using epoxy or acrylic adhesives. This avoids the long drying times associated with
` g solvents for polystyrene; caution must be exercised
`to avoid solvent crazing.
`Solvent cementing is the method of choice for many plastics. Acrylics, for example, are
`readily bonded with such chlorinated solvents such as methylene chloride, ehtylcne chloride
`1,1,2—trichlorocthane, or chloroform. If a more viscous cement is desired, a solution of
`acrylic chips (from 2 to 8% by weight) in the chlorinated solvent can be used. Cellulosics
`also are good candidates for solvent bonding. A typical cement for cellulose acetate is 3.
`10% solution of the polymer in a mixture of acetone and methyl cellosolve. For acetate
`butyrate, a cement based on equal parts of acetone and ethyl acetate is useful.
`Pol}/(vinyl chloride) is frequently bonded using solvents like acetone or methyl ethyl
`. ketone. Sometimes more powerful solventslilte cyclohexanone or tetrahydrofuran have to
`be used. Here the cements not only contain polymer (PVC) but plasticizer as well.
`
`It is important to remember that solvent cementing is generally employed only when the
`parts to be joined are of the same plastic. Finding a mutually satisfactory solvent mixture
`
`for two difierent plastics is often. difficult.
`
`117.8 PREFERRED ADHESIVES
`
`Choosing an adhesive for a particular plastic is not so easy as one might suppose. The
`adhesive providing the strongest bond to a given plastic may not necessarily be the best for
`a particular job. Primary consideration must be given to the form of the plastic, to its
`modulus, and to the conditions to which the bonded assembly will be subjected in actual
`use.
`
`TABLE 117.4. Solvents for Cementlng
`
`Plastic”
`ABS
`
`Acetal
`Cellulose acetate
`i’oly(methyl methacrylate)
`
`Phenyleneoxide
`
`Recommended Solvents"
`Blends of acetone, MEK, MIBK. THF or
`methylene chloride
`Methylene or ethylene chloride‘
`Acetone or MEK with methyl ccllosolvc
`Methylene chloride. chloroform, trichloro»
`ethylene
`
`Chlorinated solvents, xylene/MlBi‘x' (25f75)
`
`PoIy(butylcne tercphthalate)
`Polycarbonate
`Polystyrene
`
`_
`
`I-lexaiiuoroisopropanol
`Methylene chloride
`Methylene chloride, ethyl, acetate. MEK,
`trichloroethylene
`Methylene chloride
`Polysulfone
`Mixed solvents (THF, MEK. MIBK, dioX-
`Poly(vinyl chloride)
`ane) with plasticizcr
`"Usually l to 7% of plastic is dissolved in solvent.
`”MEK = methyl ethyl ltetonc, Tl-IF = tctrahydrofuran, MIBK = methyl isohutyl kt-tone.
`
`Declaration of Robert A. Iezzi, Ph.D.
`APPENDIX C-9
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`Wavelock
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`3648
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`ADHESION AND SOLVENT BONDING
`
`Flexible parts should be bonded with flexible adhesives. When bonding dissimilar ma»
`terials. the adhesive must be resilient enough to allow for differences in coeificiezits of thermal
`expansion.
`Choice is complicated by the fact that an unfilled plastic behaves difierently from the
`same material reinforced. It frequently happens that adhesives that give relatively low bond
`strengths with the unfilled plastic will give greatly improved performance with the same
`material filled with a polar inorganic substance, particularly after abrading. As earlier noted,
`organic polymers are low energy materials, in contrast to the higher-energy surface (like
`glass) to which most adhesive readily adhere.
`Table 117.5 lists a number of plastics along with recommcncled adhesives. However, resin
`formulations often differ within the same family, and this can afiect the performance of the
`adhesive. For example, structural acrylics are often formulated with different monomers
`and a particular grade may be more (or less) receptive to one adhesive than to another.
`However, adhesives can be formulated to vary considerably in polarity and in terms of the
`flexibility of the cured adhesive. Where flexibility is crucial, rubber-based adhesives may be
`
`all TABLE 1 17.5. Recommended Adheéves for Bonding Plastics
`
`
`
` Plastic Adhesives
`
`ABS
`
`Acctal
`Cellulose acetate
`
`Elastorners
`
`Epoxy
`
`Fluorocarbon
`Nylon
`Phenolic
`
`Plrerkylcnc oxide
`
`Poly(methyl methacrylare)
`Polycarbonate
`Polyolelin (untreated)
`Polyester (linear)
`
`Polyester (unsaturated)
`
`Polysullone
`
`Polystyrene
`
`Polyurethane
`
`Epoxy, urethane, acrylic. nitrile—phenolic, cy-
`anoacrylate
`Epoxy, phenolic, polyester. EVA, cyanoaerylate
`Urethane, resorcir1ol—formaldehycle, nitrile-phcr:o-
`lic, rubber-based
`Pressure-sensitive based on similar elastomcr, ure-
`than:
`
`Epoxy (with primers), nitrilc-phenolic, acrylic,
`polyester, resorciuol—formaldehyde
`Urethane
`Phenolic, epoxy, polyamide hot melt
`Epoxy, hybrid, phenolic. poly(vinyl acetate), urea-
`formaldehydc, acrylic. urethane
`Polysultide epoxy. silicone, rubber-based, acrylic
`cyanoacrylate
`Cyanoacrylalc, nitrile phenolics, epoxy, urethane
`Epoxy, acrylic, urethane, silicone, cyanoacryl-ate
`Rubber-based, EVA, modified polyethylene
`Polyester, cyauoacrylaze, nitrile rubber, urethane,
`acrylic
`Acrylic, urethane. neoprene, nitn'le»—pl-icnolic,
`epoxy
`Epoxy, vinyl-phenolic. rubber-based, urethane,
`polyester, cyarloacrylate
`Vinyl acetate-vinyl chloride emulsions. acrylic,
`polyamidc, urethane. epoxy, polyester, hot
`melt, urea—formaldel'1yde
`Pressure-sensitive rubber emulsion, polyester,
`epoxy‘. phenolic, urethane, nitrilc rubber
`
`Poly(vinyl chloride)
`Flexible
`Rigid
`
`Nitrile rubber, neoprene, urethane
`Epoxy, urethane, acrylic, nitrile rubber, silicone,
`nitrile——phenolic
`Silicone
`Silicone
`Urea~formaldehycle
`Epoxy, nitrile-phenolic, phenolic, polyester, neo-
`prene, cyanoacrylare
`
`Declaration of Robert A. Iezzi, Ph.D.
`APPENDIX C-10
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`Wavelock
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`Exhibit1017 Page130‘"'
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`$
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`mm APPLYING THE ADHESIVE
`
`1649
`
`preferred over others that have higher adhesion values. Cyanoacrylazes, for instance, cure
`so quickly that fig or fixture time may be avoided, but they are usually quite inflexible.
`Plastics and adhesives designed for very high temperature use are not covered in this
`discussion because there are some special problems with these systems. Manufacturers,
`particularly those in the aerospace inclustry, may wish to consult government sources for
`recommendations.
`
`A comment is in order about a relative newcomer. acrylic structural adhesives. Their
`great advantage is hardening to handling, strengih in seconds without heat. This capability
`translates into markedly reduced process Costs and greatly increased process speeds. Struc-
`tural acrylics are much tougher and higher in impact resistance than cycanoacrylates, and
`L are more resistant to environmental factors.
`
`Olfshoots of this adhesive category are UV-curable and visible lighmurable types. Oth~
`erwise similar to chemically curing grades. they solidify in less than ll) seconds. Their utility
`for certain applications utilizing transparem plastics is promising.
`
`‘H7.
`
`JCXNT DESRSN
`
`3,
`/
`22 variety of ways to effect adhesive joining of plastic con1ponexyls (lap, scarf. Strap,
`There ar
`elc). Whichever is used, it is always best to design joints to minimigé peel stresses. it is
`important tllat the joint be designed so that the adhesive is subjeetegl to compressive and
`shear forces ixlflyse.
`=‘
`The effect offioint design can be summarized:
`\
`
`/'
`
`x_
`
`km‘
`
`- Butt
`' Lap
`~ Scarf
`- Joggle lap
`. Strap
`. ‘Double strap
`- Recessed double strap
`
`/”
`
`_\
`
`I
`
`Unsatisfactory
`Fmctical
`Very good
`Goocl
`\“ Fair
`Z‘(,}ood
`G33“: €XPe“5i"f?"4
`X
`).
`
`Other generalizations about adhesixlolbonrlifigz
`1. Width of the bonding area increasegifgint strength linearly; increasing the length of
`
`the bonded area, although beneficial. glee not make as great a contribution to strength.
`2. Thickness of the bond line should be cc rolled to about 4 to 6 mils (0.1——0.15 mm)
`of adhesive. A greater gap in the glfsmnce been
`an adherends has a deleterious elfect on
`peel and cleavage strength of th "bond.
`3. Still‘ adherends (lxiglvnmd us plastic substrates.) are less sensitive to joint geometry
`than flexible aclhcrends.
`;
`\
`X
`117.10 APPURNG né ADHESIVE-’.
`
`\
`
`\-x
`
`\
`Techniques for applyl g liquid adhesives depend on {he sophislication of the job as well as
`on production-volume needs. Thus, applicator equipment ran§es all
`the way from com
`veyorized and autgl/natecl dispensing systems to eyedroppers or brq§he§. Typical single type
`applications are," »
`\,\XK
`v Spray gull (air or airless)
`~ Brush ‘
`
`Declaration of Roben A. Iezzi, Ph.D.
`APPENDIX C-11
`
` a:>,.;mm~:»ww««s«.w,l,,v»,-,-.-,;;M.« <’\ .z<§;_§¢}§'ss5;&W“,AWmwmgX§LQ‘§k EXhi
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`IA 191.?
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`!
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`etafi Surface Chara€E@a‘§s%;j@:<;;
`
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`Affsming Organic Cmtmgg
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`bv
`Emma M. Perfetti
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`
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`FEDERAEYQN
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`SERIES 0N
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`COATENQ?
`
`TECHNOLOGY
`
`Declaration of Robert A. Iezzi, Ph.D.
`(cid:39)(cid:72)(cid:70)(cid:79)(cid:68)(cid:85)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:3)(cid:82)(cid:73)(cid:3)(cid:53)(cid:82)(cid:69)(cid:72)(cid:85)(cid:87)(cid:3)(cid:36)(cid:17)(cid:3)(cid:44)(cid:72)(cid:93)(cid:93)(cid:76)(cid:15)(cid:3)(cid:51)(cid:75)(cid:17)(cid:39)(cid:17)(cid:3)
`APPENDIX D-1
`(cid:36)(cid:51)(cid:51)(cid:40)(cid:49)(cid:39)(cid:44)(cid:59)(cid:3)(cid:39)(cid:16)(cid:20)
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`Wavelock
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`Exhibit 1017
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`Page 132
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`$
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`#
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`
`
`Declaration of Robert A. lezzi, Ph.D.
`(cid:39)(cid:72)(cid:70)(cid:79)(cid:68)(cid:85)(cid:68)(cid:87)(cid:76)(cid:82)(cid:81)(cid:3)(cid:82)(cid:73)(cid:3)(cid:53)(cid:82)(cid:69)(cid:72)(cid:85)(cid:87)(cid:3)(cid:36)(cid:17)(cid:3)(cid:44)(cid:72)(cid:93)(cid:93)(cid:76)(cid:15)(cid:3)(cid:51)(cid:75)(cid:17)(cid:39)(cid:17)(cid:3)
`APPENDIX D—2
`(cid:36)(cid:51)(cid:51)(cid:40)(cid:49)(cid:39)(cid:44)(cid:59)(cid:3)(cid:39)(cid:16)(cid:21)
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`Wavelock
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`Exhibit 1017
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`Page 133
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`Figure 2-Sc|':ematic representation of the typical constituents
`and contaminants on metal surfaces
`
`the tteattnents and tlttlsltes applied to their sttmtces. Al—
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`cunfllcting tlcmamls n,rtl1cp1'nhlcm.
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`1T1a1tL’1'la1lS which are cuatetl and palntetl tmtl their LlSa1;;1t:
`spams Vl}‘tL1Llll}' the entire spectrum of COl1SLl}‘l1t_’I‘ guotls and
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`;ll'l‘..l an dl't110:-SE endless llhf of other
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`tl1t.‘l1' service lives. Each of these ztppltcattons h;1’:- L‘t1”llqL1c’
`functional and quality" ptenrqttisites tmcl 5et'\'ice 1‘cqul1'e—
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`treatments al'1LlC0t1tlt1gS. lL’lSi1”1t'L‘1’C:=,tln§: that these cl1a.r:.e-
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`mined ll}? both their chemical composition dTlLl metallL1t'-
`flcetl st1‘ttctL:1'c and by the lttstury o