Patent Application
20240270423
The present invention relates to the field of the transportation and storage of goods and to a passive temperature control system for such transport and storage cartons. The present invention also relates to the field of a manufacturing assembly for cold chain cartons and box-type containers.
In the field of logistics, that is the field of movement and supply of produce and materials, there is a substantial requirement for the provision of a temperature control system to ensure that certain types of produce and materials do not pass through temperature thresholds. It is well known that, for example, vegetables when subject to extremes of temperature that they become flaccid, as the cell structure is broken down through the formation of icicles or through dehydration. Similarly, in the transport of drugs and vaccines and certain other chemicals, a solution may separate or become solid. It will also be appreciated that even relatively small amounts of pharmaceutical product can cost thousands of pounds or more; temperature deviations from an allowed temperature can become very expensive; such goods typically having journey temperature plotting indicators, whereby any temperature deviation means that product is discarded and destroyed, irrespective of the cost of the product.
In essence, in any transport container with a thermally sensitive load, the rate at which heat passes through the packaging material of the transport container—the amount of heat that flows per unit time through a unit area with a temperature gradient per unit distance must not extend beyond a permitted temperature range for the product. Temperature control of thermally sensitive goods is particularly challenging when the thermally sensitive goods must be maintained within a narrow temperature range, irrespective of the ambient temperature—from, for example, a tropical runway at 30° C. to −40±20° C. outside air temperature for an aircraft at a service ceiling of the aircraft at 42,000 feet; whilst the temperature of the hold will be greater, it will nonetheless be susceptible of getting quite cold.
Typical means for shipping temperature sensitive materials involves the use of an insulated box, with the necessary shipping and warning labels, along with some cooling agent. These cooling agents have typically been, for example, a frozen gel, dry ice, or wet ice, placed within an insulator packing agent, such as cotton or, latterly, plastics materials such as expanded polystyrene foam, wherein heat is absorbed by such cooling agents.
Multilayer insulation (MLI) is the most common passive thermal control element used in transport. MLI seeks to prevent both heat losses to the environment and excessive heating from the environment. Low cost temperature control in the transport industry relies upon MLI to retain an inside temperature subject to the thermal path to a transported product from an outside the outside to maintain ideal operating temperature. MLI can simply comprise layers of plastics foam; more complex MLI can consist of an outer cover layer, an interior layer, and an inner cover layer. Some common materials used to the outer layer are fiberglass woven cloth impregnated with PTFE Teflon, PVF reinforced with Nomex bonded with polyester adhesive, and FEP Teflon. The general requirement for interior layer is that it needs to have a low emittance. The most commonly used material for this layer is Mylar that is aluminized on both or one side. The interiors layers can be thin compared to the outer layer to save weight.
There is an increasing use of vacuum insulation panels (VIP), which have been developed for use in the manufacture of the walls of refrigerators and freezer and for transport containers and insulated shipping cartons, ice storage tanks, etc. A vacuum insulated panel (VIP) comprises a special composite made of core materials surrounded by an external impermeable, protective sleeve. The core materials comprise highly-porous materials, such as fumed silica, aerogel, perlite, or glass fibre. These core materials are rigid to space and support the sleeves from imploding due to atmospheric pressure once the air is evacuated. The vacuum insulation, provided with getters to associate and absorb any gasses that may have leaked through or have off-gassed from the protective sleeve, effectively prevent convective heat transfer to perfect its thermal insulation. Membrane walls, used to prevent air from entering the panel. The vacuum is considerable and can be as strong as 1 mbar, which make the panels susceptible to damage. VIPs are vulnerable during manufacture, transport, and fabrication, during applications and in use since the barrier film is very easily punctured. A simple puncture will immediately reduce the insulation value of the panel to no better than a PU foam.
With a thermal conductivity of as low as 0.0015 w/m·K to 0.0025 W/m·K, the thermal resistance of vacuum insulation panels can be approximately ten times higher than those conventional insulation materials. Through increasing the degree-of-vacuum of vacuum insulated panel to the limit, these thermal insulation products provide a high-performance insulation such that energy is saved in not maintaining active cooling systems etc. Vacuum insulated panels support the trend of CFC-free thermal insulation. The thermal resistance per unit price is much less than conventional materials: VIPs are more difficult to manufacture than polyurethane foams or mineral wools, and strict quality control of manufacture of the membranes and sealing joins is important if a panel is to maintain its vacuum over a long period of time. Air will gradually enter the panel, and as the pressure of the panel normalizes with its surrounding air its R-value deteriorates. Conventional insulation does not depend on the evacuation of air for its thermal performance, and is therefore not susceptible to this form of deterioration. Nonetheless, vacuum insulation panels are increasingly being used in ultra low temperature containers and cartons for medical products such as medicines, vaccines and the like, where the temperature is maintained at the sublimation temperature of dry ice.
Dry ice is a solid form of carbon dioxide. Its advantages include an ability to reduce a temperature of a body significantly lower than that of water ice and in not leaving any residue (other than incidental frost from atmospheric moisture). It is useful for preserving frozen foods where mechanical cooling is unavailable. Dry ice sublimates at 194.65K (−78.5° C.; −109° F.) under normal atmospheric pressures. This extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing (frostbite). Additionally, although not particularly toxic per se, the outgassing from dry ice as used in packaging can cause operatives involved in cold chain delivery procedures to suffer from hypercapnia (abnormally elevated carbon dioxide levels in the blood) due to build-up in confined locations. There are, however, additional problems when used in packaging which are exacerbated by this outgassing: the gaseous pressure within a container increases. Carbon dioxide is a cheap, inert, non-toxic and easy to liquefy. Although it is deadly in highly concentrated amounts, this characteristic can assist in the prevention of the multiplication of microbes in a carton or package. It will be appreciated that this pressure will be greater than an external atmospheric pressure and so any gaps between adjacent panels will be prised further open by the gas as it seeks to gain equivalence in pressure with the external atmosphere. Further, given that dry ice shipments give rise to the evolution of carbon dioxide gas during shipment it is widely considered as being so dangerous to shipping personnel that hazard warnings must be posted and additional fees are required to be paid; indeed, outright bans on dry ice are pending in several areas. With reference to
Blood, meaning transfusion blood, must be maintained within a close temperature range of between +1° C. and +6° C. during its passage between donor and receiver. Various biological products, such as platelets, whole blood, semen, organs and tissue, must be maintained above a predetermined minimum temperature and below a predetermined maximum temperature. Pharmaceutical products are also commonly required to be kept within a specified temperature range. Food products, flowers and produce frequently have preferred storage temperature ranges as well. Indeed, certain types of goods have stringent standards to be adhered to. For example, as part of a World Health Organisation (WHO) pre-qualification scheme, vaccine manufacturers are expected to ensure their packaging complies with the criteria as determined in one of three classes of packaging: Class A packaging; Class B packaging; and, Class C packaging.
Numerous insulated shipping containers have been developed over the years, with those deploying a phase change material (PCM) generally providing superior temperature control over extended periods. Insulated shipping containers employing a PCM can be deployed for a wide range of thermally sensitive goods over a wide range of target temperatures by using different PCMs. For example, D2O melts at +4° C., H2O melts at 0° C., a 20% ethylene glycol solution melts at −8° C., castor oil melts at −10° C., neat ethylene glycol melts at −12.9° C., mineral oil melts at −30° C., and a 50% ethylene glycol solution melts at −37° C. This permits use of insulated shipping containers for a broad range of thermally labile goods.
Presently, there are few containers for ultra low temperature distribution:
It is important to note that the typical value of medicines, vaccines etc. is high; if there has been a temperature excursion out of a required temperature range, then transport protocol demands that the goods are discarded given that the effects of a potentially thermally damaged medicine cannot be permitted to be utilized. All thermally labile products when transported will have temperature data logging equipment which will ensure that only properly stored goods will be used. The failure of any transport container for such goods is unacceptable. It will be realized that any failure will necessitate a repeat delivery, doubling the cost of what may so easily be an extremely valuable product, which may also delay treatment of patients in hospitals and elsewhere, often in time-critical situations, as is being borne out during the C-19 pandemic of present times.
The present invention seeks to provide a solution to the problems addressed above. The present invention seeks to provide a simple system for the manufacture of a sealed insulation panel arrangement for placement within a temperature controlled transport container or carton. The present invention also seeks to provide a temperature controlled transport/storage assembly for goods palletised or otherwise, whereby goods can be maintained within an atmosphere having a predefined temperature range. The present invention also seeks to provide a sealed insulation panel arrangement that is constructed such that it can be maintained and panels thereof be replaced in a simple and reliable fashion.
In accordance with a general aspect of the invention, there is provided a method of providing an insulating carton for use in a rectangular/cubic cold-chain container, the insulating carton being formed of four side insulating panels about an axis, together with a base insulating panel arranged orthogonally to the axis, with each insulating panel having four edges, with respective adjacent panel edges mutually abutting, the carton having side walls with mutually orthogonal first and second parallel edges having first and second lengths (L1 & L2) with the side panels extending a depth D to the base, the panels having a thickness T; wherein the method comprises the steps of: Selecting a cubic former for the insulating carton, having external dimensions in correspondence with the dimensions of an interior cavity of the insulating carton; Placing the panels about the former, whereby an inside face of each panel is directed towards a corresponding outside face of the former and an external face of each panel is directed away from the axis; Applying adhesive tape about the external faces of the panels, the tape having a width greater than the depth of the carton; and, folding tape extending from the sides of the towards the base, to secure the side panels to the base. Conveniently the tape extends from an open end of the container about an edge of the side panels and this is folded or wrapped over the edge. Conveniently the mandrel is arranged for rotation about an axis in correspondence with a central axis of the carton. In practice, the tape could be formed by two or more tapes which overlap to a degree, but are applied at the same time whereby, for example, different width tapes can be utilized to cope with different height panels, without creating significant manufacturing problems. It will be appreciated that the base panel could be arranged so as to fit inside the inside faces of the wall panels; equally the base panel could be arranged to abut the lower edges of the wall panels.
The insulation panels are preferably selected from one of the following types: Vacuum insulation panels, expanded polystyrene panels, polyurethane panels, card, plastics card, corrugated plastics, cardboard and corrugated cardboard panels. Conveniently, the mandrel is provided with tack strips such that it permits the application of a further tape which is applied to the former prior to the placement of insulation panels, whereby the adhesive tape can be applied an inside surface of the carton. The base is generally rectangular; in the event that the base is square, then the first and second lengths (L1 and L2) will be the same. Card and cardboard panels when manufactured to provide a high degree of rigidity, through the use of waterproofing and other agents and multi-layer cardboard and corrugated cardboard including multi-layer corrugated board such as tri-wall corrugated cardboard can prove to be difficult to fold, causing breakage of the board leading to the creation of cracks and fissures in the material leading to passage of gases therethrough.
Conveniently the fabrication process can be performed—at least in part—following damage suffered to one or more panels, whereby cartons that have been damaged in use can have their one or more damaged panels replaced, thereby reducing waste by not necessitating the replacement of the whole carton. It has been found that by the use of low tack adhesives, the tape can be easily removed, without providing a significant inconvenience. The present invention also provides a fabrication system including a mandrel operable to retain two or more thermally insulating panels about an axis and to maintain the mandrel in a position to receive a plastics film, to enable the adhesive tape or film to be wrapped about the panels whereby to enable the film to secure the panels one with respect to the other whereby to define an open container to be closed by a further panel and placed within a cold chain carton.
In accordance with a general aspect of the invention, there is provided a temperature controlled transport/storage container for transporting/storing temperature sensitive materials the container comprising a receptacle therewithin, wherein the receptacle comprises: a number of thermally insulating panels retained by an adhesive plastics film about an outside of the container. In use the container is closed by a closure panel or lid having similar thermal insulating properties.
The present invention also provides a fabrication system including a mandrel operable to retain two or more thermally insulating panels about an axis and to maintain the mandrel in a position to receive a plastics film, to enable the plastics film to be wrapped about the panels whereby to enable the film to secure the panels one with respect to the other whereby to define an open container to be closed by a further panel and placed within a cold chain carton.
The temperature control panels can be configured to provide a thermally stable atmosphere within a payload volume for a number of days as is typical for international travel, for example. The present invention can, by the use of specially adapted thermal modelling software, be optimised for particular goods for specific transport and storage time with respect to a specific situation.
The present invention also provides a general form of container comprising multiple panels that have been adhesively secured together, which carton can be employed in areas where gaseous control is required.
The present invention can thus provide a simple to use solution, for the preparation of a receptacle for use in a cold chain transport system that is easy to make and is less susceptible to permitting gaseous escape between the insulation panels.
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:—
There will now be described, by way of example only, the best mode 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.
In order to seek to overcome the issues of failure of multiple tape fastenings, Applicant has devised a mandrel-like support for the individual placement of insulation panels, to enable fastening thereof prior to placement within a container, such as a cardboard or plastics corrugated shipping container. With reference to
Referring now to
A source of heat such as the use of a hot air gun (not shown), or other substantially inert gas, may be applied to heat the tape and the adhesive to assist adhesion. The adhesive tape need not have a tremendous degree of strength in its bond, given that the tape contacts a large planar surface; indeed it is helpful, for maintenance that the tape be easily removable. Adhesive tack is the property of an adhesive that enables it to instantly form a bond when brought into contact with another surface (which may be another adhesive). Adhesive tack tends to be a more variable property than other properties of an adhesive since it depends on so many different factors. Control of tack is important in operations where instant bond strength is needed. However, in many assembly or packaging applications tack strengths may need to be limited to allow separation and refitting of parts. Adhesive tack depends on the adhesion between the adhesive and the surface and the cohesive strength of the adhesive. Tack properties are thought to depend on the visco-elastic characteristics of the polymer adhesives. Good adhesive tack is normally achieved when the adhesion strength is greater than the cohesive strength of the adhesive (or the substrate).
Inventors note, however, that in order to provide serviceability, the adhesive properties could be easily removable—sometimes known as “clean peel” adhesive. Although typical characteristics at STP cannot be guaranteed for applications where product would remain at temperatures in the region of −90° C.-60° C., inventors realized positive results during tests. Moreover, and as alluded to above, the folding of a “clean peel” adhesive tape will require a greater degree of tape to extend and to be folded down, since a “clean peel” tape necessarily has a reduced degree of tack.
Referring now to
In the next step of fabrication, the carton is removed from the mandrel and turned into an upright orientation as shown in
The particular tape employed needs to be operable at low temperatures and it has been found that polypropylene tapes can be used at low temperatures, especially when reinforced by fibre/mesh. Whilst it seems that tape manufacturers such as Intertape Polymer Group and 3M does not recommend the use of their low temperature tapes inventors have determined, that, nonetheless e.g. 3M VHB tapes have fared reasonably well in exceedingly cold temperatures. It is also possible to use shrink wrap tapes—commonly employed for retaining goods on a pallet; the films are stretched and then heated to tauten the wrap and secure the panels. Other types of tape can also be used such as mono-oriented polypropylene (MOPP) film, which is a film which has an ability to stretch in a direction of application. It has been found that tape with reinforcement fibres can assist in the integrity of a tape, such as by the use of glass-fibre reinforcement. The fibres assist in the maintenance procedures, since, when using a low adhesive bond the tapes can be removed, when replacing, for example one or two damaged insulation panels. Inventors have found that a range of formulations of silicone, rubber and acrylic adhesives can be employed and are known form applications such as re-sealable food packaging, powder coat paint masking, glazing, touch screens etc. It will be appreciated that latent residue could change the dynamic of any subsequent wraps that will arise in maintenance issues. It is known that typical widths of such films available in practice range from a couple of centimetres to a couple of meters, which is sufficient for the intended use of fastening insulation panels. During development, it was also noted that several tapes would tend to delaminate—i.e. a tape could not be completely be removed, which might affect intended performance or ability to be processed in a remanufacturing process.
The present invention has been deployed primarily to secure vacuum insulation panels which are quite fragile and provide extremely good thermal characteristics, especially under low temperature conditions, given that there is an elimination of draughts that would otherwise occur. This may be considered as, ordinarily speaking, rather insignificant. However, given that the temperature delta ranges that will be typically of the order 70-110K with respect to ambient, together with the off-gassing of dry ice, the effect of the present invention is significant. Applicants have found that the panels effectively eliminate the passage of gas between the panels. The adhesive types are selected to provide a simplicity of application with an ability to be easily removed when required so that damage to one or two panels does not require the replacement of a five-sided carton. Notwithstanding this, it has been found that the techniques employed with respect to panels such as vacuum insulation panels but also to other forms of panel, where ordinary folding techniques, as traditionally employed in cardboard box manufacture, for example. As discussed above, folds can lead to breakage of the board leading to the creation of cracks and fissures leading to air passages within the material, leading to gas flow therefrom and thus making such containers less useful, especially in cold chain transport applications. Indeed, thicker cardboard, notably multi-layer corrugated board (such as the so-called tri-wall quad-wall etc. corrugated board) and can have edges mitred to enable close fit between panels and then be adhesively fastened. The base panel can also have edges abutting the side panels mitred, with the sidewalls correspondingly mitred with respect the base panel, which, incidentally also may assist assembly techniques, with the apparatus necessarily being adapted to enable this to happen.
It will be appreciated that cold chain cartons need to be comply with industry standard requirements as defined by the International Safe Transit Association (ISTA) which is a global alliance of shippers, carriers, suppliers, testing laboratories, and educational and research institutions focused on the specific concerns of transport packaging. In particular, ISTA provides a drop test ISTA 3A, which address the integrity of boxes and cartons for freight; the ISTA 3A testing procedure is a general simulation test for individual product packages sent via a package delivery service such as UPS, DHL, FedEx, etc., whether by air or land. ISTA specifies that the 3A testing procedure covers the testing of individually packaged products weighing not more than 70 kilograms (150 pounds) when prepared for shipping via a package transport company.
In accordance with another aspect of the invention, there is provided a further variant in the method of fabrication, as shall now be discussed with reference to
The present invention permits a simple method of fabrication of a leak-proof insulation container, using simple and readily available adhesives: In view of the use of the material, it has been found to be simple to replace one or more insulation panels in the event of damage through mishandling or otherwise. Whilst it is possible to remove adhesive and tape, Applicants have determined that this is not absolutely necessary and that the tolerance so packaging permit one or more layers of tape to be employed as will necessarily arise in use. Whilst specific reference has been made to vacuum insulation panels, which are typically relatively brittle and more susceptible to damage, the technique can be applied to other types of insulation panel such as expanded polystyrene. Moreover the present invention provides a benefit in performance together with a benefit in reducing waste, since separate panels can be replaced rather than the inside carton of a cold chain transport product. It has also been found that the use of tape in conjunction with the sidewall material of vacuum insulation panels has reduced degradation of the panels though gas permeation.
It will be appreciated by those skilled in the art that variations can simply be applied. For example, where the height of a box is greater than the width of available roll of tape, two (or more) tapes could be applied in parallel fashion, with degree of overlap to ensure sealing is effected over the height of the box and the join with the base panel. Non-adhesive tape may be employed and adhesive may be applied by spray to either a tap or a surface to which the tape is applied. Once the arrangement of panels have been secured together by means of the tape surrounding the panels, whereby there are no gaps at the edges between adjacent panels, the section of film extending perpendicularly to the base panel 44, can be folded toward the base panel to secure the arrangement externally.
The present invention thus allows for a simple fabrication of a receptacle having extremely high thermal insulation qualities, providing elements that can be used not only in standard cold chain logistics containers and cartons abut also in ultra low temperature containers where the operating temperature can be less than −80° C.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2108341.5 | Jun 2021 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/025273 | 6/10/2022 | WO |
