Chrome-tanned leather GOST 939 88. Specifications

STATE STANDARD

UNION SSR

LEATHER FOR SHOE UPPER

TECHNICAL CONDITIONS

GOST 939 - 88

Official edition

USSR STATE COMMITTEE ON STANDARDS

UDC 675.06:685.31:006.354 MP group

STATE STANDARD OF THE UNION OF THE SSR

LEATHER FOR SHOE UPPER

Specifications GOST

upper leather. 939_88

Valid from 01.01.90 to 0 KO 1.95

Non-compliance with the standard is punishable by law

This standard applies to chrome-tanned leather for shoe uppers, produced from raw materials in accordance with GOST 382.

The standard does not apply to leathers for uppers manufactured by order of the USSR Ministry of Defense.

1. TECHNICAL REQUIREMENTS

1.1. Leathers must be manufactured in accordance with the requirements of this standard according to the technology approved in the prescribed manner, and standard samples in accordance with GOST 15.007.

1.2. Specifications

1.2.1. Skins are divided into:

outgrowth;

half-skinner;

horse fronts; camels;

Official edition

1.2.2. For the top of model shoes, they produce a calf, an outgrowth, a goby, a semi-skinner, a barn, a bull, a bull, a chevro, a goat-din.

1.2.3. By configuration, the skin is divided into: whole skins;

whole skins without collars - from medium and heavy cowhide, bullock and bullock;

half-skin - from a bull, a half-skin, an outgrowth, a yalovka, a bullock, a bull;

semi-skin without collars - from a bull, bull-calf, bull-calf, bull; fish, saddlecloths and pork croups; horse fronts and half fronts; collars.

Determination of the configuration according to GOST 3123.

Collars must be complete with a black-and-white part and match them in terms of the type of finish of the front surface and color.

1.2.4. Skins are subdivided depending on the size by area, dm 2:

1.2.5. Skins are produced with a thickness of 0.5 to 2.8 mm inclusive and are divided into groups in accordance with Appendix 1.

1.2^3. The skin thickness at any point shall be at least 80% of the thickness at the standard H-point. The standard H-point is determined in accordance with Annex 2.

1.2.7. Leathers with a thickness of over 1.6 mm and leathers of increased thickness (thickness over 2.2 mm) are produced for the top of unlined shoes.

1.2.8. By appearance skin produces:

with a natural unpolished and polished front surface and;

unpainted, drum-dyed, drum-dyed and top-dyed (with aniline finish, with casein, emulsion-casein, emulsion and nitroemulsion coating, including semi-aniline finish);

smooth, embossed, embossed, velor and nubuck;

natural, white, colored, black, multicolor.

1.2.9. Leathers for the top of model shoes are made smooth, with embossed riosh, nubuck and velor.

1.2.10. Determination of types of leather finishes - according to GOST 3123 and Appendix 3.

1.3. According to the physical and mechanical parameters of the skin must comply with the standards specified in the table. Chemical composition leather - in accordance with Appendix 4.

	Skin norm
Name of indicator	all types, except for velor and iubuk
Tensile strength 10 MPa, not less than: for all types of leather, with the exception of cowhide, bull, bull, chevret and pigskin
for cowhide, bullock, bull and pig skins
for chevret
Stress at the appearance of cracks in the front layer, 10 MPa, not less than: for all types of leather, with the exception of cowhide, bullock, bull and chevret
for yalovka, bychyna, bull
for chevret
Elongation tsri voltage 10 MPa, %: for all types of leather, with the exception of cowhide, bovine, bull, chevret and pigskin
for cowhide, bullock, bull, chevret and pig skins
Coating resistance to repeated bending, points, not less than
Cover film adhesion, N/m, not less; for dry skin: with natural face
with polished face
to wet skin: with natural face
with polished face

Notes:

1. The norms for all indicators are set for the batch.

2. The minimum value of the tensile strength of leather in par-teak must be at least 1.0X10 MPa.

3. But (rms in terms of adhesion and resistance of the coating to multiple bending - - at least 3 points are established from 01.01.91.

Color fastness for velor and unlined leather to dry friction - 4 points, to wet friction - 3 points.

1.4. Depending on the availability of the usable area of the skin, they belong to the 1st, 2nd, 3rd and 4th grades. The leather grade is determined according to GOST 338.

Leather for the top of model shoes must be at least grade 3.

1.5. Requirements for leather for the top of orthopedic shoes - in accordance with Appendix 5.

1.6. Marking and packaging of leather - in accordance with GOST 1023 and with the following addition: leather with a polished front surface must be marked with the letter "P".

2. ACCEPTANCE

Leather acceptance rules - according to GOST 938.0.

3. TEST METHODS

3.1. Sampling - according to GOST 938.0.

3.2. Determination of tensile strength, stress in the event of cracking of the front layer and elongation - according to GOST 938.11.

3.3. Preparation of samples for physical and mechanical tests - according to GOST 938.42.

3.4. Crobe conditioning - according to GOST 938.14.

3.5. Determination of the mass and linear dimensions of the samples - according to GOST 938.13.

3.6. Determination of the thickness of the samples and the thickness of the skins at the standard point - according to GOST 938.15.

3.7. Determination of the resistance of the coating to repeated bending - according to GOST 13868.

3.8. Determination of adhesion - in accordance with Appendix 6.

3.9. Testing the color fastness of leather to dry and wet friction - according to GOST 938.29.

EVIL. Determination of the cage of the front surface of leathers with a natural front surface - according to GOST 938.27.

3.11. Test for fragility of leather with a polished front surface - according to GOST 938.30.

3.12. Determination of the mass fraction of moisture - according to GOST 938.1.

3.13. Determination of the mass fraction of chromium oxide - according to GOST 938.3.

3.14. Determination of the mass fraction of substances extracted by organic solvents - according to GOST 938.5.

4. TRANSPORT AND STORAGE

Transportation and storage of leather - according to GOST 1023.

5. MANUFACTURER WARRANTY

Guaranteed shelf life of leather - 3 months from the date of manufacture.

RECOMMENDED THICKNESS GROUPS AT THE STANDARD POINT H DEPENDING ON THE TYPE OF RAW MATERIAL IN MM

Chevro and goat
Chevro and goat










Notch and camel


Equine
Equine




Outgrowth and half-skin


Goby and cow light

Yalovka medium and heavy,
bullock light and heavy,
bullshit light and heavy

APPENDIX 2 Mandatory

DETERMINATION OF THE THICKNESS AT STANDARD POINT H

The thickness of the skins is determined at the standard point H, located on each floor of the skin, semi-skin without collars, semi-front, on the grass half of the whole leather, whole leather without collars, saddle, fish, transferred, nrupon on each collar and located:

on the front ah and half lane single ah - at the intersection of the line LM, located at a distance of 75 mm from the spinal line XY, with the line I1C, located

at a distance of 150 mm from the internal tangent line 017 drawn through the point Z to the haz line. FCC (Fig. 1);

on whole leathers without collars, semi-skins, semi-skins without collars, worked out from cowhide, bullock and bullock, - at the intersection of the LM line, located at a distance of 200 mm from the XY spinal line, with the IK line, located at a distance of 250 mm from the tangent line to the hollow of the rear roar of the BG (Fig. 2);

On whole leathers, semi-skins, semi-skins without collars, chetzraks, fish, croupons, made from other raw materials - at the intersection of the LM U line located at a distance of 75 mm from the XY spinal line, with the IK G line located at a distance of 150 mm from the line, tangent to the depressions of the back cut BG (Fig. 3),

on the collars - at the intersection of the LM line, located at a distance of 100 mm from the spinal line XY, with the I K line, located at a distance of 200 mm from the AB line, separating the collar from the rest of the skin (Fig. 4) "

APPENDIX 3 Reference

DEFINITION OF LEATHER FINISHES

1. Smooth leathers include:

pressed with a smooth plate;

with intermediate pressing with a small-sized plate with a dust-like pattern, followed by pressing with a smooth plate.

2. Embossed leather includes leather pressed with plates with a honey-like pattern (chevrolet, shagreen, etc.), except for plates with a dust-like pattern.

3. Embossed leathers include leathers, the relief pattern of the front surface of which is obtained by pressing with plates with medium and large patterns and corresponds to the fashion trend,

4. Determination of types of coatings

Casein coating on leathers with a natural grain surface, fixed with formalin and gcellac-casein.

Emulsion-casein - a combination coating on leathers with a natural front surface using emulsion film-brazing agents in impregnating and pigmented primers and casein finishes in top coats.

Emulsion -■ coating on leathers with natural and polished front surface using emulsion plank formers in impregnating and pigmented primers with fixing with nitroemulsion varnishes or nitro varnishes.

Nitroemulsion - a coating on leathers with a sanded and sanded front surface using emulsion plank formers in impregnating and pigmented primers with fixing with nitro enamels mixed with nitro varnishes.

APPENDIX 4 Mandatory

SKIN CHEMICAL DATA

ANNEX 5 Mandatory

LEATHER REQUIREMENTS FOR ORTHOPEDIC SHOE UPPER

For the top of orthopedic shoes, a calciner, an outgrowth, a semi-leather, a chevro are produced:

by configuration - whole; area, dm 2 - from

thickness at the standard point H:

from 0.7 to 1.0 mm incl. - chevro;

"0.9 > 1.2 mm" - flask, outgrowth, half-skin;

in appearance - smooth, black and colored, with emulsion

and nitroemulsion coating; by grades - 1, 2 and 3 grades,

APPENDIX 6 Mandatory

METHOD FOR DETERMINING ADHESION OF EMULSION AND NITROEMULSION COATING TO SKIN

This method involves the determination of the adhesion of emulsion and nitroemulsion coatings to leather for chrome-tanned shoe uppers.

The essence of the method is to determine the load required to peel the cover film from the skin (preliminarily glued to the fabric).

1. SAMPLING

Sampling is carried out in accordance with GOST 938.0 from a skin area adjacent to the sampling site for physical and mechanical tests, 7.0x7.0 cm in size. The direction of the spinal line is marked on the sample,

2. EQUIPMENT AND REAGENTS

2.1. For testing use:

laboratory desktop press for gluing samples, providing pressing pressure of at least 0.4 MPa;

electric drying cabinet with thermostat for heating up to 100°С;

a metal ruler with a division value of 1.0 mm according to GOST 427 or another one that provides a similar measurement accuracy;

breaking machine type RM-3 or RM-30;

nitrocellulose glue "AGO" according to normative and technical documentation;

fabric (calico) in accordance with GOST 19196 or calico according to normative and technical documentation (the fabric must be washed in hot water, dried and ironed before testing).

3. PREPARATION FOR THE TEST

3.1. The skin sample is brought to an air-dry state according to GOST 938.14.

3.2. A sample of 7.9x7.0 cm in size is cut out of the fabric, on which a thin layer of glue is evenly applied with a glass rod or a sharp spatula at the rate of 1 g per 10 ohm 2 area. One edge of the fabric per 1 cm is not smeared.

3.3. The tissue sample is applied to the front surface of the skin sample and glued so that the adhesive is evenly distributed over the surface and no air bubbles remain between the tissue and the skin.

3.4. The glued sample is kept in air at a temperature of 20 ° C for 20 minutes, then under pressure for 20 minutes at a pressure of 0.5 MPa and dried in an oven at a temperature of 60 ° C for 40-60 minutes.

3.5. The glued sample is conditioned according to GOST 938.14 for 24 hours.

3.6. From each glued sample, six samples are cut in the longitudinal direction with a size of 1.0x7.0 cm with a maximum deviation in length and width of ±0.1 cm.

3.7. On each sample from the delamination side, a working section 5 cm long is marked and divided by transverse lines into 5 equal sections.

3.8. Each sample is stratified before the beginning of the working section, checking its suitability for testing. Samples are considered suitable, in which, during the test for tearing off the tissue from the skin, the tissue exfoliates along with the coating,

3.9. Three samples are tested in a dry state and three in a wet state, for which they are immersed in water with an initial temperature of (69 ± 1) ° C for 3 hours. Before testing, moisture is removed from the samples with filter paper.

4. CONDUCTING THE TEST

4.1. The test sample is fixed in the clamps of the tensile testing machine * while the skin is fixed in the upper clamp, and the fabric in the lower clamp.

4.2. The test is carried out at a speed of movement of the lower jaw (100:b ± 10) mm/min.

On the scale of the tensile machine, the loads during peeling at the end * of the 1st, 2nd, 3rd, 4th and 5th sections are noted.

5. PROCESSING THE RESULTS

5.1. Adhesion (A), N/m, is calculated by the formula

where P cv is the average load during peeling of the coating, defined as the arithmetic mean value of all loads obtained when testing the sample, N; a is the width of the skin sample, m.

5.2. The test result is taken as the arithmetic mean of the test results of all samples.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry light industry the USSR

PERFORMERS

F. V. Mironov, G. P. Rustanovich, L. F. Podolskaya

2. APPROVED AND INTRODUCED BY Decree of the USSR State Committee for Standards dated December 23, 1988 No. 4659

3. The term of the first check is 1994.

Inspection frequency - 5 years

4. INSTEAD OF GOST 939-75, OST 258-80, TU 06-32-78

5. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS

	Item number
GOST 15.007-88

	Introduction
	Appendix 6
GOST 938.0-75	2.1, 3.1; annex 6
GOST 938.1-67
GOST 938.3-77
GOST 938.5-68
GOST 938.11-69
GOST 938.12-70
GOST 938.13-70
GOST 938.14-70	3.4; Appendix 6
GOST 938.15-70
GOST 938.27-76
GOST 938.29-77
GOST 938.30-78
GOST 1023-81
GOST 3123-78	1.2.3, 1.2.10, 1.3, 1.6.2
GOST 13868-74
GOST 19196-80	Appendix 6

Odano in nab. Tvr. 12 000

Editor T. P. Shashina Technical editor M. I. Maksimova Proofreader V. S. Chernaya

01/23/89 Go, in print. 21.03.89 1.0 st. p. l. 1.0 kr.-ott. 0.70 ed. l.

Order "Badge of Honor" Publishing house of standards, 123840, Moscow, GSP, Novopresnensky per., 3 Type. Moscow printer. Moscow, Lyalin per., 6. Zak. 251

1.6, Section 4

1.2.3, 1.2.10

Appendix 6

5. The limitation of the validity period was removed according to protocol N 4-93 of the Interstate Council for Standardization, Metrology and Certification (IUS 4-94)

6. REPUBLICATION. August 2002

This standard applies to chrome-tanned leather for shoe uppers, produced from raw materials in accordance with GOST 382.

The standard does not apply to leathers for uppers manufactured by order of the USSR Ministry of Defense.

1. TECHNICAL REQUIREMENTS

1.2. Specifications

1.2.1. Skins are divided into:

flasks;

outgrowth;

half-skinner;

goby;

yalovka;

bullock;

bull;

pork;

foal;

notch;

horse fronts;

camels;

goat;

kid;

chevret.

1.2.2. For the top of model shoes, they produce a calf, an outgrowth, a goby, a semi-skinner, a barn, a bull, a bull, a chevro, a goat.

1.2.3. According to the configuration of the skin is divided into:

whole skins;

whole skins without collars - from medium and heavy cowhide, bullock and bullock;

half-skin - from a bull, a half-skin, an outgrowth, a yalovka, a bullock, a bull;

semi-skin without collars - from a bull, bull-calf, bull-calf, bull;

fish, saddlecloths and pork croups;

horse fronts and half fronts;

collars.

Configuration definition - according to GOST 3123.

Collars must be complete with a black-and-white part and match them in terms of the type of finish of the front surface and color.

1.2.4. Skins are subdivided depending on the size by area, dm:

from 20 to 40 inclusive;

St. 40"60"

" 60 " 80 "

" 80 " 120 "

" 120 " 160 "

" 160 " 200 "

" 200

1.2.5. Skins are produced with a thickness of 0.5 to 2.8 mm inclusive and are divided into groups in accordance with Appendix 1.

1.2.6. The thickness of the skin at any point shall be at least 80% of the thickness at the standard H-point. The standard H-point is determined in accordance with Annex 2.

1.2.7. Leathers with a thickness of over 1.6 mm and leathers of increased thickness (thickness over 2.2 mm) are produced for the top of unlined shoes.

1.2.8. According to the appearance of the skin, they produce:

with a natural unpolished and polished front surface and;

undyed, drum-dyed, drum-dyed and top-dyed (with aniline finish, with casein, emulsion-casein, emulsion and nitroemulsion coating; including semi-aniline finish);

smooth, embossed, embossed, velor and nubuck;

natural, white, colored, black, multicolor.

1.2.9. Leather for the top of model shoes is produced smooth, with a relief pattern, nubuck and velor.

1.2.10. Determination of types of leather finishes - according to GOST 3123 and Appendix 3.

1.3. According to the physical and mechanical parameters of the skin must comply with the standards specified in the table.


Name of indicator	Norm for skins
	all types, except for velor and nubuck	velor and nubuck
Tensile strength 10 MPa, not less than:
for all types of leather, with the exception of cowhide, bull, bull, chevret and pigskin
for cowhide, bullock, bull and pig skins
for chevret
Stress at the appearance of cracks in the front layer, 10 MPa, not less than:
for all types of leather, with the exception of cowhide, bullock, bull and chevret
for yalovka, bychyna, bull
for chevret
Elongation at a stress of 10 MPa, %:
for all types of leather, with the exception of cowhide, bovine, bull, chevret and pigskin
for cowhide, bullock, bull, chevret and pig skins
Coating resistance to repeated bending, points, not less than
Cover film adhesion, N/m, not less than:
for dry skin:
with natural face
with polished face
to wet skin:
with natural face
with polished face

Notes:

1. The norms for all indicators are set for the batch.

2. The minimum value of the tensile strength of leather in a batch must be at least 1.0x10 MPa.

3. Norms for adhesion and resistance of the coating to multiple bending - at least 3 points are established from 01.01.91.

The chemical composition of the skins - in accordance with Appendix 4.

Color fastness for velor and unlined leather to dry friction - 4 points, to wet friction - 3 points.

1.4. Depending on the availability of the usable area of the skin, they belong to the 1st, 2nd, 3rd and 4th grades. The grade of leather is determined according to GOST 338.

Leather for the top of model shoes must be at least 3rd grade.

1.5. Requirements for leather for the top of orthopedic shoes - in accordance with Appendix 5.

1.6. Marking and packaging of leather - in accordance with GOST 1023 and with the following addition: on leather with a polished front surface, the letter "P" must be marked.

2. ACCEPTANCE

Leather acceptance rules - according to GOST 938.0.

3. TEST METHODS

3.1. Sampling - according to GOST 938.0.

3.2. Determination of tensile strength, stress when cracks appear in the front layer and elongation - according to GOST 938.11.

3.3. Preparation of samples for physical and mechanical tests - according to GOST 938.12.

3.4. Sample conditioning - according to GOST 938.14.

3.5. Determination of the mass and linear dimensions of the samples - according to GOST 938.13.

3.6. Determination of the thickness of samples and the thickness of leather at a standard point - according to GOST 938.15.

3.7. Determination of the resistance of the coating to multiple bending - according to GOST 13868.

3.8. Determination of adhesion - in accordance with Appendix 6.

3.9. Testing the color fastness of leather to dry and wet friction - according to GOST 938.29.

3.10. Determination of the cage of the front surface of leathers with a natural front surface - according to GOST 938.27.

3.11. The test for fragility of leather with a polished front surface - according to GOST 938.30.

3.12. Determination of the mass fraction of moisture - according to GOST 938.1.

3.13. Determination of the mass fraction of chromium oxide - according to GOST 938.3.

3.14. Determination of the mass fraction of substances extracted by organic solvents - according to GOST 938.5.

4. TRANSPORT AND STORAGE

Transportation and storage of leather - according to GOST 1023.

5. MANUFACTURER WARRANTY

Guaranteed shelf life of leather - 3 months from the date of manufacture.

APPENDIX 1 (recommended). RECOMMENDED THICKNESS GROUPS AT THE STANDARD POINT H DEPENDING ON THE TYPE OF RAW MATERIAL IN MM


Chevro and goat	From 0.5 to 0.7 inclusive;
	St. 0.7" 1.0" ;

chevret	From 0.8 to 0.9 inclusive;
	St. 0.9" 1.2";

Pork	From 0.6 to 0.9 inclusive;
	St. 0.9" 1.2";
	" 1,2 " 2,8 " ;
Foal	From 0.6 to 0.7 inclusive;
	St. 0.7" 1.0" ;

Notch and camel	From 0.6 to 0.9 inclusive;
	St. 0.9" 1.2";

Horse fronts	From 0.7 to 0.9 inclusive;
	St. 0.9" 1.2";

	From 0.6 to 0.8 inclusive;
	St. 0.8" 1.1" ;

Outgrowth and half-skin	From 0.7 to 0.9 inclusive;
	St. 0.9" 1.2";

Goby and cow light	From 1.2 to 1.6 inclusive;
	St. 1.6" 2.8".
Yalovka medium and heavy,	From 1.2 to 1.4 inclusive;
bullock light and heavy,	St. 1.4" 1.6" ;
bullshit light and heavy	" 1,6 " 2,0 " ;
	" 2,0 " 2,2 " ;
	" 2,2 " 2,4 " ;

APPENDIX 2 (mandatory). DETERMINATION OF THE THICKNESS AT STANDARD POINT H

APPENDIX 2
Mandatory

The thickness of the skins is determined at the standard point H, located on each half-skin, half-skin without collars, half-front, on the right half of the whole leather, whole leather without collars, saddle, fish, front, croupon on each collar and located:

on the fronts and half-fronts - at the intersection of the line LM XY, with line IR located at a distance of 150 mm from the internal tangent line OP, drawn through the point C to the haza line, FCC(Fig.1);

on whole leathers without collars, semi-skins, semi-skins without collars, worked out from cowhide, bullock and bullock - at the intersection of the line LM located at a distance of 200 mm from the spinal line XY, with line IR, located at a distance of 250 mm from the line tangent to the cavity of the back cut BG(Fig.2).

On whole leathers, half-skins, half-skins without collars, saddlecloths, fish, croupons made from other types of raw materials - at the intersection of the line LM located at a distance of 75 mm from the spinal line XY, with line IR, located at a distance of 150 mm from the line tangent to the recesses of the back cut BG(Fig. 3);

on the collars - at the intersection of the line LM, located at a distance of 100 mm from the spinal line XY, with line IR, located at a distance of 200 mm from the line AB separating the collar from the rest of the skin (Fig. 4).

APPENDIX 3 (informative). DEFINITION OF LEATHER FINISHES

APPENDIX 3
Reference

1. Smooth leathers include:

pressed with a smooth plate;

with intermediate pressing with a small-sized plate with a dust-like pattern, followed by pressing with a smooth plate.

2. Embossed leather includes leather pressed with plates with a small pattern (chevrolet, shagreen, etc.), except for plates with a powdered pattern.

3. Embossed leathers include leathers with a relief pattern on the front surface of which is obtained by pressing with plates with a medium and large pattern and corresponds to the fashion trend.

4. Determination of types of coatings

Casein coating on natural grain leathers with formalin fixation and alkaline casein fixative.

Emulsion-casein - a combined coating on leathers with a natural front surface using emulsion film formers in impregnating and pigmented primers and casein finishes in top coats.

Emulsion - a coating on leather with a natural and polished front surface using emulsion film formers in impregnating and pigmented primers with fixing with nitro-emulsion varnishes or nitro-varnishes.

Nitroemulsion - a coating on leather with a sanded and sanded front surface using emulsion film formers in impregnating and pigmented primers with fixing with nitro enamels mixed with nitro varnishes.

APPENDIX 4 (mandatory). SKIN CHEMICAL DATA

APPENDIX 4
Mandatory


Name of indicator	Meaning
Moisture content, %
Mass fraction of chromium oxide, %, not less than:
for chevro
for others
Mass fraction of substances extractable by organic solvents (without polymeric compounds), %

APPENDIX 5 (mandatory). LEATHER REQUIREMENTS FOR ORTHOPEDIC SHOE UPPER

APPENDIX 5
Mandatory

For the top of orthopedic shoes, a flask, an outgrowth, a semi-skinner, a chevro are produced:


by configuration	whole;
area, dm-	from 40 to 60 incl.	Kid,
		opoek,
	" 80 " 120 "	outgrowth,
	St. 120" 160"
	" 160 " 180 "
	from 180 "200"	Half-skin
	St. 200" 220"
thickness at the standard point H:
	from 0.7 to 1.0 mm incl.
	"0.9" 1.2mm"		Opoek, outgrowth, half-skinner;

in appearance - smooth, black and colored, with emulsion and nitro-emulsion coating;

by grades - 1, 2 and 3 grades.

APPENDIX 6 (mandatory). METHOD FOR DETERMINING ADHESION OF EMULSION AND NITROEMULSION COATING TO SKIN

APPENDIX 6
Mandatory

This method involves the determination of the adhesion of emulsion and nitroemulsion coatings to leather for chrome-tanned shoe uppers.

The essence of the method is to determine the load required to peel the cover film from the skin (preliminarily glued to the fabric).

1. SAMPLING

2. EQUIPMENT AND REAGENTS

2.1. For testing use:

laboratory desktop press for gluing samples, providing pressing pressure of at least 0.4 MPa;

electric drying cabinet with thermostat for heating up to 100 °С;

a metal ruler with a division value of 1.0 mm according to GOST 427 or another one that provides a similar measurement accuracy;

breaking machine type RM-3 or RM-30;

nitrocellulose glue "AGO" according to normative and technical documentation;

fabric (calico) in accordance with GOST 19196 or calico according to normative and technical documentation (the fabric must be washed in hot water, dried and ironed before testing).

3. PREPARATION FOR THE TEST

3.1. The skin sample is brought to an air-dry state in accordance with GOST 938.14.

3.2. A sample of 7.0 x 7.0 cm in size is cut out of the fabric, on which a thin layer of glue is evenly applied with a glass rod or a sharp spatula at the rate of 1 g per 10 cm of area. One edge of the fabric per 1 cm is not smeared.

3.4. The glued sample is kept in air at a temperature of 20 °C for 20 minutes, then under pressure for 20 minutes at a pressure of 0.5 MPa and dried in an oven at a temperature of 60 °C for 40-50 minutes.

3.5. The glued sample is conditioned according to GOST 938.14 for 24 hours.

3.6. From each glued sample, six samples are cut in the longitudinal direction with a size of 1.0 x 7.0 cm with a maximum deviation in length and width of ± 0.1 cm.

3.7. On each sample from the delamination side, a working section 5 cm long is marked and divided by transverse lines into 5 equal sections.

3.8. Each sample is stratified before the beginning of the working section, checking its suitability for testing. Samples are considered suitable, in which, during the test for tearing the fabric from the skin, the fabric peels off together with the coating.

3.9. Three samples are tested in a dry state and three in a wet state, for which they are immersed in water with an initial temperature of (60 ± 1) ° C for 3 hours. Before testing, moisture is removed from the samples with filter paper.

4. CONDUCTING THE TEST

4.1. The test sample is fixed in the clamps of the tensile testing machine, while the skin is fixed in the upper clamp, and the fabric is fixed in the lower clamp.

4.2. The test is carried out at a speed of movement of the lower jaw (100 ± 10) mm/min.

On the scale of the tensile machine, the loads during peeling at the end of the 1st, 2nd, 3rd, 4th and 5th sections are noted.

5. PROCESSING THE RESULTS

5.1. Adhesion (), N/m, is calculated by the formula

where is the average load during peeling of the coating, defined as the arithmetic mean of all loads obtained when testing the sample, N;

- width of the skin sample, m.

5.2. The test result is taken as the arithmetic mean of the test results of all samples.

The text of the document is verified by:
official publication
Moscow: IPK Standards Publishing House, 2002

3.4; Appendix 6

1.6, Section 4

1.2.3, 1.2.10

GOST 19196-80

Appendix 6

5. The limitation of the validity period was removed according to protocol N 4-93 of the Interstate Council for Standardization, Metrology and Certification (IUS 4-94)

6. REPUBLICATION. August 2002

This standard applies to chrome-tanned leather for shoe uppers, produced from raw materials in accordance with GOST 382.

The standard does not apply to leathers for uppers manufactured by order of the USSR Ministry of Defense.

1. TECHNICAL REQUIREMENTS

1.2. Specifications

1.2.1. Skins are divided into:

outgrowth;

Half-skin;

Foal;

notch;

Horse fronts;

camels;

Kozlin;

1.2.2. For the top of model shoes, they produce a calf, an outgrowth, a goby, a semi-skinner, a barn, a bull, a bull, a chevro, a goat.

1.2.3. According to the configuration of the skin is divided into:

Whole skins;

Whole skins without collars - from medium and heavy cowhide, bullock and bullock;

Half-skin - from a bull, a half-skin, an outgrowth, a yalovka, a bullock, a bull;

Half-skins without collars - from a bull, bull-calf, bull-calf, bull;

Pork fish, saddlecloths and croupons;

Horse fronts and half fronts;

Collars.

Configuration definition - according to GOST 3123.

Collars must be complete with a black-and-white part and match them in terms of the type of finish of the front surface and color.

1.2.4. Skins are subdivided depending on the size by area, dm:

From 20 to 40 inclusive;

St. 40 "60"

1.2.5. Skins are produced with a thickness of 0.5 to 2.8 mm inclusive and are divided into groups in accordance with Appendix 1.

1.2.6. The thickness of the skin at any point shall be at least 80% of the thickness at the standard H-point. The standard H-point is determined in accordance with Annex 2.

1.2.7. Leathers with a thickness of over 1.6 mm and leathers of increased thickness (thickness over 2.2 mm) are produced for the top of unlined shoes.

1.2.8. According to the appearance of the skin, they produce:

With natural unpolished and sanded front surface and;

Undyed, drum-dyed, drum-dyed and top-dyed (with aniline finish, with casein, emulsion-casein, emulsion and nitroemulsion coating; including semi-aniline finish);

Smooth, embossed, embossed, velor and nubuck;

Natural, white, colored, black, multi-color.

1.2.9. Leather for the top of model shoes is produced smooth, with a relief pattern, nubuck and velor.

1.2.10. Determination of types of leather finishes - according to GOST 3123 and Appendix 3.

1.3. According to the physical and mechanical parameters of the skin must comply with the standards specified in the table.

Name of indicator	Norm for skins
	all types, except for velor and nubuck	velor and nubuck
Tensile strength 10 MPa, not less than:
for all types of leather, with the exception of cowhide, bull, bull, chevret and pigskin
for cowhide, bullock, bull and pig skins
for chevret
Stress at the appearance of cracks in the front layer, 10 MPa, not less than:
for all types of leather, with the exception of cowhide, bullock, bull and chevret
for yalovka, bychyna, bull
for chevret
Elongation at a stress of 10 MPa, %:
for all types of leather, with the exception of cowhide, bovine, bull, chevret and pigskin
for cowhide, bullock, bull, chevret and pig skins
Coating resistance to repeated bending, points, not less than
Cover film adhesion, N/m, not less than:
for dry skin:
with natural face
with polished face
to wet skin:
with natural face
with polished face

Notes:

1. The norms for all indicators are set for the batch.

2. The minimum value of the tensile strength of leather in a batch must be at least 1.0x10 MPa.

3. Norms for adhesion and resistance of the coating to multiple bending - at least 3 points are established from 01.01.91.

The chemical composition of the skins - in accordance with Appendix 4.

Color fastness for velor and unlined leather to dry friction - 4 points, to wet friction - 3 points.

1.4. Depending on the availability of the usable area of the skin, they belong to the 1st, 2nd, 3rd and 4th grades. The grade of leather is determined according to GOST 338.

Leather for the top of model shoes must be at least 3rd grade.