K K Sheets

Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets

Tensile Member for Power Transmission and Conveyor Belts

Introduction

Nylon 6 or Polyamide 6 chips are in the first process are extruded into sheet form then in the second process is

stretched 6 times in machine direction and then in third process is heat set by shrinking 20% and then in fourth

process is given controlled forced moisture absorption ranging from 2.3 to 2.6 %.

The data sheet of Nylon 6 or Polyamide 6 chips is as under:

The schematic diagram of the process is as under:

Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets due to its superior characteristics are ideal Tensile Member

for Flat Power Transmission and Conveyor Belts. These Sheets are available upto 2 mm in thickness and 520 mm

in width upto 500 kgs rolls in single piece length. They significantly reduce the cost of production as they

eliminate multiple sheets bonding. Therefore these sheets are preferred by Flat Belts manufacturer around the

globe.

Fabric / Rubberised Fabric / Leather

Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets

Fabric / Rubberised Fabric / Leather

Features

Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets are resistant to Oils, Chemicals and corrosion. These sheets

exhibit flexibility of plastics and tensile strength of steel and have very good bondibility with adhesives.

Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets are tough and suitable for high temperature, high humidity

atmospheres, low water absorption, high strength, high modulus of elasticity and high tension applications.

Specifications

Thicknesses

0.20 mm, 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.75 mm,

0.80 mm, 0.85 mm, 0.90 mm, 1.00 mm, 1.10 mm, 1.25 mm, 1.50 mm, 1.75 mm, 2.00 mm

Widths

220 mm, 240 mm, 270 mm, 320 mm, 520 mm

Length

101 mts, 128 mts, 140 mts, 150 mts, 250 mts, 310 mts or any length upto 500 kgs roll in single piece length.

Formula to Calculate Weight

Wt = Sp. Gr. X Volume

e.g.

wt. of 250 mts X 520 mm X 1.0 mm

Wt. = 1.14 X 25000 X 52 X 0.1 = 148200 gms

i.e. 148.200 kgs

Ready Recknor for Wt. of standard rolls

SN Thickness

(mm) Width (mm)

Length (mts)

Net Weight (kgs) Width wise

320 mm 520 mm

1 0.20 320 / 520 250 18.240 29.640

2 0.30 320 / 520 250 27.360 44.460

3 0.35 320 / 520 250 31.920 51.870

4 0.40 320 / 520 250 36.480 59.280

5 0.45 320 / 520 250 41.040 66.690

6 0.50 320 / 520 250 45.600 74.100

7 0.55 320 / 520 250 50.160 81.510

8 0.60 320 / 520 250 54.720 88.920

9 0.65 320 / 520 250 59.280 96.330

10 0.70 320 / 520 250 63.840 103.740

11 0.75 320 / 520 250 68.400 111.150

12 0.80 320 / 520 250 72.960 118.560

13 0.90 320 / 520 250 82.080 133.380

14 1.00 320 / 520 250 91.200 148.200

15 1.10 320 / 520 250 100.320 163.020

16 1.25 320 / 520 250 114.000 185.250

17 1.50 320 / 520 250 136.800 222.300

18 1.75 320 / 520 250 159.600 259.350

19 2.00 320 / 520 250 182.400 296.400

Physical Properties

Term Unit Value Testing method

Surface resistivity 𝞨 1014 ASTM D257

Volume resistivity 𝞨. cm 1014 ASTM D257

Water absorption rate % 3 Karl Fischer method

(23oC, 65% RH Equilibrium)

Melting point OC 220 DSC method

Specific gravity Gms/CC3 1.14 ASTM D792

Chemical Resistance

Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets under normal conditions have excellent resistance to Sea

Water, Water, Soaps, oils, hydrocarbons, ketones, ethers, alcohols, and alkalis.

Chemical Resistance at 230C

1. Little change in weight and dimension

Ammonia 10%, Sodium Carbonate 10%, Sodium Chloride 10%, Mercury, Benzene, Toluene, Xylene, Cyclohexane,

Naphthaline, Methyl alcohol, Butyl alcohol, Glycerol, Ethylene glycol, Acetone, Formaldehyde, Methyl Ethyl

Ketone, Carbon tetrachloride, Freon 12, Ethyl acetate, Butter, Camphor, Diesel, Vegetable oil, Ink, Linseed oil,

Mineral oil, Gasoline and Solvent naphtha.

2. Some changes in weight and dimension, becoming slightly brittle

Sodium hydroxide 50 % and Trichloroethylene

3. Some attack but suitable if a limited life is acceptable

Hydrochloric acid 2%, Sulphuric acid 2% and Chromic acid 10%

4. Attack in short time

Ozone and Acetic acid 10 %

5. Dissolution

Formic Acid 85%, Phenol and Resorcinol

Mechanical Characteristics

Tensile Properties

Tensile Method

Remove 3 specimens each from the middle and the ends of the sheet. Size of the specimen be 350 mm in length

and 20 mm in width. Condition the specimens for 48 hours at 23 + 30C and 65 + 5% RH and do the testing in the

same atmosphere. Ensure that moisture content level is from 2.3 to 3.5%. Distance between the grips should be

200 mm and speed of testing 50 mm/min. That is the correct international method of testing otherwise

variations may be observed in the results.

Test Result

Tensile Strength 4000 + 500 kgf / cm2

Elongation at Break 25 + 10%

Tensile stress at 1 % elongation 230 kgf / cm2

Tensile stress at 2 % elongation 397 kgf / cm2

Tensile stress at 3 % elongation 517 kgf / cm2

Tensile stress at 4 % elongation 622 kgf / cm2

Tensile stress at 5 % elongation 950 kgf / cm2

Specifications:

Thickness Tensile

Strength Elongation

at break Tensile Stress at Elongation + 8%

mm + 0.02

to + 0.05

Kgf/

cm +

8%

N/mm + 8%

% + 10%

1% 2% 3% 4% 5%

Kgf/ cm

N/ mm

Kgf/ cm

N/ mm

Kgf/ cm

N/ mm

Kgf/ cm

N/ mm

Kgf/ cm

N/ mm

0.20 80 78.48 25 4.60 4.51 7.94 7.79 10.34 10.14 12.44 12.20 19.00 18.64

0.30 120 117.72 25 6.90 6.77 11.91 11.68 15.51 15.22 18.66 18.31 28.50 27.96

0.35 140 137.34 25 8.05 7.90 13.90 13.63 18.10 17.75 21.77 21.36 33.25 32.62

0.40 160 156.96 25 9.20 9.03 15.88 15.58 20.68 20.29 24.88 24.41 38.00 37.28

0.45 180 176.58 25 10.35 10.15 17.87 17.53 23.27 22.82 27.99 27.46 42.75 41.94

0.50 200 196.20 25 11.50 11.28 19.85 19.47 25.85 25.36 31.10 30.51 47.50 46.60

0.55 220 215.82 25 12.65 12.41 21.84 21.42 28.44 27.89 34.21 33.56 52.25 51.26

0.60 240 235.44 25 13.80 13.54 23.82 23.37 31.02 30.43 37.32 36.61 57.00 55.92

0.65 260 255.06 25 14.95 14.67 25.81 25.31 33.61 32.97 40.43 39.66 61.75 60.58

0.70 280 274.68 25 16.10 15.79 27.79 27.26 36.19 35.50 43.54 42.71 66.50 65.24

0.75 300 294.30 25 17.25 16.92 29.78 29.21 38.78 38.04 46.65 45.76 71.25 69.90

0.80 320 313.92 25 18.40 18.05 31.76 31.16 41.36 40.57 49.76 48.81 76.00 74.56

0.90 360 353.16 25 20.70 20.31 35.73 35.05 46.53 45.65 55.98 54.92 85.50 83.88

1.00 400 392.40 25 23.00 22.56 39.70 38.95 51.70 50.72 62.20 61.02 95.00 93.20

1.10 440 431.64 25 25.30 24.82 43.67 42.84 56.87 55.79 68.42 67.12 104.50 102.51

1.25 500 490.50 25 28.75 28.20 49.63 48.68 64.63 63.40 77.75 76.27 118.75 116.49

1.50 600 588.60 25 34.50 33.84 59.55 58.42 77.55 76.08 93.30 91.53 142.50 139.79

1.75 700 686.70 25 40.25 39.49 69.48 68.15 90.48 88.76 108.85 106.78 166.25 163.09

2.00 800 784.80 25 46.00 45.13 79.40 77.89 103.40 101.44 124.40 122.04 190.00 186.39

Tear Strength

Testing Method

Testing is done on Elmendorf Tearing Tester with specimen of the size 63 mm X 76 mm. 63 mm is the length in

oriented direction.

20mm oriented direction

76mm

Slit

63mm

Tear strength is in between 1.1 to 1.4 kgf /cm

Bending Fatigue Strength

Testing Method

Demattia Flexing Tester ASTM D-430

Test sample JIS 2 half size

10.5mmR

5mm 12.5mm

12.5mmR

10mm

50mm

Bending speed is 300 times/minute. Stroke is 12 mm. This test is done at room temperature.

Times required to induce cracking is from 10000 minutes to 500000 minutes depending upon thickness to

thickness.

Appearance

Radius of curvature:

Take 5 meters of any thickness Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets and put on a straight line on

any flat surface. If from centre it deflects maximum upto 20 mm till then it would be treated as a workable

sheet. If it goes beyond this limit then this sheet should be stabilized again at 1800C in air tunnel.

Maximum 20 mm

5 mts

Amplitude of wave (odulations) of all

Thicknesses:

This is a measurement of waviness in the Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets.

Height of the trough of the wave if it is in the range of 5 mm to 18 mm then it would be considered as workable

sheet. For 0.2 mm, 0.35 mm, 0.5 mm, 0.75 mm, 1.0 mm, 1.25 mm, 1.5 mm, 1.75 mm and 2.0 mm it is 5mm, 6

mm, 8mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm and 20 mm respectively.

5 to 20 mm

If sheet does not meet this specification then it should be stabilized again at 1800C in air tunnel.

Belt Camber: How to Fix Cambered Nylon Core Belting and Prevent Camber in Storage

Contributed by Nitta Corporation Beltline Reprint September 2010

What is Camber? Camber is the term used to describe an arc or curve that occurs in otherwise straight material. Generally, if camber occurs in belting, it is in a nylon (polyamide) core type material. Nylon core belting is more susceptible to camber than other types of belting because nylon tends to absorb humidity from the surrounding environment more than other materials such as polyester. If there is a dramatic change in environmental conditions – for example, if material is moved from a dry

environment to a very humid environment – camber is likely to occur. Moisture is absorbed from the edges, so

the outer sections of material contain more than the middle section (see Photo 1). This can form abnormal

stresses within the belt, which release when the belt is slit, resulting in camber (see Photo 2).

“Material Absorbs Moisture from Edges, so Outer Sections Contain More”

“Abnormal Stresses within Material are Released when Belt is Slit, Resulting in Camber”

How to Fix Cambered Nylon Core Belting In general, cambering tends to lessen on its own as time goes by. A well-balanced moisture ratio and proper storage are essential to prevent any cambering or wavy edges. If cambering or wavy edges occur, there are several methods for correcting the problem:

1. If time can be allowed before the material is slit and used, firmly wind up the belt and leave it with the

cambered side of the belt on a clean table for at least a week (see Illustration 1). Or, hang the coil on a rack

(on a heavy cardboard or wooden core) so the moisture content can equalize. Depending on belt type and

width, this could take up to several weeks. Belts with a thin nylon core and/or narrow width will show good

improvement within a few days.

“Corrective Placement of Cambered Belt”

2. If cambering or wavy edges occur on a belt that isn’t coiled (such as a belt slit from a cambered or wavy roll,

which will also camber), it can be fixed by coiling and following the method described in corrective action #1.

Once the camber is corrected, it won’t occur again even if the material is made endless, provided it is properly

stored and does not absorb more moisture on one edge than the other.

3. If a cambered belt is otherwise ready to install, it may not be necessary to take any action other than to install

it. Camber usually disappears within 24 hours after a belt is installed and tensioned properly. Applying tension

reorients the fibers to relieve camber, and 95% of the time camber does not affect belt performance at all.

Some shorter, wider belts may encounter issues, but in most cases running a belt

under tension is an effective method to relieve camber. It should also be noted that belts running under

tension are extremely unlikely to experience camber even under adverse environmental conditions.

4. Distortion may occur if material has not been wound properly. If this happens, loosen the roll and leave it for a

day or two. The material should relax and correct the problem.

How to Store Nylon Core Belting to Prevent Camber The best way to prevent cambering is by using Storage Method 1. Belting should be coiled around a heavy cardboard or wooden core (for support) and hung on a rack. Core should have Outer Diameter of 6.5''.

“Hang Belting on Rack using Heavy Cardboard or Wooden Core” Storage Method 2 is also an effective way of storing material. By storing the belt upright, both edges are equally

exposed to the surrounding environment. Belting stored this way should, however, be placed on a pallet or other

elevated surface (not directly on the floor) and wound tightly (on a 6.5'' OD heavy cardboard or wooden core) to avoid

deformation.

“Store Belting Upright on Pallet or Elevated Surface”

Do not use Storage Method 3 for full or wide rolls of material. It is only appropriate for narrow rolls

of belt, and as with Storage Method 2, a pallet or other elevated surface should be used.

“(Narrow Rolls Only): Flat on Pallet or Elevated Surface”

Relationship between Tensile strength (Load carrying capacity) v/s Elongation (Tension)

4000

3000

2000

1000

10 20 30 40

Elongation (Tension) %

Uni Axially Oriented Nylon 6 or Polyamide 6 Sheets have higher elasticity and strength as compared

to conventionally available semi oriented and partially stabilized Uni Axially Oriented Nylon 6 or

Polyamide 6 sheets in the market.

Relationship between Moisture content and Tensile strength (Load Carrying Capacity)

5000

4000 Tensile strength at break at 25 + 5%

3000

2000

1000 Tensile stress at 5% elongation

0

1 2 3 4

Moisture content (%)

Nylon 6 or Polyamide 6 is a highly hygroscopic material. It maintains its equilibrium at 2.6 % but in

dipped state for 96 hours it can gain moisture content upto 9%. Uni Axially Oriented Nylon 6 or

Polyamide 6 sheets modulus of elasticity and Tensile Strength (Load Carrying Capacity) depends

upon the moisture content. The higher the moisture content lower the elasticity modulus and

Tensile strength (Load Carrying Capacity). Moisture content varies with temperature and humidity in

the atmosphere.

Relationship between ambient temperature and Tensile strength (Load Carrying Capacity)

5000

4000 Tensile strength

3000

2000 Moisture content: 2.6% at equilibrium

1000 Tensile stress at 5% elongation

-30-20 0 20 40 60 80

Temperature OC

(Lo

ad C

arry

ing

Cap

acit

y)

Ten

sile

Str

engt

h in

Kgf

/cm

2

Uni Axially Oriented Nylon 6 or Polyamide 6 sheet is affected by working temperature. Higher the

temperature lower would be elasticity modulus and Tensile strength (Load Carrying Capacity)

Relationship between Shrinkage and Heat-Treatment Temperature

7

6

5

4

3

2

1

0

80 100 120 140 160 180

Temperature (OC)

Uni Axially Oriented Nylon 6 or Polyamide 6 sheets when put under higher temperature then they

show a behavior of shrinkage. They can even shrink upto 7% at 1800C.

Packing

Uni Axially Oriented Nylon 6 or Polyamide 6 sheets in roll form are wrapped in polyethylene sheet

then in aluminium foil and then in woven sack sheet and then finally with cardboard or wooden box

packing.

Packing is sea worthy of international standard.

Uni Axially Oriented Nylon 6 or Polyamide 6 sheets are supplied globally by us since 1990 and they

have stood the grueling test of perfection. It is proven item all over the world. Thousands of Tons

have been used by the customers till now.

Shri

nka

ge in

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