Method for continuously attaching a primary substrate to a secondary substrate to form a product having indicia thereon

In one embodiment, a method of attaching one substrate to another substrate includes supplying a first substrate having an indicium thereon from a first source, supplying a second substrate from a second source, wherein the supplying is accomplished in a continuous manner, and curing the substrates until the substrates are bonded thereto to form a product. The method disclosed herein allows a fabric to be integrally bonded to either an elastomeric composition or a urethane composition utilizing a continuous process. The product includes indicium that identifies or conveys information about the product.

Not applicable

SEQUENTIAL LISTING

Not applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an apparatus and a continuous method of attaching a first substrate to second substrate, and more specifically an apparatus and a method of continuously attaching a fabric to an elastomer and/or a urethane composition to form a product, wherein the product includes indicia thereon.

2. Background of the Invention

Methods for attaching one substrate to another substrate typically involve molds that can only accommodate single-run or batch processing. For example, elastomer substrates normally require specialized processing conditions based on the properties of the elastomer. In some typical methods, an elastomer substrate is placed into a mold of the desired shape and size. A second substrate is inserted into the mold, applied to a top surface of the elastomer substrate, and then the mold is sealed or otherwise closed and heated. The finalized product is removed from the mold and a new elastomer substrate is placed into the mold. This process is repeated as desired. This system suffers from many drawbacks including the extensive physical labor involved in applying and removing the substrates and the overall time-consuming nature of the process. As a result, this method is expensive to use because of the single run nature.

Another known method to attach an elastomer to a substrate involves supplying an elastomer in the desired shape and size and separately supplying and attaching the second substrate in a separate step in the manufacturing process. An adhesive or other attaching agent is applied to a surface of the elastomer and the second substrate is placed onto the adhesive. In some cases, a press or clamp is used to secure the elastomer-adhesive-second substrate together until the bond is secure. This system includes a number of drawbacks as well. For example, the adhesive bond may degrade over time and may not be as strong as bonds formed by other methods, such as, for example, bonds formed by heating or vulcanization. Further, the steps to apply adhesive or other bonding material to attach the elastomer to the second substrate requires extra steps and equipment during the manufacturing process, which results in an increased cost to the consumer.

In many instances, a product is labeled or otherwise imprinted to designate information about the product such as manufacturer, patent number, place of origin, code date, and the like. Such labeling frequently occurs as a separate step after the manufacturing process. The labeling can be post-applied or printed onto the product using standard equipment as known in the art. Printing the product after the manufacturing process creates additional problems including increased cost to the consumer, transportation of the product from the manufacturing facility to the printing facility, and additional resources to accomplish product labeling. Frequently the product labeling process is bypassed because of the stringent requirements of commercial printers, for example, minimum quantities for print jobs. The commercial printing requirements frequently make such labeling cost-prohibitive.

It has been heretofore unknown how to attach a first substrate to an elastomer and/or a urethane composition in a continuous process involving vulcanization because of the difficulties of controlling the processing conditions. In instances where continuous processing has been attempted, the product that is made as a result of the processing may be deformed or may not include the desired properties, for example, surface properties, strength properties, and the like. It is also unknown how to label a product during the manufacturing process using the process described herein.

SUMMARY OF THE INVENTION

In one embodiment, a method of attaching two substrates includes supplying a first substrate from a first source, wherein the first substrate is a fabric having an indicium thereon. A second substrate is supplied from a second source and the substrates are cured until the substrates are bonded to each other to form a product, wherein the indicium is visible on the product.

In another embodiment, an apparatus for continuously attaching a first substrate to a second substrate comprises a first substrate supply source that continuously dispenses a first substrate onto a top surface of a second substrate, wherein the first substrate includes an indicium thereon. The apparatus also includes a second substrate supply source that continuously dispenses the second substrate onto a conveyor and a secondary conveyor system that presses the first substrate into the second substrate. A heating mechanism heats the first substrate and the second substrate, wherein the first substrate is vulcanized to the second substrate to form a product having a substantially smooth surface and the indicium is visible on the smooth surface.

In yet a different embodiment, a method of identifying a source of goods comprises the steps of providing a first substrate having an indicium, providing a second substrate comprising an elastomeric composition, and vulcanizing the first substrate to the second substrate to form a product, wherein the indicium is visible on the product to identify the source of the product.

Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1shows an embodiment of an attaching system50generally configured to attach a first substrate52to a second substrate54to form a substantially unitary product56. The system50operates in the direction indicated by arrow A in a substantially continuous manner. Specifically, the first and second substrates52,54are supplied and attached to each other continuously without stopping the process, with the exception of changing out the substrates and/or typical process stoppages such as maintenance and the like. The attaching system50includes a first substrate supply source58provided in the form of a first spool60and a second substrate supply source62provided in the form of a calendering system64. Although the first substrate supply source58is depicted as a spool60, the first substrate52can be supplied from other sources as known in the art.

The second substrate supply source62is in the form of a calendering system64and includes a plurality of rolls (not shown) configured in either an “L” or a “Z” configuration in a manner known in the art. The calendering system64applies heat and pressure to densify, smooth, or otherwise modify the properties of the second substrate54. The calendaring system64may apply further surface treatment to the second substrate54to enhance surface properties, adjust sheet thickness, and/or otherwise prepare the second substrate54for the attaching system50. Although a calendering system64is depicted, the second substrate54may be prepared for the attaching system50beforehand and thus, no calendering system64is needed. Further, the second substrate54may be supplied to the attaching system50in other ways such as using an extruder and the like.

As best seen inFIGS. 1 and 1A, the first substrate52is supplied from the first substrate supply source58as a thin strip in the form of a substantially rectangular braid66that includes a top surface68and a bottom surface70. The first substrate52is originally wound around the first spool60, wherein the bottom surface70contacts the first spool60or other braid66on the spool60and the top surface68is exposed to the surrounding environment. Although the first substrate52is supplied as a substantially flat, rectangular strip, the first substrate52could be supplied in other shapes and sizes including cylindrical, triangular, and/or any other compatible shapes known in the art. The thickness of the first substrate52may vary, but in a preferred embodiment, the first substrate52is between about 0.05 mm and about 50 mm thick, more preferably about 10 mm to about 30 mm thick, and most preferably about 15 mm thick. Preferably, the first substrate52is about 2.5 mm to about 250 mm wide, more preferably about 12 mm to about 75 mm wide, and most preferably about 20 mm wide.

The first substrate52preferably comprises fabric and/or fabric blends such as natural fibers, synthetic fibers, and/or any woven blends thereof. Specific kinds of fabric preferred for use in the attaching system50include polyester and/or cotton and the like. For example, any of the fabrics available from Shoefly Designs™ located in Hickory, N.C., are suitable for use as the first substrate52. One preferable first substrate52is similar to that of a substantially flat cotton shoelace.

The first substrate52also includes indicia80(shown inFIG. 1B), printed information, and/or other markings thereof. The indicia80may include information such as trade names, company names, product names, and the like. The indicia80may, alternatively or in addition to, be any symbol or character that conveys information. The indicia80may act as a source of the product56and/or act as a source of advertising or other information. The printed information80is preferably applied and/or is otherwise incorporated into the first substrate52on the top surface68of the first substrate52before entering the attaching system50. The indicia80are preferably a contrasting color from the first substrate52such that the indicia80is visible. The indicia80may be continuous or discrete and may comprise any number of indicia80. The indicia80allow the product56to provide a method of identifying a source the product56.

The first substrate52with pre-printed indicia80therein is supplied and a second substrate54is provided and comprises either an elastomeric composition or a urethane composition as described in more detail hereinbelow. The first substrate52and the second substrate54are vulcanized, cured, or otherwise attached to form the product56, wherein the pre-printed indicia80are visible on the product56to identify the source of the product56and/or to convey other information described herein.

Still referring toFIG. 1, the first substrate52optionally passes through a guiding mechanism in the form of a tape guide90. The tape guide90acts to properly align the first substrate52with a main conveyor100that runs throughout the length of the process. The tape guide90used in the attaching system50is one that is known in the art. Other guiding mechanisms may be used so long as the mechanism assists in properly aligning the first substrate52as it is being supplied to the main conveyor100. Alternatively, the attaching system50may operate without a tape guide90if the first substrate supply source58is adapted to supply and properly align the first substrate52directly onto the main conveyor100. Once the first substrate52passes through the tape guide90, the bottom surface70of the first substrate52is guided onto and contacts a top surface102of the second substrate54as the first substrate52is being supplied to the main conveyor100. The first and second substrates52,54are joined thereafter using the process as described in more detail hereinbelow. In some embodiments, multiple first substrates52are supplied into the attaching system50and may utilize a plurality of tape guides90to guide the substrates52individually onto the main conveyor100. The tape guide90is preferably adjustable such that it is easy for an operator of the attaching system50to adjust and move the tape guide90to an appropriate position, such as between manufacturing runs.

The second substrate54is supplied from the second substrate supply source62and is supplied onto the main conveyor100as an elastomeric composition110that includes the top surface102and a bottom surface114. The bottom surface114contacts the main conveyor100and is moved through the attaching system50in the direction indicated by arrow A. Although the second substrate54is depicted as a substantially flat mat, the second substrate54can be supplied in other shapes and sizes as known in the art. The thickness of the second substrate54may vary according to the desired product. In a preferred embodiment, the second substrate54is about 10 mm to about 500 mm thick and about 10 mm to about 500 mm wide.

The elastomeric composition110is preferably provided in a form that is initially uncured and provided in a substantially solid form. In a preferred embodiment, the composition generally comprises about 20% to about 40% rubber, about 40% to about 60% fillers, about 2% to about 10% process oil, and about 5% to about 15% other additives. One suitable composition is Kushon® brand rubber, which is available from the Griswold Corporation located in Moosup, Conn. Other suitable elastomeric compositions include a natural rubber and/or blends including neoprene, silicone, styrene-butadiene, nitrile blends, and the like. Suitable fillers for use in the elastomeric composition include clay, silica, blends thereof, and the like. Examples of other additives include blowing agents, activating agents, curing agents, and other additives known in the art.

Referring again toFIG. 1, a heating mechanism120in the form of a platen heating system is provided adjacent the main conveyor100to supply thermal energy to the second substrate54at a point B, which is adjacent the second substrate supply source62. The platen heating system operates to heat the second substrate54to the desired temperature for the curing process. In some embodiments, the heating mechanism120heats the second substrate54to a temperature of about 200° F. to about 400° F. such that the elastomeric composition becomes cured. The heating mechanism120is depicted adjacent a bottom surface122of the main conveyor100, but alternatively or additionally can be adjacent a top surface124of the main conveyor100such that the second substrate54is heated to the desired temperature. The second substrate54expands as the temperature is increased as the second substrate54moves throughout the attaching system50as described in more detail hereinbelow.

Although a platen heating system is discussed as a heating mechanism herein, other types of heating may be sufficient to heat the second substrate54to the desired temperature including gas heated ovens, microwaved heating, hot air blowers, and the like. Generally, the heating process takes between about 4 minutes and about 10 minutes, but varies according to a variety of factors including the exact composition of the elastomeric composition, the thickness of the second substrate54, the speed of the main conveyor100, and other process parameters as known in the art. A person having skill in the art should be able to choose a heating mechanism that heats the second substrate54to the desired temperature, which takes into account all of the pertinent manufacturing considerations.

Now turning to the attachment process, the bottom surface70of the first substrate52contacts the top surface102of the second substrate54at an area C adjacent a first drive roll130. A secondary conveyor system134comprises the first drive roll130and a second drive roll132with a secondary conveyor belt136attached thereto. The secondary conveyor system134is self-contained and separate from the main conveyor100and runs in a continuous manner. As the first and second substrates52,54pass under the first drive roll130and the secondary conveyor belt136, the substrates52,54are pressed together to form a unitary structure. The function of the secondary conveyor system134is to provide downward force on to the top surface68of the first substrate52to push the first substrate52into and below the top surface102of the second substrate54to form a substantially fiat top surface138of the finalized product56. After the first and second substrates52,54pass the first drive roll130, the product56enters a secondary heating area150to continue the attaching process.

The attaching process involves vulcanizing and/or curing the elastomer while the second substrate54expands into the first substrate52. As the substrates52,54undergo the vulcanization process, a substantially irreversible bond is formed to create the finished product56. In some preferred embodiments, the temperature and time for achieving vulcanization is generally between about 4 minutes to about 10 minutes at between about 200° F. and about 400° F. A vulcanized bond is formed between the first substrate52and the second substrate54, which is much more heat stable than bonds procured by, for example, adhesives used in prior art processes. Although specific parameters are given with respect to the vulcanization process described herein, one having ordinary skill in the art will understand how to adjust the process parameters (such as temperature) to achieve a particular bond quality desired for various different materials being utilized.

After the second substrate54is vulcanized with the first substrate52therein, the product56moves past the second drive roll132into a cooling zone, which is depicted as area D. During a cooling step, the cooling zone D allows the product56to cool down to approximately room temperature, which is about 20 to about 25 degrees Celsius. The cooling zone D may include cooling devices in the form of cooling cans, fans, water bottles, and/or other elements that help to facilitate the cooling process. Alternatively, the product56may proceed on the main conveyor100a length sufficient to cool the product56to an appropriate temperature without cooling devices for final processing. Depending on the cooling device(s) being utilized, cooling may be completed in less than a minute.

After the cooling step, the product56is collected onto a product roll160and is ready for final distribution. The product56may undergo additional processing steps prior to or after the collection such as cutting the product, imprinting additional surface markings, applying coatings, and the like. Other processing steps may be utilized as desired.

As shown inFIG. 1B, the final product56preferably includes the top surface138comprising the top surface68of the first substrate52that is flush with and forms a flat surface with the top surface102of the second substrate54. The product56further includes a bottom surface160that comprises the bottom surface114of the second substrate54. The final product56advantageously includes a flush top surface138so as to not disrupt the uniformity of the surface, which is a significant advantage over prior art products. Some minor imperfections may be visible on the top surface138because of the manufacturing process. The final product56may be used in a variety of manufactured goods including slip pads, yoga mats, mouse pads, and/or moving fabrics, in which items to be moved are protected with the final product56.

Another embodiment of an attaching system250is depicted inFIG. 2, which includes similar components as to those described with respect to the attaching system50described above with the exception of the differences noted hereinbelow. The attaching system250moves continuously in a direction as denoted by arrow M. A first substrate252is dispensed from a first substrate supply source254in the form of a spool256. The first substrate252is preferably a fabric and/or fabric blend with indicia as described previously herein, wherein the fabric includes a first side258and a second side260opposite the first side258.

A tape guide270may optionally be included to assist in guiding the first substrate252through the attaching system250. An idler roll272is preferably present in an area adjacent the tape guide270to guide a release liner274onto the second side260of the first substrate252. The release liner274provides a substantially stable surface in which the first substrate252can be supported thereon. The first substrate252travels through the attaching system250and approaches point N, which is where a second substrate280is supplied onto the first side258of the first substrate252.

The second substrate280is preferably supplied in liquid form and is preferably a urethane composition. The urethane composition generally comprises about 40% to about 70% polyols, about 15% to about 25% isocyanates, about 10% to about 20% fillers and about 1% to about 5% catalyst. A suitable urethane composition is available under the trade name Enlighten-u® from Griswold Corporation, Moosup, Conn.

The urethane composition is dispensed out of a dispensing tube290onto the first side258of the first substrate252. The dispensing tube290preferably dispenses the urethane composition at a speed between about 3 feet/min to about 40 feet/min. Although a dispensing tube is depicted, the urethane composition may be dispensed or supplied to the attaching system250through other mechanisms as known in the art. As the urethane composition is dispensed, the first substrate252with the release liner274on the second side260thereof and the urethane composition on the first side258travel in the direction M to move through the system to undergo the attaching process as described in more detail below.

A doctor knife300is disposed adjacent the dispensing tube290that forms the urethane composition into a thin layer that contacts the first substrate252as the urethane composition and first substrate252are moved through the attaching system250. The knife300is disposed about 0.5 mm to about 30 mm above the first side258of the substrate258such that a layer of the urethane composition is dispensed onto the first substrate252.

As the first substrate252and the urethane composition move past the knife300, a heating mechanism302in the form of a platen heating system is provided adjacent the first substrate252to supply thermal energy. Similar to the first attaching system50, the heating mechanism302heats the urethane composition to a temperature of about 200° F. to about 400° F. The urethane composition expands as the temperature is increased and the first substrate252is pressed into the expanded urethane composition during a curing process. As the urethane composition and the first substrate252go through the curing process, the first substrate252becomes embedded into the urethane composition thereby forming a substantially flat product304.

The product304moves away from the heating mechanism toward a cooling zone306. The cooling zone306allows the product304to cool down to approximately room temperature. The cooling zone306may include cooling devices in the form of cooling cans, fans and/or other blowing elements that help to facilitate the cooling process. Depending on the cooling device(s) being utilized, cooling may be done in less than a minute.

After exiting the cooling zone306, the product304is collected onto a product roll308and is ready for final distribution. The product304may undergo additional processing steps prior to or after the collection such as cutting the product, imprinting additional surface markings, applying coatings, and the like. Other processing steps may be utilized as desired.

As shown inFIG. 2B, the final product304includes the urethane composition280that surrounds the first substrate252and the release liner274on an opposing side thereof. The release liner274is adapted to be removed prior to the final product304being utilized. In some forms, the release liner274may be excluded from the process. A conveyor or other suitable mechanism may be employed to support the first substrate252and urethane composition as they are moved through the attaching system250.

In a preferred form, various components throughout the attaching systems50,250described herein are electrically connected to a controller180. The controller180sends operational parameters to the individual components with respect to speed of the conveyors and spools, temperature of the heating elements, and all other parameters needed to operate the system. The controller180can be any kind known in the art, but typically includes a computer and appropriate process control software and data and/or control connections to the components in a manner sufficient to control the systems50,250as described herein.

Other substrates may be used including other heat curable and/or thermoformable materials and other fabric-like materials, including other materials that exhibit sufficient properties to accept the heat curable and/or thermoformable materials.

In any of the embodiments herein, it is to be understood that a plurality of fabrics in varying shapes and sizes can be utilized in the attaching process at the same time, which results in a product having multiple fabric strips embedded therein. Further, other processing equipment may be utilized in addition to or in place of the various components described herein.

INDUSTRIAL APPLICABILITY

An apparatus and method for a continuous attaching system is described that overcomes numerous disadvantages disclosed in the prior art. The continuous method includes attaching a first fabric substrate having indicia thereon to a second substrate comprising either an elastomeric composition or a urethane composition. The first and second substrates are vulcanized to form a product having increased bond strength and stability.