GB2141376A - Apparatus for making sheet material - Google Patents

Abstract

An apparatus for making a sheet of material from a fiber textile-like mat comprises a press having a pair of movable belts 120, 122 having adjacent runs 125, 126 adapted to receive a mat 36 of fibers of thermoplastic material mixed with other fibers therebetween. The press has a compressing unit for compressing the mat between the adjacent runs of the belts to densify the mat. The press has a heating unit 116, for heating the mat between the adjacent runs of the belts, and a cooling unit 117, for cooling the mat between the adjacent runs of the belts after the mat has been heated and densified by the heating unit and the compressing unit. The heating unit and the compressing unit comprise a pair of platens 118, 119 of a first press 116 between which the runs 125, 126 of the belts are disposed. The cooling unit comprises a pair of platens 118, 119 of a second press 117 between which the runs 125, 126 of the belts are also disposed. <IMAGE>

Description

SPECIFICATION Method and apparatus for making a sheet of material This invention relates to an improved method and apparatus for making a sheet of material from a fiber textile-like mat means formed of fiber means mixed with fibers of thermoplastic material.

It is known in the art to provide a sheet of material having fiber means and thermoplastic means bonding the fiber means and the thermoplastic means together. For example, the thermoplastic means comprises a thermoplastic resin, such as polypropylene, and the fiber means comprises fibers of synthetic or natural origin, such as cellulose, fiberglass, etc., wherein the resulting sheet of material is densified under heat and pressure so as to be substantially flat while being adapted to be subsequently contoured or molded into a desired shape by heat and pressure. One such sheet of material is sold under the trade name or trademark "Azdel" by the Pittsburgh Plate Glass Company of Pittsburgh, Pennsylvania, and another such material is known as "Masonite".

It is believed that the apparatus for producing the aforementioned prior known sheets of material each comprises an arrangement wherein the fiber means and theromoplastic means are carried between adjacent runs of two endless belts that pass through a first section of the apparatus wherein the thermoplastic means and fiber means are heated and compressed between the adjacent runs of the belts and then pass through another section of the apparatus where the densified material is cooled so as to set the melted thermoplastic means to produce the substantially rigid sheet of material that exits from between the two belts. However, it is not known how the heating section of such an arrangement is provided, or how the cooling section thereof is provided.

It is also believed that neither of these two prior known sheets of material are formed by having the thermoplastic means thereof initially in fiber form as required by this invention.

However, it is known to applicant to form the thermoplastic material in fiber form and to use belt means in forming the sheet of material. For example, see the co-pending Allen Industries patent application, U.S. Serial No. 499,605, filed 31 May 1983, and Figures 1-24 of this application, wherein an apparatus is disclosed for making a sheet of material from a fiber textile-like mat means which is made of fiber means mixed with fibers of thermoplastic material and is subject to heat and pressure by press means to melt the thermoplastic fibers and densify the mat means so that upon subsequent cooling of the thermoplastic material in the densified mat means the cooled thermoplastic material sets and thus causes the cooled densified mat means to be a substantially rigid sheet of material.The press means comprises a pair of movable belt means having adjacent runs adapted to receive the mat means therebetween. The press means has compressing means for compressing the mat means between the adjacent runs of the belts to densify the mat means. The press means has heating means for heating the mat means between the adjacent runs of the belts. The press means also has cooling means for cooling the mat means between the adjacent runs of the belts after the mat means has been heated and densified by the heating means and the compressing means.

It is one feature of this invention to provide an improved method and apparatus for making a sheet of material having fiber means and thermoplastic means bonding the fiber means and the thermoplastic means together, wherein the thermoplastic means comprise fibers of thermoplastic material.

In particular, it was found according to the teachings of the invention of the aforementioned copending patent application that the thermoplastic means can comprise fibers of thermoplastic material that can be mixed with the other fiber means to provide a fiber textile-like mat means that can be subject to heat and pressure to melt the thermoplastic fibers and densify the mat means so that upon subsequent cooling of the thermoplastic material in the mat means, the cooled theremoplastic material sets and thus causes the cooled densified mat means to be a substantially rigid sheet of material that can be subsequently reheated and deformed under pressure to provide a contoured sheet of material that has many uses, such as being utilized to form various components of a transportation vehicle, as will be apparent hereinafter.

For example, it has been found according to the teachings of that invention that such fibers of thermoplastic material can comprise waste fibers of polypropylene, and the other fiber means can comprise recycled textile fibers of synthetic or natural materials or combinations thereof. When mixed in a preferred ratio of between 55% to 65% polypropylene fibers and the remaining percent being the recycled fibers, such fibers can be readily formed into a flat moldable textile-like mat means by conventional textile equipment, such as garnett machines or airlay machines.Such fiber textile-like mat means can be subsequently placed in a press with heated platens where the platens compress the mat means to the desired thickness while the polypropylene fibers thereof melt and flow throughout the resulting densified sheet of material to bind all of the other fibers together, so that when the densified sheet of material is subsequently cooled, the same can be removed from the press and can be cut into rectangular sizes or other shapes as required for further processing thereof into final contoured products.

It was also disclosed in the aforementioned copending patent application that an improved method and apparatus can be provided for making the aforementioned sheet of material if movable belts are utilized in serial manner.

For example, one embodiment of that application provides an apparatus for making a sheet of material from a fiber textile-like mat means which is made of fiber means mixed with fibers of thermoplastic material and is subject to heat and pressure by press means to meltthe thermoplastic fibers and densify the mat so that upon subsequent cooling of the thermoplastic mateial in the densified mat means the cooled thermoplastic material sets and thus causes the cooled densified mat means to be a substantially rigid sheet of material. The press means comprises a pair of movable belt means having adjacent runs adapted to receive the mat means therebetween. The press means has compressing means for compressing the mat means between the adjacent run of the belts to densify the mat means.The press means has heating means for heating the mat between the adjacent runs of the belts. The press means has cooling means for cooling the mat means between the adjacent runs of the belts after the mat means has been heated and densified by the heating means and the compressing means.

However, it was found according to the teachings of this invention that such an apparatus would be relatively expensive, and therefore it is believed according to the teachings of this invention that the belt means can be utilized with a pair of presses to form the sheet of material without requiring relatively expensive equipment.

For example, one embodiment of this invention provides an apparatus for making a sheet of material from a fiber textile-like mat means which is made of fiber means mixed with fibers of thermoplastic material and is subject to heat and pressure by press means to melt the thermoplastic fibers and densify the mat means so that upon subsequent cooling of the thermoplastic material in the densified mat means the cooled thermoplastic material sets and thus causes the cooled densified mat means to be a substantially rigid sheet of material. The press means comprises a pair of movable belt means having adjacent runs adapted to receive the mat means therebetween. The press means has compressing means for compressing the mat means between the adjacent runs of the belts to densify the mat means. The press means has heating means for heating the mat means between the adjacent runs of the belts.The press means also has cooling means for cooling the mat means between the adjacent runs of the belts after the mat means has been heated and densified by the heating means and the compressing means. The heating means and the compressing means comprise a pair of platens of a first press between which the runs of the belts are disposed. The cooling means comprises a pair of platens of a second press between which the runs of the belts are also disposed.

Accordingly, it is an object of this invention to provide an improved apparatus for making a sheet of material from a fiber textile-like mat means of fiber means mixed with fibers of thermoplastic material, the apparatus of this invention having one or more of the novel features of this invention as set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved method for making a sheet of material from a fiber textile-like mat means of fiber means mixed with fibers of thermoplastic material, the method of this invention having one or more of the novel features of this invention as set forth above or hereinafter shown or described.

The features of the invention, and its technical advantages, can be seen from the following description of embodiments together with the claims and the accompanying drawings, in which: Figure 1 is a schematic view illustrating a method and apparatus known to applicant for forming a sheet of material and subsequently reforming that sheet of material into a contoured product; Figure 2 is an enlarged fragmentary crosssectional view of the fiber textile-like mat means which is being formed in the method and apparatus of Figure 1; Figure 3 is a fragmentary cross-sectional view of the improved sheet of material which has been made by the method and apparatus of Figure 1;; Figure 4 is a perspective view of one example of a contoured product that can be formed from the sheet of material made by the method and apparatus of Figure 1, the product of Figure 4 comprising a door and quarter interior trim panel for a transportation vehicle made by a compression molding process; Figure 5 is a perspective view of a transportation rear package tray made from the sheet of material of Figure 3 by a compression or flow molding process; Figure 6 is a perspective view of a rear hatch cover for a three-door transportation vehicle, the cover being made from the sheet of material of Figure 3 by a compression or flow molding process; Figure 7 is a perspective view of a transportation fender liner or splash shield made from the sheet of material of Figure 3 by a compression molding process;; Figure 8 is a perspective view of a transportation vehicle rear deck lid, lift gate, or hood liner panel made from the sheet of material of Figure 3 by a compression molding process; Figure 9 is a perspective view of a transportation vehicle heater or air-conditioning ductwork made from the sheet of material of Figure 3 by a compression molding process; Figure 10 is a perspective view of a transportation vehicle seat back foundation panel made from the sheet of material of Figure 3 by a compression molding process; Figure 11 is a perspective view of a transportation vehicle l.P. close out cover made from the sheet of material of Figure 3 by a compression or flow molding process; Figure 12 is a perspective view of a transportation vehicle trunk liner made from the sheet of material of Figure 3 by a compression molding process; ; Figure 13 is a perspective view of a transportation vehicle wiring harness protective cover made the sheet of material of Figure 3 by a compression molding process; Figure 14 is a perspective view of a transportation vehicle formed headlinerfoundation panel made from the sheet of material of Figure 3 by a compression molding process; Figure 15 is a perspective view of a transportation vehicle battery case made from the sheet of material of Figure 3 by a flow molding process; Figure 16 is a perspective view of a transportation vehicle electrical component cover made from the sheet of material of Figure 3 by a flow molding process; Figure 17 is a perspective view of a transportation vehicle blower housing made from the sheet of material of Figure 3 by a compression or flow molding process;; Figure 18 is a perspective view of a transportation vehicle air cleaner cover made from the sheet of material of Figure 3 by a compression or flow molding process; Figure 19 is a perspective view of a transportation vehicle fan shroud made from the sheet of material of Figure 3 by a compression molding process; Figure 20 is a perspective view of a transportation vehicle belt or chain guard made from the sheet of material of Figure 3 by a compression or flow molding process; Figure 21 is a perspective and schematic view illustrating a compression or flow molding press apparatus for forming the sheets of material illustrated in Figure 3 into various contoured products, such as the contoured products illustrated in Figures 4-20; Figure 22 is an exploded perspective view illustrating the two die members of the press of Figure 21;; Figure 23 is a schematic cross-sectional view of a method and apparatus known to applicant for continuously forming the sheets of material of Figure 3; Figure 24 is a fragmentary enlarged crosssectional view of one of the roller means, and a center support therefor, of the apparatus of Figure 23; Figure 25 is a fragmentary schematic side view of the method and apparatus of this invention for forming the sheet of material of Figure 3.

Figure 26 is a fragmentary enlarged side view of a portion of the apparatus of Figure 25 with the die members thereof in one operating position thereof; and Figure 27 is a view similar to Figure 26 and illustrates the die members of the apparatus of Figure 25 in another operating position thereof.

While the various features of this invention are hereinafter illustrated and described as being particularly adapted to provide a sheet of material for forming contoured products for a transportation vehicle, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide sheets of material for other products as desired.

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate some of the wide variety of uses of this invention.

Also, while it is preferred to utilize recycled and/or waste fibers of either natural or synthetic materials to form a sheet of material as hereinafter set forth because of the lower cost of such fibers, it is to be understood that some or all of the various fibers utilized to form the sheet of material can be virgin if desired.

As previously stated, it is a feature of this invention to provide an improved method and apparatus for making a sheet of material that is disclosed and claimed in the co-pending Allen Industries patent application, U.S. Serial No. 499,605, filed 31 May 1983, and therefore it is believed that in order to fully understand the features of this invention, a full disclosure of the features of such of such co-pending patent application is desirable. Thus, Figures 1-24 comprise part of the subject matter of such co pending patent application, and will now be described.

As illustrated in Figure 1, the method and apparatus of the co-pending application (for forming a substantially flat rigid sheet of material that is generally indicated by the reference numeral 30 in Figure 3) is generally indicated by the reference numeral 31 in Figure 1, and comprises a fiber textile-like mat forming section 32, a heat and pressure mat densifying section 33, and a forming press section 34.

While the fiber textile-like mat forming section 32 can comprise any suitable equipment for receiving a volume of blended fibers, as represented by the reference numeral 35 in Figure 1, and for forming the same into a relatively thick fiber textile-like mat means 36, as illustrated in Figures 1 and 2, the apparatus 32 can comprise conventional textile equipment, such as one or more garnetting machines or one or more airlay machines, whereby the blended fibers 35 are layered or folded into the relatively thick fiber textile-like mat means 36, which has a thickness represented by the reference numeral 37 in Figure 2, such as between 12 and 18 inches thick. However, it is to be understood that the fiber textile-like mat means 36 could have a thickness greater than 18 inches, or could be less than 12 inches, as desired.The method and apparatus 31 of Figure 1 takes the fiber textile-like mat means 36, and by means of heat and pressure compresses and densifies the same in a manner hereinafter set forth to form the relatively flat sheet of material that is generally indicated by the reference numeral 30 in Figures 1 and 3, and has a thickness represented by the reference numeral 38 in Figure 3, such as between 0.08 of an inch and 0.15 of an inch thick.

The densifying apparatus 33 can comprise a conventional heated press means wherein the fiber mat 36 is heated and compressed between opposed platens of the press to form the mat means 36 into the densified sheet means 30 of Figure 3 in a manner hereinafter set forth, and then permits the densified sheet means 30 to cool so that the same can be removed from the press in a substantially rigid sheet-like form.

It is believed that in order to produce such sheet means 30 in a continuous manner, the densifying section 33 can comprise the method and apparatus 39 which is illustrated schemcatically in Figures 23 and 24, and which will be hereinafter described.

However, it is also believed that the densifying section 33 can comprise the method and apparatus 40 of this invention, which is illustrated schematically in Figures 25-27, and which will be hereinafter described.

In any event, it can be seen that the sheet of material 30 can be fed to a press forming section 34 to form a particular contoured product that is generally indicated by the reference numeral 41 in Figure 1 and comprises a transportation vehicle trim panel that is best illustrated in Figure 4. However, it is to be understood that the press section 34 can produce other contoured products, such as illustrated in Figures 5-20, as will be described hereinafter, as well as entirely different products than products for the transportation vehicle field.

While any suitable press apparatus can be utilized for the forming press section 34 of the method and apparatus 31, one typical arrangement is generally indicated by the reference numeral 42 in Figures 21 and 22, and will be hereinafter described.

As previously stated, a plurality of fiber means 43 and fibers 44 of thermoplastic material are blended together in any suitable apparatus and are fed by the supply means 35 to the fiber textile mat making means 32 to produce the fiber textile-like mat means 36 having the thickness 37 previously. While the fibers 44 of thermoplastic material can comprise any suitable thermoplastic material, as will be apparent hereinafter, it has been found that the same can comprise polypropylene and can be either virgin or waste fibers, such as from carpeting and the like, or various combinations thereof, and can be blended with the fiber means 43, which can comprise either virgin fibers or recycled fibers of any suitable natural or synthetic material or combinations thereof, such as recycled textile fibers known as "shoddy".As previously stated, the fibers 44 of thermoplastic material can comprise any suitable percent of the total volume of fibers 44 and fiber means 43, and when the fibers 44 are polypropylene the same can comprise between 55% and 65% of the total volume.

Also, when some of the fiber means 43 comprise fibers of fibreglass, the fiberglass can comprise up to a total of approximately 20% of the volume of the fiber means 43.

In any event, the fiber textile-like mat means forming apparatus 32 causes the fiber means 43 and fibers 44to be formed into the fiber textile-like mat means 36, which in the press 33 is formed into the sheet of material 30 by having the thermoplastic fibers 44 melted and densified with the fiber means 43 to produce the sheet 30 of the thickness 38 of approximately 0.08 of an inch to approximately 0.15 of an inch thick.

The thus formed sheets 30 can be trimmed and cut to size to form substantially rectangular panels that can be fed to the press forming section 34 to form a contoured shape therefrom for a particular product.

For example, reference is now made to Figures 21 and 22, wherein the press arrangement 42 comprises a stack 45 of sheets 30 which are each preheated in a heating oven 46 at a temperature which softens the sheets 30 but does not approach the melting point of the polypropylene thereof. For example, the oven 46 can heat the sheets 30 to approximately 4250 F. As the heated sheets 30 are serially discharged from the oven, each sheet 30 is placed in a press 47 between the die faces 48 and 49 of a pair of cooperating dies 50 and 51 thereof which are closed to shape the sheet 30 therebetween in a conventional manner.

For example, when the press 47 is to be utilized in a compression molding operation, the press can exert pressures between 200 to 500 psi, and can have the dies 50 and 51 water cooled to a nominal temperature of approximately 1000 F. to dissipate the residual heat from the hot plastic sheet 30. Cooling time in the closed die or press 47 necessary to cool the thus formed thermoplastic sheet 30 can vary from approximately 10 seconds to approximately 25 seconds, at which time the completed part 41 is removed therefrom.

If desired, a trim operation can complete the molding phase of the part 41.

Should the press 47 be a flow molding press, the heated sheet 30 is compressed between the dies 50 and 51 under pressures of approximately 2,000 psi, so that the material of the sheet 30 flows to fill the mold cavity provided between the dies 50 and 51 and to thereby be shaped into the desired configuration for the final product 41. A cooling period of approximately 20 seconds to 30 seconds may be required before the part 41 can be removed from the dies 50 and 51, the dies 50 and 51 in the flow molding process are also water cooled to approxi mately 1000 F. to dissipate the residual heat from the plastic sheet 30. With the flow molding process, and with proper die design, there should be little or possibly no flash to remove from the finished molded product 41.

Therefore, it can be seen that the method and apparatus 31 is adapted to produce a substantially flat thermoplastic sheet 30 of a given density or densities with the capability of thereafter being subject to post compression molding in a set of matched metal dies,orto postflowmolding under high pressure in a set of matched metal dies, to form a desired product.

While it has been found that the final product is particularly adapted for the transportation industry, it is to be understood that there are other products for which the sheet 30 can be contoured to form a desired final product.

Nevertheless, it can readily be seen in Figure 4 that one such product that the method and apparatus 31 can produce from the sheet of material 30 Figure 3 is a transportation vehicle interior trim panel 41, and the same can be formed by a compression molding process as previously set forth. Obviousl, the trim panel 41 of Figure 4 could be any formed foundation panel such as a door and quarter interior trim panel, as desired.

As illustrated in Figure 5, the product formed from the sheet of material 30 of Figure 3 can comprise a transportation rear package tray 52 that can be formed from the sheet 30 of Figure 3 by a compression or flow molding process as previously described.

As illustrated in Figure 6, the sheet 30 of Figure 3 can be formed by a compression or flow molding process as previously described into a rear hatch cover 53, such as for a three-door transportation vehicle.

As illustrated in Figure 7, the sheet of material 30 of Figure 3 can be formed by a compression molding process into a fender liner or splash shield 54 for a transportation vehicle or the like.

As illustrated in Figure 8, the sheet of material 30 of Figure 3 can be formed by a compression molding process as previously described into a rear deck lid, lift gate, or hood inner panel 55 for a transportation vehicle or the like.

As illustrated in Figure 9, the sheet of material 30 of Figure 3 can be formed by a compression molding process as previously described into a heating or air-conditioning duct work 56 for a transportation vehicle or the like.

As illustrated in Figure 10, the sheet of material 30 of Figure 3 can be formed by a compression molding process as previously described into a seat back foundation panel 57 for a transportation vehicle or the like.

As illustrated in Figure 11, the sheet of material 30 of Figure 3 can be formed by a compression or flow molding process as previously described into an l.P.

close-out cover 58 for transportation vehicle or the like.

As illustrated in Figure 12, the sheet of material 30 of Figure 3 can be formed by a compression molding process as previously described into a trunk liner 59 for a transportation vehicle or the like.

As illustrated in Figure 13, the sheet of material 30 of Figure 3 can be formed by a compression molding process as previously described into a wiring harness protective cover 60 for a transportation vehicle or the like.

As illustrated in Figure 14, the sheet of material 30 of Figure 3 can be formed by a compression molding process as previously described into a formed headliner foundation panel 61 for a transportation vehicle or the like.

As illustrated in Figure 15, the sheet of material 30 of Figure 3 can be formed by a flow molding process as previously described into a battery case 62 for a transportation vehicle or the like.

As illustrated in Figure 16, the sheet of material 30 of Figure 3 can be formed by a flow molding process as previously described into an electrical component cover 63 for a transportation vehicle or the like.

As illustrated in Figure 17, the sheet of material 30 of Figure 3 can be formed by a compression or flow molding process into a blower 64 for a transportation vehicle or the like.

As illustrated in Figure 18, the sheet of material 30 of Figure 3 can be formed by a compression or flow molding process as previously described into an air cleaner cover 65 for a transportation vehicle or the like.

As illustrated in Figure 19, the sheet of material 30 of Figure 3 can be formed by a compression molding process as previously described into a fan shroud 66 for a transportation vehicle or the like.

As illustrated in Figure 20, the sheet of material 30 of Figure 3 can be formed by a compression or flow molding process as previously described into a belt or chain guard 67 for a transportation vehicle or the like.

Obviously, there are other products for a transportation vehicle that the sheet of material 30 can form by a compression or flow molding process as previously described, such as non-conductive housings, glove boxes, inner panels, etc.

Therefore, it is readily apparent that the press section 34 of the method and apparatus 31 can be utilized to form the sheet of material 30 into any desired contoured product, whether for the transportation field or for other fields, in the manner previously set forth forthe method and apparatus 42 of Figures 21 and 22.

Thus, it can be seen that the invention of Figures 1-22 not only provides an improved sheet of material having fiber means and thermoplastic means bond ing the fiber means and thermoplastic means together, and a method of making the same, but also that invention provides an improved contoured sheet of such material, wherein the contoured sheet of material comprises a shaped product.

For example, the method of that invention is adapted to make a sheet of material 30 having fiber means 43 and thermoplastic means 44 bonding the fiber means 43 and thermoplastic means 44 together, the method comprising the steps of forming the thermoplastic means 44 to comprise fibers 44 of thermoplastic material, mixing the fibers 44 with the fiber means 43 with means 32. to provide a fiber textile-like mat means 36, applying heat and pressure to the mat means 36 with means 33 to melt the thermoplastic fibers 44 and densify the mat means 36, and then cooling the thermoplastic material 44 in the densified mat means so that the cooled thermoplastic material 44 sets and causes the cooled densified mat means 30 to be a substantially rigid sheet of material 30.Such sheet of material 30 can then be heated and shaped between a pair of dies by means 34 to produce a contoured sheet of material that comprises a desired shaped product.

In one example of that invention, the sheet of material 30 was formed from approximately 60% fibers 44 of polypropylene, and approximately 40% textile fibers 43, with the resulting sheet 30 having a thickness of approximately 0.080 of an inch. Such sheet 30 has a flexural strength (ASTM D790) of approximately 6,619 psi and a tensile strength (ASTM D638) of approximately 4,621 psi with a stiffness at 1/4 of an inch of approximately 1.50 Ibs.

and at 1/2 of an inch of approximately 3.00 Ibs., the sheet 30 having a specific gravity of approximately 0.94.

While the fibers 44 of thermoplastic material and the fiber means 43 can be of any suitable length, the same can be anywhere from approximately 1/2 inch to approximately 6 inches in length. However, it is to be understood that any desired length fiber means can be utilized.

As previously stated, the densifying apparatus 33 of the method and apparatus 31 of Figure 1 can comprise the method and apparatus 39 that is illustrated in Figures 23 and 24; such method and apparatus 39 will now be described. However, while the method and apparatus 39 is disclosed in the aforementioned co-pending patent application, the method and apparatus 39 comprises the sole invention of Thomas E. Lohr and is disclosed and claimed in the co-pending Allen Industries patent application, U.S. Serial NO.499,604, filed 31 May 1983.

The method and apparatus 39 illustrated in Figures 23 and 24 comprises a frame means 68 which carries a chamber defining means 69 that has a heating section 70 and a cooling section 71 which are separated from each other by a wall means 72 through which a lower run 73 and an upper run 74 of a pair of continuous or endless belts 75 and 76 of metallic material can pass in parallel relation from left to right in Figure 23, the left hand end of the heating chamber 70 also having a wall means 77 separating the chamber 70 from an infeed area 78, while the right hand end of the cooling chamber 71 has a wall means 79 that separates the cooling chamber 71 from an out feed area 80.

The belts 75 and 76 can each comprise a steel belt that is approximately 0.048 of an inch thick and approximately 70 inches wide, the belts 75 and 76 each having a length to accommodate the structure 69, as will be apparent hereinafter.

The upper belt 75 is fed around an in feed roller 81 and an outfeed roller 82, while the lower belt 76 is disposed around an in feed roller 83 and an out feed roller 84, so that the runs 73 and 74 of the belts 75 and 76 are disposed substantially in parallel relation, and respectively pass between an upper row 85 of a plurality of rollers 86, and a lower row 87 of a plurality of rollers 88, that tend to hold the belt runs 73 and 74 in parallel relation to each other and at a distance which will effectively and completely densify the fiber textile-like mat means 36 that is being fed in between the belts 75 and 76 by a feeding conveyor means that is generally indicated by the reference numeral 89 in Figure 23.

While the chamber means 69 can have any suitable dimensions, it is believed that the same can have the heating section 70 thereof of approximately 50 feet in length, and the cooling section 71 of approximately 30 feet in length, whereby the number of rollers 86 and 88 could comprise approximately 900 rollers, each having an outside diameter of approximately 1.9 inches, a length of approximately 70 inches, and be spaced apart on approximately 2.4 inch centers.

In order to prevent deflection of the rollers 86 and 88, a central T-shaped support 90 can be disposed adjacent the medial portion of the upper row 85 of rollers 86, while a similarT-shaped support 91 will be disposed adjcaentthe medical portion of the lower set 87 of rollers 88, with approximately a 0.020 of an inch clearance therebetween to tend to prevent the respective rollers 86 and 88 from deflecting upwardly or downwardly under the pressure caused by compressing the mat means 36 between the runs 73 and 74 of the belts 75 and 76; supports 90 and 91 are at least located in the heating section 70 of the apparatus 39.

Each roller 86 and 88 has its opposed ends respectively mounted in suitable bearing means 92 carried by the chamber defining means 69 of the frame means 68, as illustrated in Figure 24.

The heating section 70 of the chamber defining means 69 can be heated with a gas fired heat exchanger blower system that is generally indicated by the reference numeral 93 in Figure 23 and can be so arranged that the same will tend to preheat the upper run 94 of the upper belt 75 as well as the lower run 95 of the lower belt 76 as the same are brought back to the respective in feed rollers 81 and 83 from the cooling section 71; the upper run 94 of the upper belt 75 is supported by upper rollers 96, while the lower run 95 of the lower belt 76 is supported on lower rollers 97.

In this manner, the upper run 94 of the upper belt 75, and the lower run 95 of the lower belt 76, are suitably preheated so that by the time the same come together at the nip area 98 between the in feed rollers 81 and 83, as illustrated in Figure 23, the belts 75 and 76 begin to melt the thermoplastic material in the fiber textile-like mat means 36 as the same is compressed between the in feed rollers 81 and 83; the runs 73 and 74 of the belts 75 and 76 maintain a compressive force agaist the fiber textile-like mat means 36 in the heating section 70 so as to insure that substantially all of the thermoplastic material thereof is melted and compressed with the remain ing fiber means 43 to form the substantially flat sheet 30 in a continuous manner by the time the sheet 30 exits the heating chamber 70 through the divider wall means 72.

When the sheet means 30 and belt means 75 and 76 reach the cooling chamber 71, the lower run 73 of the upper belt 75, and the upper run 74 of the lower belt 76, are respectively cooled by water spraying means 99 which are fed by a pump 100, the water being cooled by a chiller 101 in a manner conventional in the art.

The cooling chamber 71 has a suitable reservoir chamber 102 for receiving the water that has been utilized to chill the belts 75 and 76 so as to return to the pump 100 through a connecting pipe 103.

In this manner, the heating chamber 70 of the apparatus 39 can produce a temperature of approximately 420 F., which will be sufficient to cause the polypropylene fibers 44 to melt and fuse with the other fiber particles 43 into a homogeneous blended material or sheet 30, while the cooling section 71 can "chill" or reduce the temperature of the belts 75 and 76, as well as the material 30 therebetween, to approximately 130 F maximum, so that the chilling "gels" the thermoplastic material of the sheet 30 to set the same and enable it to "release" from the steel belts 75 and 76 so as to pass out of the nip means 104 of the exit roller means 82 and 84 as illustrated in Figure 23 to be fed on a suitable conveyor means 105 to any desired area, such as to a suitable apparatus that will, by means of edge shears and the like, fix the finish width of the sheet, with the sheet subsequently being passed through squaring shears where it can be cut into the desired lengths.

Therefore, it can be seen that in the operation of the apparatus 39 illustrated in Figure 23, the belts 75 and 76 can be driven continuously by the entrance rollers 81 and 83 and exit rollers 82 and 84, so that the runs 73 and 74 thereof move substantially in unison from left to right and carry the fiber textilelike mat means 36 therebetween, which is compressed by the entrance roller means 81 and 83 and backup rollers 86 and 88 in such a manner that in the heating section 70 of the apparatus 39, the fibers 44 of thermoplastic material are sufficiently melted, and the fiber mat 36 is sufficiently densified, so that the thickness thereof is reduced to the desired thickness for the resulting sheet 30, which will be chilled in the cooling section 71 to a temperature thereof that causes the thermoplastic material to set, and also permits the resulting sheet to release from the belts 75 and 76, so that the same can pass onto the conveyor means 105 for further processing thereof as previously set forth.

As previously started, it is believed that the apparatus and method 40 of this invention as illustrated in Figures 25-27 can be utilized for the densifying apparatus 33 of the method and apparatus 31 of Figure 1; the apparatus and method 40 will now be described.

As illustrated in Figure 25, a conveyor means 110 is arranged in such a way that the upper run 111 thereof is adapted to have the fiber textile-like mat means 36 formed thereon by a pair of garnetting machines 112; the fiber mat means 36 is fed through a pair of rollers 113 into a compensating area 114 of the apparatus 40 for a purpose as will be apparent hereinafter.

The densifying area 115 includes a pair of presses that are generally indicated by the reference numerals 116 and 117 in Figure 25, each having an upper platen 118 and a lower platen 119; the press 116 has the platens 118 and 119 thereof heated, whereas the press 117 has the platens 118 and 119 thereof cooled, such as by a refrigerated water or other suitable coolant being passed through the platens 118 and 119 thereof.

A pair of endless belts 120 and 122 are respectively guided by suitable roller means 123 and 124, so that a lower run 125 of the upper belt 120 joins in parallel relation with the upper run 126 of the lower belt 122 to convey the fiber textile-like mat means 36 through the presses 116 and 117, as illustrated in Figures 25-27.

While the belts 120 ands 122 can be formed of any suitable material, it is believed that the same can be formed of woven fiberglass which is impregnated with Teflon (RTM) so as to function in a manner now to be described.

Suitable drive mechanism and timing mechanism (not shown) are provided for intermittently moving the belts 120 and 122 in such a manner that the same are adapted to feed a certain amount of the fiber textile-like material 36 between the spaced apart platens 118 and 119 of the heated press 116 at the same time that a completed section of the densified mat means 30 is being indexed by the belts 120 and 122 between the open platens 118 and 119 of the cooling press means 117, as illustrated in Figure 26.

At this time, movement of the belts 120 and 122 is stopped and the platens 118 and 119 of the heating press means 116 are brought toward each other in the manner illustrated in Figure 27 to heat and densify the fiber textile-like mat means 36 disposed therebetween in the manner illustrated in Figure 27, while the platens 118 and 119 of the press means 117 are likewise and simultaneously brought toward each other in the manner illustrated in Figure 27 to chill the section of the densified mat means 36 that has been indexed therebetween, so that the cooled platens 118 and 119 will set the thermoplastic material thereof as well as permit the formed sheet means 30 to release from the belts 120 and 122 when the same is subsequently indexed out from between the runs 125 and 126 of the belts 120 and 122 to the right as illustrated in Figure 25.At this time, suitable cutting apparatus as well as trimming apparatus 127 can be utilized to cut the formed sheet means 30 into individual sheets, as generally indicated by the reference numeral 128 in Figure 25.

After a certain dwell time, such as 55 seconds, for having the platens 118 and 119 of the presses 116 and 117 closed, the upper platens 118 are moved away from the lower platens 119, as illustrated in Figure 25, so thatthe belt means 120 and 122 can again index their respective runs 125 and 126 to the right in Figure 25 to bring a sufficient quantity of undensified fiber textile-like mat means 36 between the platens 118 and 119 of the press 116, while the previously densified section of the fiber mat means 30 is indexed between the spaced apart platens 118 and 119 of the chilling press means 117. Such indexing time can be approximately 3 seconds.

Thus, it can be seen that during this intermittent operation of the presses 116 and 117, the garnetting machines 112 can continuously form the mat means 36, as the same will accumulate in the compensating area 114, so that there will be a sufficient quantity thereof to be indexed between the belts 120 and 122 when the same are indexed as previously set for forth.

While the press 116 can be operated in any suitable manner, it is believed the same should exert pressures of approximately 200 tons, and should have the platens 118 and 119 thereof heated to approximately 450 F. Also, the presses 116 and 117 should operate in unison, and each should have a press area of approximately 4 feet by 4 feet for performing the previously described operation.

In regards to the cooling press 117, it is believed that the same should have the platens 118 and 119 thereof water cooled, so that the same will cool the densified mat means 30 therebetween to approximately 130 F. maximum, whereby the molten thermoplastic material thereof will sufficiently gel and thereby set, so that the same will provide a substantially rigid sheet means 30 and also will readily release from the belts 120 and 122 when subsequently indexed therefrom.

Therefore, it can be seen that in the operation of the method and apparatus 40 of this invention, the fiber textile-like mat means 36 is adapted to be indexed by the belts 120 and 122 between the open platens 118 and 119 of the press 1 while the upper platens 118 of both presses 116 and 117 are in the open condition as illustrated in Figure 25 to position an undensified portion of the mat means 36 between the platens 118 and 119 of the press 116 while a previously densified portion of the mat means 30 is indexed between the platens 118 and 119 of the chilling press 117 as illustrated in Figure 26. Thereafter, the movement of the belts 120 and 122 is terminated and the upper platens 118 of the presses 116 and 117 are brought toward the lower platens 119 thereof in the manner illustrated in Figure 27, wherein the platens 118 and 119 of the press 116 sufficiently heat the thermoplastic material of the mat means 36 to melt the same as well as to densify the mat material 36 to form the same into theflat sheet-like form 30 as illustrated in Figure 27. At this same time, the cooled platens 118 and 119 of the chilling press 117 sufficiently gel the previously molten thermoplastic material to cause the same to set and thereby form the densified section 30 therebetween into the substantially rigid sheet-like material 30, which will readily release from the belts 120 and 122 when the same is subsequent indexed therefrom to the right to the trimming apparatus 127 for the purpose previously set forth.

Therefore, it can be seen that this invention provides an improved method and apparatus for making a sheet of material.

While the form and method of this invention now preferred have been illustrated and described as required, it is to be understood that other forms and method steps can be utilized and still fall within the scope of the appended claims.

Claims (12)

1. An apparatus for making a sheet of material from a fiber textile-like mat means which is made of fiber means mixed with fibers of thermoplastic material and is subject to heat and pressure by press means to melt said thermoplastic fibers and densify said mat means so that upon subsequent cooling of said thermoplastic material in said densified mat means said cooled thermoplastic material sets and thus causes said cooled densified mat means to be a substantially rigid sheet of material; said press means comprises a pair of movable belt means having adjacent runs adapted to receive said mat means therebetween, said press means having compressing means for compressing said mat means between said adjacent runs of said belts to densify said mat means, said press means having heating means for heating said mat means between said adjacent runs of said belts, said press means also having cooling means for cooling said mat means between said adjacent runs of said belts after said mat means has been heated and densified by said heating means and said compressing means; the improvement characterized in that said heating means and said compressing means comprise a pair of platens (118,119) of a first press (116) between which said runs (125, 126) of said belts (120, 122) are disposed, and in that said cooling means comprises a pair of platens (118,119) of a second press (117) between which said runs (125,126) of said belts (120, 122) are disposed.

2. An apparatus as set forth in claim 1, characterized in that each of said belts (120, 122) comprises an endless belt of woven fiberglass impregnated with teflon.

3. An apparatus as set forth in claim 1, characterized in that said first press (116) and said second press (117) are disposed in side-by-side relation.

4. An apparatus as set forth in claim 3, characterized in that said presses (116, 117) have means for operating the same substantially simultaneously.

5. An apparatus as set forth in claim 4, characterized by means for indexing said runs (125,126) of said belts (120, 122) between said platens (118, 119) of said presses (116,117).

6. An apparatus as set forth in claim 5, characterized in that said apparatus has feeding means for feeding said mat means (36) between said runs (125, 126) of said belts (120, 122).

7. An apparatus as set forth in claim 6, characterized in that said feeding means includes a conveyor means (110) spaced from said first press (116).

8. An apparatus as set forth in claim 7, characterized in that said feeding means includes a compensating area (114) between said conveyor means (110) and said first press (116).

9. An apparatus as set forth in claim 8, characterized by mat forming means (112) for forming said fibers (44) and said fiber means (43) into said mat means (36) on said conveyor means (110).

10. An apparatus as set forth in claim 9, characterized in that said matforming means (112) comprises at least one garnetting machine.

11. A method for making a sheet of material from a fiber textile-like mat means which is made of fiber means mixed with fibers of thermoplastic material and is subject to heat and pressure by press means to melt said thermoplastic fibers and densify said mat means so that upon subsequent cooling of said thermoplastic material in said densified mat means said cooled thermoplastic material sets and thus causes said cooled densified mat means to be a substantially rigid sheet of material; the method comprises the steps of forming said press means to comprise a pair of movable belt means having adjacent runs adapted to receive said mat means therebetween, compressing said mat means between said adjacent runs of said belts with compressing means of said press means to densify said mat means, heating said mat means between said adjacent runs of said belts with heating means of said press means, and cooling said mat means between said adjacent runs of said belts with cooling means of said press means after said mat means has been heated and densified by said heating means and said compressing means; the improvement characterized by the steps of forming said heating means and said compressing means to comprise a pair of platens of a first press, disposing said runs of said belts between said platens of said first press, forming said cooling means to comprise a pair of platens of a second press, and disposing said runs of said belts between said platens of said second press.

12. Apparatus constructed and arranged substantially as herein described and illustrated with reference to Figures 25 to 27 of the accompanying drawingsforthe purpose setforth.