WO2015121719A1

WO2015121719A1 - Method for dyeing a sheet of fabric comprising high density polyethylene

Info

Publication number: WO2015121719A1
Application number: PCT/IB2014/067240
Authority: WO
Inventors: Mirko PALADINI
Original assignee: Cartina S.R.L.
Priority date: 2014-02-05
Filing date: 2014-12-22
Publication date: 2015-08-20

Abstract

There is disclosed a method for dyeing at least one sheet of fabric comprising high density polyethylene (HDPE) having a grammage from 40 to 105 g/m² comprising the steps of dipping the sheet of fabric in a dyeing composition comprising 40% dimethyl ketone, at least one aliphatic solvent, at least one aniline-based dye and at least one fixing agent for a time period from 1 second to 1 minute, and laying the sheet of fabric on a support covered with an absorbing material for a time period longer than 30 minutes. There is also disclosed a method for manufacturing an article, in particular a shoe, comprising the method for dyeing.

Description

METHOD FOR DYEING A SHEET OF FABRIC COMPRISING

HIGH DENSITY POLYETHYLENE

TECHNICAL FIELD

The present invention relates to a method for dyeing a sheet of fabric comprising high density polyethylene, a method for manufacturing an article, in particular a shoe, comprising the method for dyeing, and an article obtained by this method.

The textile industry, in particular the shoe industry, continuously seeks fabrics for the manufacture of shoes and other accessories such as bags and wallets, which provide structural and aesthetical features which are advantageous for the products thereof.

BACKGROUND ART

Since 1965, DuPont has developed a group of resistant and durable lamellar products, which are made of high density polyethylene (HDPE) and are identified by the trademark Tyvek®. These materials are formed by the spinning of continuous filaments consisting of very fine fibres closely interconnected to one another and their subsequent bonding by heat and pressure. The result is a shiny white flashspun sheet that represents a printing surface with features of high opacity, resistance to chemical agents and strength.

In virtue of these special features, these materials may be used to manufacture protective work clothing. It is apparent that special aesthetical features are not required for this use. Especially effective dyeing techniques still have not been developed for this purpose.

US20030019054 discloses a method for dyeing materials produced from flash spun plexifilaments with disperse dyes blends .

US3128146 discloses a dyeing process for fabrics of polyethylene or polypropylene, the dyeing bath comprising 0.01-1% by weight of a water-insoluble, oil-soluble dyestuff, 0.05-5% by weight of an inert solvent selected from the group consisting of volatile liquid hydrocarbons, polar haloalkanes and water-soluble amides, 1-10% by weight of an emulsified organic phosphite and the remainder water.

EP1165151 discloses the coating of a Tyvek substrate with an aniline-based dye to produce a chemical indicator.

US5953542 discloses the production of a photographer's backdrop made of Tyvek and dyed with disperse dyes by immersion in a dyeing bath of alcohol-water with at least 50% water.

DISCLOSURE OF INVE TION

It is an object of the present invention to provide a method for dyeing a sheet of fabric comprising high density polyethylene so that it may be used to manufacture shoes or other accessories such as bags, wallets etc. in a simple and cost-effective manner. For shoes, the dyed material must maintain the same features of lightness, breatliability and impermeability of the starting product, as well as acquiring a pleasant aesthetical appearance.

The above object is achieved by the present invention, as it relates to a method for dyeing at least one sheet of fabric comprising high density polyethylene (HDPE) having a grammage from 40 to 105 g/m² comprising the steps of:

- dipping the sheet of fabric in a dyeing composition comprising 40% dimethyl ketone, at least one aliphatic solvent , at least one sriiline-based dye and at least one fixing agent for a time period from 1 second to 1 minute;

- laying the sheet of fabric on a support covered with an absorbing material for a time period longer than 30 minutes .

Another object of the present invention is to provide a method for manufacturing an article, in particular a shoe, which comprises the above said method for dyeing and is suitable for the processing of the specific material.

The above object is achieved by the present invention as it relates to a method for manufacturing an article, in particular a shoe, comprising the above said dyeing method, and the steps of :

- cutting at least one profile having an appropriate shape from the at least one sheet of fabric by die-cutting, and

stitching the at least one profile having an appropriate shape to obtain the article.

Definitions

By the term "grammage" there is intended the weight in grams of a sheet of fabric by square meter of surface.

DETAILED DESCRIPTION

The method for dyeing at least one sheet of fabric comprising high density polyethylene (HDPE) according to the invention comprises several steps.

In a first step, the sheet of fabric is dipped in a dyeing composition comprising 40% dimethyl ketone, at least one aliphatic solvent, at least one aniline-based dye and at least one fixing agent for a time period from 1 second to 1 minute.

In a second step, the sheet of fabric is laid on a support covered with an absorbing material for a time period longer than 30 minutes.

The high density polyethylene (HDPE) of the sheet of fabric is preferably a material that belongs to the group of products identified by the trademark Tyvek© manufactured by DuPont, in particular Tyvek 1073.

The sheet of fabric comprising high density polyethylene (HDPE) has a grammage from 40 to 105 g/m². If grammages higher than 105 g/m² are used, the fabric becom.es excessively plasticated and is not sufficiently soft. If grammages lower than 40 g/m² are used, the fabric becomes excessively fragile for use in the production of articles and accessories such as shoes or bags. The sheet of fabric comprising high density polyethylene (HDPE) preferably has a grammage from 70 g/m² to 80 g/m², more preferably a grammage of 75 g/m².

The sheet of fabric may have a size from 50 cm to 200 cm in length and from 50 cm to 100 cm in width. The preferred size is 100 cm in length and 70 cm in width.

The dyeing composition comprising 40% dimethyl ketone, at least one aliphatic solvent, at least one aniline-based dye and at least one fixing agent is, for example, the product known on the market as Colortan super manufactured by Industrie Chimiche Rindi . The content of the; dyeing composition varies depending on the desired colour.

The sheet of fabric is preferably dipped in the dyeing composition for a. time period from 3 to 10 seconds, more preferably for a time period of about 5 seconds.

The sheet of fabric is preferably laid on a support covered with an absorbing material for a time period from one hour to three hours, more preferably for a time period of about two hours.

The sheet of fabric preferably comprises a layer laminated with a vinyl adhesive of recycled and/or recyclable paper with a grammage from 25 g/m to 35 g/m . More preferably the recycled and/or recyclable paper has a grammage of about 26 g/m².

The sheet of fabric is preferably coupled to at least one reinforcing sheet of cotton, polyester, Jersey, viscose or mixtures thereof, by means of a water-based vinyl adhesive. The reinforcing sheet is preferably made of polyester, so that the whole material can be disposed of with plastic waste.

The reinforcing sheet preferably has a grammage from

20 g/m² to 30 g/m², more preferably a grammage of about 25 g/m².

The method for manufacturing an article according to the present invention comprises the dyeing method disclosed above and the steps of cutting at least one profile having an appropriate shape from the at least one sheet of fabric by die-cutting, and stitching the at least one profile having an appropriate shape to obtain the article.

The size of sewing machine needles is expressed by a two-number metrical system, for example 60/8 for thin sewing needles and 120/16 for more resistant needles. The higher number refers to the metric system and defines the diameter of the needle's shaft in hundreds of mm (Nm) . The smaller number refers to the system adopted in the United States and represents an arbitrary number from 8 to 19 also used to indicate the diameter of the needle's shaft.

Preferably, the sewing machine needle system is the 134 system.

A Groz-Beckert 134 DPx5 class R size 65 needle or a Schmetz 134 Serv 5 size 65 needle may be used,

The thread used for the stitching may be for example a polyester thread having titre 40 (where 40 is the size of the thread expressed in a unit known to the skilled in the art in the shoe sector; the size of the thread varies from 10, thicker size, to 80, thinner size) .

The method preferably comprises a step of milling the sheet of fabric.

The milling consists in introducing the sheet of fabric (possibly laminated with a layer of recycled and/or recyclable paper possibly coupled to a reinforcing sheet) in a milling drum together with a composition comprising 20% of an aliphatic polyurethane emulsion and 80% water and subsequently rotating the milling drum for a time period, so as to obtain a creased effect.

Depending on the article to be manufactured, one or more profiles will have to be cut and stitched together.

The article may be a shoe, a bag, a wallet, a keyholder, a belt, a hat etc. The article is preferably a shoe .

Examples The method according to the invention was used to manufacture different variants of a ballet flat and of a sneaker .

Example_^ _1

In Example 1, a neutral colour ballet flat was obtained .

500 sheets of Tyvek 1073 (DuPont) having a grammage of 75 g/m² and a size of 100 cm x 70 cm were provided.

The sheets were crumpled one by one and introduced into a milling drum (Gozzini , model 3.5 X 3.5 GIG 3500) together with 1 litre of a composition comprising 20% Urelux B129 (Keminter) and 80% water and 10 non-processed white skins weighing 1 kg each .

The milling drum was rotated at 6 rounds/minute for 120 minutes .

Once milling is completed, the sheets were extracted from the milling drum and were left drying for one hour in open air. The skins were extracted from the milling drum and kept for following milling cycles.

In virtue of the milling, the sheets of fabric became soft and had an aesthetically pleasant appearance.

A milled sheet of fabric was cut by a dye-cutting process into several appropriately shaped pieces. The pieces were then assembled and stitched with a needle with a round point (Goz Beckert needle, model 134 DPx5 class R size 65 ) .

Incidentally, in an alternative example which is not shown for sake of conciseness, a Schmetz 134 Serv 5 needle having size 65 was used and the results were identical.

The resulting ballet flat was not only soft, comfortable to wear, resistant and impermeable to rain, but also had a very fine aesthetical appearance.

Example 2

The shoe obtained in Example 1 was subjected to tests for measuring resistance to tearing, to stitching, to abrasion and to repeated flexures to verify the quality thereof. The tests were standard tests in the shoe manufacturer industry. Table 1 summarises the results of the tests.

Table 1

Feature Test Standard Result Reference* method

Resistance to C-002/m Internal 34.3 N/mm² > 10.0 tearing Tensile method

strength

Resistance to A-010/m Internal 8.7 N/mm > 8.0 stitching Res istance method

to

stitch1 rig Resistance to A-023 UNI EN 12800 cycles in No more than abrasion Martindale 13520 dry conditions = moderate (Martindale ) abrasion mod . very slight wear wear after

12800 cycles

3200 cycles in wet No more than conditions = moderate moderate wear wear after

3200 cycles

Resistance to C-017 UNI EN No visible damage No more than repeated Vamp flex 13335 after 500000 si ight flexure (Vamp- flexures mod . flexures damages or flex) cracking after 500000 flexures

* reference values normally required for materials to be used as upper for a walking woman's shoe

The shoe fully passed all tests .

Example 3

In Example 3, the procedure was the same as in Example 1 with the difference that the sheets were laminated with a recycled and recyclable paper ( grammage 26 g/m²) soaked in vinyl adhesive (latex).

Results for resistance to tearing, to stitching, to abrasion and to repeated flexures were comparable to those shown in Example 2. For the sake of conciseness these results will not be shown. Furthermore the resulting shoe was more comfortable and softer.

Example 4

In Example 4, the procedure was the same as in Example 3 with the difference that an additional pure cotton reinforcing sheet was used. The reinforcing cotton sheet had a grammage of 25 g/m and was cold coupled to the milled sheet of fabric with a water-based vinyl adhesive by means of monocylindrical machinery for coupling leather (PCM Engineering) .

Results for resistance to tearing, to stitching, to abrasion and to repeated flexures were comparable to those shown in Example 2. For the sake of conciseness these results will not be shown. Furthermore the resulting shoe was much more resistant .

Example 5

In Example 5, the procedure was the same as in Example 4 with the difference that, as an additional reinforcing sheet, a polyester sheet having grammage of 25 g/m² was used.

Results for resistance to tearing, to stitching, to abrasion and to repeated flexures were comparable to those shown in Example 2. For the sake of conciseness these results will not be shown. Furthermore, the resulting shoe was extremely solid and could be disposed of as a whole with plastic waste .

Example 6

In Example 6, the procedure was the same as in Example 1 with the difference that the sheets were dyed manually with a black paint before milling. In particular, each sheet of fabric was dipped at a. room temperature for about 5 seconds in a dyeing composition comprising 40% dimethyJ, ketone, aliphatic solvents, aniline dyes and fixing agents.

After dipping, each sheet of fabric was laid on supports covered with an absorbing material for about 2 hours. This allows the complete evaporation of the solvents contained in the paint.

Results for resistance to tearing, to stitching, to abrasion and to repeated flexures were comparable to those shown in. Example 2. For the sake of conciseness these results will not be shown.

The dyeing of the shoe therefore does not modify the structural features thereof and improves the aestheticai appearance thereof.

Example 7

In Example 7, the procedure was the same as in Example 1 with the difference that the sheets were dyed with an orange paint after milling.

In particular, each sheet of fabric was dipped for about 5 seconds in a dyeing composition comprising 40% dimethyl ketone, aliphatic solvents, aniline dyes and fixing agents.

After dipping, each sheet of fabric 'was laid on supports covered with an absorbing material for about 2 hours. This allows the complete evaporation of the solvents contained in the paint.

Results for resistance to tearing, to stitching, to abrasion and to repeated flexures were comparable to those shown in Example 2. For the sake of conciseness these results will not be shown.

The dyeing of the shoe therefore does not modify the structural features thereof and improves the aesthetical appearance thereof.

Example 8

The sheet of fabric in Example 1 was subjected to a series of tests to verify the non-toxicity thereof.

Table 2 shows the results.

Table 2

METHOD DESCRIPTION OF ANALYSIS RESULT

Method for determining Aromatic amines deriving from azo

specific aromatic dyes on fabric

amines derived from

azoic dyes 4-Aminodiphenyl (CAS 92-67-1) N.D for all

Benzidine (CAS 92-87-5) ( N. D= not

Part 1: Detection of 4-Chloro-o-Toluidine (CAS 95-69- detected) the use of specific 2)

azoic dyes detectable 2-Naphthylamine (CAS 91-59-8) (detectab i. ] i. ty with or without 2-Amino-4-Nitrotoluene (CAS 99- threshold extraction 55-8 ) 5 mg/kg)

4-Chloroaniline (CAS 106-47-8)

Test method: 2, -Diaminoanisole (CAS 615-05-

UNI EN ISO 14362-1:2012 04 )

4-4 ' -Diaminophenylmethane (CAS

Operating Conditions 101-77-9)

-GC-MS/HPLC-DAD 3, 3' -Dichlorobenzidine (CAS 91- 94-1)

3, 3' -Dimethoxibenzidine (CAS 119- 90-4 )

3 , 3 ' -Dimethylbenzidine (CAS 119- 93-7)

3,3' -Dimethyl-

4,4' Diaminodiphenylmethane ( CAS

838-88-0)

4-Cresidine (CAS 120-71-8)

4,4' -Methylene-Bis- (2- Chloroaniline) (CAS 101-14-4)

4, 4' -Oxydianiline (CAS 101-80-4)

4 , 4 ' -Thiodianiline (CAS 139-65-1)

2, 4-Diaminotoluene (CAS 95-80-7)

2, 4 , 5-Trimethylaniline (CAS 137- 17-7)

o-Toluidine (CAS 95-53-4)

o-Aminoazotoluerie (CAS 97-56-3)

o-Anisidine (CAS 90-04-0)

2,4-Xylidine (CAS 95-68-1)

2,6-Xylidine (CAS 87-62-7)

4-Aminoazobenzene (CAS 60-09-3)

Determination of

formaldehyde

Part 1: Free and

hydrolysed formaldehyde Free and hydrolysed formaldehyde N. D

(aqueous extraction

method) (detectability threshold

Test method: 16 mg/kg)

U I EN ISO 14184-1:2011

Operating Conditions

-Calibration by linear

regression from 0.15 to

0.3 g/l

Organos ann c compounds

N.D for all lest method:

UNI CEN ISO IS Organic Compounds of (detectability 16179 : 2012 Tin threshold)

DBT 0.2 mg/kg

TBT 0.02 mg/kg

TPhT 0.2 mg/kg

DOT 0.2 mg/kg

MBT 0.2 mg/kg

Determination of Phthalates in the Substrate N.D for all

Phthalates

Bis-2-Ethylhexyl Phthalate (DEHP) 0.001%

Test method: (CAS N. 117-81-7)

UNI CEN ISO TS Dibuthyl Phthalate (DBP) (CAS N. 0.001%

16181: 2011 84-7 -7) Buthylbenzyl Phthalate (BBP) (CAS 0.001%

Operating Conditions N. 85-68-7)

Diisononyl Phthalate (DINP) ( CAS 0. 005%

--Test performed on the N. 68515-48-0)

total mass of sample Diisodecyl Phthalate (DIDP) (CAS 0. 005%

N. 68515-49-1)

-Extraction performed Dioctyl Phthalate (DnOP) (CAS 0. 001% with ultrasound bath N.117-84-0)

Sum of DEHP, DBP, BBP, DINP, DIDP 0 , 014 % and DNOP

Diisobuthyl Phthalate (DIBP) (CAS 0. 001

. 84-69-5)

Di-n-hexyl Phthalate (DnHP) (CAS 0. 001%

N. 84-75-3)

Diundecyl Phthalate (DHNUP) (CAS 0. 001%

N. 68515-42-4)

Diisohexyl Phthalate (Dl-hP) (CAS 0. 001%

N. 146-50-9)

Dipenthylphthalate (DPP) (CAS 0. 001%

131-18-0)

Bis (2-methoxyethyl) Phthalate 0. 001%

(DMEP) (CAS N.117-82-8)

Determina ion of the Content of Chloroalkanes

content of (CIO - C13)

chloroalkanes in the N. D

f£LbnG ( detectability threshold

Chromatographic method 10 mg/kg) for short chained

chlorinated paraffins

(SCCP)

Test method:

ISO/DIS 18219

Operating Conditions

-Ultrasound extraction :

60°C for lh.

Determination of the pH aqueous extract pH 6. 9

of the aqueous extract

Test method:

UNI EN ISO 3071:2006

Operating Conditions

-Extracting solution:

water (pH=6; T=20°C) Evaluation of To al Cadmium (Cd) content N. D

ecological criteria : (detectability

Determination of the Total Lead (Pb) content threshold total content of metals 0.5 mg/kg)

Test method:

UNI EN ISO 14602:2011

Operating Conditions

Microwave digestion

according to method C

Determination by ICPOES

analysis

As can be seen from Table 2, the sheet of fabric obtained by the method according to the invention contains none of the tested toxic agents.

Example _ 9

In Example 9 , the procedure was the same as in Example 1 with the difference that the sheets were laminated with a recycled and/or recyclable paper ( grammage 26 g/m ) soaked in vinyl adhesive (latex) and an additional reinforcing sheet of polyester was used. The reinforcing polyester sheet had a grammage of 25 g/m² and was cold coupled to the milled sheet of fabric with a water-based vinyl adhesive by means of a monocylindrical machinery for coupling leather (PCM Engineering) .

A few sheets were manually dyed -with a fuchsia paint before milling.

In particular, each sheet of fabric was dipped for about 5 seconds in a fuchsia paint comprising 40% dimethyl ketone, aliphatic solvents, aniline dyes and fixing agents.

A dyed and milled sheet of fabric was cut by means of a dye-cutting process into several pieces having an appropriate shape for manufacturing a sneaker shoe. The pieces were then assembled and stitched with a needle having a round point (Goz Beckert needle, model 134 DPx5 class R size 65) using a stitching distance of 2 stitches per centimetre with a low thread tension.

The resulting shoe WclS Subjected to a series of tests to verify thickness, resistance to stitching, tensile strength, elongation strength, resistance to bending, resistance to abrasion, maintenance of colour intensity upon light exposure, rubbing and aging.

Table 3 summarises the results of the tests.

Table 3

METHOD DESCRIPTION OF ANALYSIS RESULT

Average thickness

Test method: Average Thickness Result 1.6 mm

UNI EN ISO 2589:2006 Resistance to stitching Resis tance to stitching

Test method: Average Value - Parallel 15.1 N/mm UNI 10606:2009 Average Value - Perpendicular 15.1 N/mm

Average Value 15.1 N/mm

("parallel" and "perpendicular"

indicate the test samples cut with

the longer sides orthogonal to one

another )

Average thickness

Average Thickness Result 1.6 mm

Test method:

UNI EN ISO 2589:2006

Tensile s rength and

breaking percentage

elongation

Test method: Tensile s rength

UNI EN ISO 3376:2012 Average Value - Parallel 6.6 N/mm²

Average Value - Perpendicular 7.0 N/mm² Average Value 6.8 N/mm²

Average breaking percentage

elongation

Average Value - Parallel 25.9 % Average Value - Perpendicular 23.9 % Average Value 24.9 %

("parallel" and "perpendicular"

indicate the test samples cut with

the longer sides orthogonal to one

another )

Flexure strength

by continuous flexure -

"BALLY FLEX TEST"

Test method: No. of tested samples 1

UNI EN 13512:2002

Flexure streng h

Operating Conditions WEFT

-Test in DRY conditions

No. of flexure cycles performed 50000

De t ec t ed damage No damage

( vi sual observation )

No. of tested samples 1 Flexure strength

WARP

No. of flexure cycles performed 50000 Detected damage No damage

(visual observation )

Flexure strength by

continuous flexure -

"BALLY FLEX TEST"

No. of tested samples 1

Test method:

UNI EN 13512:2002 Flexure strength

WEFT

Operating Conditions

-Test performed in WET No. of flexure cycles performed 10000 conditions

Detected damage No damage

(visual observation)

No. of tested samples

1

Flexure strength

WARP

No. of flexure cycles performed

10000

Detected damage

No damage

(visual observation)

Resistance to abrasion

Test method:

UNI EN ISO 12947-2:2000

Operating Condi,t ions No. of cycles performed 2000

-Test in DRY conditions

- Pressure: 12kPa Abrasive effect end point End point

(visual observation )

Degradation of colour

2 (grey scale ) * Maintenance of colour

in ensity upon light

exposure

- xenon arc lamp

Test method: Hours of exposure : 48h

UNI EN ISO 105-B02:2013

Maintenance of colour intensity 6 (grey

Operating Conditions upon artificial light exposure scale) **

- Instrument used:

Xenotest very slight

150S+ (Atlas® ) with chromatic

Xenon arc lamp MXe 2000 varia tion

HE (Atlas© )

~ Radiation level: 42

W/rrh

Test conditions :

Europe, normal

conditions (50°C BST;

50% U.R. )

- Method 3

- Alternate mode not

used

Accelerated aging in

climatic chamber -

"TROPICAL TEST"

Test method:

UNI EN ISO 7228:2006 Check in changes occurred 4 (grey

scale ) *

Operating Conditions

- Aging by: Heat and No migration high humidity among

- Aging method: 7B (96i componen ts

2h at 50±2°C and

90±5%UR)

Maintenance of colour

upon rubbing -

"Crockmeter Test"

Tested side: Right side

Test method:

UNI EN ISO 105-X12 : 2003 Colour release on white cotton

Operating Conditions

- Rubbing cylindrical Test in DRY conditions - 10 cycles 2/3 (grey ankle scale ) * exerting a downward

force of 9.0 t 0.2 N Test in WET conditions - 10 cycles 3/4 (grey- scale ) *

Degradation of colour of

the fabric: Test in DRY conditions -- 10 cycles 5 (grey seal e ) *

Test in WET conditions ^■ - 10 cycles 5 (grey scale ) *

* Visual observation according to grey scale 1/5 (1= Clear colour release / variation ; 5= No colour release /variation) determined in the artificial light cabin using illuminating D65

** Visual observation according to the scale of the blue wool references 1/8 (1= Clear variation ; 8= No variation) determined in the artificial light cabin.

As can be seen from Table 3, the shoe obtained by the method according to the invention has an excellent stitching resistance, tensile and elongation strength, flexure strength and resistance to abrasion. Furthermore, the colour of the shoe does not vary after exposure to light, aging and rubbing.

From an analysis of the features of the method according to the present invention, the advantages it allows to obtain are apparent.

I particular, in virtue of the fact that the solvents of the dyeing compositions are very volatile, they evaporate totally without modifying the chemical features and the pH of the sheet of fabric. The colour remains fixed to the sheet of fabric and does not fade even in the presence of water.

The step of laying a sheet of paper on a support covered with absorbing material for a time period longer that 30 minutes allows to eliminate excess dyeing composition and the complete evaporation of the solvents of the dyeing composition.

Dipping in the dyeing composition for a short time allows an optimal dyeing and at the same time a short procedure .

The use of layer laminated with a vinyl adhesive of recycled and/or recyclable paper with a grammage from 25 g/m² to 35 g/m² allows to increase the softness of the fabric while maintaining it light and resistant.

Furthermore, by coupling the sheet of fabric to at least one reinforcing sheet of cotton, polyester, Jersey, viscose or mixtures thereof, the material is considerably strengthened for specific applications and processing. In particular, by using a reinforcing polyester sheet, the whole product can be disposed of with plastic waste. Furthermore, by using a grammage from 20 g/m² to 30 g/m² for the reinforcing sheet, an optimal balance is obtained between lightness and resistance of the sheet of fabric.

The method for manufacturing an article, in particular a shoe, according to the invention, allows to obtain a soft and light article which is at the same time resistant and waterproof. The article also has a pleasant aesthetical appearance .

Furthermore, the additional step of milling the sheet of fabric allows to considerably soften the sheet of fabric without modifying its resistance features. Furthermore, the resulting sheet of fabric has a pleasant aesthetical appearance .

The use of a needle with a round point having a size of 65/9 and a distance between stitches from 2 to 3 stitches per centimetre with a low thread tension allows an effective stitching of the material.

Finally, it is clear that modifications and variants to the method and article disclosed and shown herein can be made without departing from the scope of protection defined by the claims.

Claims

1. A method for dyeing at least one sheet of fabric comprising high density polyethylene (HDPE) having a grammage from 40 to 105 g/m² comprising the steps of:

- dipping the sheet of fabric in. a dyeing composition comprising 40% dimethyl ketone, at least one aliphatic solvent, at least one aniline based dye and at least one fixing agent for a time period from 1 second to 1 minute; and

2. The method according to claim 1 , wherein the sheet of fabric is dipped in the dyeing composition for a time period from 3 to 10 seconds .

3. The method according to claim 1 or 2, wherein the sheet of fabric is laid for a time period from one hour to three hours .

4. The method according to any of the preceding claims, wherein the sheet of fabric also comprises a layer laminated with a vinyl adhesive of recycled and/or recyclable paper with a grammage from 25 g/m² to 35 g/m².

5. The method according to any of the preceding claims, wherein the sheet of fabric is coupled to at least one reinforcing sheet made of cotton, polyester, Jersey, viscose or mixtures thereof, by means of a water-based vinyl adheS1V6.

6. The method according to claim 5, wherein the reinforcing sheet has a grammage from 20 g/m² to 30 g/in².

7. A method for manufacturing an article, in particular a shoe, comprising the method for dyeing according to any of the preceding claims, and the steps of:

8. The method according to claim 7, also comprising a step of milling the sheet of fabric.

9. The method according to claim 7 or 8, wherein the at least one profile having an appropriate shape is stitched by means of a needle with a round point having a size of 65/9 and a distance between stitches from 2 to 3 stitches per centimetre with a low thread tension is used.