1

DEFINITION OF MICROCELLULAR & SPONGE PRODUCTS

1. MICROCELLULAR PRODUCTS HAVE SUBSTANTIALLY CLOSED CELLULAR STRUCTURE - HAVING INDIVIDUAL CELL WALL

WHEREAS

2. SPONGE RUBBER HAS OPEN OR INTERCONNECTING STRUCTURE.

TYPES OF CELLULAR RUBBER

1. EXPANDED RUBBER

2. MICROCELLULAR PRODUCT

3. SPONGE RUBBER

2.

TYPES OF MICROCELLULAR SOLING

I.SOFT MICROCELLULAR SOLING FOR HAWAI OR BEACH SLIPPERS.II.MEDIUM HARD MICRO CELLULAR FOR LEATHERS TOP CHAPPALS.III.HARD MICROCELLULAR SOLING FOR LEATHER SHOES SOME CHARACTERISTICS OF THESE SOLES ARE AS FOLLOWS.CATEGORY

APPROX

APPROX SHORE A

DENSITY

HARDNESSHAWAI / BEACH

0.3- 0.4

30 - 45SLIPPERMED. HARD

0.5 0.6

55 - 65

MICRO SOLING

HARD MICRO

0.7- 0.8

70 - 80

SOLING

3

HAWAI SLIPPERS:ORGINALLY THESE SLIPPERS WERE MEANT FOR USING ON BEACHES OR INDOOR BECAUSE OF THEIR LOW COST THESE CHAPPALS HAVE BECOME VERY POPULAR AMOUNGST THE POOR POPULATION WHO USE IT AS ALL PURPOSE FOOTWEAR.

MEDIUM HARD MICRO SOLING

GENERALLY USED FOR LEATHER OR RESIN UPPER CHAPPALS. THESE ARE VERY MUCH IN HIGH DEMAND FOR FASHION CONSCIOUS URBAN PEOPLE WHO NEED MORE ELEGANT AND LIGHT WEIGHT FOOTWEAR THEN LEATHER SOLE CHAPPAL.

HARD MICRO SOLINGTHIS SUPERIOR PERFORMANCE SOLING MATERIAL IS GENERALLY USED FOR LIGHT WEAR AND HEAVY DUTY SHOE SOLES BECAUSE OF ITS LIGHT WEIGHT AND BETTER WEAR RESISTANCE.THE QUALITY OF MICROCELLULAR MATERIAL CAN BE JUDGED FROM:A.DENSITYB.HARDNESS

C.SPLIT TEAR RESISTANCE

D.SHRINKAGE CONTROL

E.FLEX RESISTANCE

4.METHODS OF MANUFACTURING MICROCELLULAR SOLEA.PRODUCED FROM RUBBER COMPOUND CONTAINING ORGANIC BLOWING AGENT.

B.MOULDING BY COMPRESSION MOULDING SYSTEM.

C.MOULD FILLED WITH COMPOUND 3% EXCESS IN VOLUME

D.MOULDING AT HIGH PRESSURE IN A HYDRAULIC PRESS

E.TEMP NORMALLY 145 155 DEGREE C

F.PRECURED SHEETS ARE FOLLOWED BY POST CURING IN A CHAMBER (HOT AIR CURE) AT 100 DEGREE C FOR 3-4 HRS.

5.

PHYSICAL REQUIREMENT FOR MICROCELLULAR RUBBER SHEETS

TYPE-1

TYPE-2

I. RELATIVE DENSITY 0.60-0.70

0.45-0.55

II HARDNESS IRHD, MIN.

65 Degree

50 Degree

III CHANGE IN HARDNESS

+5 TO 0

+5 TO - 0

AFTER AGEING AT 100 +

1 Degree C FOR 24 HRS.

IV COMPRESSION SET AT

12

15

27 + 1 Degree C FOR 24

HRS., % MAX.

VSPLIT TEAR STRENGTH

8.0

6.0

KG. MIN.

VIHEAT SHRINKAGE AT

2

3

100 Degree C FOR 1 HOUR

IN BOTH DIRECTIONS,

% MAX.

VIIWATER ABSORPTION, % 1.5

2.0

BY MASS, MAX.

6.PHYSICAL REQUIREMENT FOR STANDARD QUALITY HAWAI SOLE

I. RELATIVE DENSITY

0.3-0.6

II. HARDNESS IRHD

45 degree-50 degree

III.CHANGE IN HARDNESS

+ 5- - 0

AFTER AGEING AT 100 +

1 degree C FOR 24 HRS.IV.COMPRESSION SET AT 27 15

+ 1 Degree C FOR 24 HRS.

% MAX

V.SPLIT TEAR STRENGTH, kg.

4-5

VI. ROOM TEMPERATURE

1.0 2.0

SHRINKAGE AT 27 + 1 degree

C FOR 4 WEEKS, % MAX.

VII. FLEX RESISTANCE, NUMBER

OF CYCLES ROSS FLEX

TESTING MACHINE

A. INITIAL CRACK, MIN.

40,000 60,000

B. 600% CUT GROWTH

60,000 100,000

7

PHYSICAL REQUIREMENT FOR STANDARD HAWAI STRAP

I.RELATIVE DENSITY

1.3 1.4

II.TENSILE STRENGHT, kg /cm2

150-160

III. ELONGATION, %

400-500

IV. HARDNESS IRHD

60 +5

CHANGE IN INITIAL HARDNESS

+5 TO -5

AFTER ACCELERATED AGEING

FOR 24 HOURS AT 100 + 1 degree C

VI. FLEX RESISTANCE NUMBER OF

CYCLES ON ROSS FLEX TESTER

A. INITIAL CRACKS

60,000-85,000

B. 600% CUT GROWTH

100,000-130,000

VII. TEAR STRENGTH, kg. / cm2

30-45

8RECIPE RUBBER MICROCELLULAR SOLE

INGREDIENTS

PBW

Kgs.

NR

-

60.00

HSR

-

40.00

WOOD ROSIN

-

2.00

ZINC OXIDE

-

4 5.00

STEARIC ACID

-

4 5.00

ANTI OXIDANT

-

1.00

VALCAFOR F

-

0.80

MBTS

-

0.30

PROCESS OIL

-

5.00

SALICYLIC ACID

-

0.50

PPT. SILICA

-

10.00

ALUM. SILICATE

-

20 30.00

HARD CLAY

-

60 70.00

SULPHUR

-

2.50

DNPT

-

6 7.00

COLOUR

-

AS. REQD.

MICROCELLULAR -

70 80.00

CRUMB

CURE 7 8 MINUTE AT 155 160 Degree C.

PROPERTIES:

DENSITY 0.45 0.50

HARDNESS 48 50 IRHD

SPLIT TEAR - 3.5 4.0 kgs.

SHRINKAGE (OVEN) 1.5 %

TYPICAL FORMULATION MICRO COMPOUND

INGREDIENTS

QUANTITYRMA

20.0

20.0

SBR 1958

60.0

10.0

SBR 1502

20.0

-

RB 820

-

70.0

ZINC OXIDE

4.0

6.0

STEARIC ACID

5.0

5.0

PHENOLIC ANTI

1.0

1.0

OXIDANT

SILICA

20.0

20.0

ALUMINIUM SILICATE40.0

35.0

CHINA CLAY

70.0

50.0

MICRO CRUMB

50.0

-

PETROLEUM JELLY

5.0

5.0

PROCESS OIL

10.0

5.0

WOOD ROSIN

4.0

4.0

DEG

2.0

2.0

TITANIUM DIOXIDE

5.0

5.0

SULPHUR

2.2

1.5

MBTS

-

1.4

F

1.2

-

TMT

0.1

-

BLOWING AGENT

5.0

5.0

(DNPT)

ORGANIC COLOUR

as reqd.as reqd.

CURED AT 150 degree C6.0

12.0

DENSITY

0.5

0.4

HARDNESS SHORE A Deg.620.0500.0

SPLIT TEAR STRENGTH4.0

3.0

Kg. / cm 2

% SHRINKAGE

1.50

2.0

ROSE FLEX TEST

- -

CRACK INITIATION, KC35.0

45.0

10

RECIPE STRAP COMPOUNDS

INGREDIENTS

QUANTITYRMA

100.0

ZINC OXIDE

6.0

STEARIC ACID

1.50

PHENOLIC ANTI OXIDANT

1.00

ALUMINIUM SILICATE

30.00

PPTD. CALCIUM CARBOINATE

30.00

CHINA CLAY

30.00

PETROLEUM JELLY

6.00

CI RESIN

2.00

DEG

1.00

TITANIUM DIOXIDE

5.00

MBTS

1.20

TMT

0.20

SULPHUR

1.80

SANTOGARD PVI-50

0.25

CURED AT 150 Deg. C (M)

4

SPECIFIC GRAVITY

1.37

TENSILE STRENGTH, kg / cm2

170

ELONGATION AT BREAK %

430

300% MODULS, kg / cm2

65

ANGULAR TEAR STRENGTH,

27

Kg / cm2

HARDNESS SHORE A

54

11TESTING OF MICROCELLULAR SOLING

SOLE

STRAPS

PARAMETERS

1. DENSITY (gms. cc)

1. SP. GRAVITY

2. HARDNESS-(IRHD)

2. HARDNESS

3. SPLIT TEAR-kgs.

3. TEAR STRENGTH

(kgs)

4. THICKNESS (m /m)

4. THICKNESS )m/m)

5. FLEXIBILITY (ROSS-CYCLES)

6. SHRINKAGE-%

OVEN 1hrs. AT 100 Degree C

ROOM TEMP.

60 Degree C-1 hrs. EVA

7. COMPRESSION SET (%)

12

EVA MICROCELLULAR

VARIOUS USE OF EVA MICROCULLULAR IN FOOTWAR INDUSTRY

1. AS SOLING MATERIAL

2. AS MIDSOLE (JOGGER TYPE SHOE)

3. INSOLING MATERIAL (MOULDED)

4. LAMINATED INSOLE

5. UPPER MATERIAL FOR SANDALS

6. VARIOUS THERMO FORMED COMPONENTS

13EVA MICRO SOLING PROPERTIES

A. VERY LIGHT & COMFORTABLE PRODUCT POSSIBLE

B. NO ROOM TEMP. SHRINKAGE

C. NO POST TEMPERING & STORAGE

D. REQUIRED PHYSICALS FOR MICRO SOLING ACHIEVABLE.

E. BRIGHT & ATTRACTIVE COLOUR POSSIBLE

14PHYSICAL PROPERTIS EVA SOLING

PROPERTIES

BEACH SANDAL SHOE SOLING1. DENSITY (gm/cc)

0.20 0.25

0.35 0.40

2. HARDNESS (IRHD)

25 30

50 55

35 40

3. SPLIT TEAR kgs.

(2.5 cm Width test piece) 2.5 3.0

5.0

4. SHRINKAGE

OVEN (%)

A. AT 60 degree C. 1 hrs. 1.0

0.5

B. ROOM TEMP. 1 wk. 0.5 nil

nil

5. COMPRESSION SET (%)80

70

15BASIC DESIGNING OF COMPOUNDA.EVA COPOLYMER

B.CROSS LINKING AGENT

C.BLOWING AGENT

D.ACTIVATOR

E.LUBRICANT

OTHER COMMON INGREDIENTSI.INORGANIC FILLER

II.PIGMENT

III.POLYMER MODIFIER

IV.MICRO WASTE (EVA)

16

EVA SOLE RECIPE (TYPICAL)

INGRIDIENTS

BEACH LEATHER SHOES

SANDAL SOLING

1. EVA (16 18 % VA)

100.00

70.00

2. HIGH STYRENE RESIN --

30.00

3. AZO TYPE BLOWING8.00

5.00

AGENT (ADCL)

4.DCP 90 %

1.0

1.3

5.ZINC OXIDE

1.0

1.0

6.STEARIC ACID

1.0

1.0

7. PPT. CAL. CARB.

30.00

30 40.00

8. PIGMENTS

AS REQD.

AS REQD.

9. EVA CRUMB

10 20.00

20 30.00

17EVA MOULDING

1. TIME

13 15 MINS. (15 m/m THICK SHEET)

2. TEMP. -

160 165 Degree C.

3. HYD. PRESSURE 150 200 kg / cm sq.

4. LOADING-

0.5 1% EXCESS

1. QUICK OPENING PRESS (6 10 Sec.)

MOULD

A. THE EDGE OF THE MOULD MUST BE PROVIDED WITH A GENEROUS TAPER (45 degree ANGLE)

B. THE TAPERED SECTION SHOULD BE SMOOTH.

C. THE PRESS MUST OPEN VERY RAPIDLY (10 cm / sec) Minimum.

D. THE ENTIRE SURFACE OF THE MOULD MUST BE SPREAD WITH MOULD RELEASING AGENT.

19RECENT POLYMER BLENDS

POLYMERS

CURE

FEATURES1.NR + SBR + HSRSULPHURCONV. CURING

POST CURING &

STORAGE REQD.

2.NR + HSR + EVAPEROXIDELOW SHRINKAGE

NO. POST. CURING

3. NR. + PE

NO. SHRINKAGE

NO. POST CURE

NO. STORAGE

4. NR + LDPE + EVA

5. PVC + NITRILESULPHORNO POST CURE

NO. SHRINKAGE

MOULDING

PROBLEM

6. LDPE + NR + HSRSULPHORSATIFACTORY

QUALITY

ACHIEVABLE

20SHRINKAGE CONTROL OF MICROCELLULAR PRODUCTS

1.BY USING SUITABLE POLYMER OR BLEND OF POLYMERS

2.BY USING APPROPRIATE REINFORCING FILLER

3.BY PROPER PROCESSING METHODS

a.SUFFICIENT MASTICATION

b.STORAGE AFTER MIXING AND SHEETING

c.STAGE CURING

e.STORAGE AFTER CURING