WO2017025960A2

WO2017025960A2 - System and method for the manufacture of vertically oriented fluted multiwalls

Info

Publication number: WO2017025960A2
Application number: PCT/IL2016/050869
Authority: WO
Inventors: Oren Sitton
Original assignee: Oren Sitton
Priority date: 2015-08-09
Filing date: 2016-08-08
Publication date: 2017-02-16
Also published as: IL240450A0; WO2017025960A3; IL240450A

Abstract

Methods and machine for manufacturing vertically oriented core of multiwalls and multiwalls comprising such core. Multiwalls or cores of multiwalls with transversely oriented flutes in their core are sliced perpendicularly relative to the axis of rotation of the flutes The slices are bent 900 relative to the origin multiwall or core, packed together, welded or fused and their top and bottom surface leveled to provide a vertically oriented shortened flutes that form the core. The top and bottom surfaces of the core are then laminated, Machine configurations are also provided for continuous manufacturing of vertically oriented cores of multiwalls.

Description

System and Method for the Manufacture of Vertically

Oriented Fluted Multiwalls

Technical Field

The present invention pertains to means and method for manufacturing multiwalls. More particularly, the present invention pertains to systems and methods for converting transversely to vertically oriented cores of multiwalls.

Background

Multiwalls are commonly used in the construction of different types of plastic furniture. Their basic structure is sandwich having skin surfaces on top and bottom that enclose a core in the middle. The core is usually formed of transversely extending flutes along the length or width of the multiwall relative to the top and bottom skins. The core provides the mulitwall the strength to bear loads, particularly, when used in shelf systems, closets, cupboards and the like. To increase the strength of multiwalls the core is oriented upright relative to the skins. Several technologies have been developed for manufacturing a core that is 90° oriented relative to the top and bottom skins. These technologies essentially manufacture hollow vertical poles on the bottom surface then laminated from top with the upper surface, which evidently leads to complicated, time consuming and expensive process, resulting in a more expensive product.

There is, therefore, a need to provide cost-effective, relatively simple, faster and cheaper method for forming vertically oriented core of multiwalls and multiwall comprising such core.

Further, there is a need to provide relatively simple means for manufacturing such vertically oriented core of multiwalls and multiwall comprising such core.

The present invention responds to these objectives as detailed in the following description with exemplary reference to the accompanying drawings. Summary

In one aspect, the present invention provides a method of manufacturing vertically oriented core of multiwall and multiwall comprising such core. The manufacture of multiwalls with a core that contains vertical flutes is more complicated and time consuming than a core with a smaller number of transversely oriented flutes. This is due to the need to produce a larger number of shortened vertical flutes relative to a smaller number of transverse flutes to cover the same area. The method of the present invention essentially uses available materials, constructions and devices that make it

technologically simple and cost-effective relative to current technologies to obtain the same product.

Therefore, the method comprises a method for the manufacture of vertically oriented multiwall core, namely a core of a multiwall that comprises vertically oriented flutes relative to top and bottom skins that cover them. Such method comprises the following:

(a) providing fluted multiwall or fluted core of multiwall that comprises at least one array of transversely oriented flutes;

(b) providing at least one cutting means configured for slicing the array of transversely oriented flutes of the fluted multiwall or fluted core of multiwall;

(c) placing the cutting means in contact with first transverse edge and at selected distance from first longitudinal edge or previous point of contact with at least one surface of the fluted multiwall or fluted core of multiwall;

(d) cutting through a selected thickness of the fluted multiwall or fluted core of multiwall with the cutting means;

(e) generating a slice by traveling the cutting means through along longitudinal axis until reaching second transverse edge parallel the first transverse edge of the fluted multiwall or fluted core of multiwall; (f) folding the slice 90° clockwise or counterclockwise relative the fluted multiwall or fluted core of multiwall or a slice previously cut off from said fluted multiwall or fluted core of multiwall;

(g) welding the folded slice to the previous folded slice;

(h) repeating steps (c)-(g) until reaching second longitudinal edge parallel the first

longitudinal edge of the fluted multiwall or fluted core of multiwall.

Optionally, the slices are heat-welded or heat-fused after folding. To form the multiwall of the present invention, further step is required of thermal treatment for leveling the open bases of the shortened vertical flutes formed. A further step of laminating the top and bottom surfaces of the core completes the process of manufacturing the multiwall. Therefore, the method as detailed above further comprises: (i) stabilizing the upper and lower surfaces of the vertically oriented core multiwall; (j) laminating said upper and lower surfaces of said vertically oriented core multiwall.

The slicing of the origin multiwall with transversely oriented flutes half- or part- thickness essentially creates accordion configuration of the slices that may be folded 90° relative each other clockwise or counterclockwise around the newly formed axis between them. To achieve that the slicing may be carried out with at least one knife that cuts through the thickness of the origin multiwall and along the longitudinal length perpendicular to the flutes between the first and second transverse edges of the origin multiwall. This slicing is done at a selected distance from the longitudinal edges of the multiwall or previous cuts. Thus an array of slices is obtained that may be folded one upon the other in an accordion configuration.

When the slicing is carried out in only one direction from one surface to the opposite surface, then the slices are completely cut and separated from the origin multiwall. Then the slices are folded by rotating them 90° clockwise one over the other, then welded to each other, for example by heat-welding or heat-fusion, thereby forming the core of vertically oriented shortened flutes of the multiwall of the present invention. When only partial slicing is desired, keeping the slices connected to each other, then slicing in opposite directions from the top and bottom surfaces should be done. In the general case, a selected horizontally measured distance is set between the cutting means placed on each surface of the origin multiwall. One cutting means, for example a roller knife or a blade, cuts through the multiwall in opposite direction relative the other cutting means. This opposite cutting is required to enable the folding of adjacent slices over each other in 90° alternating clockwise and counterclockwise directions, where the slices are still connected to each other in alternating upper and lower connecting lines.

The number of cutting means may be one or more. When the origin multiwall is mounted, for example, on conveyor belt, then it is transported relative to a cutting means placed in fixed position. The cutting means is moved down to cut a slice off of the multiwall, then moved up and the multiwall transported the distance selected for creating another slice. The slicing repeats itself until reaching the longitudinal edge of the multiwall.

In an alternative, cog-wheel with blades between neighbor teeth constantly rolls over the surface of the multiwall or core of multiwall, enabling the blades to cut through its thickness and throughout the length. For example, top and bottom cog-wheels with blades between their teeth may be used to continuously cut slices off from a multiwall or core of multiwall traveling between them. The distance between the cog-wheels provides sufficient space to allow a multiwall or core of multiwall to pass through while being cut part-, half- or full- way through their thickness. In still another alternative, a plurality of cutting means may simultaneously cut through the thickness of the origin multiwall either completely when cutting from one surface or partially from the two surfaces.

The folding step may be simultaneous with the cutting step, where every slice formed is folded over a previously cut slice and welded to it, for example by heat-welding or heat- fusion, while a new slice is formed. Thus a continuous process for manufacturing vertically oriented multiwalls or cores of multi walls is obtained.

Stabilizing with thermal treatment for leveling the top and bottom surfaces of the core and lamination are done when completing the slicing and folding as described above. In particular, the lamination may be carried out by heat-welding, heat-fusion or gluing.

The method of manufacturing the multiwall with vertically oriented shortened flutes is not limited to a particular shape of flutes. Particular non-limiting examples of cross sections of the flutes in the origin multiwall may be selected from circular, rectangular, pentagonal, hexagonal, octagonal, parallelogram and diamond. The number of layers of flutes in the origin multiwall may also be more than one. Such example is illustrated in Figs. 10A-12C and 15 of the present application. Further, combinations of flutes with different cross-sections are also contemplated within the scope of the present invention (see Fig. 15).

The material from which the origin fluted multiwall or fluted core of multiwall is made is also not limited. In particular, the material may be selected from polypropylene (PP), polyethylene (PE), polyethylenterphthalate (PET), polystyrene (PS) and polycarbonate (PC).

In another aspect, the present invention provides a machine configured for

manufacturing vertically oriented multiwall core, where the system comprises:

conveyor belt configured for conveying fluted multiwall or fluted core of multiwall that comprises at least one array of transversely oriented flutes;

at least one cutting means configured for cutting through the fluted multiwall or fluted core of multiwall; and

positioning means configured for positioning the at least cutting means in contact with upper and lower surfaces of the fluted multiwall or fluted core of multiwall. Further, the machine may comprise:

thermal treatment means configured for heat-welding or heat-fusing neighbor slices cut off from the origin multiwall to each other;

thermal treatment means configured for leveling the upper and lower surfaces of the newiy formed core; and

laminating means configured for laminating these upper and lower surface.

In still another aspect, the present invention provides vertically oriented multiwall manufactured according to the method or with the machine as described above.

The following will describe particular and non-limiting examples of the present invention with exemplary reference to the drawings without departing from the scope and spirit of the present invention. Brief Description of the Drawings

Figs. 1A-C schematically illustrate different perspectives of horizontally fluted multiwall. Figs. 2A-B schematically illustrate first step in a process manufacturing fluted multiwall. Figs. 3A-B schematically illustrate another first step a process of manufacturing vertical fluted multiwall.

Figs. 4A-B schematically illustrate second step in a process of manufacturing vertical fluted multiwall.

Figs. 5A-B schematically illustrate third step in a process of manufacturing vertical fluted multiwall.

Figs. 6A-C schematically illustrate last step in a process of manufacturing vertical fluted multiwall and the multiwall manufactured.

Figs. 7A-C schematically illustrate different perspectives of hexagonal fluted multiwall. Figs. 8A-B schematically illustrate first step in a process of manufacturing vertical hexagonal fluted multiwall. Figs. 9A-D schematically illustrate second to last steps in a process for manufacturing vertical hexagonal fluted multiwall.

Figs. lOA-C schematically illustrate different perspectives of double-layer hexagonal fluted multiwall.

Figs. 11A-C schematically illustrate the steps in a process for manufacturing vertical double-layer hexagonal fluted multiwall.

Figs. 12A-C schematically illustrate different perspectives of the vertical double-layer hexagonal fluted multiwall manufactured.

Figs. 13A-E schematically illustrate and summarize the steps of manufacturing vertical fluted multiwall.

Figs. 14 schematically illustrates a particular machine for manufacturing vertical fluted multiwall.

Fig. IS illustrates triple layer core of transversely oriented multiwall with combination of cross-sections of its flutes.

Detailed Description of the Drawings

The following describes different aspects of the method and machine of the present invention and in further detail and for demonstration purposes without departing from the scope and spirit of the present invention. It is understood that the configuration(s) and mode(s) of operation described herein do not limit the present invention to the particulars detailed below.

Figs. 13A-E summarizes the process for manufacturing vertically oriented core and multiwall comprising it according to the present invention. A fluted core of a multiwall is first provided (Figs. 13A) with a transversely oriented array of flutes, namely the flutes that support the top and bottom skins of a multiwall stretch along its width. The core of the multiwall is vertically cut to selected depth through the thickness of the multiwall core and along its length with a plurality of cuts at selected distance from each other. As illustrated in Fig. 13B, a plurality of cutting means may simultaneously cut through the thickness of the core of a multiwall in parallel lines, where each two adjacent cuts are made from opposite sides to enable the folding step of the slices formed fluent and simultaneous with the cutting step. The third step in the process involves heat treatment of the top and bottom surfaces of the slices (Fig. 13C) to heat- or fuse- weld the slices to each other and form unified smooth surfaces for laminating the top and bottom skins as illustrated in Fig. 13D. The product of the process, which is vertically oriented core multiwall, is shown in Fig. 13E.

Figs. 1 through 5 illustrate the schematics of forming vertically oriented core and multiwall thereof in further detail. In Figs. 1 A-C a transversely oriented core of a multiwall (1) is illustrated in different perspectives. The flutes (2) are perpendicular to the top and bottom skins (3a, 3b), adjacent each other, and extend along the width of the multiwall. The first step of converting transversely to vertically oriented core of multiwall can be carried out in two exemplary methods as illustrated in Figs. 2A-2B and 3A-3B. Knives or blades (4a, 4b) are simultaneously placed in contact with the top and bottom surfaces of the core or skins (3a, 3b) for that matter and at selected distance between their points of contact. The knives/blades (4a, 4b) cut through the depth of the core/multiwall a selected depth (5a) that enables folding the slices (S) formed in the next step (shown in Fig. 2B). After reaching the desired depth, the knives/blades (4a, 4b) extend the cut formed at the point of entry along the length of the core or multiwall. As a result, a slice is cut off from the entire row of flutes (2). The knives/blades (4a, 4b) then define another distance between them that is adjacent the former distance, and repeat the cutting process forming another slice (5). Each slice (5) is folded 90° around the newly formed axis represented by (Sa) relative to the original axis of rotation of the flutes, where each two adjacent slices are folded one in clockwise direction, the other in counterclockwise direction in accordion fashion. As shown in Fig. 2B the steps of slicing and folding can be carried out continuously with each other. Namely, the slices formed are folded 90° while

knives/blades (4a, 4b) continue to cut new slices. The particular example in Fig. 2B shows that the core/multiwall advances a selected distance towards the folding area while the knives/blades (4a, 4b) stay in fixed position relative to it. Alternatively, the core/multiwall may be fixed in place, while the knives/blades (4a, 4b) move along its width a selected distance each time.

Figs. 3A-B exemplify variation of the method of forming a vertically oriented core of multiwall. In this method the slices (5) are entirely cut off and separated from the core/multiwall (1). Accordingly, only one knife or blade (4a) is required. The slices (5) are collected and packed in vertical position relative to their axis of rotation and top and bottom surfaces of the skins that will cover them. Thermal treatment and lamination follow the cutting and folding steps.

Figs. 4A-B illustrate the following step of stabilizing the core of arrays of vertical shortened flutes adjacent each other. Presses (6a, 6b) apply isostatic pressure on the open ends of the slices of flutes (S) from parallel opposite sides, thereby leveling and smoothing the surfaces for the following step of lamination and heat- of fuse- welding adjacent flutes to each other. Figs. 5A-B show the final step of laminating the slices (5) according to each of the cutting versions presented in the previous Figs. For each, the lamination is essentially the same, closing the open ends of the slices (5) with laminates (7a, 7b) attached to them with heat-welding, heat-fusion or gluing. The core obtained may then be used for different purposes and uses by overlaying different covers on it.

The vertically oriented core multiwall (1') is shown in different perspectives in Figs. 6A- C. The slices or arrays (5) of now vertically oriented shortened flutes are packed one next to the other welded or fused together and covered with top and bottom laminates (7a, 7b). The multiwall (1') formed is, therefore, obtained in a relatively simple and cost-effective process without complex technologies or machinery.

Vertically oriented core multiwall can be essentially done with any shape of flutes and/or any form of packing. Figs 7A-9D demonstrate the same process described above for flutes with hexagonal cross section (8a). Here also the array of flutes is sliced to multiple slices. The gap between adjacent flutes (8a) contains a horizontal film (8b) connecting between them, which is cut and separated from the array (8) in the slicing step. The slices (8c) formed may remain connected to each other in an axis of rotation (8d) and rotated 90° clockwise or counterclockwise to form adjacent arrays of shortened vertically oriented hexagons (8c) packed together to form the core of the multiwall (see Fig. 9D). Otherwise, they may be completely cut off from each other and then packed in vertical position relative to their axis of rotation. Thermal treatment and lamination with laminates (7a, 7b) are then carried out on the top and bottom surfaces.

Double layer core of hexagonal flutes (9) is demonstrated in Figs. lOA-C in which the gap in the lower array of hexagonal flutes (9a) is now occupied with a second layer of hexagonal flutes (9b). The process of manufacturing a vertically oriented core multiwall (1') is illustrated in Figs. 11A-C and essentially the same as the process shown in Figs. 2A-5B. This time, however, two layers of hexagonal flutes (9a, 9b) are sliced in each cut, folded 90° (clockwise or counterclockwise) around the axis (9e) formed between adjacent slices to form vertically oriented arrays of shortened hexagonal flutes (9c). The two layers now result in fully packed core without gaps between the shortened hexagonal vertical flutes (see Figs. 12A-C). The top and bottom surfaces of the double-layer hexagonal flutes core are stabilized and laminated to form the vertical core multiwall (see Figs. 11B-C),

Fig. IS shows a triple layer core of multiwall with alternating layers of pentagonal and hexagonal flutes. Essentially, the arrangement or layer number of flutes in the core does not affect the method of the present invention for manufacturing multiwalls with vertically oriented core. Therefore, any number of layers of flutes with varying cross sections is well within the scope of the present invention.

Fig. 14 schematically illustrates particular machine for manufacturing vertically oriented core multiwalls. Two cog-wheels (10a, 10b) are placed beside each other, with, their axes or rotation parallel one to the other. Blades (11) are inserted between adjacent teeth of each cog-wheel to cut slices from multiwalls (1) with transversely oriented core that pass between the wheels (10a, 10b). The slices leaving the space between the two wheels (10a, 10b) are then folded 90° and processed further with thermal treatment and lamination (12).

It should be noted, that the cross sectional shapes of the flutes described above and illustrated in the accompanying drawings are only examples of the possible shapes of flutes that may be used to form vertically oriented flute core. Therefore, rectangular, circular, parallelogram, octagonal and diamond shapes are other examples that may be used to manufacture vertically oriented core multiwall. Further, transversely oriented cores with more than one layer may be used to manufacture the vertically oriented core multiwall.

Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations and modifications can be made without departing from the scope of the invention mutatis mutandis.

Claims

1. A method for manufacturing vertically oriented multiwall core, said method

comprising:

(a) providing fluted multiwall or fluted core of multiwall comprising at least one

array of transversely oriented flutes;

(b) providing at least one cutting means configured for slicing said array of

transversely oriented flutes of said fluted multiwall or fluted core of multiwall;

(c) placing said cutting means in contact with first transverse edge and at selected distance from first longitudinal edge of or previous point of contact with at least one surface of said fluted multiwall or fluted core of multiwall;

(d) cutting through a selected thickness of said fluted multiwall or fluted core of

multiwall with said cutting means;

(e) generating a slice by traveling said cutting means through along longitudinal axis until reaching second transverse edge parallel said first transverse edge of said fluted multiwall or fluted core of multiwall;

(f) folding said slice 90° clockwise or counterclockwise relative said fluted multiwall or fluted core of multiwall or slice previously cut off from said fluted multiwall or fluted core of multiwall;

(g) welding the folded slice to previously folded slice;

(h) repeating steps (c)-(g) until reaching second longitudinal edge parallel said first longitudinal edge of said fluted multiwall or fluted core of multiwall.

2. The method according to claim 1, further comprising:

(i) stabilizing upper and lower surfaces of said vertically oriented core multiwall;

(j) laminating said upper and lower surfaces of said vertically oriented core multiwall.

3. The method according to claim 1, wherein folding one slice is done simultaneously with generating second slice.

4. The method according to claim 1, wherein said at least one cutting means comprises a single cutting means, said selected thickness equals the entire thickness of said fluted multiwall or fluted core of multiwall. S. The method according to claim 1 , wherein said at least one cutting means comprises two cutting means, wherein first cutting means is configured to cut through first surface and second cutting means is configured to cut through second surface opposite said first surface of said fluted multiwall or fluted core of multiwall. 6. The method according to claim 1, wherein said cutting means is selected from roller knife, blade knife and cog-wheels comprising blades between adjacent teeth of said cog-wheels.

7. The method according to claim 1 , wherein cross section of said transversely oriented flutes is selected from circular, rectangular, pentagonal, hexagonal, octagonal, parallelogram and diamond shapes.

8. The method according to claim 1 , wherein said fluted multiwall or fluted core of multiwall comprise a plurality of two arrays of transversely oriented flutes.

9. The method according to claim 8, wherein said fluted multiwall or fluted core of multiwall comprise two arrays of hexagonal transversely oriented flutes, wherein one array is layered in gaps between flutes of second array. 10. The method according to claim 1 , wherein material from which said fluted multiwall or fluted core of multiwall is made is selected from polypropylene (PP), polyethylene (PE), polyethylenterphthalate (PET), polystyrene (PS) and polycarbonate (PC).

11. The method according to claim 2, wherein said stabilizing comprises thermal treatment for leveling said upper and lower surfaces of said vertically oriented core multiwall and heat-welding or heat-fusing slices adjacent each other. 12. The method according to claim 2, wherein said laminating is carried out by heat- welding, heat-fusion or gluing.

13. A machine configured for manufacturing vertically oriented core multiwall, said machine comprising:

conveyor belt configured for conveying fluted multiwall or fluted core of multiwall comprising at least one array of transversely oriented flutes;

at least one cutting means configured for cutting through said fluted multiwall or fluted core of multiwall; and

positioning means configured for positioning said at least cutting means in contact with upper and lower surfaces of said fluted multiwall or fluted core of multiwall.

14. The machine according to claim 13, farther comprising:

thermal treatment means configured for leveling said upper and lower surfaces and heat-welding or heat-fusing slices adjacent each other; and

laminating means configured for laminating said upper and lower surface.

15. The machine according to claim 13, wherein said cutting means comprises at least one cutting means selected from roller knife, blades and cog-wheels comprising blades between each adjacent teeth.

16. Vertically oriented fluted core of multiwall and multiwall comprising said wall manufactured according to the method as claimed in any one of claims 1-12.

17. Vertically oriented fluted core of mulitwall and multiwall comprising said core manufactured with the machine as claimed in any one of claims 12-15.