PROBLEM	POSSIBLE CAUSES	POSSIBLE SOLUTIONS
Film Puncture	Hold up particle Contamination Moisture in Material	Clean die lip Change screen pack Pre-dry all raw materials up to 70*C Check heat stability of filler & master batch Optimize Temperature Profile
Gel, Hard/unplasticized Profile	Low back pressure Improper temperature gradient Moister in master batch	Use one step fine wire mesh Check and correct temperature Profile Reduce die lip opening Check screw dimensional status Pre-dry all raw materials up to 70*C
Denier Variation	Surging in Extruder Film thickness variation across the width Spacer thickness variation Temperature and/or Air Velocity variation across the width of Die and/or Orientation Unit	Reduce throughput rate. Increase die volume. Clean and Adjust die lip for even gap/opening throughout. Check uniformity of die temp. Ensure even spacer thickness. Ensure even temperature/airflow across the width of orientation unit
Tape Breakage	Excessive stretch ratio. Cold stretching of Tapes. Gel/particle in film. Check uniformity of die temp. Extruder surging/uneven melt flow	Gradually Increase stretch ratio. Reduce gap between die lip and water level. Gradually Increase orientation temperature. Reduce quench water temperature.
Low Tenacity Higher Elongation	Low stretch ratio. Too soft film. Low orientation temperature	Gradually Increase stretch ratio. Reduce gap between die lip and water level. Gradually Increase orientation temperature. Reduce quench water temperature.
Tape Fabilation	Damaged traverse guide of winders. Low sharpness of slitter Blades. Wrinkles in the film/tapes. Excessive winding tension.	Replace damaged traverse guide. Gradually reduce stretch ratio. Replace slitter Blades with new one. Use anti fibrillation MB. Reduce winding tension.
Shrinkage In Fabric Curved Tape	Residual stress in tape.	Check annealing ratio. Increase annealing temperature. Ensure cooling efficiency of roller.

PROBLEM	POSSIBLE CAUSES	POSSIBLE SOLUTIONS
Poor Adhesion	Melt temperature too low Low back pressure Melt temperature too high or polymer thermally degraded Inadequate oxidation Premature cooling Chill roll tack Poor substrate surface Additive effects	Increase overall temperature. Increase screen mesh size. Decrease overall temperature. Replace Polymer Increase air gap Lower line speed. Increase corona treatment. Decrease air gap. Increase chill roll temperature. Decrease chill roll temperature. Pre-treat substrate. Confirm that proper type and level of additive are used.
Draw Resonance	Draw ratio too high	(See Edge Tear).
	Temperature too high	Decrease polymer temperature.
EDGE TEAR	Draw ratio too high	Decrease die gap. Increase coating weight
	Die end temperature too low	Increase temperature of die ends.
GAUGE BANDS	Unclean die	Clean die lips regularly.
	Improper die gap	Adjust die bolts for even die gap across the die.
	Temperature variations	Keep and maintain proper heating systems to deliver accurate temperature.
	Temperature too high	Gradually reduce temperature.
GELS	Temperature too high	Gradually reduce temperature.
	Resin contamination	Use clean raw materials.
	Incorrect melt temperature.	Optimize temperature profile.
	Poor purging	Use proper purging techniques.
	Poor mixing	Increase back pressure by using fine mesh screen.
Molten Curtain Breaks	Draw ratio too high	Decreases die gap. Increase coating weight.
	Incorrect melt temperature.	Optimize temperature profile.
ODOUR	Over-Oxidation	Decreases melt temperature. Decrease air gap.
Oxidation	Degradation	Decrease temperature. Increase screw speed.
	Poor purging	Always purge out copolymer with a homopolymer before turning off extruder.
Heat Sealability	Over-oxidation	Decrease melts temperature. Decrease air gap. Check and optimize corona treatment.
Surging	Hopper bridging (improper feeding)	Reduce feed zone temp
Voids	Moisture	Protect hygroscopic resins from humidity. Condensate in feed throat
	Polymer degradation	Do not exceed recommended maximum melt temperatures.

• Spacer Size (mm) = (Stretching Ratio) ^1/2 x Width of Tape
• Stretching Ratio = (Spacer Size/Tape Width) ^2
• Stretching Ratio = Stretching Godet Speed / holding Godet Speed
• Stretching Ratio = Stretching Godet Speed / holding Godet Speed
• Production Kg/hr = Denier x Final Line Speed x No of Tapes/ 150000
• Elongation % = Tape Final Length - Initial Length x 100 / Final Length
• Tape Thickness Stretched = denier / (9000 x Tape Width x Density)
• Unstarched Tape Thickness = (Stretch Ratio) ^1/2 x stretched Tape Thickness
• Screw Speed = Motor Speed x Motor Pulley Diameter / (Gear Ratio x Gera Box Pulley Diameter)
• Main Motor RPM = (Gear Ratio X Screw RPM X Gear Box Pulley Día)/ (Motor Pulley Dia.)
• Thickness of unstretchef film = Final Tape Thickness x √stretch Ratio
• Final Tape Thickness mm = Denier/Density x 9000 x Final Tape Width
• Annelling Ration = 2nd Godet Speed - 3rd Godet Speed/ 2nd Godet Speed x 100
• Tenacity (gpd) = Breaking Load(Kgf)/ Denier x 1000
• Production / Hr = Line Speed x Denier x Nos of Tape X 60 / 9000 x 1000
• Stretch Ratio = 2nd Godet Speed/ 1nd Godet Speed
• Denier = 9 x Tex Where Tex = Wt Of 1000 meter Tape in Grams

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• Picks per minute = cam RPM x Number of shuttles
• Gear Ratio = Haul off gear ratio X no of teeth of Haul off Sprocket ÷ motor gear Sprocket.
• Weaving Ring I.D = 2 x fabric width(mm)/3.14 OR = 2 x fabric width(inch) x 25.4/ 3.14
• Elongation = Increase in length x 100 / Initial sample length
• Number of warp = 2 x fabric width x Warp Mesh (Inches)

• = 2 x fabric width x Warp Mesh / 2.54 (centimetres)

• Fabric Production per minute = 1.524 x PPM / Weft mesh
• Fabric GSM = Warp mesh x Warp Denier + Weft mesh x Weft Denier/228.6
• Bags Weight = 50.8 x fabric width x Cut length x Warp mesh x Warp Denier + Weft mesh x Weft Denier/ 90,00,000

• = Fabric Dfl. x Cut length X GSM/ 5000 (warp mesh and weft mesh in inches, fabric width and cut length in inches)

For PP Unlaminated Fabric

For Example, if you want to Produce 60cm x 90cm single fold bottom stitch 90-gram bag. For Production you need Two Things

1. Cut Length and

2. Denier

1. For Cut Length:

Your Bag Length is 90cm + 4cm for single fold = 94cm is your final length. Width will remain same = 60cm.

2. For Denier:

Now, we have to calculate Sq. Meter of Bag. = Length x (Width x 2) in meter = 0.94 x (0.6 x 2) {cm/100 = meter} = 1.128 sq. meter.

3. So, your 90gm Bag weight is of 1.128 sq. meter. i.e. GSM of the Bag is 90/1.128 = 79.79 GSM

4. Now, follow below Thumb Rule Table for How much denier to set in Tape Plant ?

Base Thumb Rule taken is 1000 Denier = 90 GSM

Now, coming to our Bag Sample, for 10x10 Mesh, we have to Produce 11.11 (As per Table) x 79.79 GSM of the Bag = 887 Denier in the Plant.

How to measure shrinkage in Tape?

for PE (polyethylene) tape

5 randomly selected tape samples are cut to the exact length of 100 cm (39.37”). These are then immersed in a water bath maintained at a constant temperature of 212°F (100°C) for 1 minute. The tapes are then removed from the bath and are allowed to cool and dry. The tapes are then measured and percentage of shrink is calculated from the difference between the original length and the reduced length after the water bath, all divided by the original length.

for PP (polypropylene) tape

5 randomly selected tape samples are cut to the exact length of 100 cm (39.37”). These are then put in an oven at a constant temperature of 270°F (132°C) for a duration of 15 minutes. The tapes are removed from the oven and allowed to cool. The tapes are then measured and the percentage of shrink is calculated from the difference between the original length and the reduced length after the oven, all divided by the original length.

Determination of Screw Rpm for Specified Coating Gauge and Line Speed

• Screw Rpm = Gauge x 39.37 x Width f Fabric X Line Speed / Gear Box Ration (25.5) x 6600
• Wt of material Required in Lamination/Mtr = 2 x W" X 39.37 X Gauge/ 3300

In Lamination 100 Gauge = 25 Micron = 23.4 Gsm

Gsm Of Lamination = D x T

Where as D = Density of Material Gms / Cm³,

T = Thickness of Lamination in Micron