High-barrier PE, chosen by structure
A selection guide rather than another product page: two metallized PE grades get barrier into a PE pack in different places, and only one of them seals. Read the structure first, the numbers second.
Two ways to get barrier in PE
Both grades are vacuum-metallized PE. What separates them is the face that has to do work afterwards: the seal, or the lamination.
VMNCPE — the barrier core
Goes in as the middle layer of a three-layer PE structure: printed PE / adhesive / VMNCPE / adhesive / PE sealant. It carries no heat seal — the seal comes from the PE web on the inside — so its only job is the barrier. WVTR ≤ 1 g/(m²·24h), OTR ≤ 1 cm³/(m²·0.1MPa·24h), and after lamination its oxygen barrier is better than the original single film. This is the grade for a structure that is already PE and wants the barrier buried where it cannot be scratched.
VMCPE — the sealant
Metal on one face, high seal strength on the other, so one web closes the pack and carries the barrier. It makes a two-layer recyclable structure: reverse-printed PE / adhesive / VMCPE, the replacement for a traditional reverse-printed / adhesive / barrier / adhesive / sealant stack. WVTR 2.1 g/(m²·24h), OTR ≤ 80 cm³/(m²·0.1MPa·24h). Runs on VFFS and HFFS lines, and in stand-up and peg-display pouches.
Numbers, side by side
Standard and typical figures for the two PE grades, with the AlOx films alongside so the polymer decision can be made before the grade decision.
| Property | VMNCPE (PE core) | VMCPE (PE sealant) | ALOX BOPP-A | ALOX PET |
|---|---|---|---|---|
| Oxygen transmission (OTR) | ≤ 1 | ≤ 80 | ≤ 1 · typ 0.63 | typ 0.11–1.55 |
| Water vapour transmission (WVTR) | ≤ 1 | 2.1 | ≤ 1 · typ 0.89 | typ 0.18–1.25 |
| Thickness | 40–100 µm | 40 µm std · 50–80 on order | 18 µm | 12.0–12.5 µm |
| Recycling stream | PE | PE | PP | PET — not mono-material |
| Appearance | Metallized | Metallized | Transparent | Transparent |
| Heat seal | No — core layer only | Yes — one face | Seal face on one side | Seal face on one side |
Test basis
| Family | OTR | WVTR |
|---|---|---|
| PE — VMNCPE, VMCPE | ASTM D3985 · cm³/(m²·0.1MPa·24h) | ASTM F1249 · g/(m²·24h) |
| AlOx — ALOX BOPP-A, ALOX PET | GB/T 19789 / ASTM D3985 · 23 °C / 0 % RH · cm³/(m²·24h) | GB/T 26253 / ASTM E398 · 38 °C / 90 % RH · g/(m²·24h) |
When PE is not the answer
The film is half the decision. If the pack is not already PE, or the process is not a PE process, the right answer is a different polymer.
Transparent, in a PP stream
Metallized PE is not a clear film: the metal layer is the barrier, and it reflects. Where the pack has to show the product, the barrier has to be transparent — AlOx on BOPP. ALOX BOPP-A is 18 µm, OTR ≤ 1 (typ 0.63) and WVTR ≤ 1 (typ 0.89), and the structure stays in the PP stream. It prints and laminates; the barrier is the coating, not a metal layer.
Retort, stiffness or flat lid stock
Where the pack takes boil or 121 °C retort, or a lid has to stay flat, the base film has to be PET. ALOX PET is 12.0–12.5 µm with OTR typ 0.11–1.55 and WVTR typ 0.18–1.25 depending on grade, and seven of its ten grades are listed for 121 °C retort. It belongs to the PET stream — this is not a mono-material structure, and no claim here says otherwise.
What PE does not give you
A metallized PE pack is not transparent, and no retort claim is made for the two PE grades — where the process needs it, trial ALOX PET. The barrier figures above are the film's; the number your customer will measure is the finished laminate's, so the structure and the lot certificate are part of the specification rather than an afterthought. And a mono-material claim is a statement about the whole structure, not about the film on its own.
How to qualify it
Three steps from an A4 to a running order, with the documents that go with each one.
Ask for an A4
Free, in both grades if the structure is still open. The sample roll that follows is slit to your width and ships with its dimension sheet and lot data.
Run your structure
Three-layer with VMNCPE in the middle, or two-layer with VMCPE as the sealant. Record the seal window, the adhesion after lamination and the barrier of the finished pack.
Put the lot on record
The trial lot becomes the reference. Repeat orders carry the same dimension sheet and lot data, so the next roll can be compared with the one that passed.
Supply, both grades
- VMCPE gauge
- 40 µm standard · 50–80 µm made to order
- VMNCPE gauge
- 40–100 µm quoted per order
- Roll width
- Up to 3,000 mm slit to order
- Outside diameter
- 440 mm max
- Standard roll length
- 3,700 m
- Minimum order
- 1 pallet
- Lead time
- 10–15 days by width
- Samples
- A4 free
Documents
Technical data sheet
Every value above with its method and condition, one sheet per grade.
Certificate of Analysis
COA per roll, carrying the measured thickness, width and barrier of the lot.
FDA compliance
Written food-contact compliance statement for both PE grades, with the grade sheet.
EU 10/2011 migration report
Migration test report to EU 10/2011, issued on request for the grade you trial.
Tell us where the barrier has to sit
Middle layer or seal face, the polymer you are already running, the width and the gauge. A4 samples are free; VMPE minimum order is one pallet and lead time is 10–15 days by width.
- Sales
- [email protected]
- Phone
- +86 532 6776 6956
- Works
- Qingdao, Shandong, China