Our film thickness guide
Our polythene thickness guide aims to help new cutomers choose the correct polythene and plastic bags. Polythene is produced in different sizes and strengths to suit different applications. The following polythene film thickness guide aims to provide advice on film material and thickness so that you can make an informed purchase.
The following tables list common film material and gauge and the properties of each in terms of strength and clarity.
Low density polythene film
Low density polythene film is referred to as LDPE. It is resistant to punctures and tears, non-porous and stretchable. LDPE is a relatively strong transparent film with good tensile strength. LDPE resin has good clarity but weak film strength. Low density polythene film is primarily used for plastic food bags and poly sheeting.
| Thickness | Strength | Clarity | Usage |
|---|---|---|---|
| 80g 20mu | Low | Excellent | General purpose polythene film where load carrying capacity is not required. |
| 100g 25mu | Low | Excellent | General purpose polythene film where load carrying capacity is not required. |
| 120g 30mu | Medium | Excellent | Slightly thicker polythene film that makes packing items easier. |
150g 38mu 180g 45mu | Medium | Good | Thicker polythene film that protects items with smooth edges. |
| 200g 50mu | Good | OK | Thick polythene film suitable for heavy awkward items. |
| 250g 63mu | Very good | OK | Thick polythene film suitable for protecting heavy and abrasive items. Has OK clarity, therefore suitable for packing items. |
| 400g 100mu | Excellent | Slightly cloudy | Very thick polythene film suitable for protecting abrasive items such as bolts and screws. Slightly cloudy but packed goods are visible. |
| 500g 127mu | Excellent | Slighly cloudy | Very thick polythene film suitable for protecting abrasive items such as bolts and screws. Poly bags made from this gauge have excellent load carrying capcity. |
High density polythene film
High density polythene is referred to as HDPE. This film that has much higher stiffness, higher temperature resistance and much better water vapour barrier properties than LDPE film. However, the main drawback of HDPE film is it is hazier that LDPE. HDPE film is typically used for grocery bags and trash bags.
| Thickness | Strength | Clarity | Usage |
|---|---|---|---|
| 72g 18mu | OK | Cloudy | A strong thin material with a crinkly feel. |
Polypropylene film
Polypropylene film is stiffer than LDPE and HDPE. It acts a moisture barriers and preserves the freshness of items stored within. It is non-porous and offers excellent clarity. Polypropylene film can withstand high temperatures.
| Thickness | Strength | Clarity | Usage |
|---|---|---|---|
| 150g 38mu | Good | Superb | Extremely hard wearing film. |
| 200g 50mu | Good | Superb | Extremely flat film. Suitable for flat packing shirts. |
Gauge and micron
The thickness of material used in our products are listed as gauge and micron.
One micron is about 4 gauge. One micron is equal to one thousandth of a millimeter (0.001mm).
A 20 microns or 80 gauge bag is able to hold items up to about 1.5kg. This makes it good for light duty protection from dust and moisture.
Heavy duty polythene bags are 125 microns or 500 gauge. 125 microns is extremely tough and highly resistant to tears and punctures. In terms of load, 125 micron bags are able to hold up to about 20kg.
The following gauge to micron conversion chart converts between gauge, micron, mill, millimeter and inch.
| Gauge | Mill | Micron | Millimeter | Inch |
|---|---|---|---|---|
| 30 | 0.3 | 7.6 | 0.0076 | 0.0003 |
| 40 | 0.4 | 10 | 0.0101 | 0.0004 |
| 50 | 0.5 | 12.5 | 0.0127 | 0.0005 |
| 60 | 0.6 | 15 | 0.0152 | 0.0006 |
| 75 | 0.75 | 19 | 0.0190 | 0.0007 |
| 80 | 0.80 | 20 | 0.0203 | 0.0008 |
| 90 | 0.9 | 23 | 0.0228 | 0.0009 |
| 100 | 1 | 25 | 0.0254 | 0.0010 |
| 120 | 1.2 | 30 | 0.0304 | 0.0012 |
| 150 | 1.5 | 38 | 0.0380 | 0.0015 |
| 160 | 1.6 | 40 | 0.0406 | 0.0016 |
| 180 | 1.8 | 45 | 0.0457 | 0.0018 |
| 200 | 2 | 50 | 0.0508 | 0.002 |
| 300 | 3 | 75 | 0.075 | 0.003 |
| 400 | 4 | 100 | 0.1 | 0.0039 |
| 430 | 4.3 | 107.5 | 0.1075 | 0.0042 |
| 450 | 4.5 | 112.5 | 0.1125 | 0.0044 |
| 500 | 5 | 125 | 0.125 | 0.0049 |
| 600 | 6 | 150 | 0.15 | 0.0059 |
| 700 | 7 | 175 | 0.175 | 0.0069 |
| 800 | 8 | 200 | 0.2 | 0.0079 |
| 900 | 9 | 225 | 0.225 | 0.0089 |
| 1000 | 10 | 250 | 0.25 | 0.0098 |
