A card or corrugated board mailer

Abstract

A process for manufacturing and filling mailers, the process comprising the steps of receiving a roll of cellulose board or sheet, feeding the first end of the roll of cellulose board or sheet into a

Description

Field of Invention

[0001] The present invention relates, in general, to the field of the transportation and storage of goods and, in particular, to a container or mailer that can be 5 fabricated, with a product inserted therein and sealed for distribution in a reduced number of steps. More particularly, the present invention relates to storage containers formed and packed as mailers in a distribution hub. Background to the Invention

[0002] Recent advances in communications technologies enable access to the 10 Internet from anywhere in the world. Concomitant with this, in the field of logistics, an area which has seen a significant rise in activity, is the area relating to internet delivery services industry. Moreover, there has been a shift in consumer preferences driven by convenience and an easy accessibility to the internet, assisted by the C-19 pandemic, with lockdowns of various degrees 15 reducing or indeed preventing footfall in shops. In fact, many companies provide direct to customer goods from an online shop

[0003] Further, cyclical recessionary worries aside, the improving macro-economic environment provides strong support to the increasing income levels of consumers, which in turn boosts their willingness to spend. This is evident from 20 the surge in demand for food delivery, online travel booking, direct marketing and media services, web hosting among others. However, an increasing demand for delivery services has caused associated industries to spring up. Rather than shops providing a mail-order service, industry has seen the growth of companies such as Amazon with distribution centres, having robot picking and highly 25 automated packaging machinery. As is well known, the Covid-19 crisis became an unprecedented global health issue impacting communities and families across the globe; at least one internet based agency supported the UK Government by using their logistics networks to deliver test kits to the homes of essential workers. In turn such collaboration extended so as to provide new testing capacity with the 30 creation of additional hub laboratories, test centres and a delivery service for home testing, employing return of test kits - provided in suitable mailers.

[0004] Various types of envelopes having cushioning properties for packaging precision machines, electrical parts, medical instruments, jewellery, cosmetics, CDs, cassette tapes and the like that are fragile and / or brittle have been 35 proposed. For example, in US7108650, and as shown in Figure 1, there is taught an envelope comprising of layers of plain un-coated kraft paper and of bubble wrap polyethylene. A stack of the layers is joined at the marginal edges of the envelope by squeezing the stack between a pair of points-dies, which are formed with points that puncture the kraft paper but do not puncture the polyethylene. The points push crowns of un-punctured polyethylene through the punctured 5 boles in the paper and the marginal edges are squeezed flat between flat-dies, the flat-dies being heated enough to cause fuse-bonding of the stretched plastics material. The margins of the finished envelope are held together not only by fusebonding, but by the presence of the crowns, which, penetrating right through the holes in the paper, serve as mechanical rivets, akin to the edge crimping of a 10 pastry. However, in such an envelope, the paper of the envelope and the plastic bubble sheet cushioning material must be separated when discarding, which takes time and effort. Accordingly, substantial forces and heat are applied in the manufacturing process, with the envelopes being manufactured of a uniform size for distribution and subsequent use. Additionally, the fused and mechanically 15 compromised plastics cushioning and paper presents further recycling challenges. Figure 2 shows a still further piece part envelope blank 20, of a uniform size. Figure 3 shows an early form of bubble - wrap envelope 30, per US3018015, dating from 1957. Such envelopes are fabricated from piece-part sheet material 31, 32 that have been stamped from a flat sheet of corrugated board, using a 20 die-board cutting process.

[0005] Cardboard and corrugated cardboard is widely used in packaging. However, the construction of boxes, necessarily requires a piece-part form of manual construction, filling and closing. Moreover, there is always a problem with substantial "dead" space within a box, especially in the field of internet-25 purchases, where any such dead space in a box is frequently occupied by bubblebags - plastics bag filled with gas which are employed to prevent substantial movement of a product when placed within a cardboard delivery box. Again, similar to envelopes, cardboard boxes are fabricated from piece-part sheet material that have been stamped from a flat sheet of corrugated board, using a 30 die-board cutting process, with the resultant mailers being of uniform size. Notwithstanding the above, substantially planar card is frequently employed in the mailing of magazines, calendars and the like, where the substantially rigid card ensures integrity can also be employed; pre-formed envelopes can be provided with short edge openings, but these are slow to pack and despatch; 35 others exist with brown paper on one side with folding tongue for securement against a stiff card backing side.

[0006] In automated systems, double-sided adhesive tape has been employed, but such methods of fastening are susceptible to dust problems. Glue based systems have not been widely successful, despite the wide range of glues available. PolyVinyl Acetate glue (PVA) or is a colourless, odourless, transparent 5 glue that is often used with respect to cardboard and paper, and provides a benefit in that it forms a degree of water resistance, but takes hours to dry. Rubber cement comprises liquefied rubber retained within chemical solvents; when the glue dries, the solvents evaporate leaving a thin solid layer of rubber on the substrate. Whilst rubber-based glue holds pretty well for all cardboard 10 products and benefits from providing a degree of weather-resistance, it is nonetheless, sensitive to the passage of time when the bonds become less secure and the adhesion provided will diminish over time. So called "super glue" or cyanoacrylate gives a fast, permanent bond on many substrates - but it can't be used on porous materials such as paper and cardboard. Craft glues can be 15 employed in a number of situations including paper and cardboard, is relatively thicker than most glues and need time to dry. Hot melt adhesives are basically a gluing material that sticks as it cools down. The product itself came in the form of a solid stick which is dispensed by a heater applicator, but results in relatively inflexible joins between paper and cardboards. However, if too hot the glue will 20 take time to set and too cold, the glue would solidify before you could bond the other piece. Polyurethane adhesive can be applied on basically anything including wood, plastic, glass, and even concrete, but needs hours to properly adhere materials together.

[0007] There exists a need for a more adaptable process for manufacturing 25 cardboard mailers to enable manufacture and filling thereof to be simply, rapidly and sustainably created. Moreover, by providing a body formed from cardboard -or other cellulose fibre - then the item can be readily be recycled after use, using glues that can also be properly recycled as such. Object of the Invention 30

[0008] The present invention seeks to provide a solution to the problems addressed above. The present invention seeks to provide a postal / courier package or mailer which can be manufactured from cellulose board or similar at low cost and can readily, rapidly and easily be constructed. The present invention also seeks to provide a postal / courier package or mailer which can be 35 manufactured in different lengths in a production cycle. Furthermore, the present invention seeks to provide a container that is manufactured from readily recyclable products and when completed can maintain goods within a protective arrangement to protect from physical damage under typical transport conditions. Statement of Invention

[0009] In accordance with a first aspect of the invention, there is provided a 5 process for manufacturing and filling mailers, the process comprising the steps of: receiving a roll of cellulose board or sheet, the roll having an axis of rotation about which the roll can rotate to provide a continuous sheet of cellulose board or sheet in a direction of output, the roll of cellulose fibre board or sheet having a first end distal to the roll, and a second end being at the centre of the roll; 10 feeding the first end of the roll of cellulose board or sheet into a sack forming machine; folding the cellulose board or sheet about a fold axis along a first side in the sack forming machine, whereby to define a central cavity extending from an overlapping edge portion at a distal end to an overlapping edge portion at a proximal end, with an axial overlap section depending from the distal end to the 15 proximal end along a second side; placing an item to be mailed within the cavity; applying a heat sensitive glue on at least one face of mutually opposing overlap edge portions whereby to provide substantially instant adhesion; applying heat and compressive forces to seal an edge portion of the cellulose board or sheet at the distal end; applying heat and compressive forces to seal an edge portion of 20 the cellulose board or sheet along the overlap section; applying heat and compressive forces to seal an edge portion of the cellulose board or sheet at a proximal end; whereby the edges about the cavity are secured; further comprising the step of cutting the cellulose board or sheet at the proximal end whereby to form a mailer. 25

[0010] This procedure is repeated to provide a plurality of mailers. Conveniently, the mailers are labelled whereby to enable mailing of the mailers by a postal system, courier or otherwise. Conveniently, the distance of the axial length between the distal and proximal ends can be varied, whereby to provide appropriately sized mailers, enabling products to be more securely packaged and 30 less susceptible to damage through unwanted movement arising from handling during delivery. This requires association of destination label and product, which can be conveniently be performed by a system controller. It may be preferred to seal a first edge prior to placement of a package with the mailer as it is being formed. The edge can assist with placement and can prevent the package 35 slipping out as the mailer is formed. It will also be appreciated that it would be possible to perform sealing along two edges, leaving one edge unsealed and which edge is sealed subsequent to the placement of the product within the mailer.

[0011] Conveniently the sealing is performed by the use of a glue which can be applied such that it provides substantially instant adhesion. Applicants have 5 found that a cellulose adhesive such as a starch based adhesive can provide a rapid bond for use in sack closing operations, whereby mailers of card or corrugated board can be simply created. Further, by the use of a heater, the adhesive can act in a substantially Instant fashion, noting that this starch adhesive can penetrate into paper fibre providing additional strength to the 10 sealed edges. A system may also operate utilizing the process heat, requiring no or little use of additional heaters. It is of further benefit that starch based 15 adhesive is readily available, provides strong bonds and can be provided at an economical cost. The starch is typically derived from sources like maize and tapioca. Presently, it is the widely used adhesive in the corrugated carton manufacturing industry. Cellulose glue is already used in many corrugated board manufacturing processes and is readily available. The strength of starch glue depends on glue formulation, type of starch, temperature, paper quality, paper quality, glue penetration, running speed. Nonetheless, starch glue, even if appropriately prepared, is water-soluble - i.e. starch glue can reduce in its adhesive strength in a humid environment, and the board loses its strength until total separation occurs. Therefore, additives are generally provided to reduce or prevent such tendencies. For example, water-resistance can be achieved by the use of a resin to cause a cross-linking reaction between the starch / cellulose and the resin, whereby a grid of covalent bonds are formed. 25

[0012] The cellulose glue can be similar to the starch-based adhesives for corrugated boxes have been used in the formation for corrugated products for several years, but have not otherwise been employed. By the provision of a heated roller or other compressing feature - such as opposing die features, the sealed edges are more than sufficiently secure. The adhesion base is on a 30 hydrogen bond between starch molecules of the glue and cellulose molecule of the paper. It has been found that a roller in the form of a "pastry wheel" as used for crimping pastry, additionally with a trimmer disc to ensure that the sealed edges are uniform and coextensive.

[0013] In accordance with one aspect of the invention, the board - plain card, 35 single face corrugate of creased multiwall corrugated board is fed into the sack making machine. In accordance with another aspect of the invention, the sack making machine is positioned downstream of a corrugated board making machine. In accordance with another aspect of the invention, corrugated board of single or twin planar wall construction is also creased with creases defined in directions oblique to the axis of rotation of the roll of card or board. By the provision of such oblique creases, the corrugated paper is permitted to flex in a 5 limited fashion, whereby to permit the corrugated paper to provide an enclosed container with sufficient protection for use in mailers as discussed above. The oblique depression can be formed by one or more rollers which pass over the upstanding corrugations or over one or more of the outer boards or sheets of corrugated board conveniently by way of compressing the corrugations in a 10 specific fashion or by the use of cutting through the corrugations,

[0014] Conveniently, as adhesive is applied to seal the proximal edge seal of a mailer, it has been found convenient to simultaneously or subsequently operate a cutter, to separate the mailer from what then becomes a distal end of the corrugated paper feed. The cutter is conveniently a sharp blade, drawn across the 15 width of the folded over mailer. It will be appreciated that other forms of cutter can be employed.

[0015] Conveniently the application of an oblique compression tool to the upstanding corrugations can reduce the height of the corrugations in a defined pattern whereby to permit a degree of flexibility along an axis defined by such 20 compression markings, enabling a greater degree of freed for placement of a product with a mailer, as it is produced. Alternatively, the markings arise following the application of a scoring device or blade in a series of oblique strokes, whereby to permit a similar degree of flexibility along the axis of the corrugations affected that have been scored or cut. 25

[0016] A benefit of a compression marking or scoring marking along the middle is to provide a simple fashion of folding; this may be offset from a centre; two sets of continuous markings may be applied to permit a mailer with a general triangular section; three sets of continuous markings may be applied to permit a mailer to be formed with a generally quadrilateral section. 30

[0017] In accordance with another aspect of the present invention, there is provided a mailer formed from a single cellulose board or sheet - such as cardboard and corrugated cardboard - which has been folded about an axis closed to define an envelope, with a product volume defined thereby, wherein a perimeter edge is fastened by means of cellulose glue. The axial length is 35 variable on a mailer by mailer basis, if desired or can be changed for different batches of product. As is known, mailer sack-packing system controllers can be programmed or otherwise adapted to associate an addressee with a product and the axial dimensions of the product - as would have been received by an assistant in a manual system or as pre-determined in the case of an automatic system. Whilst each mailer can will be formed from simple, planar card, single sided corrugated paper could be employed. Additionally, such card or board can be 5 provided with a linear region about which a fold can be defined in a packaging machine, where each side of the roll are brought towards each other to enclose a product as the mailer is formed. Conveniently, a starch adhesive is employed which can dry rapidly whilst as the same time being drawn in by surface tension to create a strong bond. Conveniently, the adhesive is heated to ensure a rapid 10 setting of the adhesive.

[0018] In accordance with a general aspect of the invention, there is provided a cardboard mailer for the transport of small - size piece goods wherein the mailer can be produced in a continuous basis; the size of the mailer can be varied between consecutive mailers and between batches of mailings. 15 Brief Description of the Figures

[0019] For a better understanding of the present invention, reference will now be made, by way of example only, to the Figures as shown in the accompanying drawing sheets, wherein: CM Figure 1 illustrates a completed mailer formed from a blank of single face 20 corrugated paper; Figure 2 illustrates a plan view of a blank of a mailer prior to folding and sealing; Figure 3 shows an early form of plastics bubble-pack-lined envelope; Figure 4 shows a typical apparatus employed for manufacturing single face corrugated paper; 25 Figure 5 shows a simple overview of an apparatus of the a mailer production system in accordance with the present invention; Figure 6a shows the portion of sheet material once folded over in an initial step; Figure 6b shows how the folded sheet material with a seal along a first edge; Figure 6c, d show placement of a product in mailer in a third step; 30 Figure 6e shows mailer with product enveloped in mailer during sealing of axial edge; Figure 6f shows a completed mailer 70 with product fully enclosed; Figure 6g shows a mailer that has been sealed ready for separation from the reel of single corrugated paper; Figure 6h shows a simplified manufacturing and control layout of a system in accordance with the invention; Figure 7a shows a section of single face corrugate prior to treatment; Figure 7b shows an apparatus where a single face corrugated paper is treated in 5 accordance with an aspect of the invention; and, Figure 7c shows a section of single face corrugated paper following treatment in accordance with an aspect of the invention; Detailed description of the Preferred Embodiments

[0020] There will now be described, by way of example only, the best mode 10 contemplated by the inventor for carrying out the present invention. In the following description, numerous specific details are set out in order to provide a complete understanding to the present invention. It will be apparent to those skilled in the art, that the present invention may be put into practice with variations of the specific. 15

[0021] Referring now to Figure 4, there is shown an apparatus 40 for making single face corrugated paper. The apparatus 40 comprises a roller 41 for providing a first paper web; a corrugated roller pair 42a, 42b for corrugating a second paper web 18 to produce a corrugated paper web. A mechanism 43 comprising an adhesive tray 43a, a roller 44 operably positioned adjacent 20 corrugated roller 42b, with the amount of glue being controlled by a limit brush 45 whereby adhesive can be applied to the upstanding peaks of the corrugated sheet of paper whereby to enable attachment of the corrugated paper with respect to the first paper web, the second corrugated roller being positioned so as to bring the peaks of the corrugated paper - having glue applied thereto - into 25 contact with the first paper web so as to produce single face corrugated paper 22.

[0022] Sack systems are known in relation to the use of plastics films and the application of the such sack generating systems to provide and fill plastics film mailers - creating mailer bags in the process. The present invention provides an input device for a sack system whereby a proportion of previously developed 30 technology can be adapted to provide a mailer system employing corrugated paper board. Referring in particular to Figure 5, there is shown an input device for a sack system 50. Cardboard sheet 24, optionally printed, embossed or otherwise marked corrugated paper 24 is input into the sack system: roller 51 permits the cardboard paper to be introduced in a downward direction, with any 35 tensioning means (if required) not being shown, the cardboard sheet shown is provided with corrugations on side A, but the invention is not so restricted. The sheet 24 approaches a ploughshare-like feature 52, which causes the corrugated paper to fold about the embossed feature 54, enabling the corrugated paper to overlap itself by way of a fold line 55; roller 53 helps assist the cardboard to be folded, whereby side B provides an external surface to the mailer. Conveniently, 5 the marked corrugated paper is ruled in the sense of providing the fold line 55; the left and right panels to the sides of the ruled line permit folding of the right hand side.

[0023] Turning now to Figure 6a, there is shown a folded-over distal end of the reel of corrugated paper 60, yet to be sealed etc. Simple card could be employed, 10 instead of corrugated board. Figure 6b indicates the provision of a first fastening 61, widthways at the distal end of the paper 60, the fastening being the result of cellulose adhesive being applied followed by the use of a heated roller or stamp (neither shown) which heats up and ensures contact of the two opposing inside edge perimeter portions, with the cellulose binding the two inside faces together 15 in the matter of milliseconds. It will be appreciated that the definition of a closed end 66 to the folded sheet assists with subsequent insertion of a package 65 in the subsequent action - per Figures 6c and 6d - where the package 65 is effectively placed within a half closed / half open mailer-envelope. The apparatus may be provided with an opening device (not shown) operable to ensure that the 20 gap 67 is sufficient to enable placement of the package within the half closed mailer envelope. Once the package has been placed in the mailer-envelope, per Figure 6e, then the side can be sealed, for example by a roller, to traverse the side edge 62, in the direction indicated by the arrow - with an outline of the product 65 being indicated; as the roller approaches the end of the required 25 length of mailer - as determined according to requirements (standard or variable length), then the edge sealing is stopped and a transverse seal applied, by roller or press or the like, whereupon the third sealed edge 63 is created. An "L"-shaped sealing crimp device could be employed to seal two edges simultaneously; two separate sealing crimps, two heated rollers etc., as would be considered 30 appropriate in relation to a specific situation, noting that the lengths of the mailer can be fixed or variable and that different width mailers - as determined by the overall width of the incoming roll of sheet material which is folded over. The sack machine could also provide heated rollers which are utilised as glue is applied and preferably heated to enable setting of the adhesive in a very short period of 35 time.

[0024] Referring now to Figure 6g, there is shown a mailer with edges 61, 62 &63 sealed, with the item ready to be cut from the roll of corrugated paper along line 69. It will be appreciated that in this respect a totally recyclable mailer can be provided. Thus, the mailer envelope is conveniently made from single corrugated paper comprising two-ply corrugated paper preferentially with the exposed corrugation flutes on the inside of the mailer giving optimum cushioning 5 protection effect. The corrugation flutes act as a protection cushioning barrier to protect the contents of the envelope. It will be apparent to the skilled man that a number of variations in the specific procedure can be changed without changing the overall result.

[0025] The glue or adhesive can be applied, generally speaking, by way of a 10 number of processes; it can be applied by brush, it can be applied by roller; it can be applied by continuous dispensing by nozzle or it can be applied by way of focussed, discrete amounts of glue; upon compression and heating the glue is substantially evenly spread. It is presently preferred to employ a liquid glue applied by jet nozzles, with a glue feeder comprising a milk churn-like container 15 which can accommodate sufficient glue for a procedure - time limited in terms of the length of card / cardboard that can be provided from a roll in a particular application. For example, the glue feeder can comprise a 10 litre container, provided with approximately 8Kg of glue - approx. 75% full - with compressed air acting as a propellant and operating at a pressure of 50 Bar. The glue will be 20 provided by nozzles guided to the edge portions of the mailers to be formed. As will be appreciated, a number of fixed jets could apply glue in a regular fashion to the proximal and distal edge, which are perpendicular to the axial direction of movement of the mailer; whilst the edge opposite to the fold could apply the adhesive concurrent with an axial movement of the mailer. It will be appreciated 25 that the nozzles can be fixed, mounted for linear motion or be provided on an articulated platform. Additionally, for certain types of glue, there may need to be provided nozzle-baths for the periods of inactivity of the dispensing nozzles, so that glue does not set upon the nozzles in between use. Such nozzle-baths may also be provided with a water supply and a level control since the processing are 30 will generally operate in a raised temperature atmosphere, noting that the systems uses heaters.

[0026] Viscosity is a principal parameter when any flow measurements of fluids, such as liquids, semi-solids, gases and even solids are made; initial results have been provided with a glue viscosity between 9000 and 1500 milli-Pascal-seconds 35 (mPa-s). It will be appreciated that viscosity measurements are necessary to ensure uniformity of application and to enable adjustments to determined, as known to those skilled in the art of flow characterization, in research or development, etc.. Nonetheless, other manufacturers of spray systems can provide spray systems that utilise pressurized glue to enable sufficient coating on a timed basis without the use of compressed air, whereby to provide controlled delivery of glue. It is worth noting that in paper processing industries, print and 5 glue applicators can define widths of 1mm with respect to sheet material passing such applicators at rates of 14ms 1 or more. By the use of spray nozzles, then articulated mounts for the nozzles can assist in ensuring appropriate uniformity of application, even when traversing about corner sections. It is typical for glue jets to be placed 1cm apart for the widths of mailers to be sealed. 10

[0027] Referring now to Figure 6h, there is shown a first system; the roller referenced 18 in Figure 5 is powered by a motor Ml; the motor is under the control of a controller Cl, having an input console IS. The controller is also operable to control a second motor M2, which assists in folding the sheet prior to placement of the product. Additionally, the controller also provides signals to 15 actuators associated with the glue applying system, comprising jets operable across the width of the sheet JW (once folded) and along the axial path, at the side, JA, together with trimming element, which is used in conjunction with heated press, HPW and HPA, comprising a heated die and a heated roller, respectively, for enabling the glue to be heated and fasten the respective 20 opposing distal, proximal and side edge portions. The die and the roller compress against a support surface - which supports the board as it passes through the machine. An edge trimmer, ET, is provided to ensure the edges of the mailer are as smooth as possible. The edge trimmer and heated side roller could be combined into a single unit. A guillotine could be provided, but the movement 25 must be synchronized as the sack producing equipment, in operation, is continuously producing mailers.

[0028] It will be realized that when the edge seams are brought together, the system must be set up such that compressive forces do not permit glue to be squeezed out of a seam margin. Also, as described above, by crushing both ends 30 in the width direction of the envelope front surface portion and the envelope back surface portion to form a glue margin portion, when the adhesive is applied in a line shape to the upper and lower sides of the envelope of the adhesive. It is possible to prevent any unwanted spread of the glue. That is to say, according to the present invention, the adhesive is compressed as described above to form an 35 adhesive margin, and an appropriate amount of adhesive is applied to the adhesive margin from the folded portion to a predetermined range in the length direction of the envelope. It also needs to be stated that the glue is selected to set extremely quickly to prevent this from occurring and can be attached with sufficient adhesive strength. Whilst the width of the sealed edges can be as low as a couple of millimetres, and be greater than 1cm, however, for a normal mailer, it has been found that a width of 3 - 6mm has been found to be suitable 5 for most applications. Notwithstanding this, it will be appreciated that the present invention need not be so limited.

[0029] It will be realized that whilst the width of the mailer is pre-determined by the width of the board introduced Into the sack making machine and Is approximately half - noting that the cavity will tend to reduce the width of the 10 package, the axial length of the edge seem is not so limited - rather it is determined by the size of the sack making machine and the capability of the seam forming wheels / plates employed to apply adhesive / glue and heat the same with a degree of compression to ensure that a good seal is consistently made. 15

[0030] Figure 7a shows a portion of single face corrugated paper 70 in plan view indicating troughs 72 and peaks 73 of such paper. A central axis 75 is indicated, where the paper is conveniently folded to provide a single wrap for a mailer as CM shall be discussed below. CM

[0031] Figure 7b shows an apparatus wherein single faced corrugated paper 22 is 20 treated by a roller 76 having at least one of flattening ridges or cutter elements, O) the ridges or cutting elements being operable to at least flatten or cut slits in the upstanding peaks 73, in accordance with the pattern 77 as indicated especially in Inset Figure 7b, so as to form a criss-cross or patterned arrangement of flattened or cut upstanding elements 29 in the resulting processed single faced corrugated 25 paper, as indicated in Figure 7c. This criss-cross or patterned arrangement enables the single face corrugated paper to be less still in the direction of the corrugate flutings. Additionally, the central axis is also one of flattened / compressed or cut to assist in subsequent folding.

[0032] As will be known to the skilled man, cardboard, corrugated paper and 30 card is produced in many styles. Firstly, the paper from which the facing side is manufactured can be of variable quality; it can be relatively stiff or flexible, noting that once cardboard has been formed the flutings of corrugations add stiffness. As discussed above, effectively, a standard sheet of single faced corrugated cardboard is made from two components. Each side of the fluted 35 material is glued to the flat paper liner during manufacture. The glue fixes the flutes in position and adds rigidity and stability to the papers. One of the key factors that define the properties of the corrugated material is the types of paper used.

[0033] Despite the widespread use of cardboard, there are two main types of paper that are generally used for the liners. These are known as Kraft and Test 5 liners. Kraft paper is manufactured from softwood trees. Due to the "virgin" fibres, it is both the strongest type of paper and also the easiest to print on. As a result, it is the most commonly used outside liner when selecting material to produce corrugated boxes and packaging. Each liner type is actually comprised of two distinct layers. A basic layer is used adhesion and strength, whilst a finer 10 "cover" layer is used mainly for improved aesthetics and to aid printing. However, despite Kraft and Test liners being so popular, there are in fact a number of other options as can be seen form the following list of commonly available paper grades for outer and inner liners when manufacturing cardboard, employing various amounts of recycled paper and virgin fibres, depending upon 15 the quality desired or required.

[0034] Another significant issue to consider is the weight of paper employed, generally expressed in grammes per square metre, gsm, whilst the type (and CM number) of fluting must also be considered in relation to corrugated board. The £\j flute is the "corrugated" section between the two liners, and by changing its' 20 height (and therefore the size of the flutes) it is possible to achieve different Q} performance characteristics, here are also a number of commonly used flute profiles or sizes, which are as follows:

[0035] Whilst this list is not exhaustive, the issue is complicated by the fact that many producers of corrugated material make very similar products which referred 25 to by trade names, which are very often quite arbitrary and will necessarily be exclusive to such a manufacturer or re-seller. Whilst the present invention has been described in relation to single face corrugated board, it will be appreciated that a two-faced corrugate board could also be treated in a similar fashion, although it has been found to be less successful when crushed or rolled and the 30 use of a knife to enable bending is preferred, in a similar fashion to the cutting of slots in plywood to permit bending thereof.

[0036] In the case of such an envelope, as described above, the single-sided corrugated cardboard is used so that the ridges of the corrugated step portion of the central base paper are perpendicular to the axial movement of the reel of 35 single corrugated paper. Necessarily, this product is manufactured in a continuous web fashion and discrete mailers can be continuously manufactured, filled and then despatched, which lends the system to simple and rapid 09 12 24 automation. It will be appreciated that the whilst the fluting is normally most easily produced with the axis of the corrugate flutings being perpendicular to an axial length of corrugated paper stored on a reel, variations where the flutings are arranged in distinct angles to the perpendicular. 5

[0037] It will be appreciated that the rulings created when forming the creases may be of two or three or more, to enable the mailer to be formed in an overall triangular, rectangular etc. in cross section, although this would require complex handling equipment to enable seemingly awkward shapes to be produced as mailers. 10

[0038] The corrugated material in respect of either or both the liner and corrugate sheet material can be coated with a water resistant coating such as Polyethylene or BioP BS or similar bio-degradable coatings. The BioP BS coating is one of a number of coatings made from bio-degradable materials and is preferentially incorporated into the tamperproof design to water proof the exterior 15 or interior or both. The coatings are also used to increase tensile strength plus puncture and tear strength of the envelope. The coatings also eliminate any paper smell as the coating seals the paper or envelope medium and is odourless. BioPBS is a biodegradable and compostable bioplastic material which can be used as a barrier on paper products such as cups and bowls. Available from the 20 Mitsubishi Corporation, it is fully certified and food-safe. Nonetheless, it is preferred that the mating surfaces of the materials are not treated, given that the coating can reduce the efficacy of the starch glue.

Claims

1) A process for manufacturing and filling mailers, the process comprising the steps of;5 receiving a roll of cellulose fibre board or sheet, the roll having an axis of rotation about which the roll can rotate to provide a continuous sheet of cellulose board or sheet in a direction of output, the roll of cellulose board or sheet having a first end distal to the roll, and a second end being at the centre of the roll;feeding the first end of the roll of cellulose board or sheet into a sack forming 10 machine;folding the cellulose board or sheet about a fold axis along a first side in the sack forming machine, whereby to define a central cavity extending from an overlapping edge portion at a distal end to an overlapping edge portion at a proximal end, with an axial overlap section depending from the distal end to the 15 proximal end along a second side;placing an item to be mailed within the cavity;applying a heat sensitive glue on at least one face of mutually opposing overlap edge portions whereby to provide substantially instant adhesion when heated;applying heat and compressive forces to seal an edge portion of the cellulose 20 board or sheet at the distal end;applying heat and compressive forces to seal an edge portion of the cellulose board or sheet along the overlap section;applying heat and compressive forces to seal an edge portion of the cellulose board or sheet at a proximal end;25 whereby the edges about the cavity are secured;further comprising the step of cutting the cellulose board or sheet at the proximal end whereby to form a mailer.2) A process for manufacturing and filling mailers, according to claim 1,30 wherein the claimed process is repeated to provide a plurality of mailers.3) A process according to claim 2, wherein the mailers are labelled whereby to enable mailing of the mailers by a postal system, courier or otherwise, upon packaging.4) A process according to any one of claims 1-3, wherein the distance of the axial length between the distal and proximal ends can be varied, whereby to provide appropriately sized mailers.5) A process in accordance with any one or more of claims 1-4, wherein first and second edges are sealed prior to insertion of the product to be mailed.56) A process in accordance with any one or more of claims 1-5, wherein the sealing is performed by the use of a glue which can be applied prior to placement of a product and that heat is applied to the unsecured edges as the mailer is sealed, in a subsequent step.107) A process in accordance with claim 6, wherein the glue comprises a cellulose based composition.8) A process in accordance with claim 7, wherein the cellulose based glue15 further comprises additives provided to reduce or prevent water solubility.209) A process in accordance with claim 7 or 8, wherein the adhesive comprises a starch based adhesive.10) A process in accordance with any one or more of claims 1-9, wherein the board is corrugated and oblique markings are defined by way of compressing the corrugations in a specific fashion, whereby the corrugated paper is permitted to flex in a limited fashion.25 11) A process in accordance with any one or more of claims 1-9, wherein theboard is corrugated and oblique markings are defined by the use of cutting through the corrugations, whereby the corrugated paper is permitted to flex in a limited fashion.30 12) A process in accordance with any one or more of claims 1 - 11, whereinthe sealing is performed with the assistance of a heater to assist in a rapid setting of seams.13) An apparatus for manufacturing and filling mailers, the apparatus 35 comprising;an input device for providing a roll of cellulose fibre board or sheet, the roll having an axis of rotation about which the roll can rotate to provide a continuous sheet of cellulose board or sheet in a direction of output to a sack formingmachine, the roll of cellulose board or sheet having a first end distal to the roll, and a second end being at the centre of the roll;an input roller to a sack forming machine, operable to receive cellulose board or sheet from the roll of cellulose board or sheet and to feed the first end of the roll5 of cellulose board or sheet into the sack forming machine;the sack forming machine having a folding tool, operable to fold the cellulose board or sheet about a fold axis along a first side in the sack forming machine, whereby to define a central cavity extending from an overlapping edge portion at a distal end to an overlapping edge portion at a proximal end, with an axial 10 overlap section depending from the distal end to the proximal end along a second side;a product placement arm, operable to place an item to be mailed within the cavity;a heat sensitive glue applicator operable to apply a heat sensitive glue on at least 15 one face of mutually opposing overlap edge portions;a heated roller operable apply heat and compressive forces about the edge portions to seal said edge portions operable to provide substantially instant adhesion when heated and to seal the edges whereby the edges about the central cavity are secured; and20 a cutter operable to cut the cellulose board or sheet at a proximal end whereby to form a mailer.14) An apparatus for manufacturing and filling mailers, according to claim 13, wherein the claimed process is repeated to provide a plurality of mailers.2515) An apparatus according to claim 13 or 14, further comprising a labelling device whereby the mailers are labelled whereby to enable mailing of the mailers by a postal system, courier or otherwise, upon packaging.30 16) An apparatus according to any one of claims 13 - 15, wherein the distanceof the axial length between the distal and proximal ends can be varied, whereby to provide appropriately sized mailers.17) An apparatus according to any one or more of claims 13 - 16, wherein the 35 glue applicator is selected from one of a brush, roller or nozzle.18) An apparatus according to claim 17, wherein the glue nozzle is provided with a nozzle-bath to keep glue free-running during periods of inactivity.19) An apparatus according to any one or more of claims 13 - 18, wherein a first edge is sealed prior to insertion of the product to be mailed.5 20) An apparatus according to any one or more of claims 13 - 18, wherein firstand second edges are sealed prior to insertion of the product to be mailed.21) An apparatus according to any one or more of claims 13 - 20, wherein thefolding tool of the sack forming machine is operable to create a plurality of10 creases to enable a mailer to be formed having a general triangular orrectangular shape22) An apparatus according to any one or more of claims 13 - 21, wherein there is further provided a roller placed between the supply roll and the input 15 roller, wherein the roller is provided with oblique upstanding ridges which act to define oblique markings which are operable to compress the upstanding corrugations in a specific fashion, whereby the corrugated paper is permitted to flex in a limited fashion.20 23) An apparatus according to any one or more of claims 13 - 21, whereinthere is further provided a roller placed between the supply roll and the input roller, wherein the roller is provided with oblique cutting ridges which act to define oblique markings which are operable to cut through the upstanding corrugations, whereby the corrugated paper is permitted to flex in a limited 25 fashion.

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