Description:FORM 2

THE PATENT ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(See Section 10, and rule 13)

TITLE OF THE INVENTION
PU-PU BONDING FILM MOULDING METHOD AND FOOTWEAR THEREOF

APPLICANT(S)
NAME: WALKAROO INTERNATIONAL PRIVATE LIMITED
NATIONALITY: LARGE ENTITY
ADDRESS: PLOT NO 10- 12, SIDCO INDUSTRIAL ESTATE, MALUMICHAMPATTY P.O., COIMBATORE- 641050

The following specification particularly describes the invention and the manner in which it is to be performed

[001] FIELD OF THE INVENTION
[002] Embodiments of the present invention pertain to articles of footwear and methods of making articles of footwear and, more specifically, relate to the process of manufacturing a Double density PU-PU (Polyurethane moulding) bonding film footwear.
[003] DESCRIPTION OF RELATED ART
[004] Footwear is the basic need of human beings for their daily use. The footwear is of different types and is designed for different purposes, like for the fashion industry, for athletic purposes, for daily usage and for kids with different soles and structures.
[005] Conventional footwear uses chemical preparation with adhesive to enable the midsole–outsole fusing, and is supposed to keep both as a single unit during the lifetime of the footwear.
[006] The convention technology has limitations since the bonding between both soles is based on adhesive properties and application will lead to improper bonding between midsole and outsole. Even with the application of adhesive at different compositions and methods, this method failed to achieve the desired bonding strength which has increased the rejection rate of the product.
[007] The skilled application requires more time and a higher labour cost, as well as cost of chemical treatment is also high compared to the poor effectiveness. There was no scope for improvement in this method as the chemicals used will be expensive to develop for tailor made requirements. The lifetime of the footwear is less.
[008] Therefore, there is a pressing need to address the above-mentioned problem and the present invention come up with a method that replace the chemical application process hence removing the vulnerability associated with adhesive bonding, improving the bonding strength between midsole and outsole, and reducing the associated manpower and chemical consumption.
[009] SUMMARY OF THE INVENTION
[0010] One embodiment of the present invention discloses a double density PU-PU Bonding film moulding method for manufacturing footwear comprising the steps of: casting a midsole with a fabric film, placing the casted midsole into the outsole mould, moulding the outsole with PU, bonding the PU with the fabric which is attached to the midsole, finishing the footwear, wherein the midsole is casted with the fabric film, the outsole is casted with PU bond, thereafter the casted midsole is placed into the outsole mould.
[0011] Another embodiment of the present invention disclose a footwear manufactured from the method of the present invention.
[0012] The objective of the present invention is to manufacture double-density PU-PU footwear using PU-PU Bonding film moulding method.
[0013] Another objective of the present invention is to provide double-density PU-PU footwear without any chemical or adhesive for inducing bonding between two PU materials.
[0014] Another objective of the present invention is to provide double-density PU-PU footwear with improved bonding strength between the midsole and outsole.
[0015] Another objective of the present invention is to reduce the manpower to manufacture double density PU-PU footwear.
[0016] Another objective of the present invention is to provide a double density PU-PU footwear that is durable, user-friendly, adjustable and has long life.
[0017] These and other advantages will be apparent from the present application of the embodiments described herein.
[0018] The preceding is a simplified summary to provide an understanding of some embodiments of the present invention. This summary is neither an extensive nor exhaustive overview of the present invention and its various embodiments. The summary presents selected concepts of the embodiments of the present invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the present invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and still further features and advantages of embodiments of the present invention will become apparent upon consideration of the following detailed description of embodiments thereof, especially when taken in conjunction with the accompanying drawings, and wherein:
[0020] Figures 1A to 1C depict conventional technology for manufacturing a Double density PU-PU footwear;
[0021] Figure 2A to 2D depicts a new technology for manufacturing a Double density PU-PU footwear, according to an embodiment of the present invention; and
[0022] Figure 3 depicts a comparison between the methods for manufacturing a Double density PU-PU footwear as per conventional or new method.
[0023] The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. Optional portions of the figures may be illustrated using dashed or dotted lines, unless the context of usage indicates otherwise.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto. Therefore, the present description should be seen as illustrative and not limiting. While the invention is susceptible to various modifications and alternative constructions, it should be understood, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0025] In any embodiment described herein, the open-ended terms "comprising," "comprises,” and the like (which are synonymous with "including," "having” and "characterized by") may be replaced by the respective partially closed phrases "consisting essentially of," consists essentially of," and the like or the respective closed phrases "consisting of," "consists of, the like.
[0026] As used herein, the singular forms “a”, “an”, and “the” designate both the singular and the plural, unless expressly stated to designate the singular only.
[0027] The embodiment of the present invention discloses methods of making articles of footwear and, more specifically, relate to manufacturing a Double density PU-PU (Polyurethane moulding) footwear from a double density PU-PU Bonding film moulding method.
[0028] Figure 1A to 1C depicts conventional technology for manufacturing a Double density PU-PU footwear. The conventional technology for manufacturing a Double density PU-PU footwear includes casting the soft midsole material on to a mould, creating the one of the two parts (midsole and outsole) of double density footwear, after the first part has been moulded it goes to a process of fitted upper preparation, along with a series of chemical treatments to prepare the midsole for next level of casting with outsole.
[0029] The chemical treatment includes the following activities
• First level of cleaning using a cleaning solvent-and drying
• Applying primer and drying
• Applying adhesive for PU-PU bonding
[0030] The conventional process repeated three times consecutively to fix the midsole on the outsole mould, then casted with harder outsole material. The chemical preparation with adhesive will enable the midsole – outsole fusing, and is supposed to keep both as single unit during the lifetime of the footwear.
[0031] Figure 2A to 2D depicts a new technology for manufacturing a Double density PU-PU footwear, according to an embodiment of the present invention; as shown in Fig. 2A midsole is casted with a fabric film attached to it, Fig. 2B once the midsole is casted it can be placed into the outsole mould, around 55o C temperature is maintained while casting midsole and also during casting the film with midsole, Fig. 2C when outsole mould is casted with PU, the PU will bond with the fabric which is attached to the midsole, hence the fabric work as a bonding agent between both PU systems, Fig. 2D shows the finished product of footwear manufacture by the Double density PU-PU bonding film moulding method.
[0032] The present invention removes the chemical or adhesive treatment process all together, and replace it with a fabric film to induce the bonding, the fabric acts as a bonding agent between the two soles. Double density PU-PU moulding with fabric film placed in between. The fabric attached to the midsole mould before casting, which later is sandwiched between midsole and outsole.
[0033] The fabric which acts as a bonding agent is a LAMINATED FABRIC UI-2087-TPU-BLACK with thermoplastic polyurethane coating with variable thickness as per the height of the sole of the footwear. The fabric can be single-spectrum and multiple spectrums of materials having TPU coating for same use. (Any Bonding film which have PU Coating on both sides). The fabric has a PU bonding which act as a double side tape, creating a single unit PU system.
[0034] Figure 3 depicts a comparison between the methods for manufacturing a Double density PU-PU footwear as per conventional or new method; the conventional method uses adhesive or chemical for bonding the midsole with the outsole before casting. In conventional method the chemical is first applied to the midsole then adhesive is applied on it, after that the midsole is casted with outsole for manufacturing final footwear. However, in present method, the fabric film is attached to the midsole mould before casting, which later is sandwiched between midsole and outsole.
[0035] Table 1 discloses the comparative difference between the conventional method and the new method for manufacturing a Double density PU-PU footwear:
Table 1
Criteria Conventional Method New Method
chemical usage different combinations of chemical treatment to be used to induce bonding no chemical application needed
manpower requirement 3 manpower required for chemical applications in one shift no additional manpower required
reduced cost chemical costs and manpower costs outweighs the fabric cost lesser cost of production
productivity Lower output observed due to higher curing time of chemicals Higher output due to zero chemical procedure (200 pairs production increase/day with one set of mould)
quality Lower bonding strength due to volatile chemicals and skilled application higher bonding strength between chemicals observed
Higher rejection rate observed due to lack of bonding Near zero rejections observed with respect to bonding

[0036] Table 2 discloses wear test comparison by comparing footwear made using the conventional method and new method of the present invention in real world, data are taken by real usage and taking feedback after a span of 2 weeks.
In method column:
R- Footwear which is having bonding film (Fabric) in between soles as per method of present invention
L- Footwear bonding with use of adhesives as per conventional method
Table 2
Given date Days used method Bonding issue Smell IMC Colour fade Midsole comfort Insole stitching Outsole Abrasion Upper tear Buckle
30-11-2023 11 L Ok Ok Ok Ok Ok Ok Ok Ok
R Ok Ok Ok Ok Ok Ok Ok Ok
30-11-2023 11 L Ok Ok Ok Ok Ok Ok Ok Ok
R Ok Ok Ok Ok Ok Ok Ok Ok
29-11-2023 12 L Bonding initiated in 2 spots Ok Ok Ok Ok Ok Ok OK
R Ok Ok Ok Ok Ok Ok Ok OK
29-11-2023 12 L Bonding initiated in 2 spots Ok OK Ok OK Ok Ok OK
R Ok Ok Ok Ok Ok Ok Ok OK
29-11-2023 12 L Ok Ok Ok Ok Ok Ok Ok OK
R Ok Ok Ok Ok Ok Ok Ok OK

[0037] Table 3 discloses Tear test results – for PU-PU bonding strength measurement
Table 3
Type Bond strength in N/mm Bond opening/Material tear
Bonding Film (Fabric) ATTACHING
(New Method of Present Invention) 3.25 Material tear
3.35 Material tear
4.25 Material tear
Adhesive ATTACHING
(Conventional Method) 3.3 Bond opening
4.35 Bond opening
2.98 Material tear

# Material tear denotes that bonding strength has surpassed the PU materials tear value, hence when pulled apart, material fails before bonding strength. The method as per present invention where fabric film is attached as a bonding agent showed material tear and has higher values than chemical attaching process, which shows the efficacy of new method of the present invention.
[0038] Table 4 discloses output comparison between conventional method and fabric method
Table 4
OUTPUT Conventional method (prs/hr) FABRIC METHOD (prs/hr)
machine o/p possible 70 70
Conveyor o/p 60 same as machine o/p
loss of output-bottleneck 10 0

Table 4 shows the output of machine, conveyor & bottleneck. As shown above the output results of the method of the present invention is better than the conventional approach.
[0039] Table 5 discloses manpower comparison between conventional method and fabric method
Table 5
WORKCENTRE CONVENTIONAL METHOD FABRIC METHOD MANPOWER SAVINGS
PAD PRINTING 1 1 0
MARKING &ATTACHING 4 4 0
SOLE STITCHING 2 2 0
THREAD CUTTING 4 4 0
CLEANING 6457 1 0 1
BOSTIK ADHESIVE APPLICATION 1 0 1
BOSTIK 1815 APPLICATION 1 0 1
14 11 3

Table 5 discloses the use of man power for each steps, as shown above as compare to the conventional approach the manpower reduced to 3 numbers.
[0040] While the invention has been described in connection with what is presently considered to be the most practical and various embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

, Claims:WE CLAIM,
1. A double density PU-PU Bonding film moulding method for manufacturing footwear comprising the steps of:
• casting a midsole with a fabric film;
• placing the casted midsole into the outsole mould;
• moulding the outsole with PU;
• bonding the PU with the fabric which is attached to the midsole;
• finishing the footwear.
wherein the midsole is casted with the fabric film, the outsole is casted with PU bond, thereafter the casted midsole is placed into the outsole mould.
2. The method as claimed in claim 1, wherein the fabric film works as a bonding agent between both PU systems.
3. The method as claimed in claim 2, wherein the fabric film is a laminated fabric UI-2087-TPU-BLACK- cloth with thermoplastic polyurethane coating or any fabric with PU coating on both sides.
4. The method as claimed in claim 1, wherein the footwear can be manufacture of any size and shape or designed with different requirement as per user requirements.
5. The method as claimed in claim 1, wherein the fabric film thickness vary as per the height of the sole of the footwear.
6. A double density PU-PU footwear manufactured using the method as claimed in claim 1.

Dated this 1st day of February, 2024

Md. AZHARUDDIN
AGENT FOR THE APPLICANTS
IN/PA No. 3823