The present invention relates to water resistant footwear such as, preferably but not limited to footwear used in the agri-food and catering sectors.
As known to those working in the sector, the HACCP system (acronym from English of Hazard Analysis and Critical Control Points) is a system of risk analysis and control of critical points to ensure the prevention of risks and safety in the preparation processes of food and beverages.
In the catering and food industry, the HACCP system regulates the behavior of operators in the processing and cleaning or sanitizing phase of food. This system involves risk assessment, evaluation of possible alternatives for risk management and the adoption of measures and of Individual Protective Device (IPD) in order to prevent or avoid such risks.
The European legislation sets precisely the specifications of professional clothing, and therefore also of footwear, in the agri-food and catering sectors.
With reference to professional footwear, it is required that the upper, whatever the material that constitutes it, must meet the technical specifications relating, among other things, to the following parameters: permeability to water vapor, coefficient of water vapor, water penetration and absorption. The integral footwear must also meet water resistance requirements.
Furthermore, in relation to hygienic requirements, it is required that the professional clothing items be such as to reduce the presence and extent of forms that facilitate the entrapment or retention of impurities.
Professional footwear is known in which the upper is obtained by sewing several portions or more flaps of a shaped piece made of leather or a synthetic material (such as microfiber). Furthermore, according to this type of professional footwear, the waterproofing characteristics are obtained by using a waterproof membrane (typically, made either of PTFE or polyester) which internally covers the upper or is interposed between the upper and the inner lining.
Document WO2010/066656 describes a method of manufacturing a shoe in which a functional waterproof element interposed between the upper and lining is provided.
Document GB1144564 discloses a method of manufacturing footwear in which portions of the upper are bonded together by the application of heat and pressure.
The Applicant has noted that the traditional manufacturing techniques of footwear with waterproof characteristics (including professional footwear in the agri-food and catering sectors) are not satisfactory both because of their constructive complexity and in relation to some specifications, such as those concerning cleaning or sanitizing requirements.
The technical problem faced by the present invention is that of proposing a type of footwear of the water resistant type that is an alternative to the traditional ones and the manufacture of which is not complex, while offering satisfactory performances, for example, in relation to their cleaning and sanitization.
According to a first aspect, the above described problem is solved by a footwear as described by claim 1 and by preferred embodiments thereof as defined by dependent claims 2-7.
In accordance with a second aspect, the above problem is solved by a method of manufacturing a footwear as described by claim 8 and by preferred embodiments thereof as defined by dependent claims 9-14.
The present invention is described in detail below, by way of a non limiting example, with reference to the attached drawings, in which:
While the invention is susceptible of various modifications and alternative constructions, some particular embodiments are shown in the drawings and will be described in detail below. In the present description, similar or identical elements or components will be indicated in the figures with the same identification symbol.
An example of a manufacturing method of a footwear 100 (
Even if the one piece construction is the preferred one because it allows to make a single joint between two flaps of the upper, it is possible to provide, for the construction of the upper, several separate pieces (for example, from two to four pieces) to be joined.
Advantageously, the material of the upper 1 is also breathable, that is, it is permeable to water vapor so as to facilitate the transpiration of the foot.
For example, the outer part of the upper 1 is made of microfiber. Other possible materials for the upper 1 are leather or other types of synthetic materials. In particular, if the upper 1 is used in a safety footwear, its material can be such as to satisfy the technical specifications established by a European Union standard according to tests 1) and 2), indicated below:
Water penetration and absorption of test 1) define, according to an example, the resistance to water of the material of which the upper 1 is made. Instead, the permeability and the water vapor coefficient of test 2) define, according to a standard, the perspiration of the upper 1.
Regarding water absorption, it is preferable to use an upper 1 that has an absorption between 0.00% and 20%, i.e., not more than 20%.
Furthermore, the material of the upper 1 is advantageously chosen so as to be mechanically resistant and dimensionally stable if placed in contact with chemically aggressive substances (for example, acidity of food or elements with which the food are treated). The upper 1 is also preferably of the washable type. It should also be noted that in the selection of the material for the upper 1, the above preferred values regarding water absorption are advantageously taken into account, but also the requirements regarding the breathability of the upper itself as defined, for example, by the above standard.
Referring to the particular “one piece” solution, as shown in
In particular, marks 5 are also formed on the upper 1 which can be used as references for subsequent operations. More in detail, the marks 5 made in an area of the main portion 2 (for example, with a pencil or a felt-tip pen) are indicative of the area to which to fix a tongue of the footwear 100.
In a subsequent step, the first flap 3 and the second flap 4 are machined to reduce their thickness with respect to the initial value; this initial value is instead maintained for the main portion 2. In particular, a chamfering and/or skiving of the first flap 3 and of the second flap 4 is carried out in order to reduce their thickness.
Furthermore, this thickness reduction operation is also repeated for a portion of a tongue 6 which will be applied to the upper 1, as indicated below.
According to the example described, a reinforcement fabric 7, provided with an adhesive film that allows a thermo-adhesion, is fixed to an internal face of the upper 1 (
The method described also comprises a step of fixing the first flap 3 and the second flap 4 so that the upper 1 assumes a closed configuration.
This step of fixing the flaps 3 and 4 comprises the application of a thermo-double-sided adhesive tape 8 to the first flap 3 (
Subsequently, the second flap 4 is placed in contact with the free face of the thermo-double-sided tape 8 and then a thermo-sealing operation is carried out which activates the adhesive of the free side of the thermo-double-sided tape 8, by raising the temperature, with a simultaneous application of pressure. The pressure exerted on the second flap 4 which is superimposed on the first flap 3 facilitates its adhesion to the double-sided adhesive tape 8.
For example, for this operation the same hot press machine mentioned in relation to the application of the reinforcement fabric 7 can be used.
According to a preferred embodiment, the heat-sealing of the second flap 4 to the first flap 3 is performed using the following process parameters:
The above values, combined with the use of an upper 1 having a water absorption not exceeding 20%, are particularly suitable to ensure waterproofness of the footwear.
It must be noted that for making the joint of the flaps 3 and 4 the upper 1 is closed in itself in a three-dimensional way, therefore the upper itself is, according to an example, inserted in a long and narrow plate, while an upper plate can be of the flat type.
In this way, the first flap 3 and the second flap 4 are fixed to each other without making seams that pierce the waterproof upper 1. The physical parameters of the process of thermo-adhering the thermo-adhesive 8 to the first flap 3 and thermo-welding the second flap 4 to the first flap 3 are chosen to ensure that the resulting upper 1 is impermeable to water by completely sealing the attachment areas of the two flaps.
Furthermore, it should be noted that as the first flap 3 and the second flap 4 have a reduced thickness with respect to that of the main portion 2 of the upper 1, the area of the upper 1 in which the two flaps 3 and 4 are superimposed (zone 9 in
In the event that several distinct pieces are used for forming the upper 1 (that is, a material in “one piece” is not used), the joints of these pieces advantageously take place in the same way as described above with reference to the extreme flaps 3 and 4.
Furthermore, preferably, the fixing zone 9 of the two flaps 3 and 4 is in a position which corresponds to a rear side area of the footwear 100. It should be noted that this position of the fixing zone 9 is advantageous in that it presents reduced stresses. Furthermore, the fixing zone 9 preferably has a vertical trend to reduce any possibility of stagnation of impurities or liquids.
According to the herein described example, the method continues with the fixing to the upper 1 of an under-tongue element 10 (
As can be seen from
According to the example described, the manufacturing method proceeds with phases of application of linings and buttresses.
In particular, a front lining portion 12 is sewn to a rear lining portion 13 so as to form a complete lining 14, as illustrated in
The lining 14 obtained as indicated above is then sewn to the upper 1;
The lining 14 is realizable, for example, in one of the following materials: polyester, polyamide, recycled polyester.
Note that the lining 14 is directly facing the upper 1 or between the lining 14 and the upper 1 is interposed only the reinforcement fabric 7 (if provided). Note that, advantageously, there is no waterproof membrane associated with the upper 1.
Advantageously, a buttress 15 and a padding 22 are applied to the upper 1, for example, by underneath sewing between the buttress 15 and the upper 1 and then by gluing the padding 22 to the buttress, as indicated in
Subsequently, the upper 1 is turned over so that it assumes the configuration shown in
In this configuration it is advantageously possible to complete the sewing of the rear lining 13, on the lower flaps, to the upper 1 (lower sewing 27).
Subsequently, it is possible to proceed with the steps of applying the tongue 6 (shown in
The tongue 6 has already been subjected to the thickness reduction operation, as described above. Advantageously, the tongue 6 is fixed to the upper 1 with a thermo-sealing procedure similar to that used for fixing the two flaps 3 and 4 of the upper 1.
In greater detail, the area of application of the tongue 6, defined by the marks 5 is cleaned, and then the application is made of a further thermo-double-sided tape 16 (
The adhesion of the tongue 6 is favored by a thermo-welding operation that includes a thermal stabilization (raising the temperature) and a pressing carried out by means of a shaper 23 that also allows to give the desired shape to the upper 1 (
Also in this case, the process parameters indicated are useful for obtaining impermeability. The tongue 6 is intended to result, in the footwear 100 as completed, higher (evaluating this height from the sole of the footwear) than the portion of the upper 1 to which it is attached, which results lower and that is closer to the sole. In order to avoid that the mode of fixing the tongue 6 to the upper 1 may form a substantially horizontal step capable of collecting and retaining dirt, in the application of the tongue 6 to the upper 1 it is advantageously proceeded in such a way that the portion of the upper 1 interested in the fixing results below (i.e., more internal) the tongue 6, which instead surmounts the upper 1, resulting external to the finished footwear. Thanks to the fact that the tongue 6 overlaps the portion of upper 1 to which it is fixed, it favors the sliding of dirt/impurities, possibly present on the tongue 6 towards the ground, on which the footwear rests.
As shown by way of example in
As known, “cambering” (in Italian language also known as “garbatura”) is an operation consisting in giving, generally through a special machine, to a piece (particularly the upper) that has been obtained flat from the model, a curvature such as to make it adhere easily to the form and to facilitate the assembly of subsequent components. In this phase, due to the raising of the temperature, the glue present on the buttress 15 is reactivated and with the pressure the buttress 15 adheres to the upper 1.
Subsequently, as shown in
This insole 19 can advantageously be of the anti-perforation type.
If the insole 19 is of the anti-perforation type, it can be of the textile type, i.e., it can be made for example with a multilayer fabric in ballistic polyester, but other materials are not excluded. Alternatively, the anti-preformation property can be obtained by using an insole made of a traditional material (for example, a non-woven fabric-TNT; fiber cardboard, or synthetic material) with the interposition, between the insole itself and the sole of the footwear 100, of a metal foil.
Furthermore, according to the example, a band 29 is glued to a toe protection tip 20.
By using, for example, a grinding wheel, it is also possible to remove the excess parts of the upper 1.
The sole 21 is then constructed (
The footwear 100 is then completed, as shown in the views of
The footwear 100 in its entirety can be made, using the method described above, in such a way as to be waterproof. In particular, considering the requirement shown in EN ISO standard “paragraph 6.2.5, EN ISO 20345: 2011”, the footwear 100 can be such that after a dynamical flexion test in water for 4800 cycles lasting 80 min, carried out according to the test method described in EN ISO 20344 standard: 2011 ref. 5.15, has an internal humid area of less than 3 cm2.
The footwear 100 and the manufacturing method described have numerous advantages.
An advantage is due to the fact that the fixing of the flaps 3 and 4 of the upper 1 and the fixing of the tongue 6 to the upper 1 are carried out without seams but by thermo-sealing. According to traditional techniques, the seams made for the purpose of joining have a component of the upper that surmounts the other one and the step that is formed (greater than 1 mm) is a source of accumulation of impurities (dirt) and stagnation of liquids which could therefore more easily infiltrate. The technique described above avoids the formation of such a thick step and consequently the accumulation of dirt and stagnation of liquids. The feature whereby the tongue 6 overlaps the portion of the upper 1 to which it is attached helps to prevent step formation, as discussed above.
Furthermore, it should be noted that often in the workplace there is a strong presence of liquids and there are climatic conditions with high temperatures (such as, for example, the kitchens). The absence of seams between portions of the upper 1 and with the tongue 6 of the footwear 100 reduces the risk of penetration of liquids from the cracks caused in traditional footwear by the passage of the needle. It should also be noted that the construction technique of the present solution avoids the use of waterproof membranes to be provided inside the upper, as instead occurs in some types of footwear of the known art. These membranes are not very breathable, therefore they are highly not recommended in work environments with high temperatures (kitchen).
In addition, it should be noted that the sole-making technique which uses liquid polyurethane is particularly advantageous and allows at the same time to seal the insole 19 and to make the sole 21 by direct injection onto the upper, without the need to glue and/or sew it subsequently.
Number | Date | Country | Kind |
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102021000001952 | Jan 2021 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2022/050730 | 1/27/2022 | WO |