WO2001030555A1

WO2001030555A1 - Process and apparatus for forming various foam-core products, and products made thereby

Info

Publication number: WO2001030555A1
Application number: PCT/US2000/018481
Authority: WO
Inventors: Washington P. Timmerman, Iii; M. Allen Ivester
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-07-06
Filing date: 2000-07-06
Publication date: 2001-05-03
Anticipated expiration: 2002-01-06
Also published as: AU6072900A

Abstract

A process and apparatus for producing an article (20) having an inner foam core (36) and an outer layer of flexible web material (10). Flexible web material is dispensed from a roll (12) in a machine direction. The web material enters a forming structure where it is folded into an outer package defining an open interior. Adhesive (34) is supplied from a suitable source (16) to overlapping lateral edges (10e, 10d) of the web material (10) so as to attach the lateral edges together and close the outer package. A liquid foam material is then supplied into the open interior of the outer package. A structure downstream of the foam source maintains the outer package in a selected configuration of the article until the liquid foam material has sufficiently cured. Individual products, such as winding boards, corner boards, tubes and divider boards, may then be cut.

Description

PROCESS AND APPARATUS FOR FORMING VARIOUS FOAM-CORE PRODUCTS, AND PRODUCTS MADE THEREBY Background of the Invention

The present invention relates to a process and apparatus for producing various products that may be used in the packaging and winding industries .

For example, novel winding boards, corner protection boards, foam-core tubes and other such products may be produced in accordance with the present invention.

A wide variety of ancillary products are used for various purposes by both the packaging and winding industries. For example, bolts of cloth are often wound onto tubular cores or rectangular winding boards. An L-shaped product known as "corner board" (or "angle board") is frequently utilized to protect the edges of palletized freight from damage. Bottles or other secondary containers are often placed into a box which is separated into smaller compartments by partitions referred to as divider boards.

Due to the volume of goods packaged during the course of a day, it will be appreciated that large quantities of these ancillary products are used. In the past, many of these products have been made from corrugated paper or heavy paperboard. While such products have worked generally well for their intended purpose, they have often been difficult to manufacture . As an example, consider the case of winding boards used as a center about which a length of cloth or other fabric can be wrapped for transport or storage. As described in U.S. Patent No. 3,780,855, incorporated herein by reference, winding boards made from corrugated material have required the use of a special die to cut the corrugated sheet into a specific pattern. The pattern is then folded multiple times' to produce the resulting winding board.

It will be appreciated that the production of winding boards in this manner has been generally inefficient. In addition, corrugated winding boards have a tendency to crush during use . Because the corrugated material lacks memory which would allow it to return to its original shape, the crushed winding board must generally be discarded and is not available for reuse.

Summary of the Invention The present invention recognizes and addresses the foregoing disadvantages, and others, of prior art constructions and methods. It is thus an object of the present invention to provide various products of novel construction for use in the packaging and winding industries .

It is a more particular object of the present invention to provide various novel products for use in the packaging and winding industries having a foam-core. It is a further object of the present invention to provide a novel process for forming various foam-core products.

It is a still further object of the present invention to provide a novel apparatus for forming various foam-core products. Some objects of the invention are achieved by a process of producing an article having an inner foam core and an outer layer of flexible web material . One step of the method involves providing a sheet of the flexible web. material , which will often be selected from the group consisting of paper, plastic film or foil. In accordance with another step of the method, the sheet of flexible web material is then formed into an outer package defining an open interior. Another step of the method involves supplying a liquid foam material into the open interior of the outer package, which then expands to fill the open interior. In accordance with a still further step of the method, the outer package is maintained in a selected configuration of the article until the liquid foam material has sufficiently cured. Preferably, the outer package is continuously conveyed in a structure maintaining the selected configuration of the article while the liquid foam material is curing.

In accordance with preferred methodology, the sheet of flexible web material is continuously dispensed from a roll. Preferably, the outer package may be formed by overlapping lateral edges of the sheet of flexible web material . For example, the lateral edges may be attached to one another by adhesive which is applied prior to the liquid foam material being supplied.

The article may be formed having at least one longitudinal void. In addition, the process may involve the step of cutting the article to yield a product. The product itself may be a winding board, corner board, tube, divider board or the like.

In some cases, it may be desirable to also provide a second sheet of said flexible web material . The second sheet may be formed into an inner package located inside of the outer package, wherein the open interior into which the liquid foam material is supplied will be a space between the outer package and the inner package. The article may be cut to yield a product, such as an envelope .

Other objects of the invention are achieved by a product having an axial dimension exceeding a transverse dimension thereof. The product comprises an inner foam core having a selected cross-sectional configuration in the transverse dimension. An outer layer formed from a unitary sheet of flexible web material extends about the inner foam core to encase same in the axial dimension. The outer layer defines an overlap region at which lateral edges of the flexible web material are adhered together. Furthermore, the product is configured such that respective ends of the inner foam core are not covered by the unitary sheet of flexible web material. Preferably, the outer layer is directly adhered to the inner foam core without glue.

In some embodiments, the inner foam core may be configured having a substantially rectangular cross section in the transverse dimension. In this case, the inner foam core may be covered by respective end caps. Often, the end caps will be substantially U-shaped.

In other embodiments, the inner foam core may be configured having a substantially L-shaped cross section in the transverse dimension. A stiffening agent may be applied to at least one outer face of the flexible web material .

Other embodiments are contemplated in which the inner foam core is configured having a substantially circular cross section in the transverse dimension. In such embodiments, the inner foam core may be configured defining a longitudinal void along the axial dimension of the product. The inner foam core in such embodiments may be located between the outer layer and an inner layer of flexible web material .

Still further objects of the present invention are achieved by a continuous motion apparatus for producing an article having an inner foam core and an outer layer of flexible web material . The apparatus comprises means for dispensing a roll of flexible web material in a machine direction. A forming structure is operative to fold a sheet of web material dispensed from the roll into an outer package defining an open interior as the sheet continuously moves in the machine direction.

The apparatus further includes an adhesive source operative to supply adhesive to overlapping lateral edges of the sheet so as to attach the lateral edges together and close the outer package. A foam source is operative to supply a liquid foam material into the open interior of the outer package. A structure located downstream of the foam source maintains the outer package in a selected configuration of the article as the outer package continuously moves in the machine direction until the liquid foam material has sufficiently cured.

Other objects, features and aspects of the present invention are provided by various combinations and subcombinations of the disclosed elements, as well as methods of utilizing same, which are discussed in greater detail below. Brief Description of the Drawings A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic perspective view illustrating an apparatus for manufacturing product according to the present invention;

Figure 2 is a diagrammatic sectional view as taken along line 2-2 of Figure 1 ;

Figure 3 is a diagrammatic sectional view as taken along line 3-3 of Figure 1 ;

Figure 4 is a diagrammatic sectional view as taken along line 4-4 of Figure 1 ;

Figure 5 is an enlarged cross-sectional view of a product produced by the apparatus of Figure 1 ; Figure 6A is a cross-sectional view, similar to Figure 5, illustrating an alternative embodiment having a longitudinal void along the axial length thereof ; Figure 6B is a diagrammatic sectional view similar to Figure 2 further illustrating the manner in which the longitudinal void of Figure 6A can be formed;

Figure 7A is a perspective view of a winding board produced in accordance with the present invention;

Figure 7B is an enlarged fragmentary view taken along line 7B-7B of Figure 7;

Figure 8 is a perspective view of a corner board that may be produced in accordance with the present invention;

Figure 9 is a cross-sectional view taken along line 9-9 of Figure 8 ;

Figure 10 is an enlarged fragmentary view of the area so indicated in Figure 9;

Figure 11 is a perspective view of a foam core tube produced in accordance with the present invention;

Figure 12 is a diagrammatic plan view of a foam-core sheet that may be produced in accordance with the present invention; Figure 13 is a perspective view of a flat board that may be cut from the sheet of Figure 12 ;

Figure 14 is a perspective view of a box illustrating a plurality of section dividers located therein;

Figure 15 is a perspective view of a section divider board constructed in accordance with the present invention;

Figure 16 is a perspective view of a padded envelope constructed in accordance with the present invention;

Figure 17 is a side elevation of the envelope shown in Figure 16;

Figure 18 is a diagrammatic view transverse to the machine direction showing the manner in which sheet material for padded envelopes or similar products may be made according to the present invention; and

Figure 19 is a diagrammatic view along the machine direction showing the manner in which sheet material for padded envelopes or similar products may be made according to the present invention. Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.

Detailed Description of Preferred Embodiments It is to be understood by one skilled in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.

Products of the present invention are characterized by an outer package of flexible web material, such as paper, plastic film, foil and the like. The outer package contains a core of semirigid foam which provides structural integrity to the overall product. In some embodiments, a longitudinal void may be provided such that the foam core is sandwiched between inner and outer packages of the web material . Various products may be made according to the present invention, each of which is believed to be novel in its own right.

Figure 1 illustrates a continuous process by which various products of the present invention may be produced. While product may be produced individually, or in an intermittent process, a continuous process is preferred to efficiently yield high production rates. In a continuous process according to the present invention, flexible web material 10 is preferably dispensed from a roll 12 in the machine direction ( "MD" ) . After being dispensed from roll 12, suitable apparatus are provided to form, support and hold web material 10 in a manner that achieves the desired shape of the outer package. In this case, web material 10 is being folded into a package shape having a substantially rectangular cross-section. As indicated at 14, glue or other adhesive is typically applied prior to the final folding in order to seal down the slight overlap between the lateral edges of web material 10.

At a suitable time either before_., after or simultaneously with the closing of the outer package, foam is inserted in the outer package to achieve the final product. The foam is preferably injected in the form of a liquid, which will expand and cure to produce the foam core. As shown, the foam liquid is preferably supplied from a suitable source 16 including an injection head 18 situated at the desired injection location. A suitable structure is provided to adjust and then maintain the package shape until the foam has fully cured. For example, it may be desirable in many cases to alter the shape of the package after injection of the foam, but prior to the time that the foam has hardened. After curing of the foam, individual products 20 are cut from the axial length of the composite strip.

Various types of foam materials that may be suitable for use in the present invention are well known in the art. Typically, these foam materials may be made as two component mixtures, which react and expand when injected to fill the interior space provided by the outer package. A more detailed discussion of the chemistry involved with expanding foams is provided by U.S. Patent No. 4,459,334, incorporated herein by reference.

In many cases, it may be desirable to utilize a foam material of a type which hardens in about 1- 20 seconds. In addition, a foam density of less than one (1) pound per cubic foot will often be desirable. Presently preferred embodiments use a polyurethane foam material, although one skilled in the art will appreciate that other suitable types of foam material may also be used in accordance with the present invention. Furthermore, although a liquid foam material has been described, it is contemplated that some embodiments of the present invention may utilize a particle foam or a solid foam material . Further details of the apparatus used in performing the process shown in Figure 1 can be most easily described with reference to Figures 2- 4, which show various stages of the manufacturing process. As shown in Figure 2, web material 10 is being transported by a suitable conveyor apparatus 22 having a top run 24 and a bottom run 26. At this point, two of the four folds have been formed in web material 10. As such, web material 10 has a bottom portion 10a along with side portions 10b and 10c. The folding is accomplished using suitable folding guides, such as those indicated at 28a-b and 30a-b.

In Figure 3 , the remaining two folds have been formed in web material 10, thus producing top flaps lOd and lOe. These final two folds are produced by a downstream portion of folding structures 28a-b, as well as additional folding structures 32a-b provided at the location of the respective folds. A bead 34 of glue is provided at the location where flap lOd overlaps flap lOe, as shown. The tube through which the component mixture for forming the foam travels to the injection head is depicted at 35.

In Figure 4, foam material 36 has been injected into the outer package, and has expanded to fill the interior space thereof. The resulting composite is maintained between lower conveyor 22 and upper conveyor 38 for an appropriate dwell time until the foam material is sufficiently cured. It may be desirable in some applications to provide heating or cooling means along the axial length of the forming apparatus in order to facilitate curing of the foam. As shown, top conveyor 38 includes a bottom run 40 and a top run 42.

Figure 5 is an enlarged view of the resulting product formed by the process as described above. As shown, foam material 36 has completely filled the interior space of the outer package, resulting in a substantially unitary composite structure. With many types of outer web material, such as brown paper, foam material 36 will directly adhere to the inner walls of the outer package. As such, it is not necessary to apply a layer of adhesive to the inner surfaces of the outer package before the foam is injected. Figure 6A illustrates an alternative embodiment that is identical in many respects to the embodiment shown in Figure 5. In this case, however, a longitudinal void is formed along the axial length by providing an inner package 44 of the flexible web material, which is coaxial with the outer package. In this case, foam material 36 is injected into the space between inner package 44 and the outer package formed by web material 10.

Preferably, inner package 44 may be formed of a sheet of web material which has been folded and glued to yield the desired package shape. As illustrated in Figure 6B, inner package 44 is preferably formed about an elongate mandrel 46 prior to formation of the outer package. Preferably, inner package 44 will be moved along mandrel 46 in synchronization with web material 10 until after the foam material is injected. In the case of a two package embodiment such as this, the outer package may remain unsealed until shortly after injection of the foam. When the foam material has sufficiently cured, mandrel 46 may terminate .

In other cases, it may be desirable to provide multiple voids inside of the outer package instead of a single void as illustrated in Figure 6A. In addition, it may be possible to eliminate the inner package in some cases by employing a suitable mandrel. In such cases, the foam material may cure in the space provided between the mandrel itself and the outer package. Assuming the mandrel is coated with Teflon^® or similar low friction material, the foam may move along the mandrel as the product proceeds in the machine direction.

It will be appreciated that the present invention allows a variety of products to be made. For example, Figure 7A illustrates an improved winding board 47 constructed in accordance with the present invention. Winding board 47 has a main portion 48 of pre-determined axial length. Main portion 48 is produced as described above having an outer package of flexible web material surrounding a foam core. The desired length of main portion 48 is simply cut from the continuous strip as it emerges from the forming apparatus . Because main portion 48 will have exposed foam on its axial ends, end caps 50a-b may be provided. As shown in Figure 7B, the end caps may be simply formed of U- shaped paper which is glued to the top and bottom surfaces of main portion 48.

Figures 8-10 illustrate another product 52 that may be produced according to the. teachings of the present invention. Product 52 may be used, for example, as a "corner board" (or "angle board") for protecting the edges of palletized freight from damage .

As shown, product 52 is configured as a right angle structure having an outer package 54 of flexible web material containing a core 56 of foam material . The overlap region between the two sides of web material forming outer package 54 is indicated at 57. Product 52 is produced in the manner described above, except that outer package 54 is formed into an L-shaped configuration, instead of a rectangular configuration as illustrated in Figure 1.

As can be seen in Figure 10, a stiffening agent 58 such as a starch or a glue may be added to portions of the outer surface of product 52. In this case, for example, agent 58 is applied to sides 59a and 59b of the product's outer surface. As one skilled in the art will appreciate, these sides will be engaged by straps when the corner board is placed on palletized freight. Another preferred embodiment involves adding longitudinal strips (s) of the same or other flexible material to sides 59a and 59b, or to other locations on product 52. A further alternative product made in accordance with the present invention is illustrated in Figure 11. In this case, a tube 60 is formed of an outer package 62 and a coaxial inner package 64. A core 66 of foam material is located in the radial region between packages 62 and 64. The overlap region of package 62 is indicated at 68, whereas the overlap region of package 64 is indicated at 70. Again, tube 60 is formed as a continuous strip of material which is cut to desired lengths after the foam material has been sufficiently cured. Thus, the forming machine is adapted in this case to produce cylindrical packages, instead of a rectangular package as illustrated in Figure 1. It is contemplated that tube 60 may be used in a variety of applications where tubes of paper or foam have been used in the past. For example, paper tubes are often used as a core for rolls of web material, such as cloth, paper, plastic films and the like. Tube 60 is well-suited for use in these applications. In addition, tubes made according to the present invention may also be used as storage tubes, such as those used to store blueprints and the like.

Alternatively, tube 60 can be utilized as an insulator for pipe. For example, a longitudinal slit may be cut along the axial length of tube 60.

Tube 60 can then be spread apart and located about the pipe to be insulated. The memory characteristics of the foam will cause tube 60 to substantially resume its original shape once the spreading force has been removed. Often, it may be desirable to wrap tube 60 in tape to ensure a tight fit about the pipe.

In some cases, it may be desirable to form relatively thin sheets of product according to the present invention, which may then be used in a manner similar to a corrugated sheet of the prior art. For example, Figure 12 illustrates a sheet 72 formed in a manner similar to that described above having a thickness approximately equivalent to that of a corrugated sheet. Like corrugated product, sheet 72 may be transported to another facility for conversion into a desired product. Alternatively, sheet 72 may proceed directly into a cutting machine in which individual boards 74^' are cut . (An enlarged view of board 74 is illustrated in Figure 13. ) Boards 74 can then be further cut or folded in a manner similar to corrugated product for use as desired. Referring now to Figures 14-15, it is well known that various secondary packages, such as bottles, are often packaged in larger boxes partitioned by corrugated divider boards. In the case of box 76, however, the various divider boards, such as divider board 78, are cut from sheet 72. It will be appreciated that the resilient foam material of divider board 78 provides an effective cushion for protection of the secondary packages contained in the box.

Figures 16 and 17 illustrate a padded envelope 80 that may be constructed in accordance with the present invention. Envelope 80 comprises a first sheet 82 and a second sheet 84 which have been joined together, as indicated at 86, along three peripheral sides. The fourth peripheral side is left open to allow access to the interior of the envelope. A flap 88 is provided to allow the envelope to be closed once the desired contents are inserted.

Sheets 82 and 84 of envelope 80 are each formed according to the present invention having an inner foam core sandwiched between layers of flexible web material. It is contemplated that sheets 82 and 84 may be individually cut from a larger sheet of product and then combined so as to form envelope 80.

Another preferred method of producing envelope 80 can be described with reference to Figures 18 and 19. In this case, product 90 is formed having an outer package 92 and an inner package 94 forming a space therebetween for receipt of liquid foam. A longitudinal void 96 is defined by the region inside of inner package 94. (Conveyor 95, which carries product 90 in the machine direction, is not shown in Figure 18 for purposes of clarity, but is shown in Figure 19.) A series of pinch rollers 98a-d are provided at selected positions across the transverse dimension of product 90. For example, pinch rollers 98a-d may be situated at four equally spaced positions downstream of the location at which foam is injected. The pinch rollers will tend to squeeze foam from the nip between their respective rollers, thus creating pinch areas 100a- d in the longitudinal direction of the product. Because the foam has been squeezed out, pinch areas lOOa-d will simply have four adjacent layers of flexible web material .

It can thus be seen that pinch rollers 98a-d divides product 90 into a series of transverse segments. Referring specifically to Figure 19, product 90 may also be divided into axial segments using an overhead segmenting device 102. Device 102 includes an endless conveyor mechanism 106 having a series of flights 108 located thereon. Flights 108 rotate into engagement with product 90, thus producing pinched areas 108a-c in the transverse direction of product 90.

After the transverse and longitudinal segments are formed, product 90 may then be cut along the pinched areas to provide the basic shape from which the envelopes can be formed. The longitudinal cutting of product 90 may be accomplished utilizing a fixed slit knife, such as that indicated at 110.

It can thus be seen that the present invention provides a process and apparatus in furtherance of the noted objects for forming various foam-core products. While preferred embodiments and preferred methods of using same have been shown and described, modifications and variations may be made thereto by those of ordinary skill in the art without departing from the spirit and scope of the invention. For example, forms for pouring concrete may also be manufactured in accordance with the present invention. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part . Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention particularly set forth in the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A process of producing an article having an inner foam core and an outer layer of flexible web material, said process comprising steps of: (a) providing a sheet of said flexible web material ;

(b) forming said sheet of said ^'flexible web material into an outer package defining an open interior; (c) supplying a liquid foam material into said open interior of said outer package, said liquid foam material expanding to fill said open interior; and

(d) maintaining said outer package in a selected configuration of said article until said liquid foam material has sufficiently cured.

2. A process as set forth in claim 1, wherein said sheet of flexible web material is continuously dispensed from a roll.

3. A process as set forth in claim 2, wherein said outer package is formed by overlapping lateral edges of said sheet .

4. A process as set forth in claim 3, wherein said lateral edges of said sheet are attached to one another by adhesive, said adhesive being applied prior to said liquid foam material being supplied.

5. A process as set forth in claim 3, wherein said article is formed having at least one longitudinal void.

6. A process as set forth in claim 3, further comprising the step of cutting said article to yield a product .

7. A process as set forth in claim 6, wherein said product is a winding board.

8. A process as set forth in claim 6, wherein said product is a corner board.

9. A process as set forth in claim 6, wherein said product is a tube.

10. A process as set forth in claim 6, wherein said product is a divider board.

11. A process as set forth in claim 1, wherein said outer package is continuously conveyed in a structure maintaining said selected configuration of said article until said liquid foam material has sufficiently cured.

12. A process as set forth in claim 1, further comprising steps of:

(e) providing a second sheet of said flexible web material ; and (f) forming said second sheet of said flexible web material into an inner package located inside of said outer package, said open interior into which said liquid foam material is supplied being a space between said outer package and said inner package .

13. A process as set forth in claim 12 , further comprising the step of cutting said article to yield a product.

14. A process as set forth in claim 13, wherein said product is an envelope.

15. A process as set forth in claim 1, wherein said flexible web material is paper.

16. A process as set forth in claim 1, wherein said flexible web material is plastic film.

17. A process as set forth in claim 1, wherein said flexible web material is foil.

18. A product having an axial dimension exceeding a transverse dimension thereof, said product comprising: an inner foam core having a selected cross- sectional configuration in said transverse dimension; an outer layer formed from a unitary sheet of flexible web material extending about said inner foam core to encase same in said axial dimension, said outer layer defining an overlap region at which lateral edges of said flexible web material are adhered together; and said product being configured such that respective ends of said inner foam core are not covered by said unitary sheet of flexible web material .

19. A product as set forth in claim 18, wherein said inner foam core has a substantially rectangular cross section in said transverse dimension.

20. A product as set forth in claim 19, wherein said ends of said inner foam core are covered by respective end caps.

21. A product as set forth in claim 20, wherein said end caps are substantially U-shaped.

22. A product as set forth in claim 18, /30555 PCΪ7US00/1 wherein said inner foam core has a substantially L- shaped cross section in said transverse dimension.

23. A product as set forth m claim 22, wherein a stiffening agent is located on at least one outer face of said flexible web material .

24. A product as set forth in claim 18, wherein said inner foam core has a substantially circular cross section m said transverse dimension.

25. A product as set forth in claim 24, wherein said inner foam core defines a longitudinal void along said axial dimension of said product.

26. A product as set forth m claim 25, wherein said inner foam core is located between said outer layer and an inner layer of flexible web material .

27. A product as set forth in claim 18, wherein said outer layer is directly adhered to said inner foam core without glue.

28. A product as set forth in claim 18, wherein said flexible web material is paper.

29. A product as set forth in claim 18, wherein said flexible web material is plastic film.

30. A product as set forth in claim 18, wherein said flexible web material is foil .

31. A continuous motion apparatus for producing an article having an inner foam core and an outer layer of flexible web material, said apparatus comprising: means for dispensing a roll of flexible web material in a machine direction; a forming structure operative to fold a sheet of said web material dispensed from said roll into an outer package defining an open interior as said sheet continuously moves in said machine direction; an adhesive source operative to supply adhesive to overlapping lateral edges of said sheet so as to attach said lateral edges together and close said outer package; a foam source operative to supply a liquid foam material into said open interior of said outer package ; and a structure downstream of said foam source to maintain said outer package in a selected configuration of said article until said liquid foam material has sufficiently cured as said outer package continuously moves in said machine direction.