GB2413757A

GB2413757A - A bag formed from a material having antibacterial, ultraviolet blocking and water repellence properties

Info

Publication number: GB2413757A
Application number: GB0410125A
Authority: GB
Inventors: Yi Li; Jun-Yan Hu; Qing Wen Song; Meng Cheung Andrew Young
Original assignee: KAN HING PLASTIC PRODUCTS FACT; Hong Kong Polytechnic University HKPU
Current assignee: KAN HING PLASTIC PRODUCTS FACT; Hong Kong Polytechnic University HKPU
Priority date: 2004-05-06
Filing date: 2004-05-06
Publication date: 2005-11-09
Also published as: GB0410125D0

Abstract

A bag, soft sided article-carrying enclosure or the like is fabricated at least in part from a material having antibacterial, ultraviolet blocking and water repellence properties. The bag may be of a layered construction comprising at least two or at least three layers, one of which may have antibacterial, ultraviolet blocking and water repellence properties, one of which may comprise regular air channels and a microcapsule phase change material to control temperature and one of which may have moisture management properties.

Description

24 1 3757 Bags Made from Materials with Functional Properties

Field of Invention

The present invention relates to a bag made at least in part from materials with functional properties.

Background of the Invention

Bags are well known in the art. They are widely used for carrying and storing items and play an important part in daily life. Bags can be made from a variety of flexible materials, such as paper, plastic or leather, which can be stitched or bonded together to form a bag.

Improvements have been made to bags in the past to aspects of their mobility, economy, reusability or security. Nevertheless prior art bags still have a number of shortcomings, for example most bags are difficult to clean and are therefore seldom washed. Such a shortcoming is particularly significant given that bags are very easily contaminated by microorganisms such as bacteria and viruses.

Microorganisms are found throughout the environment and can cause infection and disease in their hosts. As microorganisms are not visible to the naked eye, it is difficult to detect their presence. Microorganisms can therefore be spread between individuals via everyday items, such as bags, without any visible sign that a particular individual or item is contaminated with a potentially dangerous microorganism.

Bags are often in close contact with human skin and may be used for food storage. With conventional bag technologies there is ample opportunity for a microorganism to contaminate a bag and thereby cause infection via contact with the skin or food stored within the bag.

Overthe past few decades, due to population growth, poverty, poor hygiene and environmental degradation, the world has witnessed an increased frequency of disease outbreaks. Infectious agents that can cause incurable diseases, such as Methicillin-Resistant Staphylococcus aureus (MRSA), HIV and Hepatitis C, have become a significant cause of illness and death in many parts ofthe world. Given the seriousness of the threat posed by infectious microorganisms, any new product that protects against the transmission of infections is of great value to public health.

Children are particularly susceptible to infections and often use school bags or backpacks to transfer books and food to and from school. Infection and disease in children are of particular concern and any means by which the risk of infection could be reduced would therefore be of great comfort to parents.

In addition to protecting users from infections, a bag that gives its contents and its user extra protection against the elements and harmful UV light exposure is desirable.

Moreover, it is of great advantage if a bag is comfortable in use. Two of the principal factors that adversely affect comfort when using a bag are heat and moisture build up next to the user's skin or clothing. A bag that could ameliorate heat and moisture build up would therefore be much more comfortable in use and of great benefit to the user.

There are thus many advantageous properties that are desirable in a bag. Since bags inevitably come into contact with microorganisms through everyday use and are often used to carry food, a bag that is resistant to microorganisms would be highly desirable. In addition, as bags are often used out of doors, a bag that protects its contents and the user against the elements and ultra violet light exposure is also highly desirable. However, it is important that any bag having these properties should also be comfortable in use. As bags known in the art are made from conventional materials there is little scope for providing a bag with the multiple advantageous properties discussed above.

Therefore, a bag made from a material and/or a number of materials that is simultaneously resistant to contamination with microorganisms, has water repellence properties and ultra violet protection, while at the same time being comfortable in use, would be of great benefit.

Object of the Invention It is an object of the present invention to provide a bag with improved performance.

Summary of the Invention

There is therefore provided a bag made at least in part from a material with functional properties.

There is further provided a bag according to the present invention, wherein said material is incorporated into a multilayer.

There is further provided a bag according to the present invention, wherein said multilayer has two or more layers of material with functional properties.

There is further provided a bag according to the present invention, wherein said multilayer has three or more layers of material with functional properties.

There is further provided a bag according to the present invention, wherein individual layers of said multilayer have different functional properties.

There is further provided a bag made in part from a single layer of material wherein said material has functional properties and in part from a multilayer of materials wherein at least one of said materials has functional properties.

There is further provided a bag according to the present invention, wherein said functional properties include one or more ofthe following properties: antibacterial, ultra violet blocking, water repellence, thermal regulation and moisture management.

In a preferred form the bag is a backpack, a school bag, a shopping bag, a sleeping bag or a stationary case.

There is further provided a bag according to the present invention, wherein said material or wherein at least one of said materials is in contact with the user's skin or clothing under normal conditions of use.

There is further provided a bag made at least in part from material with functional properties, wherein said material is incorporated into a multilayer and wherein the middle layer is a soft pad with regular channels on its surface to promote air ventilation and incorporates microcapsule phase change material to control temperature.

There is further provided a bag made at least in part from material with functional properties, wherein said material is incorporated into a multilayer and wherein the multilayer structure has three layers; one layer having antibacterial, UV blocking and water repellence functional properties; another layer made up of a soft pad with regular channels on its surface to promote air ventilation and incorporating microcapsule phase change material to control temperature; and another layer having antibacterial and moisture management functional properties.

Definitions Definitions of terms within the context of this document are detailed below.

The term "bag" includes any type of bag, especially those bags that come into close contact with the human body. The term "bag" includes carry bags, for example: carrier bags, hand bags, shoulder bags, school bags, shopping bags, backpacks, and stationary cases. Sleeping bags are also compatible with the present invention.

A material with "functional properties" is defined as a material with one or more properties over and above structural integrity, for example antibacterial, water repellence, UV blocking, thermal regulation or moisture management properties.

The term "material" includes any flexible material suitable for making a bag. The material can be woven, for example cotton or synthetic fibres, or non-woven in sheet plastic form, for example PVC, or leather.

The term "multilayer" is defined as multiple layers of the same or different materials, stitched or bonded together to form a composite. The multilayer can include two layers of material, preferably three layers of material, or alternatively four or more layers of material.

The term "water repellent" includes any material with good water repellent properties in the range of ISO 4 to 5, preferably 5, as defined by the AATCC standard 22 Water Repellency: Spray Test". In this test, a testing value of 100 (ISO 5) means that there is no sticking or wetting of the upper surface.

The term "UV blocking" includes any material with good UV blocking properties, preferably with UPF greater than 15 according to standard AS/NZS 4399:1996.

A material having "thermal regulation" functional properties or "thermal management" functional properties means any material that incorporates a phase change material (PCM) capable of absorbing heat in response to an increase in temperature in the local environment or releasing heat in response to a decrease in temperature in the local environment. PCMs are known for their thermal characteristics in that during their phase change stage they can absorb or release latent heat while the temperature of the material is kept constant.

The term "moisture management properties" is used to describe the beneficial multi dimensional properties of liquid moisture transfer in a material and can be measured by an apparatus named a Moisture Management Tester (MMT). Detailed information can be found in US Patent 6499338. A functional material compatible with the present invention with good moisture management properties should have a measured Overall Moisture Management Capability (OMMC) index greater than 50.

The term "microorganism" includes bacteria and viruses.

List of Drawings Fig. 1. Shows a bag of a type compatible with the present invention. Portions of the bag with particular functional properties are shown.

Fig. 2a. Shows the portion of a bag that in the particular bag depicted would contact the user's back. This portion of the bag is made from a multilayer as illustrated in the enlarged detail.

Fig. 2b. Shows the enlarged detail of Fig. 2a in a larger scale. Individual layers within the multilayer are numbered 1, 2 and 3.

Fig. 3. Shows that compared to a control material without functional properties (bottom half of plate) a material with antibacterial functional properties (top half of plate) prevents the growth of Staphylococcus aureus (ATCC6538) in an antibacterial ring around the material.

Fig. 4 Shows a typical result for a fabric with moisture management properties.

Fig. 5. Summary of measured results of One Way transport Capacity (OWTC) and Overall Moisture Management Capability (OMMC).

Fig. 6. Shows an infrared thermal image demonstrating that when placed on a hot plate the surface temperature of a fleece fabric treated with PCM microcapsules (right) is significantly lower than the surface temperature of an untreated fleece fabric of the same type (left).

Fig. 7 Boxplot chart of thermal regulation with PCM level.

Fig. 8 Boxplot chart of time duration with PCM level.

Detailed Description of the Invention

In order to overcome the shortcomings of conventional bags, in the present invention materials with functional properties are used to make a bag.

A bag made from materials with functional properties is of great advantage to the user. The specific benefits will depend upon the selection of functional properties incorporated into the material. For example any one or more of the following properties may be incorporated into the material to provide a bag with beneficial properties: antibacterial, UV blocking, water repellence, thermal regulation or moisture management.

Antibacterial functional properties are of clear benefit given that bags may be contaminated with microorganisms and such microorganisms are capable of infecting the bag user or its contents. A bag with antibacterial properties is therefore of great public health benefit in the fight against the spread of infections.

UV blocking functional properties are of benefit because they protect the user from UV- induced skin damage. This is a particularly important feature given that bags are often used outside in direct sunlight.

The water repellence functional properties ensure that the contents ofthe bag stay dry and offer the user some protection against the elements. Without such properties the contents ofthe bag can become wet. A bag with water repellence properties would also give the user some protection against the rain, especially if the bag is of a backpack design.

The thermal regulation functional properties ensure that the bag feels comfortable in use. This property is especially important if the bag is of a backpack design. Under conditions of use, heat will inevitably build up where the backpack contacts the user as a result of heightened metabolic activity. This heat is absorbed by materials with thermal regulation properties so that the during use the bag does not feel uncomfortably warm. After use, as the local environmental temperature decreases, the bag material with thermal regulation properties releases heat ready for reuse.

The moisture management functional properties also ensure that the bag feels comfortable in use. If the user is engaged in physical activity when using the bag and the environmental conditions are sufficiently warm, he/she will inevitably sweat. The build up in moisture that occurs as a result of sweating is uncomfortable. However, the moisture management properties of the bag materials wick the moisture away from the user's skin or clothing so that the bag feels dry and comfortable in use.

Materials with functional properties can be used to make any portion of the bag including shoulder straps and belts.

A bag made from a material with functional properties wherein one or materials are incorporated into a multilayer is advantageous because the resulting composite will not only add the functional properties to the bag but will also provide the bag with features resulting from the other materials incorporated into the multilayer. Therefore if a particular material with functional properties was lacking in some other desirable property these deficiencies could be overcome by incorporating the material into a multilayer with other materials that compensated for these deficiencies. For example if a material with functional properties was considered to be too weak and too unyielding to be used to make a bag, these deficiencies could be overcome by incorporating a softer material and a material of greater structural integrity into the multilayer.

Layers of materials with one or more different functional properties can be incorporated into a multilayer so that the resulting composite has the best possible combination of features.

In addition, a bag made from materials with functional properties may incorporate different types of materials in different parts of the bag.

A backpack bag compatible with the present invention is shown in Fig. 1. The surfaces of the backpack that come into contact with the user's back and shoulders are made from a multilayer of materials having moisture management, thermal management, antibacterial, water repellence and UV blocking functional properties, whereas the panels on the outer surfaces are made of a material having antibacterial, water repellent and ultra violet blocking functional properties.

Individual materials with one or more functional properties can be stitched or bonded together to form a multilayer. The detailed structure of a multilayer suitable for use in the portion of a backpack that comes into contact with the user's back and shoulder is shown in Figs. 2a and 2b. The numbers in Figs. 2a and 2b refer to individual layers 1, 2 and 3: Layer 1 is an inner layer exposed to the interior of the bag. The material of this inner layer may incorporate antibacterial, ultra violet blocking and water repellence functional properties.

Therefore, this layer can stop liquid permeating into the bag, kill microorganisms and block UV light.

Layer 2 is a thermal regulatory layer. The layer is made from a soft hydrophilic pad, such as a sponge with a functionally designed structure, that contains a phase change material (PCM) microcapsule. Regularly spaced channels (A) are provided on the surface ofthe pad to promote air ventilation and moisture evaporation. As moisture is absorbed from the inner or outer layer it migrates to the surface of the channels where it can evaporate into the atmosphere. Thermal regulation is provided by the PCM.

Layer 3 is an outer layer that contacts the skin or clothing of the user. The material of this layer may incorporate antibacterial, UV blocking and moisture management properties. This layer ensures that the bag feels dry during use. Furthermore this outer layer will kill any microorganism with which it comes into contact and further protects the user from UV induced damage.

When using a bag as described in Fig. 1, made at least in part from a multilayer as described in Figs. 2a and 2b, sweat can easily and quickly transfer from the skin to the surface of the channels in the thermal regulatory layer and evaporate into the environment. Furthermore, by means of the PCM, heat can be absorbed from the user's body and released into the environment, thereby controlling the temperature between the bag and the skin. As a result the bag is more comfortable in use than conventional bags.

In addition, when using a bag as described in Figs 1,2a and 2b, the user and the bag's contents are protected from microorganisms that come into contact with the bag and furthermore the user is partially protected from UV-induced damage.

S Examples of styles of bags compatible with the present invention are given by US patent 5,964,384 that discloses a travelling bag with expandable storage volume and US patent 4,236,559 that discloses a school bag that includes a snap-on cover and adjustable shoulder strap. Chinese patents 86205748, 87214410, 88206017.1 and 89201221.8 provide relevant background in the area of bag structure and functional design.

Any suitable materials known to the skilled person can be modified, for example by coating, to provide materials with functional properties. Individual functional properties, for example water repellence, antibacterial or UV-blocking, can be achieved by methods that are well known to those skilled in the art. In addition, certain materials may have inherent functional properties without the need for coating.

Materials compatible with the present invention can be modified to provide materials with combined functional properties, for example water repellence, antibacterial and UV blocking.

Materials with moisture management functional properties can be prepared and tested by methods known in the art, US Patents 6,454,814 and US Patent 6,499,338.

Materials with thermal regulation functional properties can be prepared by methods known in the art, US Patent 5,465,852, US Patent 5,916,478, US Patent 4,756,958, US Patent 5,290,904 and US Patent 6.077,597.

Methods of preparing the materials with functional properties include at least one of the following processes: coating, printing, spraying, dipping, padding, curing and molding.

Examples of Materials with Functional Properties Example 1, Material with Antibacterial, UV blocking and Water Repellent Functional Properties A soft substrate material can be modified to provide it with antibacterial, UV blocking and water repellent properties by treatment with a solution containing the following: Avd WRS c35, (product of Advanced Chemicals Co. Ltd., Shenzhen China), provides water repellent functional properties.

MFS200 (product of Zhoushan Mingri Nano Material Co. Ltd.), provides antibacterial functional properties via the antibacterial function of Ag+ STK (product of Zhoushan Mingri Nano Material Co. Ltd.), provides antibacterial functional properties via far infrared radiation HR3 (product of Zhoushan Mingri Nano Material Co. Ltd.), anatase TiO2 nano scale particles provide photocatalysts oxidation, UV blocking and antibacterial functional properties.

Advan LEV LAP/IF, (product of Advanced Chemicals Co. Ltd., Shenzhen China), surfactant.

Advan Print PEA, Acrylate Polymer, (product of Advanced Chemicals Co. Ltd., Shenzhen China), binder.

Advan AV-940, (product of Advanced Chemicals Co. Ltd., Shenzhen China), softner.

The material can be treated with the solution using a spray coating machine or by dipping the fabric into the solution directly. The material is then passed through a padding machine, cured at 130 C for 1-5 minutes and then dried to obtain the final product.

Such a soft substrate material can be woven, knitted, or used in a nonwoven plastic form. In this example cotton fabric was treated with the solution and antibacterial testing carried out to determine it's antibacterial properties.

Sample Structure Unit weight/m2 Thickness (mm) under a pressure of 1 lb/inch2 Treated School Woven 299.54 1.38 0.51 0,011 Bag Fabric Table 1, Basic fabric properties. s

According to AATCC standard 100-1999, 1). Escherichia cold (E. coli) ATCC25922 and 2), Staphylococcus aureus (S. aureus) ATCC6538 were used to test the antibacterial effect of treated fabrics in bag manufacturing. The test was conducted as follows: Sample disinfection: Ultraviolet-C lamp for 1 min Neutralisation with saline solution.

Contact time: 24 hours Incubation at 37 C Incubation period of 48 hours Test culture: Escherichia cold (E. coli) ATCC25922 and Staphylococcus aureus (S.

aureus) ATCC6538 Agar Medium: Nutrient Agar Test Specimen: Circular 3.8 cm in diameter.

Treated school E. Coli S. aureus bag fabric A(CFU/ml) R (%) A(CFU/ml) R (%) number 100 100 100 100 4 50 99.9 0 100 Table 2, Results of the Antibacterial Tests, where, A = the number of bacteria recovered from the inoculated treated samples over the desired period (48 hours).

R = % reduction Numbers 1, 2, 4 and 4 mean the 15', 2nd' 3rd and 4th treated samples.

Fig. 3 shows the antibacterial effect of a fabric with antibacterial functional properties.

Example 2, Material with Moisture Management Functional Properties The multi-dimensional liquid water transfer properties of a fabric are known as its fabric moisture management properties. Research has shown that the humidity between the fabric and the skin significantly influences the wearer's sensation of comfort. Moisture management fabric can be used as a material in bag manufacturing. When the fabric is used at a site which is in close contact with the skin the sweat is quickly and easily transferred from the side of the fabric next to the skin to the opposite side where it evaporates into the environment. These properties give the fabric a dry feeling even when the bag is worn during strenuous activity.

The moisture management functional properties of fabrics have been tested on a patented instrument, the "Moisture Management Tester" (MMT). A typical result for a fabric with moisture management properties is shown in Figure 4. The fabric has good moisture management and anti-bacterial properties.

To determine the moisture management functional properties of pure cotton fabric treated with a nano functional agent and the influence of wash cycles, a series of trials were carried out.

The basic physical properties are listed in the following table: 1 _.

Fabric ID Content Construction Thickness 98 pa Weightg/m2 pressure, mm A 100% cotton denim Woven 0.790 79 B 100% nano finished cotton twill Woven 0.796 82 fabrics _ _....... - Table 3 Fabric with moisture management properties Before the experiment, two fabrics were fabricated on the same machine with the same structure parameters. One was treated with a nano functional emulsion and the other was a control fabric. The detailed information of the fabric is listed in Table 3.

The experiment was carried out in a condition room following the requirement of standard ASTM 1776. First of all, the fabric specimens without treatment were prepared and tested.

The treated fabric specimens were then prepared. The treated fabric was washed in a washing machine following the standard wash processing (AATCC 135 1995). After each wash cycle was finished, individual fabric specimens were tested. 50 wash cycles were performed in total.

All the specimens were tested on a MMT, and the measurement results of indexes OWTC (One Way Transport Capacity) and OMMC (Overall Moisture Management Capability) are summarized in Fig. 5.

Compared with the untreated specimen, in which OWTC and OMMC is less than 0, the same index values of treated specimens are significantly higher than 0. This suggests that the water content on the bottom surface of the nano functional agent treated fabric is higher than it is on the top surface even after 50 times standard washing.

Example 3, Material with Thermal Management Functional Properties Encapsulated phase change material (PCM) is an advanced technology which can be used to endow a soft substrate material with smart thermal regulation functional properties. The melt point of the PCM is defined so that the encapsulated PCM changes from solid to liquid when the environmental temperature reaches a defined melt temperature, thereby absorbing heat and reducing temperature in the local environment. On the other hand, when the environmental temperature drops below a defined set point the state ofthe PCM changes from liquid to solid, thereby releasing energy and increasing the temperature of the local environment. By means of this mechanism the soft substrate material containing the encapsulated PCM functions as a smart thermal regulator while the bag is in use.

The PCM microcapsules were coated onto a sample fabric. Scientific experiments were carried out to measure the dynamic surface temperature changes when the fabrics, equilibrated to an environmental temperature of 20 C, were brought into contact with a hot plate of 33 C to simulate the temperature of human skin. Compared with the control fabric sample, significant differences were found in the surface temperature changes of the fabric as measured using an infrared thermal image camera. This test shows that, compared to conventional products, the PCM microcapsules used in a preferred embodiment of this invention are able to provide an improvement in thermal functional performance.

Sample Structure Unit weight g/m2 Thickness (mm) under a pressure of 1 Ib/inch2 Treated fleece Fleece 251.41 0.19 2.29 0.046 fabric Table 4 Physical properties of PCM fabrics The infrared thermal image in Fig. 6 shows that when placed on a hot plate the surface temperature of a fleece fabric treated with PCM microcapsules (right) is significantly lower than the surface temperature of an untreated fleece fabric of the same type (left).

The fleece fabric was coated with PCM material of different concentration from 0, 10, 20, 40, 80n, 120 g/m2 respectively. The thermal regulation properties such as thermal regulating capacity and thermal regulating duration are shown in Figures 7 and 8. The higher the concentration of PCM microcapsules, the higher the thermal regulation capacity ofthe fabrics.

Claims

Claims 1. A bag made at least in part from a material with functional

properties.
2. A bag according to claim 1, wherein said material is incorporated into a multilayer.
3. A bag according to claim 2, wherein said multilayer has two or more layers of material with functional properties.
4. A bag according to claim 2, wherein said multilayer has three or more layers of material with functional properties.
5. A bag according to any one of claims 2 to 4, wherein individual layers of said multilayer have different functional properties.

6. A bag according to claim 1, made in part from a single layer of material wherein said material has functional properties and in part from a multilayer of materials wherein at least one of said materials has functional properties.

7. A bag according to any one of claims claim 2 to 6, wherein one of the layers is a soft pad with regular channels on its surface to promote air ventilation and incorporates microcapsule phase change material to control temperature.

8. A bag according to any one of claims 2 to 7, wherein the multilayer structure has three layers; one layerhaving antibacterial, UV blocking and water repellence functional properties; another layer made up of a soft pad with regular channels on its surface to promote air ventilation and incorporating microcapsule phase change material to control temperature; and another layer having antibacterial and moisture management functional properties.

9. A bag according to any one of claims 1 to 8, wherein the functional properties include one or more of the following properties: antibacterial, ultra violet blocking, water repellence, thermal regulation and moisture management.

10. A bag according to any one of claims 1 to 9, wherein said bag is a backpack, a school bag, a shopping bag, a sleeping bag or a stationary case.

1 1. A bag according to any one of claims 1 to 10, wherein said material or wherein at least one of said materials is in contact with the user's skin or clothing under normal conditions of use.

Amendments to the claims have been filed as follows Claims i 1. A bag made at least in part from a material with antibacterial, ultra violet blocking and water repellence functional properties.

2. A bag according to claim 1, wherein said material is incorporated into a multilayer.

3. A bag according to claim 2, wherein said multilayer has two or more layers of material with functional properties.

4. A bag according to claim 2, wherein said multilayer has three or more layers of material with functional properties.

S. A bag according to any one of claims 2 to 4, wherein individual layers of said multilayer have different functional properties.
6. A bag made in part from a material with antibacterial, ultra violet blocking and water repellence functional properties and made in part from a multilayer of materials wherein at least one of the materials of the multilayer has functional properties.
7. A bag according to any one of claims claim 2 to 6, wherein one of the layers is a soft pad with regular channels on its surface to promote air ventilation and incorporates microcapsule phase change material to control temperature.
8. A bag according to any one of claims 2 to 7, wherein the multilayer structure has three layers; one layer having antibacterial, UV blocking and water repellence functional properties; another layer made up of a soft pad with regular channels on its surface to promote air ventilation and incorporating microcapsule phase change material to control temperature; and another layer having antibacterial and moisture management functional properties.
9. A bag according to any one of claims 2 to 8, wherein the multilayer additionally includes materials with one or more of the following properties: thermal regulation and moisture management. l9
10. A bag according to any one of claims 1 to 9, wherein said bag is a backpack, a school bag, a shopping bag, a sleeping bag or a stationary case.
11. A bag according to any one of claims 1 to 10, wherein said material or wherein at least one of said materials is in contact with the user's skin or clothing under normal conditions of use.