Binder Assembly System Employing Special Plastic Spine

Technical Field

The present invention relates to a binder assembly system for binding together a series of sheet materials, such as, for example, paper, for business reports and the like by an office worker, with the binding typically being done along one edge using either a cover-less spine or a spine with a front and/or back cover attached, wherein the sheet materials are brought together as a unit, placed into the spine, and adhesively affixed to the spine, binding all of the components together. More particularly, the present invention relates to a spine of the type of which the inside or interior of the spine is provided with an amount of glue meltable under the influence of heat . When the glue solidifies, the sheets are joined together and retained in the spine. Even more particularly, the present invention relates to a spine made of a single piece of special, extruded or molded plastic material, on which a series of preferably cold-melt, heat-flowable glue spots or areas is applied along the spine's length preferably at spaced intervals.

Background Art

It is a common desire in, for example, office settings, to bind sheet materials together, such as, for example, a selected collection of papers, along one edge for finished reports, product information, data collection, etc., and the like. To achieve this, a binding industry has been created to produce various approaches to binding the selected materials together using, for example, spiral binding, adhesive binders, pin binders, etc.

In a simple method of adhesive binding, the binding assembly includes a binding element, typically a file consisting of a front cover, a back cover and a spine, on

the inside of which is provided an amount of glue which melts upon the influence of heat. The sheet materials (or sheets) are joined together as a unit and placed inside the binding element in contact with the glue. Upon application of heat, the glue melts and the edges of the sheets intrude into the glue layer. After the heat is removed from the binding element, the glue solidifies, which results in the sheets being bonded to each other and retained in the binding element by means of the glue. See, for example, U.S. Patent 5,078,563 (Lolli) , U.S. Patent 5,425,554 (Lamanna) , and G.B. 2,145,033 (Smith) .

Typically, the spine has a "U" shape cross-section. A heat-flowable, relatively thick, adhesive strip layer is located inside the "U"-shape and along its bottom. Addi- tionally, back and front covers (transparent or opaque) may be attached along each of the spine side walls or edges.

It is also known in the prior art to apply an element of a heat conducting material, such as metal, on the spine. The heat conducting element allows an efficient transfer of heat to the glue, such that the glue melts uniformly across the inside of the spine. The heat conducting element may have a "U-shaped" profile which also functions to reinforce and support the connection between the glue and the edges of the sheets. When the bundle of sheets are laid down and opened, or when the pages are turned, the parallel walls of the U-shaped element supports the weight of the paper and guards the glued connections. See, for example, Lamanna '554, and G.B. 2,197,156 (referenced in Lamanna '554) .

Typically, the U-shaped heat-conducting element is located at the inside of the file. In such an arrangement, it is difficult to place uniformly all the sheets into the U-shaped profile, especially when dealing with thick bundles. The most recent, asserted improvement to the prior art, as disclosed in U.S. Patent 5,425,554, issued to Lamanna, attempts to address that problem by positioning the actual file on the inside of the heat conducting element. A further disclosure has the file covers only partially adjacent the "U-shaped" heat conducting element; the typical

spine is replaced with the heat-conducting element, then acting as the spine of the binding element. The glue is applied directly to the inside of the spine/heat-conducting element . In this '544 disclosure, the spine is specifically manufactured from a hard, heat-conducting material with little or no bendability, typically, a metal, such as steel. For primarily aesthetic purposes, a covering is applied on the exposed exterior of the spine or completely around the spine. The cover is usually an "elegant", decorative material such as printed paper.

The above-mentioned spine design may be incorporated with another recent improvement in binding assemblies, the cover-less spine. In this approach, the front and back covers of the file are excluded and the cover-less spine is equipped with temporary, easily removable, guide members for guiding the sheets into the spine.

Another approach allowing customized or user-provided covers is a mechanical one, which does not use heat-acti- vated, flowable adhesive, but instead uses a plastic spiral or extension binding element, which requires that the covers and sheets of paper being bound be punched with several, spaced, hole slots along their binding edge, with a special mechanical tool being necessary to apply the spiral or extension binding element through the slots in the final binding step.

Although recent improvements in the prior art have resulted in a simpler, less expensive method of binding sheet materials, there is still room for further improve- ments. Problems persist in the prior art which have not been successfully addressed. Meanwhile, new challenges have surfaced from recent improvements.

A primary problem with the use of a metal element for the spine or heat-conducting element arises when the spine is subject to certain bending loads and other external loads and strain present during shipping, handling and use. The stiff, un-resilient metal element, and thus the spine, has a tendency to become and stay crimped, thereby mis-aligning

the sheet materials, and further inducing excessive wear. This crimping will often occur when a user places in the mail the bound materials with the metal spine in a normal envelope, and the metal spine becomes crimped and uncorrect- ably bent as result of normal mail handling, causing the bound materials to arrive in a relatively unattractive and unprofessional condition.

It also difficult for a book or bound collection of sheet materials to remain open at certain page when laid down. This is not only unattractive and burdensome, but it also creates an unprofessional appearance to the bound report, product catalog, etc.

Another undesirable aspect of the metal spine is that it generally appears dull and uninviting. As noted above, an attempted remedy of the prior art has been the addition of a decorative covering around the binding element usually added to hide the metal surface; see, e. g. , the Lamanna

('554) patent. This approach, however, adds to the cost of the binding assembly and compromises the simplicity in the manufacture and application of the binding assembly.

Additionally, the covering can come loose from the metal spine, exposing the sharp, cutting edges of the metal material .

Finally, the cost of manufacturing such a composite, covered metal spine is relatively complex and more expen¬ sive.

The present invention is designed to provide an alternative, binding spine solution which avoids, or at least greatly diminishes, these problems, while providing new, valuable and innovative improvements over the prior art by using a special, preferably cover-less, flexible but self- or shape-sustaining, plastic spine with a "U" shaped, channel-type cross-section, preferably with heat-activated adhesive on the interior bottom of the "U" shape placed along its length, and having significant or strong but flexural rigidity, typically using relatively thick wall thicknesses for its sides and bottom of its "U" shape, with the plastic being capable of withstanding relatively high

heat levels without puddling using preferably a re-enforced plastic, with a preferred plastic being re-enforced polypro- pelene.

Thus, although it has been generally suggested in the prior art to use plastic for certain types of binding spines, noting, for example, U.S. Patents 4,928,995 of Dennison Manufacturing and 5,078,563 of Carla P. Lotti et al , the structures specifically disclosed would not work in the way the present invention does nor be effective in manner of the present invention. Thus, the '995 patent uses contact adhesive and does not use thermal binding, and, although its suggests the use of inter a2ia polypropelene, such in and or itself would not work and would not have the necessary high heat capabilities needed in the present invention. Likewise, the '563 patent uses a very thin, continuous sheet comparable to the thickness of a cardboard cover with no self-sustaining rigidity, which merely falls flat (note Figs. 1, 4-6) when not supported, in which it is suggested that the inner, integral front sheet and back sheet and central area "spine" could alternatively be made of "plastic", but with no meaningful materials disclosure for the plastic, all for use in a four layered or part structure, namely, a (1) first, upper, thicker layer of thermal binding adhesive in the top center, (2) the com- bined, integral inner sheets and central "spine" sheet portion, (3) a bottom-sandwiched, thinner layer of thermal binding adhesive, and (4) an over-all, foldable cover.

General Summary Discussion of Invention

Thus, the present invention is directed to a binder assembly system for binding together a selected collection or sheaf of sheet materials, e . g. , paper, including any cover(s) typically to be provided by the user and not initially an integral part of the spine, wherein the binding spine is a single piece of flexible, resilient material with the ability to avoid permanent crimping when subjected to significant external loads yet has sufficient strength and shape-retaining rigidity to perform the material holding and

binding function with a melting point significantly higher than that of the adhesive used in the heating binding process. The material is also preferably relatively inexpensive, readily available, attractive in appearance, and preferably available in multi-colors with preferably a textured exterior surface for enhanced attractiveness.

An example of such a special material is a special, molded or extrudable plastic which exhibits the necessary and desirable characteristics of the invention, such as, for example, re-enforced polypropylene.

This special plastic extrusion provides a superior spine in practically every regard, while doing so with a unitary structure which is much less in weight, resulting in great savings in shipping costs, as well as a less expensive yet more attractive and versatile product which can be cut to any desired length by even the end user using, for example, standard office scissors or a paper cutter, producing a straight, clean cut. This latter advantage allows, for example, the user to take a standard size or length spine designed for a letter size or A4 document and cut it into a smaller length to make a smaller pad size bound at either the edge or the top of the smaller pad.

Thus, in the present invention, the binder assembly comprises a binding spine made preferably from an elongated, single, unitary piece of molded or extruded, resilient but strong plastic material with or without covers or guides attached. The spine has a flat or curved base with opposed, side walls, wherein the walls form a "U" shape profile with the base. In the interior of the "U" shaped profile, a reduced amount of heat-flowable glue may be applied, preferably in the form of, for example, spaced dots or drops of adhesive glue, although a strip or spaced strips of glue can be used, if so desired. The sheet materials, with or without cover (s) , are collected together and their collec- tive side edges are placed into the interior of the spine, in contact with the glue.

Under the influence of externally applied heat, the glue melts, causing it to flow in and around the edges of

the sheet materials positioned at the base. When the heat is removed, the glue cools and solidifies, thereby binding all the individual sheets material together and retaining them within the spine. In the preferred, exemplary embodiment, a re-enforced polypropylene is formed, preferably by extrusion, and cut to an appropriate length to make up the binding spine. Re-enforced polypropylene has been selected because of its unique properties. However, it is noted that there are other plastics which will work similarly in this applica¬ tion. At this time, re-enforced polypropylene appears to provide the best results for the currently preferred purposes of the invention.

As with many other plastics, propylene is lightweight, is generally chemical resistant and has excellent strength. It is also heat resistant to two hundred and eighty (280°F) degrees fahrenheit. Therefore, it is not affected by the heating method of the present invention, which occurs at a lower temperature than is typical (as will be explained more fully below) . Another benefit is that polypropylene is available in a variety of natural or custom colors, visually appealing, and thus can be particularly suited to the user's aesthetic demands. This, of course, eliminates the need for a costly and burdensome, separate covering. Finally, re-enforced polypropylene meets the require¬ ments of flexibility, shape-maintaining resiliency and high strength, without brittleness, while complementing the unique structural design of the "U" shaped profile of the spine. When the spine is subjected to bending loads in any direction, its flexibility allows it to bend without shearing, even to the point of being bent back unto itself, and then, when the load is released, the spine and its "U"- shaped profile returns to its original configuration without deformation or crimping, although in some embodiments some easily achieved, manually accomplished, reverse bending or straightening may be required. A minimum of about at least thirty (30°) degrees of bending from the straight is

desirable, whether from a plan (top/bottom) perspective or from either side.

These recuperative characteristics are further aided by the unique spine design. The side walls and preferably also the base are structurally resilient as well. The side walls preferably are oriented at either ninety (90°) degree angles, i.e., are orthogonal to the base, or are at out¬ wardly directed angles, greater than ninety (90°) degrees from the base and preferably less than about one hundred and five (105°) degrees.

Typically, when a force acts perpendicularly on the side walls, laterally out away from the preferred beefed-up base, the wall will bend, almost rotate, allowing, for example, the bound papers to be open down relatively flat for, for example, reading or writing on the paper. In response, the base will arch slightly. When the load is released, the side wall, the base, and the U-shaped profile return to their original form. The same is generally true if the force (s) are in the opposite directions, namely, the side walls and base resilient return to their original form. In alternative embodiments, the U-shaped profile is modified to accommodate different binding applications.

In the preferred, exemplary embodiment, the binding glue employed in the special plastic spine is, for example, Dexter Hysol, a cool melt glue which is heat-flowable at a temperature below the two hundred and eighty (280°F) degrees fahrenheit melting temperature for polypropylene. Thus, although the polypropylene material may not have the conductive properties of steel or other metals, this is offset by the reduced heat required for melting the glue and causing it to flow, during the heating and binding step.

It is an object of the invention to provide a binding system which remains structurally intact during shipping, handling and use and, more specifically, a system which avoids permanent crimping.

It is a further object of the invention to provide a binding system with a flexible spine capable of bending

under the influence of external loads, and returning to its original shape and configuration when the load is released. It is a further object of the invention to provide a binding spine which is aesthetically pleasing and which offers the user a variety of colors or designs, including texturized surfaces, to choose from without compromising structural and functional integrity or significantly adding to the cost of manufacture and preferably reducing the cost of manufacture. It is a further object of the invention to provide a spine which can be cut to a desired length by the end user using readily available office implements, such as, for example, standard office scissors or paper cutters.

It is a further object of the invention to provide a spine which is simple to manufacture, user-friendly, and compatible with other binding accessories including a variety of covers and improvements in cover-less or covered, binder assembly systems .

It is a further object of the invention to provide such a system which is relatively inexpensive and reliable in operation and easy to use.

It is still a further object of the invention to replace traditional spiral binding, allowing the binding of documents with independent front and back covers or the use of two (2) piece cover sets.

It is finally a further object of the invention to provide such a system which uses a special plastic spine having the desired characteristics of flexibility and strength, while being usable in relative high temperatures allowing the use of heat melt adhesives in the binding process, with re-enforced polypropelene being a particularly preferred plastic for this use. Brief Description of Drawings

For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers, and wherein:

Figure 1 is a plan view illustrating the interior side of an exemplary embodiment of the single-piece, re-enforced plastic binding spine as used in a cover-less binder assembly system with, if so desired, temporary side, guide connections, showing inter alia the spots of cool-melt adhesive spaced at regular intervals ultimately used to secure and bind the sheet materials or papers to the interior surface of the base of the spine after the appro¬ priate sheet material to be bound has been inserted into it and the adhesive heated and set.

Figure 2 is an end view of the plastic binding spine with the sheet materials or papers properly inserted therein, and secured to the base of the spine after adhesive heating and set . Figure 3 is an end view of an alternative, U-shaped plastic binding spine, similar to that of Figure 2, showing exemplary, alternative dimensions in a normal application, and also illustrating the slight obtuse angle between the spine walls and the base of the spine. Figure 4 is an end view of an alternative, currently preferred design of the U-shaped binding spine of the invention with orthogonal or ninety (90°) degree walls with respect to the spine's base.

Figure 5 is an isometric, side view of the completely associated selected collection of sheet materials and binder assembly (including the plastic spine and exemplary, temporary, alternative guide member, if such are desired) inserted into the slot of an exemplary heating unit (drawn in phantom line) for heating the adhesive in the interior of the binding spine, causing it to flow and bind all of the individual sheets of material to the spine when it cools.

Exemplary Modes for Carrying Out the Invention

As can be seen in Figs. 1 & 2, the exemplary, simple, binding spine 10 of the currently preferred, exemplary embodiment of the present invention includes a body 11 having a base 12 and two, opposed, side walls 13. The side walls 13 and the base 12 form a "U" -shaped interior, which

"U"-shape could have either a flat base (bottom 12) , as illustrated or, for further example, a curved contour. The sheet materials or paper 30 to be bound are in use inserted or placed in this interior, ultimately to be bound to the spine 10 in a heat, binding step described more fully below in connection with Fig. 5.

Again, with reference to Figs. 1 & 2, the binding glue 14 is applied on the inside surface 65 of the base 12, preferably as a series of spaced, glue spots 14 along the length of the spine 10. Typically, the glue spots 14 are, for example, an eighth (1/8") of an inch in diameter, and are spaced such that there are between about fourteen and sixteen (14-16) glue spots 14 along a standard eleven inch (11") long spine 10. In this regard, the amount of glue used, as applied by the spot method, is significantly reduced from the amount that would be used if a continuous strip of thick-layer adhesive were applied instead.

In the preferred embodiment, a cool-melt glue 99 such as the Dexter Hysol Cool-Melt is used. This glue 99 starts to flow at an elevated temperature of approximately two hundred and seventy (270°F) degrees fahrenheit, relatively cooler than for conventional hot glues. After the heating step, the flowing cool-melt glue 99 solidifies, i.e., is no longer flowable, within only ten (10) seconds after heat is removed.

The first glue spot 14 is placed, for example, approxi¬ mately a half inch to about an inch (1/2" to 1") from the ends of the length of the spine 10, depending on whether a temporary, removable guide 90, 90 is used, as with a cover- less binding assembly. If this is the case, a pair of glue spots 15 is provided on each end of the spine 10, for the purpose of connecting the temporary, guide panels to the spine 10. Preferably, the glue spot 15 is made of non heat- flow adhesive or glue, or an adhesive heat-flowable at a temperature substantially higher than that of the series of cool-melt glue spots 14. During the heat and bind method, while the binding glue spots 14 melt and flow, the adhe¬ sive 15 and the connected panels remain undisturbed.

The binding spine 10 is preferably formed from extruded, re-enforced polypropylene material in a process described more fully below. Fig. 2-4 show cross-sections of alternative embodiments of the binding spine 10. In Fig. 2, typical, exemplary dimensions of the cross- section of a spine 10 for binding documents and reports are

- for the base, four hundredths (0.040") of an inch thick, with an outside, bottom edge 56 approximately two-tenths (0.200") of an inch long (i.e. wide) , and an inside or interior edge 55 of approximately twelve hun¬ dredths (0.120") of an inch long (i.e., wide) ,

- with each side wall 13, 13 being, for example, twenty-four hundredths (0.240") of an inch high measured from the bottom edge of the base and about four hundredths (0.040") of an inch thick, and

- an over-all width at its top, outside edges of twenty-six hundredths (0.260") of an inch.

In Fig. 3, typical, exemplary dimensions of the cross- section of a spine 10 for binding a thicker set of documents and reports are -

- for the base, five hundredths (0.050") of an inch thick, with an outside, bottom edge 66 approximately fifty-eights (0.580") of an inch long (i.e. wide) , and an inside or interior edge 65 of approximately forty-eight hun¬ dredths (0.480") of an inch long (i.e., wide) ,

- with each side wall 13, 13 being, for example, twenty-four hundredths (0.240") of an inch high measured from the bottom edge of the base and about five hundredths (0.050") of an inch thick, and

- an over-all width at its top, outside edges of sixty-four hundredths (0.640") of an inch.

The side walls 13, 13 are bent slightly away from the base 12. Typically, the angle 61 between the base 12 and each side wall 13, 13 is an obtuse angle of slightly less than a hundred (100°) degrees, just greater than a right, ninety degree (90°) angle. This angle 61 helps the spine 10 to accommodate for the sheets 30 such that, when the bound

book or bundle is opened, it folds back a bit more easily and can remain in an open, folded position with little difficulty. Moreover, the angle also enhances the spine's ability to bend when subjected to, for example, a load acting perpendicular to the outside surface 68 of the side wall 13, and then return to its original configuration when the load is released.

As can be seen in Figs. 2-4, the upper, inside corner of each side walls is beveled to a smooth, curved, camber 16 for preventing damage to said sheet materials. The side walls 13 preferably each form an obtuse angle of less than about one hundred and five (105°) degrees with the base, with one hundred degrees (100°) being exemplary.

However, when the spine 13 and any adjacent cover or outer sheet are of different colors, the gaps G (note separation distances between the vertical sides of the outer sheets 30 and the tips of the walls 13 in Fig. 3) caused by the outward angling of the walls 13 with respect to the bound sheets 30 are not aesthetically pleasing to some people. To avoid this, the side walls of the spine can be provided orthogonally to the base, i.e., at right angles, as shown in Fig. 4.

Fig. 4 thus illustrate yet another, exemplary variation to the cross-section of the spine 10. In this design, the side walls 13 make ninety (90°) degree angles to the base 12, that is, they are orthogonal to the base. As a result there are no significant gaps between the upper tips of the side walls 13 and the adjacent covers or outer pages 30. Variation in the dimensions of the "U" -shape profile of the spine may be changed to accommodate the different types and thicknesses of documents, sheets, etc . , to be bound. These variations are easily attained with the use of re-enforced polypropylene for the spine material. The manufacturability of this plastic is excellent, as it can be extruded into various shapes and dimensions appropriate for the present invention.

To illustrate the heating and binding method, reference is directed to Fig. 5, showing a cover-less spine 10. In this figure, temporary, removable guide sheets 22 are also used, if so desired. A selected collection of sheet materials 30, such as, for example, a collection of individual sheets of paper, with or without a user provided or selected, back and/or front, decorative and/or protective cover (s) , is inserted with their collective side edges inserted down into the open, "V" shaped entry formed by the side, guide panel 22 of the guide sheet (s) or member(s) 20. The side, wide panels in turn lead down into the interior of the "U" shaped spine 10.

Alternatively, a cover can be attached to the spine 10 itself, including hard covers comparable to a hard-bound book ( vis -a -vis a paper back book) . The spine 10 can be secured to the center area of any such attached cover with the cover coming up around its exterior surfaces.

Again referring back to Fig. 5, after the side edges of the selected collection of sheet materials 30 have been fully inserted into the interior of the spine 10 and straighten out (if such is needed) , the assemblage 10/20/30 is then inserted into the entry slot 41 of an appropriate heater 40, such as, for example, the UNIBIND ^® model "S50", or other appropriate heating unit, to heat the binding adhesive or series of glue spots 14 (Fig. 1) and cause the layer of adhesive to pool or puddle around the side edges of the inserted paper to be bound. This heating step is accom¬ plished by holding the assemblage by grasping the side panels 22 at both ends between the fingers of each hand and lowering the spine end into the slot 41 into which the combined materials 10/20/30 are inserted.

The spine end rests on a shelf (not illustrated) , and heat is applied by the electrically heated element 43 in the basic, extended body or housing 42 using, for example, an "on/off" switch (not illustrated) , with the bottom 21 of the guide member 20 located between the spine 10 and the heating

element 43. Power is supplied to the heating element 43 through the AC power plug 44.

The heat flows through the bottom 21 of the guide member to the series of glue spots 14 of the spine 10. Thus, it is desirable that the bottom 21 be flat and the material be of reasonably good heat conductive material.

In the heating step, as is well known, the glue spots 14 pools, puddles and flows up and around and between the side edges of the inserted papers 30. After the heater 40 is turned off and the assemblage 10/20/30 is allowed to appropriately cool, the now spread-out adhesive firmly binds the side edges of the inserted pages 30 to the interior of the binding spine 10, binding them all together. In this preferred embodiment, the cool-melt glue 14 solidi- fies in only about ten (10) seconds of cooling.

The special plastic spine 10 can be made in the following, exemplary process.

An extrusion die is produced to the dimensions for the desired cross-section size and configuration of the spine 10 from, for example, an eighth (1/8") of an inch to one and a half (1.5") inches in width. This is made using a standard work plan for an extrusion die, and the extrusion die is then fastened unto an appropriate extruder.

An appropriate mix of, for example, four (4%) percent Glass Load, Poly Olafin - polypropylene (re-enforced polypropylene) , and an appropriate Color agent for poly materials is prepared. This mixture will produce a high melt, high shear compound to which is added the appropriate color for the desired product. An exemplary re-enforced polypropylene usable in the present invention is that provided by Montell North America, Inc. under the "Astryn™ (BA16G) " brand, which, according to its published specification sheet is a fractional melt flow, UV-stabilized polypropylene copolymer with a good balance of colorability, impact resistance, flexibility and process- ability. Typical prior applications for this product have included extruded profiles and weatherstripping.

According to the published specification sheet, this re-enforced polypropylene has the further following physical characteristics or properties based on test:

Property Units ISO Method Typical Value

Molt Flow Rate g/10 min D1236 0.50

Specific Gravity D792 0.89

Hardness, D785 71.00 Rockwell R

Tensile Strength (MPa) psi D638 (27.5) @ Yield 4, 000

Mold Shrinkage (subject to mils/in Montell 14.00 variables)

Elongation @ % Montell 12.00 Yield

Flexural Modulus (MPa) psi D790 (1,000) (Tangent) 145,000

Heat Deflection Temperature @ (degrees C) D648 (48) 118 264 psi (1.82 degrees F MPa)

Notched Izod (J/m) D2S6 (690) 130 Impact lbs/in

Gardner Falling Dart Impact D3209 @ 23 degrees C (J) in-lbs (38) 320 @ -30 degrees C (J) in-lbs (10.8) 96

UV Resistance 3-5 years

The published "Astryn"™ spec, sheet noted that the property values shown above were measured, where applicable, on injection molded test specimens and were based on a limited number of tests and judged accordingly.

The extruder is turned on and the compound is brought up to, for example, three hundred and thirty (330°) degrees using a combination of applied heat and pressure. The part is then formed using air and water while passing the heated material through the extruder template.

The extruded, formed plastic material is cut to the desired length using, for example, a saw with a reverse rake tooth while supporting the extruded plastic material on all three sides in a molded table. Using, preferably a "cool melt" glue (e.g. "HYSOL" Cool Melt from Dexter HYSOL Engineering Adhesive) , a series of glue dots 14, preferably equal in size of diameter to the width of the spine back or base 13, is deposited on the interior bottom of the spine 10. The glue application preferably is followed with a steady jet of hot air to flatten the dome height of the glue dots. Also preferably, for example, three dots 15 of "hot melt" glue (e.g. "UNI- FLEX" 34-1211 from National Starch and Chemical Co., Bridgewater, NJ) are placed one in the center of the spine length and the other two spaced from the ends by, for example, one eighth (1/8") of an inch.

If such are desired as part of the spine 10, guide strip and tabs 200 are placed on, for example, an air cylinder or hydraulic press platen, with the plastic binder on top, and the press is then activated, producing the desired end product. Twenty-five (25) of such units can, for example, be nested, placed on a cardboard backing and shrink-wrapped for shipment.

If a leather textured look is desired for the exterior surfaces of the spine 10, a slightly unpolished surface can be left on the die with the mix of the compound used. It is noted that humidity can affect the mixed compound's reaction and, as is known in the art, must be taken into account to produce the desired end product . The foregoing exemplary dimensions and details in both structure, specific materials and methodology are, of course, subject to great variation.