EP3693292A1

EP3693292A1 - Method for transporting frozen products

Info

Publication number: EP3693292A1
Application number: EP19155954.1A
Authority: EP
Inventors: designation of the inventor has not yet been filed The
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever IP Holdings BV
Priority date: 2019-02-07
Filing date: 2019-02-07
Publication date: 2020-08-12

Abstract

Disclosed is a method for transporting frozen products. The method employs a sleeve (1) comprising an outer layer (2) of thermally insulating material; an inner layer (3) comprising a phase change material with a melting temperature below -5 °C; and a fastener system (4). The sleeve is flexible sufficient to convert between an enveloping configuration wherein the fastener system (4) is engaged to hold the sleeve (1) around the frozen products (20) to be enveloped with the inner layer (3) facing the frozen products (20); and a charging configuration wherein the fastener system (4) is disengaged and the sleeve (1) is unfurled. The method comprises the steps of: arranging the sleeve (1) in the charging configuration; placing the inner layer (3) in contact with a cooled flat surface (12) for sufficient time to solidify the phase change material; removing the sleeve (1) from contact with the flat surface (12); converting the sleeve (1) to the enveloping configuration around the frozen products (20); and then transporting the enveloped frozen products (2) to a remote location.

Description

Field of the invention

The present invention relates to methods for transporting frozen products. In particular the invention relates to methods that employ flexible sleeves comprising phase change material and an insulating layer.

Background of the invention

Portable containers which are insulated and comprise phase change material for keeping products cool during transportation have been known and used for many years. Most common are cool boxes and the like wherein packs of phase change material are simply placed inside an insulated box along with the products that are desired to be kept cool. Such containers are inconvenient, especially where rapid refilling of containers is desired as the phase change material must be brought separately to the insulated box. Furthermore, the boxes themselves need separate storage whilst the phase change material is being frozen and so can take up valuable space in a retail environment.
Containers which comprise sleeves comprising phase change material and an insulating layer and which are flexible sufficient to be collapsed after use have been disclosed.
US 6,128,915 (Peter P. G. Wagner ) discloses a portable food and beverage cooling device that includes a flexible cooling pouch having outer and inner faces. A cooling pack is provided in the cooling pouch. The cooling pack comprises a plurality of alternating cooling cavities and connecting portions. Each of the cooling cavities of the cooling pack has a cooling substance therein capable of is cooled. A flexible insulating panel is provided in the cooling pouch. The insulating panel has a central region interposed between the outer face of the cooling pouch and the cooling pack. The insulating panel also has a pair of opposite side regions overlapping the cooling pack such that each side region of the insulating panel has a side portion interposed between the cooling pack and the inner face of the cooling pouch. The side portions of the side regions of the insulating panel face one another and are spaced apart from one another to define an air gap therebetween positioned between the cooling pack and the inner face of the cooling pouch. The device is said to collapse into a small, convenient package after use.
US 5,490,396 (Richard Morris ) discloses a portable container which may be refrigerated and which is composed of a flexible floor, walls, and lid and composed of inner and outer walls with flexible refrigerant gel captivated between these walls, floor and lid. The lid may be closed to the container with a device selected from the group consisting of nylon zippers and velcro seals. The entire container may be compressed or folded in a relatively flat position in order to be easily placed into the freezer so that the gel can be frozen for cooling purposes.
Whilst containers such as those disclosed in US 6,128,915 or US 5,490,396 overcome at least some of the aforementioned problems with cool boxes, the present inventor has found that folding / collapsing the containers after use and during freezing of the phase change material is not ideal, especially where freezing time of the phase change material is desired to be at a minimum. Such fast freezing is especially desirable in quick serve restaurants and the like that provide a delivery service wherein frozen products are constantly being transported to consumers.
Thus the present inventors have provided an improved method for transporting frozen products.

Summary of the invention

The present invention relates to a method for transporting frozen product, wherein the method comprises the steps of:

i. providing a flexible sleeve comprising:
1. a) an outer layer of thermally insulating material,
2. b) an inner layer comprising a phase change material with a melting temperature below -5 °C, and
3. c) a fastener system;
ii. arranging the sleeve in a charging configuration wherein the fastener system is disengaged and the sleeve is unfurled;
iii. placing the inner layer in contact with a cooled flat surface for sufficient time to solidify the phase change material;
iv. removing the sleeve from contact with the flat surface;
v. converting the sleeve to an enveloping configuration wherein the fastener system is engaged to hold the sleeve around the frozen product enveloped with the inner layer facing the frozen product; and then
vi. transporting the enveloped frozen product to a remote location.

As used herein "charging" refers to cooling the phase change material sufficient to lower its temperature below its freezing point.
By unfurling the sleeve during charging to allow the inner layer to contact a cooled flat surface, the phase change material can be charged much quicker than if the sleeve were placed in a freezer in a collapsed configuration wherein the insulating layer is between the phase change material and the cold surfaces of the freezer.
Moreover, unfurling the sleeve allows for it to be placed against the wall of a storage freezer and thus take up minimum space within the storage freezer. Thus in a preferred embodiment the cooled flat surface is the inner surface of the wall of a storage freezer. Especially preferred is that the storage freezer comprises a coolant evaporator mounted in and/or on the wall as then the inner surface of the wall will be colder than, for example, the wall of a freezer cooled by forced air circulation. Additionally or alternatively, the storage freezer used for charging the phase change material is the same as that use to store the frozen products prior to being enveloped as this dispenses with the need to have separate freezers for the products and the sleeves.
As used herein "remote location" refers to a location remote from the location where the frozen products are enveloped in step v (the "storage location"). Typically the remote location will be the home of a consumer who has ordered the frozen product.
Preferably the distance between the remote location and the storage location is at least 500 m, more preferably from 1 km to 60 km and most preferably from 2 km to 20 km.
Typically the sleeve is removed from the frozen product at the remote location. The removed sleeve is then preferably returned to the storage location. The removed sleeve is preferably arranged in the charging configuration and the inner layer is placed in contact with a cooled flat surface for sufficient time to solidify the phase change material. The cooled flat surface could be the same surface as in step iii or another flat surface. Preferably it is the same surface, or at least is another surface at the storage location.
The utility of the present invention is increased where particularly low temperatures are needed to keep products stable during transport. This is because rapid charging of the phase change material is particularly advantageous when low temperatures need to be reached. Thus it is preferred that the melting temperature of the phase change material is between -30 and -10 °C, more preferably between -15 and -25 °C.
The microstructure and so the quality of frozen confections is particularly sensitive to transport temperature. Thus it is preferred that the frozen product is one or more frozen confections. The frozen product may be, for example, ice cream product, water ice product, sorbet or the like.

Brief Description of the Drawings

The invention will now be illustrated by way of example and with reference to the following figures, in which:

Figure 1 shows a schematic plan view of the inner side of an unfurled sleeve for use in an embodiment of the invention.
Figure 2 shows a schematic perspective view of the sleeve of Figure 1 in the process of enveloping a frozen product.
Figure 3 is a schematic perspective view of a storage freezer for use in an embodiment of the present invention with the sleeve of Figures 1 and 2 in a charging configuration and placed against the inner surface of the wall of the storage freezer.
Figure 4 is a schematic cross-sectional view of the sleeve and freezer wall of Figure 3 taken through a plane containing line A-A.

Detailed description of the invention

There is no particular limitation on the sleeve that can be used in the present invention provided that it comprises the outer layer, inner layer and fastener system as described hereinabove and can be converted between the charging and enveloping configurations. Thus the sleeve may be, for example, as described in US 6,128,915 , the disclosure of which is hereby incorporated by reference in its entirety.
A preferred embodiment of a sleeve for use in the present invention is illustrated in Figures 1 and 2. The sleeve comprises a plurality of packets of phase change material (5) mounted on a sheet of flexible insulating material (2).
The sheet of insulating material (2) may be flexible or may be relatively stiff but made flexible through the presence of folds, pleats and/or hinges and the like. Preferably the outer layer comprises a flexible material, more preferably consists essentially of flexible material and most preferably consists of flexible material. Preferred materials are flexible foams such as foam rubber, foamed plastics and the like. Especially preferred is bubble-wrap as this provides insulation as well as mechanical protection for the contents of the sleeve. Most preferable is metal foil-coated bubble-wrap as this provides flexibility and optimum thermal insulation.
The packets of phase change material (5) form an inner layer (3) of the sleeve (1) and become rigid when in the charged (frozen) state. Thus to keep the flexibility of the sleeve (1) it is preferred that the packets (5) are separated by spaces (6) or flexible junctions that allow the layer (3) of packets (5) to be articulated sufficient for the sleeve (1) to be converted between different configurations.
As the sleeve (1) is used for transporting frozen products, it is preferred that the phase change material has a melting temperature sufficiently low to keep the products in a deep-frozen state for extended periods of time. Suitable materials include, for example, the range of COOL eutectic gels manufactured by COOL Sari (La Voulte-sur-Rhône, France, or the PlusICE Eutectic (E) range of phase change materials manufactured by Phase Change Material Products Limited (Cambridgeshire, UK).
Around the periphery of the inside of the sleeve (1), a fastener system (4) is mounted on the sheet of flexible insulating material (2). The fastener system is preferably reversibly fastenable. Suitable fastener systems include, for example, zippers, press-studs, clips, clamps, pressure-sensitive adhesive and hook-and-loop type fasteners such as those available under the Velcro® brand. In the embodiment shown in Figures 1 and 2, a hook-and-loop type system is employed and so the fastener system comprises regions of hook-type fastener (4a) and complimentary regions of loop-type fastener (4b). These regions are complementary in that they are located such that they can easily be mated when the sleeve (1) is folded to envelope a frozen product (20) as shown in Figure 2.
Charging of the phase change material is illustrated in Figures 3 and 4 wherein the sleeve (1) is shown with the inner layer (3) placed against the inside surface of a side wall (12) of a freezer cabinet (10).
The freezer cabinet (10) comprises a chest formed by four side walls (12, 13, 14, 15) and a base (16) delimiting a chamber (11) for storing the frozen products. Although not shown, the chamber (11) would typically be closed on its top by a lid.
Several types of refrigeration systems for freezer cabinets are known in the art. Known systems include, for example, forced-air systems where air is forced over a cooling element in order to cool the air and then the cooled air is forcefully circulated around the chamber. The air is moved over the cooling element and/or around the chamber with the use of one or more fans. Another type of system is more passive and relies on a coolant evaporator mounted in and/or on the side walls of the chamber. Where the evaporator is mounted on the wall it typically comprises one or more metal plates which are shaped to contain channels for the coolant and is commonly referred to as a "roll-bond evaporator".
In the embodiment shown in Figures 1 and 2, an evaporator is mounted in the side walls. Where the evaporator is mounted within the side walls it typically comprises tubes (17) coiling around the side walls (12, 13, 14, 15, 16) and is commonly referred to as a "skin evaporator".
In use, the sleeve (1) is unfurled and placed inside the chamber (11) of a storage freezer (10) located in a storage location such as a restaurant or shop, with the inner layer (3) against the surface of one of the side walls (12).The sleeve (1) is kept in this charging configuration for sufficient time for the phase change material in the packets (5) to solidify.
When a frozen product (20) is desired to be transported to a remote location (such as delivered to a customer in response to an order), the sleeve (1) and product (20) are removed from the chamber (11) and the sleeve (1) wrapped around the product (20) as shown in Figure 2, wherein the fasteners (4a, 4b) are engaged to hold the sleeve (1) around the frozen product (20) enveloped with the inner layer (3) facing the frozen product (20).
The enveloped product is then transported to the remote location where the fasteners (4a, 4b) are disengaged and the frozen product (20) removed from the sleeve (1). The sleeve (1) is then returned to the storage location wherein the sleeve (1) is once again unfurled and placed in the chamber (11) in the charging configuration.

Claims

A method for transporting frozen product, wherein the method comprises the steps of:
i. providing a flexible sleeve comprising:
a) an outer layer of thermally insulating material,

b) an inner layer comprising a phase change material with a melting temperature below -5 °C, and

c) a fastener system;

ii. arranging the sleeve in a charging configuration wherein the fastener system is disengaged and the sleeve is unfurled;

iii. placing the inner layer in contact with a cooled flat surface for sufficient time to solidify the phase change material;

iv. removing the sleeve from contact with the flat surface;

v. converting the sleeve to an enveloping configuration wherein the fastener system is engaged to hold the sleeve around the frozen product enveloped with the inner layer facing the frozen product; and then

vi. transporting the enveloped frozen product to a remote location.
The method as claimed in claim 1 wherein the cooled flat surface is the inner surface of the wall of a storage freezer.
The method as claimed in claim 2 wherein the storage freezer comprises a coolant evaporator mounted in and/or on the wall.
The method as claimed in any one of claims 2 or 3 wherein the frozen product is stored in the storage freezer prior to being enveloped.
The method as claimed in any one of the pervious claims wherein the sleeve is removed from the frozen product at the remote location.
The method as claimed in claim 5 wherein the removed sleeve is arranged in the charging configuration and the inner layer is placed in contact with a cooled flat surface for sufficient time to solidify the phase change material.
The method as claimed in any one of the preceding claims wherein the melting temperature of the phase change material is between -30 and -10 °C.
The method as claimed in any one of the previous claims wherein the frozen product is one or more frozen confections.