If you're importing PE plastic bags from China, one of the most confusing things is thickness measurement. Chinese factories use "丝" (si), US buyers use "mil" or "gauge", and Europeans use "microns". Which one should you use? And what thickness do you actually need?
This guide covers everything you need to know about PE bag thickness — with a handy conversion chart and recommendations for different applications.
What is PE Bag Thickness?
PE (polyethylene) bag thickness refers to how thick the plastic film is. It directly affects the bag's strength, durability, cost, and suitability for different products. Thicker bags are stronger but more expensive. Thinner bags save money but may not protect your products adequately.
Thickness Units: The Complete Conversion Chart
Different countries use different units. Here's how they compare:
| 丝 (Si) | Micron (μm) | Mil | mm |
|---|---|---|---|
| 1 丝 | 10 μm | 0.39 mil | 0.01mm |
| 2 丝 | 20 μm | 0.79 mil | 0.02mm |
| 3 丝 | 30 μm | 1.18 mil | 0.03mm |
| 5 丝 | 50 μm | 1.97 mil | 0.05mm |
| 8 丝 | 80 μm | 3.15 mil | 0.08mm |
| 10 丝 | 100 μm | 3.94 mil | 0.10mm |
| 15 丝 | 150 μm | 5.91 mil | 0.15mm |
What Thickness Do You Need? By Application
📦 Lightweight Items (1-3 丝 / 0.01-0.03mm)
- Garment bags — 1-2 丝 for dry cleaning and apparel
- Grocery/shopping bags — 1.5-2.5 丝
- Produce bags — 1-1.5 丝 for fruits and vegetables
- General merchandise — 2-3 丝 for light products
📦 Medium Items (3-5 丝 / 0.03-0.05mm)
- Food packaging — 3-4 丝 for snacks, dry foods, frozen items
- Hardware parts — 4-5 丝 for screws, nuts, small components
- Electronics accessories — 3-4 丝 for phone cases, cables
- Sample bags — 3 丝 for product samples and promotional items
📦 Heavy Items (5-10 丝 / 0.05-0.10mm)
- Industrial parts — 6-8 丝 for heavy components
- Chemicals/ powders — 8-10 丝 for thick protection
- Shipping packaging — 5-8 丝 for mail order bags
Relative Material Use by Thickness
The ratios below compare nominal film thickness only. They are planning aids, not product weights or prices; seals, gussets, tolerances and resin density must be included in the final calculation.
| Nominal thickness | Relative film mass | Quotation treatment |
|---|---|---|
| 2 丝 (0.02mm) | 1.0× baseline | Quote by specification |
| 3 丝 (0.03mm) | 1.5× baseline | Quote by specification |
| 5 丝 (0.05mm) | 2.5× baseline | Quote by specification |
| 8 丝 (0.08mm) | 4.0× baseline | Quote by specification |
Need a written quote for a specific size and thickness? Use our RFQ Specification Builder to organise the required details before contacting us.
Common Questions About PE Bag Thickness
Is thicker always better?
No. Thicker bags cost more and generate more plastic waste. Choose the thickness that matches your product's weight and protection needs. Over-packaging wastes money and material.
What thickness do most e-commerce businesses use?
Most e-commerce and retail packaging uses 2-4 丝 (0.02-0.04mm) PE bags. This range offers good protection at an economical price point.
How do I measure bag thickness?
Use a digital micrometer or thickness gauge. Measure the film in multiple spots and average the readings. Film thickness can vary slightly across the bag width.
Can I mix thicknesses in one order?
Yes. We can produce different thicknesses in the same order. Each size/thickness combination is treated as a separate line item. Contact us for a multi-item quote.
Need Help Choosing the Right Thickness?
Not sure what thickness you need? Send us your product details and we'll recommend a starting specification to test.
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