Production Standard Tolerances

The Information below details our Production Standards. Should you like a printed copy or PDF document please click on the image on the right.

1. Production Standard:

A. Purpose:
i) To provide a basis for agreement between purchaser and supplier
ii) To provide information for the guidance of the producers, distributors and users

B. Scope:
This standard covers dimensional and thickness tolerances, using the relevant PIFA Standards as a guideline, for the following products manufactured from Low Density Polythene, printed and unprinted, natural and pigmented

i) Layflat Tubing, Gusseted Layflat Tubing, Centre-Fold Sheet, Single Wound Sheet and J-Fold Sheet
ii) Bottom Weld Bags including Heavy Duty Sacks
iii) Side Weld Bags, excluding Skirt Side Weld

C. Tolerances
i) Film Thickness
Parameters: All film within a range of 25-250 microns

The average thickness shall be within +/- 10% of the nominal and be the mean of 10 individual measurements taken at random over the circumference of the tubing

Nominal Minimum Maximum
 25 Microns  22.5mu  27.5mu
30 Microns  27mu  33mu
 40 Microns 36 mu 44mu
 50 Microns 45 mu 55 mu
60 Microns 54 mu 66 mu
 70 Microns 63 mu 77 mu
 80 Microns 72 mu 88 mu
 90 Microns 81 mu 99mu
100 Microns 90mu 110 mu
 150Microns 135 mu 165 mu
 200 Microns 180 mu 220 mu
 250Microns 225mu 275 mu

Tolerances for intermediate thickness shall be interpolated from these values


 

i) Film Width
Parameters: All Reel Film, except that for conversion into Heavy Duty Sacks, with a width of up to 1800mm and within a thickness range of 25-250 microns

The width of the film, and the width of open gussets (see page 6, figure 1) shall be measured off the reel and the tolerances shall be as follows:

Widths Upto 250mm +/-6mm
Widths above 250 – 499mm +/-9mm
Widths above 500 – 749mm +/-12mm
Widths above 750 – 999mm +/-15mm
 Widths above 1000 – 1499mm  +/-25mm
Widths above 1500 – 1800mm  +/-40mm

OPEN GUSSETS

+/- 5% of nominal width


iii) Film width – Heavy Duty Sacks
Parameters: All LFT and GLFT for conversation into Heavy Duty Sacks, within a width range of 380-810mm and a thickness of 100-250 microns

The width of the film, and the width of the open gussets, shall be measured off the reel and the tolerances shall be as follows:

Widths 380 – 600mm +/-7mm
Widths 601 – 810mm +/-15mm

OPEN GUSSETS

+/- 5% of nominal width


iv) Bottom Weld Bags
Parameters: All bags manufactured from LFT and GLFT and within a width range of up to 1100mm, a length range of up to 2795mm and a thickness range of 25-250 microns

The width of the bag and the width of open gussets shall be measured using the C (ii) film width chart. The length of the bag is measured from the top to the bottom.

The thickness shall be measured as at C (i)

The length tolerances shall be as follows:

Nominal Length 200mm -3mm & +5mm
Nominal Length 300mm -3mm & +5mm
Nominal Length 400mm -3mm & +5mm
Nominal Length 500mm -5mm & +8mm
Nominal Length 1000mm -5mm & +8mm
Nominal Length 2000mm -5mm & +8mm
Nominal Length 2795mm -5mm & +8mm

Tolerances for intermediate lengths shall be interpolated from these values.


v) Side Weld Bags
Parameters: Within a width range of up to 900mm, a length range of up to 1160mm and a thickness range of 25-100 microns

The tolerances for the length of the bag are as for the widths in C (ii), due to the side welding

The thickness shall be measured as at C (i)

The width tolerances shall be as follows:

Nominal Opening Width 100mm +/-3mm
Nominal Opening Width 200mm +/-5mm
Nominal Opening Width 300mm +/-6mm
Nominal Opening Width 400mm +/-8mm
Nominal Opening Width 500mm +/-10mm
Nominal Opening Width 600mm +/-12mm

Tolerances for intermediate widths shall be interpolated from these values


 Figures

1.Open Gusset

open gusset

2.Length of Bag: Top to Bottom ( Unless otherwise stated)

open gusset 3

 

 

Production Tolerances

Please click the image below to download a PDF copy of our Production Tolerances

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