WO2016162451A1

WO2016162451A1 - A multi-layer cold specimen transport container without active cooling.

Info

Publication number: WO2016162451A1
Application number: PCT/EP2016/057679
Authority: WO
Inventors: Theo VAN DER LEIJ; Srinivas VANAPALLI
Original assignee: Twente Universiteit; PamGene BV
Current assignee: Twente Universiteit; PamGene BV
Priority date: 2015-04-09
Filing date: 2016-04-08
Publication date: 2016-10-13
Anticipated expiration: 2017-10-09

Abstract

The present invention relates to a system and method for transporting frozen samples. More particularly the system and method preserves the low temperature of the samples during transport without requiring active cooling to take place. By providing a highly efficient form of insulation materials combined with thermal storage materials the increase of the temperature during transport is so low that active cooling is no longer required.

Description

A MULTI-LAYER COLD SPECIMEN TRANSPORT CONTAINER WITHOUT ACTIVE

COOLING

FIELD OF THE INVENTION

The present invention relates to a system and method for transporting frozen samples. More particularly the system and method preserve the low temperature of the samples during transport without requiring active cooling to take place. By providing a highly efficient form of insulation materials combined with thermal storage materials the increase of the temperature during transport is much lower than the conventional cold logistics containers and also eliminates the need of active cooling.

BACKGROUND OF THE INVENTION

Access to frozen biopsies is of tremendous importance to improve the treatment choices for patients. In order to be able to perform contemporary molecular biology technologies, such as RNA testing or protein (kinase, protease, nucleic hormone receptor...) activity testing, fresh/frozen tissue samples are a prerequisite. The problem is that frozen patient material such as a biopsy is not regarded as a routine source for diagnostic testing in clinical practice, and the routine practice in a hospital does not include a simple and reliable solution for collecting, storing, preserving and transporting these samples.

When a disease such as cancer, a cardiovascular, an inflammatory or an infectious disease is suspected, the best hope for long-term survival for the patient is an accurate diagnosis in the earliest detectable stage of the disease. For this purpose tissue acquisition is required for which a variety of techniques can be applied such as a transdermal macro biopsy, a vacuum assisted biopsy, a laparoscopic tissue acquisition, tru-cut biopsy, or a fine needle aspiration. After freezing the samples, often a transport step is required to bring the sample to a location where the necessary test can be performed. This may be a nearby laboratory, but sometimes transport over longer distances is required. Also other temperature sensitive materials such as vaccines or enzymes are sent to remote locations for use.

In current practice, the shipping of temperature sensitive payloads typically include using insulation materials, such as foam peanuts, expanded foams, etc. Various other containers have employed the use of coolants such as dry ice to protect the payload from hotter or colder ambient temperatures during transport. Often, also during the transport of the temperature sensitive payloads, active cooling is applied to the container to ensure that the low temperature is maintained.

This practice has a large number of problems. The typically used insulation materials and coolants often do not suffice to maintain the temperature at the required level. Therefore a large number of unused materials are wasted for lack of adequate temperature control equipment. Also, there is a need for an environmentally friendly or "green" container and method of use for maintaining the payload temperature within a narrow band and which can operate without an electrical power source or without any type of active cooling.

Also, the packages used for the shipment require very specific thermal preparation. For example, known methods of temperature sensitive material product recovery require on site thermal preparation, or just in time delivery of properly thermally prepared packaging. Methods also exist in which a mechanical device is activated, such as a device that evaporates water into a vacuum and uses the latent heat of vaporization to chill and maintain the temperature of a payload. Such systems are complex and expensive. A passive shipping package with no moving parts is particularly needed. Accordingly, there is a need for improved transport systems for thermal sensitive payloads as well as methods and materials enabling frozen samples to be transported in a fast and easy manner.

SUMMARY OF THE INVENTION

Embodiments of the present invention are directed to systems and methods for transporting frozen samples as well as materials ensuring efficient transport thereof. More particularly materials, transport systems and transport methods according to the present invention allow cooled transport to take place in an efficient manner without the need for active cooling during the transport.

The materials used in the transport systems and methods according to the present invention are designed to ensure efficient insulation of the frozen samples while also providing an efficient absorption of heat thereby maintaining the required low temperature of the frozen sample during the transport or at least keeping the increase in temperature of the frozen samples to a minimum.

As disclosed herein, the inventors have found a material which can be used in cold transport systems and methods. The material is a multi-layered material comprising subsequent thermal storage layers separated from each other by insulation layers. The thermal storage layers typically comprise a phase change material (PCM) which is able to efficiently absorb heat thereby acting as a passive cooling means. The insulation layers typically comprise a thermal insulating material which ensures a good insulation of the PCM. The inventors have found that a multi-layered material comprising subsequent alternating thermal storage layers and insulation layers, will increase the overall efficiency of the material both in terms of insulation capacity and heat storage capacity. In first aspect, the present invention relates to a multi-layered body for thermal insulation, comprising consecutive thermal storage and insulation layers, wherein said thermal storage layers comprise a phase change material and said insulation layers comprise a thermal insulating material, characterized in that the thermal conductivity of the phase change material is 0.1 W/m.K or more and the thermal conductivity of the thermal insulating material is 0.05 W/m.K or smaller.

In particular, the present invention relates to a multi-layered body for thermal insulation comprising at least 4 layers, wherein said multi-layered body comprises subsequent alternating thermal storage and insulation layers, wherein said thermal storage layers comprise a phase change material undergoing phase transition at a temperature below - 20°C, preferably -80°C or more and said insulation layers comprise a thermal insulating material, characterized in that the thermal conductivity of the phase change material is 0.1 W/m.K or more and the thermal conductivity of the thermal insulating material is 0.05 W/m.K or smaller.

More particularly, said multi-layered body comprises at least 4 layers, wherein said multi- layered body comprises consecutive thermal storage and insulation layers, wherein said thermal storage layers comprise a phase change material and said insulation layers comprise a thermal insulating material, characterized in that the thermal conductivity of the phase change material is 0.1 W/m.K or more and the thermal conductivity of the thermal insulating material is 0.05 W/m.K or smaller.

More particularly, said multi-layered body comprises at least two thermal storage layers and at least two insulation layers. And more particular, said multi-layered body comprises five layers with the innermost and outermost layer being thermal insulation layer. More particularly, said multi-layered body comprises three or four thermal storage layers and three or four insulation layers.

In a further embodiment, the multi-layered body as disclosed herein further comprises additional layers.

In a further embodiment, the multi-layered body as disclosed herein provides that each of said thermal storage layers has a thickness between 1 and 50 mm, and/or wherein each of said insulation layers has a thickness between 1 and 40 mm.

In a further embodiment, the multi-layered body as disclosed herein provides that said phase change material is a phase change material undergoing phase transition at a temperature -20°C or lower and preferably -80°C or more.

In particular, said phase change material is a solid/liquid, electric (between paraelectric phase with a tetragonal symmetry to a ferroelectric phase with a orthorhombic symmetry) or magnetic (between paramagnetic and ferromagnetic phase) phase transformation material, preferably chosen from or comprising PureTemp -37 (PureTemp), PureTemp - 21 (PureTemp), Climsel C -21 (Climator), E-21 (PluslCE), E-22 (PluslCE), E-26 (PluslCE), E-29 (PluslCE), E-32 (PluslCE), E-34 (PluslCE), E-37 (PluslCE), E-50 (PluslCE), E-75 (PluslCE), E-78 (PluslCE), E-90 (PluslCE), E-1 14 (PluslCE), PCM- HS26N (SAVENRG), PCM-HS23N (SAVENRG), MPCM -30 (Microtek), and/or MPCM - 30D (Microtek).

In particular, said thermal insulating material is selected from the group consisting of polystyrene, polyurethane, polyisocyanurate, polyethylene, thermoplastic materials, cellulose, fumed silica, microporous silica, nanoporous silica, a silica based aerogel, aerogel, perlite, glass fiber, hollow glass bubbles or the materials used in or such as vacuum insulation tubes, and preferably said thermal insulating material comprises silica. Preferably, said insulation layers are vacuum insulation panels.

In a second aspect, the present invention relates to a process for manufacturing a multi- layered body for thermal insulation according to the invention, characterized in that said thermal storage layers is bonded to said insulation layers.

In a further aspect, the present invention relates to the use of a multi-layered body as disclosed herein for storing and/or transporting frozen samples.

In a further aspect, the present invention relates to a device for transporting a temperature sensitive payload comprising at least,

an inner chamber for positioning the temperature sensitive payload; and - a multi-layered body according to the invention, said multi-layered body enclosing said inner chamber.

In particular said device is not actively cooled or comprises coolants.

More in particular, said device provides that the loss of temperature inside the inner chamber is less than 10°C per 24 hours, and preferably less than 2°C per 24 hours. In a further aspect, the present invention relates to a method for transporting frozen samples, the method comprising the steps of:

a) positioning a frozen sample in a transport device comprising an inner chamber for positioning the frozen sample enclosed by a multi-layered body according to the present invention, said transport device being precooled to a temperature of -20°C or lower thereby preconditioning said phase change material in a solid form;

b) closing said device; and;

c) transporting said device without any type of active cooling;

characterized therein that the loss of temperature inside said inner chamber is less than 10°C per 24 hours, and preferably less than 2°C per 24 hours. BRIEF DESCRIPTION OF FIGURES

Figure 1 shows one conventional model and a model of the device according to the invention that are dynamically simulated.

Figure 2 shows the results of dynamic simulation of the temperature excursion of the two models.

DETAILED DESCRIPTION OF THE INVENTION

Before the present method and devices used in the invention are described, it is to be understood that this invention is not limited to particular methods, components, or devices described, as such methods, components, and devices may, of course, vary. It is also to be understood that the terminology used herein is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, the preferred methods and materials are now described.

In this specification and the appended claims, the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise.

The terms "comprising", "comprises" and "comprised of as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.

The terms "comprising", "comprises" and "comprised of" also include the term "consisting of".

The term "about" as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/-10% or less, preferably +/-5% or less, more preferably or less, and still more preferably +/-0.1 % or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier "about" refers is itself also specifically, and preferably, disclosed.

The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Embodiments of the present invention are directed to systems and methods for transporting frozen samples as well as materials ensuring the efficient transport thereof. More particularly materials, transport systems and transport methods according to the present invention allow cooled transport to take place in an efficient manner without the need for active cooling during the transport.

The materials used in the transport systems and methods according to the present invention are designed to ensure efficient insulation of the frozen samples while also providing an efficient absorption of heat thereby maintaining the required low temperature of the frozen samples during the transport or at least keeping the increase in temperature of the frozen samples to a minimum.

As disclosed herein, the inventors have found a material which can be used in cold transport systems and methods. The material is a multi-layered material comprising subsequent thermal storage layers separated from each other by insulation layers. The thermal storage layers typically comprise a phase change material (PCM) which is able to efficiently absorb heat thereby acting as a passive cooling means. The insulation layers typically comprise a thermal insulating material which ensures a good insulation of the PCM. The inventors have found that a multi-layered material comprising subsequent alternating thermal storage layers and insulation layers, will increase the overall efficiency of the material both in terms of insulation capacity and heat storage capacity. As used herein, the term "phase change material" refers to a material which uses inter molecular physical bonds to store and release heat. The thermal energy transfer of a phase change material occurs when the material changes from a solid to a liquid, or from a liquid to a solid form. In some cases thermal energy transfer occurs when the material changes from a solid to a softer solid and vice versa. Other PCM's are known for their phase transition from a paraelectric phase with a tetragonal symmetry to a ferroelectric phase with a orthorhombic symmetry or phase transitions between ferromagnetic and paramagnetic states. Initially, the material performs like a conventional storage material in that its temperature rises as it absorbs heat. Unlike a conventional storage material, when a phase change material reaches the temperature at which it changes phase (its melting point), it absorbs large amounts of heat without getting hotter. When the ambient temperature in the space around the PCM material drops, the PCM solidifies, releasing its stored latent heat. A PCM absorbs and emits heat while maintaining a constant temperature. These materials reportedly can store 5 or more latent heat per unit volume than sensible heat.

As used herein, the term "thermal insulating material" refers to an insulation material as typically known by the skilled person and providing the requisite R-value for the particular application, as known to persons skilled in this art. Typical materials that may be used include polystyrene, polyurethane, polyisocyanurate, polyethylene, thermoplastic materials, cellulose, fumed silica, microporous silica, nanoporous silica, a silica based aerogel, aerogel, perlite, glass fiber, hollow glass bubbles, or the materials used in or such as vacuum insulation tubes. Typically the thermal insulating material is used in the form of linings, sheets, boards or packing, stuffing or panels. Insulation panels can include vacuum insulation panels and/or foams and fiber-based materials. A combination of different insulation materials may be used to form the panel.

In a first aspect, the present invention relates to a multi-layered body for thermal insulation, comprising consecutive thermal storage and insulation layers, wherein said thermal storage layers comprise a phase change material and said insulation layers comprise a thermal insulating material, characterized in that the thermal conductivity of the phase change material is larger than 0.1 W/m.K and the thermal conductivity of the thermal insulating material is smaller than 0.05 W/m.K.

As referred to herein the term "thermal conductivity" refers to the property of a material to conduct heat. It is evaluated primarily in terms of Fourier's Law for heat conduction. Heat transfer occurs at a higher rate across materials of high thermal conductivity than across materials of low thermal conductivity. Correspondingly, materials of low thermal conductivity are used as thermal insulation. In SI units, thermal conductivity is measured in watts per meter kelvin (W/(m.K)). The thermal conductivity of a material is also related to the resistance of a material (also referred to as the R-value), in the R-value the thickness of the layer is also reflected. There are a number of ways to measure thermal conductivity. Each of these is suitable for a limited range of materials, depending on the thermal properties and the medium temperature. In general, steady-state techniques are useful when the temperature of the material does not change with time. This makes the signal analysis straightforward (steady state implies constant signals). However, for PCM conventional methods are difficult to apply. Therefore the thermal conductivity can be measured using for instance Scanning Thermal Microscope.

In particular embodiments the thermal conductivity of the phase change material is 0.1 W/m.K or more, more preferably between 0.1 W/m.K and 10 W/m.K, more preferably between 0.2 W/m.K and 5 W/m.K, more preferably between 0.3 W/m.K and 1 W/m.K and more preferably between 0.4 W/m.K and 0.7 W/m.K.

In particular embodiments the thermal conductivity of the thermal insulating material is 0.05 W/m.K or smaller, more preferably 0.01 W/m.K or smaller and more preferably between 0.01 W/m.K and 0.001 W/m.K.

In particular embodiments the multi-layered body according to the present invention comprises at least two thermal storage layers and at least two insulation layers.

In particular embodiments the multi-layered body according to the present invention comprises five layers with the innermost and outermost layer being a thermal insulation layer.

In particular embodiments the multi-layered body according to the present invention comprises a plurality of N consecutive thermal storage and insulation layers. Typically the number of insulation layers is equal to the number of thermal storage layers. In particular N is an integer of at least 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. Preferably, N is an integer equal to 2, 3, 4 or 5.

In particular embodiments the number of insulation layers is equal to the number of thermal storage layers plus 1 , the innermost and outermost layer being a thermal insulation layer.

By having multiple alternating layers of phase-change materials and insulation materials in the same system, one gains and enjoys the benefits of prolonged endurance as the phase-change materials pass through their phase changes. For example, if there were only one layer of phase change material being used in a system surrounding a frozen payload, that changed phase at -20°C, the system would only have the endurance of that one phase change. By including multiple layers of phase change material with layers comprising insulation materials in between, it has been found that the system provides a longer endurance and a minimal or almost no temperature change in time. The multilayered system can be shown to be more efficient compared to a system that comprises the same or a larger amount of PCM and insulation material.

In a particular embodiment the multi-layered body for thermal insulation according to the present invention further comprising additional layers. Additional layers comprising other types of materials can also be introduced in the multi-layered body. For instance, insulation materials and insulation panels are often covered with aluminum foils to provide an additional barrier and reflective layer. This further optimizes the efficiency of the multi-layered body as it protects the multi-layered body from heat leaks.

In a particular embodiment the multi-layered body for thermal insulation according to the present invention provides that each of said thermal storage layers has a thickness between 1 and 50 mm, and/or wherein each of said insulation layers has a thickness between 1 and 40 mm. Typically the thickness of the thermal storage layers and the insulation layers is kept as small as possible to enable the provision of a large amount of layers as this has been found to improve the efficiency of the multi-layered body. Typically the thermal storage layers have a thickness between 1 and 50 mm, more preferably between 10 and 25 mm, more preferably about 10 mm, 1 1 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm or 25 mm. Typically the insulation layers have a thickness between 1 and 40 mm, more preferably between 10 and 25 mm, more preferably about 10 mm, 1 1 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm or 25 mm.

In a particular embodiment the multi-layered body for thermal insulation according to the present invention provides that said phase change material is a phase change material undergoing phase transition at a temperature of -20°C or lower and preferably above - 80°C. Preferably the phase change material as used in the thermal storage layers undergoes phase transition at a temperature of -20°C or lower. Preferably said phase change material as used in the thermal storage layers undergoes phase transition at a temperature between -20°C and -80°C. While phase transition temperatures below -80°C can also be envisaged, most laboratory freezers are limited to -80°C. Therefore, devices using these multi-layered bodies can be stored in these freezers and used when required. The device itself does not require active cooling means. When using PCMs with a phase transition temperatures below -80°C (e.g. E-90 and E-1 14) the precooling of the device and the multi-layered body has to be performed by means of another cooling system e.g. liquid nitrogen as opposed to a -80°C fridge.

In a particular embodiment the multi-layered body for thermal insulation according to the present invention provides that the multi-layered body comprises at least two different types of thermal storage layers, said different types of thermal storage layers comprising different types of phase change materials, preferably undergoing phase transition at different temperatures, and preferably undergoing phase transition at temperatures with a difference of at least 10°C.

In particular, said phase change material is a solid/liquid, electric (between paraelectric phase with a tetragonal symmetry to a ferroelectric phase with a orthorhombic symmetry) or magnetic (between paramagnetic and ferromagnetic phase) phase transformation material. Preferably the multi-layered body for thermal insulation according to the present invention provides that said phase change material is chosen from or comprises PureTemp -37 (PureTemp), PureTemp -21 (PureTemp), Climsel C -21 (Climator), E-21 (PluslCE), E-22 (PluslCE), E-26 (PluslCE), E-29 (PluslCE), E-32 (PluslCE), E-34 (PluslCE), E-37 (PluslCE), E-50 (PluslCE), E-75 (PluslCE), E-78 (PluslCE), E-90 (PluslCE), E-1 14 (PluslCE), PCM-HS26N (SAVENRG), PCM-HS23N (SAVENRG), MPCM -30 (Microtek), MPCM -30D (Microtek). Preferably said phase change material is E-50 (PluslCE).

In a particular embodiment the multi-layered body for thermal insulation according to the present invention provides that said phase change material is a bulky material, a microencapsulated material or a material coupled to a carrier. The use of micro-encapsulated PCM or PCM coupled to a carrier allows for a uniform dispersion of the material in the thermal storage layer.

In a particular embodiment the multi-layered body for thermal insulation according to the present invention provides that said thermal insulating material is selected from the group consisting of polystyrene, polyurethane, polyisocyanurate, polyethylene, thermoplastic materials, cellulose, fumed silica, microporous silica, nanoporous silica, a silica based aerogel, aerogel, perlite, glass fiber, hollow glass bubbles or the materials used in or such as vacuum insulation tubes, and preferably said thermal insulating material comprises silica.

Preferably, the thermal insulating material is used in the form of linings, sheets, boards or packing, stuffing or panels. Preferably, the thermal insulating material are insulation panels such as vacuum insulation panels and/or foams and fiber-based materials. A combination of different insulation materials may be used to form the panel.

In a particular embodiment the multi-layered body for thermal insulation according to the present invention provides that said insulation layers are vacuum insulation panels.

As used herein the term "vacuum insulation panels" refers to a form of thermal insulation consisting of a nearly gas-tight enclosure surrounding a rigid core, from which the air has been evacuated. Typically vacuum insulation panels comprise (1 ) membrane walls, used to prevent air from entering the panel, (2) a rigid, highly-porous material, such as fumed silica, aerogel, perlite or glass fiber, to support the membrane walls against atmospheric pressure once the air is evacuated and (3) chemicals to collect gases leaked through the membrane or offgassed from the membrane materials. Vacuum insulation panels are highly effective insulation materials because the vacuum practically eliminates convection and also reduces conduction.

In a second aspect, the present invention relates to a process for manufacturing a multi- layered body for thermal insulation according to the present invention, characterized in that said thermal storage layer is bonded to said insulation layers. In embodiments, a mixture including one or more binder or adhesive can be sprayed or deposited onto the different layers and the layers may then be compressed to ensure a good bonding of the different layers.

In a third aspect, the present invention relates to the use of a multi-layered body according to the present invention for storing and/or transporting temperature sensitive products. Indeed the materials as disclosed herein may be effectively used for the storage and transport of temperature sensitive products such as frozen samples or samples that require maintenance at low temperatures. Preferably said samples have a temperature of -20°C or lower and this temperature should be maintained during the storage and/or transport.

Typical samples for use herein include but are not limited to biopsy samples, biological samples, enzymes, vaccines, stem cells, etc.

As used in the present invention, the term "biopsy sample" refers to a biological sample obtained from an organism (patient) such as human or from components (e.g. tissue or cells) of such an organism. Said biological sample preferably comprises sampled cells or tissues used for medical examination. A biopsy is typically removed from a living subject to determine the presence or extent of a disease. Said biopsy may be an excisional biopsy or an incisional biopsy (also referred to as core biopsy). In particular embodiments said biopsy is a tissue biopsy, fine needle biopsy, fine needle aspiration biopsy, core needle biopsy, vacuum assisted biopsy, open surgical biopsy or material from a resected tissue.

Typical surgical interventions where biopsies are obtained include for instance, a tru-cut or core needle biopsy, which uses a large, fitted needle to extract a sample of tissue about the size of a piece of pencil lead. A core needle biopsy can take place in a clinic or hospital and it can be performed by physician e.g. an internist, interventional radiologist, or surgeon. Biopsy samples are typically collected and used for the diagnoses of different diseases including, but not limited to precancerous conditions (suspicious lesions or masses), cancer, cardiovascular diseases, inflammatory diseases or infectious diseases. Some examples of different types of biopsies for specific conditions are:

· lung biopsy in a case of suspected lung cancer

• biopsy of the temporal arteries for suspected vasculitis

• bowel biopsy for conditions such as inflammatory bowel disease, Crohn's disease or ulcerative colitis

• kidney biopsy for renal conditions such as Crescentic glomerulonephritis.

· lymph node biopsy for a variety of infectious or autoimmune diseases

• gingival biopsy for amyloidosis

• a biopsy of a transplanted organ to determine rejection or that the disease that necessitated transplant has not recurred

• testicular biopsy for evaluating the fertility of men

Types of biopsy include bone marrow biopsy, gastrointestinal tract biopsy, needle core biopsies or aspirates of the pancreas, lung biopsy, liver biopsy, prostate biopsy, nervous system biopsy (brain biopsy, nerve biopsy, meningeal biopsy...), urogenital biopsies (renal biopsy, endometrial biopsy, cervical conisation...), breast biopsy, lymph node biopsy, muscle biopsy, skin biopsy...

In a fourth aspect, the present invention relates to a device for transporting a temperature sensitive payload comprising at least,

an inner chamber for positioning the temperature sensitive payload; and a multi-layered body according to the present invention enclosing said inner chamber.

More particularly, said device is not actively cooled or comprises coolants. Typically, the use of the materials as disclosed herein in a device for transporting a temperature sensitive payload allows that the temperature in the device can be maintained for prolonged periods of time without the need of active cooling or the addition of coolants such as dry ice. Therefore, the device does not require operation with an electrical power source or with one use coolants such as dry ice. The use of the materials according to the invention provide in an ecological friendly alternative while maintaining the efficiency of the cooling system.

In particular embodiments, the device according to the invention is characterized by having a loss of temperature inside the inner chamber of less than 10°C per 24 hours, and preferably less than 2°C per 24 hours. In a further aspect, the present invention relates to a method for transporting frozen samples, the method comprising the steps of:

b) closing said device; and;

c) transporting said device without any type of active cooling;

characterized therein that the loss of temperature inside said inner chamber is less than 10°C per 24 hours, and preferably less than 2°C per 24 hours.

In particular embodiments, the method according to the invention provides that said device is precooled to a temperature below the phase change temperature of the PCM used in the multi-layered body.

The following examples are offered by way of illustration, and not by way of limitation. EXAMPLES EXAMPLE 1

The following example exemplifies the efficiency and effectiveness of the multi-layered body according to the invention, compared to a conventional (non multi-layered system). Figure 1 shows the two models that are dynamically simulated. Both models weigh approximately 4 kilograms each and use E-50 PCM material for thermal storage and vacuum insulation panels (heat conductivity of approximately 0.005 W/m.K) for insulation. The outer dimensions of the model are 21 cm by 21 cm by 21 cm (cube shape). The first model (the conventional module) only comprises a single layer thermal storage material and a single layer of insulation material, whereas the second model (the multi-layered module) is a multi-layered system comprising 4 layers each of thermal storage and insulation material. Figure 2 shows the results of dynamic simulation of the temperature excursion of the two models. The result clearly demonstrates the superiority of multi-layered insulation to conventional cold storage packaging consisting of only one insulation and one storage material.

Claims

1 . A multi-layered body for thermal insulation comprising at least 4 layers, wherein said multi-layered body comprises subsequent alternating thermal storage and insulation layers, wherein said thermal storage layers comprise a phase change material undergoing phase transition at a temperature below -20°C, preferably -80°C or more and said insulation layers comprise a thermal insulating material, characterized in that the thermal conductivity of the phase change material is 0.1 W/m.K or more and the thermal conductivity of the thermal insulating material is 0.05 W/m.K or smaller.

2. The multi-layered body for thermal insulation according to claim 1 , comprising five layers with the innermost and outermost layer being thermal insulation layer.

3. The multi-layered body for thermal insulation according to claim 1 or 2, comprising three or four thermal storage layers and three or four insulation layers.

4. The multi-layered body for thermal insulation according to any of claims 1 to 3, further comprising additional layers.

5. The multi-layered body for thermal insulation according to any of claims 1 to 4, wherein each of said thermal storage layers has a thickness between 1 and 50 mm, and/or wherein each of said insulation layers has a thickness between 1 and 40 mm.

6. The multi-layered body for thermal insulation according to claim 5, wherein said phase change material is a solid/liquid, electric or magnetic phase transformation material.

7. The multi-layered body for thermal insulation according to any of claims 1 to 6, wherein said thermal insulating material is selected from the group consisting of polystyrene, polyurethane, polyisocyanurate, polyethylene, thermoplastic materials, cellulose, fumed silica, microporous silica, nanoporous silica, a silica based aerogel, aerogel, perlite, glass fiber or the materials used in or such as vacuum insulation tubes, and preferably said thermal insulating material comprises silica.

8. The multi-layered body for thermal insulation according to any of claims 1 to 7, wherein said insulation layers are vacuum insulation panels.

9. A process for manufacturing a multi-layered body for thermal insulation according to any of claims 1 to 8, characterized in that said thermal storage layer is bonded to said insulation layers.

10. Use of a multi-layered body according to any of claims 1 to 8 for storing and/or transporting frozen samples.

1 1 . A device for transporting a temperature sensitive payload comprising at least, - an inner chamber for positioning the temperature sensitive payload; and a multi-layered body according to any of claims 1 to 8 enclosing said inner chamber.

12. The device according to claim 1 1 , wherein said device is not actively cooled or comprises coolants.

13. The device according to claim 1 1 or 12, wherein the loss of temperature inside the inner chamber is less than 10°C per 24 hours, and preferably less than 2°C per 24 hours.

14. Method for transporting frozen samples, the method comprising the steps of: a) positioning a frozen sample in a transport device comprising an inner chamber for positioning the frozen sample enclosed by a multi-layered body according to any of claims 1 to 8, said transport device being precooled to a temperature of -20°C or lower thereby preconditioning said phase change material in a solid form;

b) closing said device; and;

c) transporting said device without any type of active cooling;