Abstract:
A printing blanket carcass, comprising a fabric stack substrate comprising at least one fabric ply. Each ply has a plurality of warp and fill fibers or yarns. A compressible layer comprising a moisture cured thermoset polymer matrix is deposed on top of the substrate. The compressible layer contains a plurality of closed cells distributed substantially uniformly therein such that said layer has substantially uniform compression characteristics. A top fabric stack, comprising at least one fabric ply each of said ply having plurality of warp and fill fibers or yarns, is then deposed atop the thermoset compressible layer.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates to a method for producing a multi-layer printing blanket such as an offset lithography blanket wherein the carcass of the blanket is made substantially from a thermoset material. An elastomeric printing surface is coated or laminated to the carcass containing the thermoset material. Microspheres can be incorporated into the thermoset carcass in order to provide compressibility to the blanket.  
       BACKGROUND OF THE INVENTION  
       [0002]     The use of blankets in printing techniques, such as, offset lithography, is well known, wherein such blankets have a primary function of transferring ink from a printing plate to paper. Such printing blankets are very carefully designed so that the blanket is not damaged, either by mechanical contact with the press or by chemical reaction with the ink ingredients or other solvents used in the printing process. Repeated mechanical contacts do cause a certain amount of compression of the blanket, however, integrity of the blanket must be maintained within acceptable limits so that the image is properly reproduced. It is also important that the blanket has rebound characteristics such that it is capable of eventually returning to its original thickness, and that it provide image transfer of a constant quality.  
         [0003]     Multilayer polymeric printing blankets can be broadly described as having two subcomponent layers: the printing face, and the carcass. The printing face layer is the portion of the blanket that transfers ink from plate to paper, etc. The carcass is the total construction lying beneath the face layer. In order to create a carcass that can withstand the stresses of the printing process, a number of polymeric coatings and textile layers are required. The carcass generally requires at least two woven fabrics, each having multiple coatings of polymeric material thereon, to be pressed together to form a unit. The polymeric material may include microspheres therein to make the construction compressible. A face coat or face stock, which is the printing stock, is applied to the uppermost layer of fabric. This whole process might take 15 or 20 coating passes through a polymeric laminating machine, plus 3 or 4 layers of fabric.  
         [0004]     A key to obtaining a printing blanket having the desired compressibility, stress, and resiliency is in providing a compressible layer therein. In particular, it is generally known that by including at least one layer of material comprising a fabric reinforced compressible layer of resilient polymer in a printing blanket, that printing problems such as those described above, as well as “blurring” (i.e., a lack of definition), caused by a small standing wave in the blanket printing surface adjacent to the nip of the printing press, can be avoided. Such compressible layer also can serve to absorb a “smash”, that is, a substantial deformation in the blanket caused by a temporary increase in the thickness in the material to be printed due to, for example, the accidental introduction of more than one sheet of paper during the printing operation. By incorporating a compressible layer in the blanket, a “smash” can be absorbed without permanent damage to the blanket or impairment of the printing quality of the blanket. In addition, a resilient, compressible layer helps to maintain the evenness of the printing surface and the thickness of the blanket during the printing operation by restoring the normal thickness of the blanket after compression at the nip of the press.  
         [0005]     Blankets of the type described above suffer from a variety of deficiencies, however, which negatively affect their durability and print quality. For example, they are susceptible to wicking of ink, water and solvents commonly used in a press room, through either the exposed cut edges of the blankets or, in instances where these edges are protected by the application of a sealant, directly through cracks in the blanket or the bottom ply of the fabric. Waters, solvents, and inks that wick through to the under layers of the blanket can react with or cause deterioration to the adhesives bonding the various layers of the blanket together. At best, this can result in a bubbling of the printing blanket, leading to decreased print quality and lower printing speeds due to an imbalance created in the blanket. At worst, the wicking can cause delamination of the blanket, which can result in substantial damage to the printing apparatuses and large downtimes.  
         [0006]     It would therefore be highly desirable to create a printing blanket that does not require as many polymeric layers and laminations, while still retaining the desired stress characteristics of the multilayer blanket. It would also be desirable if this blanket were resistant to solvent and other chemicals to resist delamination of the blanket. It is also environmentally desirable to eliminate as many of the volatile solvents. It would further be desirable to manufacture these blankets at a lower cost than that required by the multi-layer, multi-laminated blankets currently known in the art.  
       DESCRIPTION OF THE PRIOR ART  
       [0007]     U.S. Pat. No. 6,645,601 issued to Serain et al., describes a printing blanket that includes at least one thermoplastic elastomer layer. This layer can be made of polyurethane.  
         [0008]     U.S. Pat. No. 6,071,620 issued to Kuczynski et al., discloses a lithographic layer for a printing blanket. The lithographic layer (i.e., the printing surface) is a layer of thermoplastic material, which ensures maximum transfer of the printing ink from the blanket cylinder to the paper. The thermoplastic is preferably polyurethane or ethylene-propylene that has been polarized through the incorporation of additional ingredients, such as ethylene vinyl acetate, mineral loading, plastifier, and pigments.  
         [0009]     U.S. Pat. No. 6,027,789 issued to Canet et al., discloses a printing surface for a printing blanket. A substrate beneath the printing surface is disclosed, that can be made of a hydrophobic or hydrophilic elastomeric material such as formulated polyolefin or polyurethane.  
         [0010]     U.S. Pat. No. 5,974,974 issued to Agnew et al., discloses a printing blanket, wherein the printing layers are formed from elastomeric polymers formed via photopolymerization. The polymer can be polyurethane.  
         [0011]     U.S. Pat. No. 5,549,68 issued to Byers et al., discloses a printing blanket, wherein the traditional compressible layer can be eliminated by incorporating an impregnated compressible fabric. The impregnated fabric can consist of thermoset polymers having microspheres therein.  
         [0012]     U.S. Pat. No. 5,487,339 issued to Breventani et al., discloses a method of attaching a holding bar to a printing blanket, wherein a strip of thermoplastic or thermoset hot melt material such as polyurethane or nylon is used to attach the holding bar to the printing blanket.  
         [0013]     U.S. Pat. No. 5,389,171 issued to Bartholmei et al., discloses a method of making a printing blanket where the outer cover layer (i.e., the printing layer) is preferably made of elastic cured polymers such as polyurethane.  
         [0014]     U.S. Pat. No. 5,352,507 issued to Bresson et al., discloses a seamless multilayer printing blanket, wherein the resiliently compressible layer comprises a foamed elastomeric material such as polyurethane that can be reinforced with fibers.  
         [0015]     U.S. Pat. No. 4,303,721 issued to Rodriguez discloses closed cell foam printing blanket, wherein the compressible layer can include polyurethane.  
         [0016]     U.S. Pat. No. 4,174,244 issued to Thomas et al., discloses a method of making a printing blanket, wherein the cover, or top printing layer, may comprise any material having rubbery or compressible properties, which will cure and, optionally, foam under the conditions of molding. Examples of acceptable material include polyurethane.  
         [0017]     U.S. Pat. No. 3,983,287 issued to Goosen et al., discloses a printing blanket, wherein the resilient layer contains polyurethane.  
         [0018]     Additional objects and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and attained by means of instrumentalities and combinations particularly pointed out in the appended claims.  
       SUMMARY OF THE INVENTION  
       [0019]     Generally, elastomers are any elastic materials having properties similar to rubber. They can be stretched tremendously and will typically return to their pre-stretched shape without deformities. This pliability is due to elastomers&#39; glass transition temperatures (T g ) being at or below room temperature. Furthermore, an elastomer&#39;s molecules are typically unoriented, but will readily align to an oriented arrangement upon stretching.  
         [0020]     In contrast to elastomers, thermoplastics are generally rigid, having a T g  above room temperature, but will fuse or soften when heated, and harden again when cooled. Both thermoplastics and elastomers can be molded and shaped when heated above their respective T g . Processing methods for thermoplastic products thus involves heating and applying pressure to the material in order to reach its T g . The materials can then be extruded or molded into their desired shapes.  
         [0021]     A thermoset is completely different from an elastomer or moldable thermoplastic. Thermoset polymers are crosslinked to such an extent that they “set” into a given shape when first made, and cannot be shaped or molded later when heated to their T g . Rather, the thermoset will decompose upon heating past its T g . They are typically hard, strong, and brittle, but they may soften slightly when heated to below their T g . Because of this extensive crosslinking, the thermoset is very resistant to interactions with other chemicals, as well as high temperatures and abrasions. It is therefore often utilized as a coating or adhesive in order to prevent corrosion of the underlying materials. Phenolic, melamine, resorcinol formaldehyde, furan, polyester, polyimide and urea formaldehyde resins are thermosetting adhesives that offer strong bonds and good resistance to high temperatures.  
         [0022]     The blanket of the present invention utilizes a thermoset material in the carcass of the printing blanket, and can be manufactured in a variety of ways. Thermoset material can be used in any or all of the layers, depending on the desired properties. The thermoset material can comprise a single large compressible layer with microspheres therein. Additionally, the thermoset material can be utilized as an adhesive between fabric layers. In one specific embodiment, the thermoset material containing microspheres to form the compressible layer is applied to the reinforcing fabric base. A top fabric is then laminated onto the compressible layer for additional support, followed finally by the face stock over that. In one specific embodiment, the blanket is comprised of two-ply base layer fabric, a compressible thermal set polyurethane or polyurea layer atop the two-ply base layer, and a top fabric. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0023]      FIG. 1  is a greatly enlarged cross-sectional view of the invented multilayer printing blanket. 
     
    
     DETAILED DESCRIPTION  
       [0024]     The fabric substrate  12  is comprised of at least one fabric ply, having warp fibers  14  and fill fibers  16 , which are formed of natural or synthetic material. These fibers are woven and produced from spun or filament yarn of the desired length. Cotton, polyester, nylon, rayon, etc. are typical materials which may be used as fibers or yarns of the fabric substrate  12 .  
         [0025]     Preferably, the warp fibers  14  are formed from natural material such as cotton, whereas the fill fibers  16  are comprised of a synthetic textile (e.g., polyester). Both the warp and fill fibers or yarns should have a tensile strength of at least 30 psi. The substrate preferably has a yarn count per inch ranging between about 55-61 (warp) and 57-63 (fill). The fabric substrate ranges between about 5.8 to 6.2 ounces/sq. yd. in weight and from 0.014 to 0.016 inches in thickness (also referred to as “gauge”). The warp direction has a tensile strength of at least about 150 pounds/inch, whereas that of the fill direction is at least about 60 pounds/inch. Moreover, in the preferred embodiment, the fabric substrate should be capable of no more than about 1.9% residual stretch.  
         [0026]     In general, in the fabric plys used in the present invention, the fiber or yarn counts per inch for both warp or fill directions can vary between 20 and 150, depending upon the denier of the fiber or yarn. Moreover, fabric weights of 2 to 8, preferably about 4 to 8, ounces per square yard and thicknesses of 0.005 to 0.03″ can be utilized for particular applications of the various fabric plys of this invention.  
         [0027]     Fabric substrate  12  is additionally spread coated, calendared, dipped, or otherwise contacted upon only its upper surface with an adhesive material  20 . Suitable adhesive materials include thermoplastic resins, thermosetting resins, polyurethanes, and natural or synthetic elastomers. PVC and other polyolefins are suitable thermoplastic resins, while polyurethanes are preferred.  
         [0028]     Suitable adhesives include those of the acrylonitrile, neoprene, and acrylic families. Polysulfides, alone or in combination with acrylonitrile or neoprene, can also be used. Any natural or synthetic elastomer can be used if desired, and such materials are preferred for use with the invention.  
         [0029]     Preferably, the adhesive can be a thermoset resin, most preferably a thermoset polyurethane or polyurea. The preferred viscosity for the matrix material ranges between about 10,000 to 25,000 cps.  
         [0030]     Moisture-cure polyurethanes are formed with resins having terminal isocyanate NCO groups in the molecule. They are normally a single-package polyurethane prepolymer. Following application, the prepolymer or the isocyanate group reacts with moisture in the atmosphere to form the final cross-linked coating.  
         [0031]     These are generally low molecular weight, linear polymers, with isocyanate end groups. Such isocyanate-terminated prepolymers can be produced by reacting an excess of polyisocyanate with high molecular weight hydroxyl polyester or polyether polyols.  
         [0032]     The isocyanate end-groups react with any compound containing an active hydrogen, such as alcohols, amines, or other polyurethanes and ureas. For moisture curing systems, the active hydrogen is provided by atmospheric moisture. Thus, the relative humidity will effect the speed at which the system cures.  
         [0033]     The reaction is a two stage process where water first reacts with the isocyanate groups to produce an amine and carbon dioxide. The amine will then react with other isocyanate groups to form a urea until all available isocyanates are consumed. Carbon dioxide that is generated diffuses through the film and is then evaporated from the system. The reactions can be summarized as follows:
 
—NCO+H2O→—NH2+CO2
 
—NCO+—NH2→—NH—CO—NH
 
—NCO+—NH—CO—NH→—NH—CO—NH—CO—N
 
         [0034]     The adhesive material used with the fabric plys may additionally contain a plurality of cells therein. These cells, either closed or open, are similar to the formation of the compressible layer, described infra.  
         [0035]     Located directly above the adhesive  20 , and bonded thereto, is fabric  30  comprising at least one fabric ply. Fabric plies of fabric  30  are similar in many respects to fabric substrate  12  discussed above in that the plies of fabric  30  are comprised of warp fibers  32 , and fill fibers  34 , respectively, formed of natural or synthetic material. These fibers, as in the case of substrate  12 , are woven and are comprised of spun or filament yarn of the desired length. Preferably, the warp fibers are formed from natural material such as cotton, whereas the fill fibers are comprised of a synthetic textile (e.g., polyester). Both the warp and fill fibers or yarns should have a tensile strength of at least about 30 psi.  
         [0036]     In a preferred embodiment, plies of fabric  30  have a yarn count per inch ranging between about 75-80 (warp) and 53-58 (fill). Fabric  30  ranges in weight between about 4.9 to 5.3 ounces/sq. yd. The thickness, i.e., gauge, of fabric  30  ranges between about 0.0105 and 0.0115 inch. The warp fibers  32  have a tensile strength of at least about 150 pounds/inch. The tensile strength of fill fibers  32  is at least about 40 pounds per inch. Fabric  30  should be capable of no more than about 2.2% residual stretch.  
         [0037]     Located above the fabric  30  is compressible layer  40 . Compressible layer  40  is made from a suitable resilient thermoset polymer matrix  42 , into which a quantity of cell-forming materials, or microspheres  44 , are evenly dispersed to form a compound. The polymer matrix can be a material similar to that used in adhesive layer  20 , including acrylonitrile, neoprene, and acrylic families. Polysulfides, alone or in combination with acrylonitrile or neoprene, can also be used. Preferably, the polymer matrix is a thermoset resin, most preferably a thermoset polyurethane or polyurea. The preferred viscosity for the matrix material ranges between about 50,000 to 60,000 cps.  
         [0038]     Generally, the microspheres are formed from materials such as, i.e., thermoplastic resins, thermosetting resins, and phenolic resins. The microspheres range in diameter between about 1-200 and preferably 50-130 microns, with an average size of about 90 microns being most preferred. They are dispersed relatively uniformly throughout the matrix material such that, upon application of the matrix to the fabric ply, they become thoroughly embedded in its interstices. Thus, when applied, the microsphere loaded material described herein will substantially impregnate the fabric substrate on its upper side.  
         [0039]     The microspheres are uniformly distributed throughout the elastomer in such a way to avoid any appreciable crushing of the microspheres. Additionally, the microspheres are incorporated in the elastomeric material at a loading of about 1-20% by weight and preferably 1-10% of the solid contents. This percentage will vary based on such factors as microsphere dimension, wall thickness, extent of any crosslinking and bulk density, or if blowing agents are additionally incorporated within the matrix.  
         [0040]     To form the cells in the embodiment described above, any of a wide variety of microspheres  44  can be added to a solution or dispersion of the matrix  42 . If solvent solutions are utilized, the selected microspheres must be resistant to chemical attack from the solvents.  
         [0041]     Several acceptable types of thermoplastic microspheres for use with the present invention are marketed, for example, by Expancel and Dualite. Microspheres of a thermoplastic resin are preferred for this embodiment.  
         [0042]     If desired, the microspheres may further include a coating thereon to prevent them from aglomerating. Any one of a variety of coatings thereupon, such as talc, calcium carbonate, zinc oxide, titanium dioxide, mica, calcium sulfate, barium sulfate, antimony oxide, clay, silica, and aluminum trihydrate may be used. Improper selection of the sphere/coating can interfere with the desirable properties of the matrix, which can adversely effect polymerization thereof.  
         [0043]     Preferably, the urethane compressible layer  40  of the present invention is a hot-melt, moisture-cured system similar to that of adhesive  20 , and does not utilize a solvent carrier. It can therefore be applied without the repetitive layer passes inherent in the prior art. The compressible layer  40  can be applied as a single layer, which can be applied in excess of 0.04 inches in a single pass. In blankets typical of the prior art, the compressible layer is formed by depositing a number of thin layers onto a fabric in successive applications to build up the desired thickness. This is necessary to afford efficient volatizing of solvent from the coated elastomer without forming voids in the compressible layer. Thus, preparation and curing time for the blanket has been drastically reduced.  
         [0044]     Compressible layer  40  may be adhered to fabric  30  with, for example, the use of a layer of a suitable adhesive (not shown). The particular adhesive will depend upon the specific elastomers utilized to form the plys. Preferably, compressible layer  40  is bonded directly to fabric  30 , without the use of additional adhesives.  
         [0045]     Located above the compressible layer  40  is a top fabric  50  comprising at least one fabric ply. Fabric  50  can then be bonded to compressible layer  40  with the use of a suitable adhesive such as those described above. Preferably, fabric  50  is nipped directly into the compressible layer  40 , alleviating the need for an adhesive.  
         [0046]     Fabric plies of the top fabric  50  are similar in many respects to fabric substrate  12  discussed above in that the plies of fabric  50  are comprised of warp fibers  52  and fill fibers  54 , respectively, formed of natural or synthetic material. These fibers, as in the case of substrate  12 , are woven and comprised of spun or filament yarn of the desired length. Both the warp and fill fibers or yarns should have a tensile strength of at least about 30 psi.  
         [0047]     In a preferred embodiment, plies of fabric  50  have a yarn count per inch ranging between about 100-105 (warp) and 77-82 (fill). The fabric used to form 50 ranges in weight between about 3.7 and 3.9 ounces/sq. yd. The thickness, i.e., gauge, of top ply  50  ranges between about 0.008 and 0.010 inch. The warp direction of top ply  50  has a tensile strength of at least about 70 pounds per inch. The tensile strength in the fill direction of ply  50  is at least about 60 pounds per inch. In top fabric ply  34 , the stretch of the fabric may range between about 6 and 10%.  
         [0048]     Bonded to the upper portion of fabric  50  is elastomeric subface  60  formed from a high durometer, high tensile, low elongation compound (i.e., in comparison to the material used to form the printing face, as described below), which is preferably a compounded nitrile rubber. Alternately, however, a variety of water and solvent based elastomeric compounds, well known in the art, may be used instead of nitrile rubber in forming the subface. Subface  60  is provided to re-enforce the printing face, thus resulting in improved blanket life and resistance to cutting while in use.  
         [0049]     Elastomeric printing face  70 , adapted to accept the print image from the printing plate and transfer it to, e.g., a paper substrate, is the uppermost layer on laminated/coated blanket  10 . In prior art blankets, the application of the elastomeric printing face is typically carried out by the well known method of knife over roll spreading in which a solvated elastomeric compound is spread in numerous successive passes, applying a thickness of about 0.001″ with each pass, over, e.g., a subface or upper fabric layer. Moreover, as pointed out above, in comparison to the material used to form the subface, the elastomeric material used to form the printing face is lower in durometer and tensile strength and higher in elongation.  
         [0050]     In addition, printing blankets of the type described above are typically provided with a roughened surface profile in an effort to reduce dot gain, while maintaining good release properties for the blanket. Such roughness profiles have, in the past, been produced either by molding during cure, or by buffing the cured face with medium or coarse grit sandpaper, which is well known in the art. The surface profile is thereafter measured by, e.g., a device known as a profilometer (manufactured by the Perthen Corporation), which is also well known in the art. The surface profiles of prior art laminated blanket printing faces typically have a roughness average (i.e., “RA”) of 1.0 to 1.8 microns while cast blankets, which do not have good release properties, typically have an RA of 0.3 to 0.5 microns. In this regard, it is important to note that the higher the roughness average, the worse the print quality becomes due to decreasing uniformity of the dots.  
         [0051]     In blanket  10  of the present invention, however, the roughness average of printing face  70  is adjusted to above about 0.6 microns but below about 0.95 microns, and preferably between about 0.7 to 0.9 microns by buffing with fine sandpaper. The advantage of this treatment is that it affords excellent release properties to the blanket while also resulting in an improved structure of the printed dots, thus providing both improved print quality and releasability to the blanket of the invention. This effect may also be achieved by a number of alternate methods well known in the art, such as molding.  
       EXAMPLES  
     Example 1  
       [0052]     The adhesive was conditioned in an oven at 85° C. for 2 hours prior to coating. The samples were prepared by coating S/4195 (base-ply) with the shown sample at 0.010 inch K/R gap setting. S/4200 (middle-ply) was then nipped/laminated to the coated base-ply. The samples were allowed to cure for 24 hours.  
         [0053]     The polyurethane composition was heated at 120° C. for two hours. The carcass middle layer was then coated with the shown PU composition at 0.035 inch K/R gap setting. Top layer S/4232 was then laminated into the hot adhesive. The sample was allowed to cure for 72 hours.  
         [0054]     The following PUs were supplied:  
                                                                         Viscosity (cps)   % Microspheres           Composition #   @ 100° C.   (by weight)                           A (SG 15 16-31)   29400   2.0           B (SG 15 16-32)   43600   2.5           C (SG 15 16-33)   34200   3.0                D (SGH 0005-3A)   SGH0005-3A                      
 
         [0055]     Viscosity was measured with a Brookfield TT-100 inline viscometer. Gauge was measured with a Cady deadweight bench micrometer, or Cady Gauge. E130-095AD microspheres manufactured by Dualite were utilized in the compressible polyurethane layer. The following blanket carcasses were made utilizing the provided compositions, and obtaining the following results:  
                                                                             Compressible       Stress       Carcass #   Adhesive Layer   Layer   Gauge   (Kg/cm 2 )                                1   D (SGH 0005-3A)   A (SG 1516-31)   0.049   50.1       1   D (SGH 0005-3A)   A (SG 1516-31)   .051   40.6       2   D (SGH 0005-3A)   B (SG 1516-32)   0.051   45.1       2   D (SGH 0005-3A)   B (SG 1516-32   .050   39.0       3   D (SGH 0005-3A)   C (SG 1516-33)   0.051   35.3       3   D (SGH 0005-3A)   C (SG 1516-33)   .051   34.3                  
 
       Example 2  
       [0056]     The adhesive was conditioned in an oven at 120° C. for 2 hours prior to coating.  
         [0057]     The samples were prepared by coating S/4195 (base-ply) with the shown sample at 0.010 inch K/R gap setting. S/4200 (middle-ply) was then nipped/laminated to the coated base-ply. The samples were allowed to cure for 24 hours.  
         [0058]     The polyurethane composition was heated at 120° C. for two hours. The carcass middle layer was then coated with the shown PU composition at 0.045 inch K/R gap setting. Top layer S/4232 was then laminated into the hot adhesive. The sample was allowed to cure for 96 hours.  
         [0059]     The compressible layer PU contained Dualite E130-095AD microspheres.  
         [0060]     The following PUs were supplied:  
                                               Viscosity (cps)       % Microspheres       Composition #   @ 100° C.   Open-time (sec.)   (by weight)                   A (SG 1516-137)   12200   24   0       B (SG 1516-138)   11270   55   0       C (SG 1516-144)   23950   60   0       D (SG 1516-148)   65000   10   6       E (SG 1516-149)   62800   30   6                  
 
         [0061]     Viscosity was measured with a Brookfield TT-100 inline viscometer. Gauge was measured with a Cady deadweight bench micrometer, or Cady Gauge. E130-095AD microspheres manufactured by Dualite were utilized in the compressible polyurethane layer.  
         [0062]     The following blanket carcasses were made utilizing the provided compositions, and obtaining the following results:  
                                                       Compressible       Stress       Carcass #   Adhesive Layer   Layer   Gauge   (Kg/cm 2 )                   1   A (SG 1516-137)   D (SG 1516-148)   0.0555   29.69       2   A (SG 1516-137)   E (SG 1516-149)   0.0555   29.56       3   B (SG 1516-138)   D (SG 1516-148)   0.0555   28.64       4   B (SG 1516-138)   E SG 1516-149)   0.0590   26.31       5   C (SG 1516-144)   D (SG 1516-148)   0.0540   25.21       6   C (SG 1516-144)   E (SG 1516-149)   0.0530   27.21                  
 
       Example 3  
       [0063]     The adhesive was conditioned in an oven at 120° C. for 2 hours prior to coating. The samples were prepared by coating S/4195 (base-ply) with the shown sample at 0.010 inch K/R gap setting. S/4200 (middle-ply) was then nipped/laminated to the coated base-ply. The samples were allowed to cure for 24 hours.  
         [0064]     The polyurethane composition was heated at 120° C. for two hours. The carcass middle layer was then coated with the shown PU composition at 0.045 inch K/R gap setting. Top layer S/4232 was then laminated into the hot adhesive. The sample was allowed to cure for 96 hours.  
         [0065]     The following PUs were supplied:  
                                               Viscosity (cps)       % Microspheres       Composition #   @ 100° C.   Open-time (sec.)   (by weight)                   A (SG 1516-148)   65000   10   6       B (SG 1516-149)   62800   30   6                  
 
         [0066]     Viscosity was measured with a Brookfield TT-100 inline viscometer. Gauge was measured with a Cady deadweight bench micrometer, or Cady Gauge. E130-095AD microspheres manufactured by Dualite were utilized in the compressible polyurethane layer. The following blanket carcasses were made utilizing the provided compositions, and obtaining the following results:  
                                                       Compressible       Stress       Carcass #   Adhesive Layer   Layer   Gauge   (Kg/cm 2 )                   1   A (SG 1516-148)   A (SG 1516-148)   0.055   20.28       2   B (SG 1516-149)   B (SG 1516-149)   0.055   22.89                  
 
       Example 4  
       [0067]     The adhesive was conditioned in an oven at 120° C. for 2 hours prior to coating. The samples were prepared by coating S/4195 (base-ply) with the shown sample at 0.010 inch K/R gap setting. S/4200 (middle-ply) was then nipped/laminated to the coated base-ply. The samples were allowed to cure for 24 hours.  
         [0068]     The polyurethane composition was heated at 120° C. for two hours. The carcass middle layer was then coated with the shown PU composition at 0.045 inch K/R gap setting. Top layer S/4232 was then laminated into the hot adhesive. The sample was allowed to cure for 96 hours.  
         [0069]     The following PUs were supplied;  
                                               Viscosity (cps)       % Microspheres       Composition #   @ 100° C.   Open-time (min.)   (by weight)                   A (SG 1516-188)   27400   3.0-6.0 minutes   0       B (SG 1516-189)   27800   3.5-6.5 minutes   0       C (SG 1516-193)   52800   3.5-6.0 minutes   6       D (SG 1516-194)   50250   2.0-3.0 minutes   6                  
 
         [0070]     Viscosity was measured with a Brookfield TT-100 inline viscometer. Gauge was measured with a Cady deadweight bench micrometer, or Cady Gauge. E130-095AD microspheres manufactured by Dualite were utilized in the compressible polyurethane layer. The following blanket carcasses were made utilizing the provided compositions, and obtaining the following results:  
                                                       Compressible               Carcass #   Adhesive Layer   Layer   Gauge   Stress                   1   A (SG 1516-188)   D (SG 1516-194)   0.054   20.02       2   B (SG 1516-189)   C (SG 1516-193)   0.059   20.07                  
 
         [0071]     Additionally, carcass #1 exhibited an adhesion between the bottom-ply and the center-ply of 2.7 lbs/inch. Carcass #1 also had an adhesion between the center-ply and the top-ply of 13.1 lbs/inch.