# Multi-Layer EVOH Barrier Bottles: Oxygen Transmission Rate (OTR) vs. Recyclability Delamination Limits
TL;DR — Multi-layer EVOH barrier bottles live at the tension between barrier performance and recycling-oriented design, and that tension shows up in the evidence layers themselves. The recorded side is concrete: PET, PE, and PP are the registered bottle materials, the dropper family spans 73 catalog models with glass and PET bodies, the airless family spans 89 catalog models with body material rows including PE and PET, and trigger bottle components are recorded across PE/PP/PET. The barrier side is a claim direction — no EVOH material is recorded in the material register — so any multi-layer story must be established first, with per-project material and layer-structure evidence. Oxygen transmission rate is a materials-science subject with no published values; delamination and recycling-oriented claims close per project, and the drop test and the compatibility test are the registered hooks, with criteria configured per project.
Why: Barrier Performance and Recycling-Oriented Design Are Different Evidence
- A bottle name carries two claims. "Multi-layer barrier" is a statement about wall construction and oxygen tightness; recycling-oriented behavior is a statement about the part's end state — they are verified by different evidence;
- The recorded side is limited and stable. PET, PE, and PP are the registered bottle materials, with family anchors in the dropper, airless, and trigger families — nothing more is on record;
- EVOH is not a registered material. No EVOH material is recorded in the material register, so a multi-layer barrier story is a claim direction requiring per-project material and layer-structure evidence — structurally the same boundary held for bio-based PE;
- OTR, delamination, and recycling-oriented state are per-project outcomes. The quality program supplies the hooks; the test conditions and acceptance criteria are configured per project.
How: Separating the Recorded Bottle from the Claimed Barrier
3.1 The recorded side: what the bottle families actually are
The verified facts are precise. PET, PE, and PP are the registered bottle materials. The dropper family spans 73 catalog models with glass and PET bottle bodies. The airless family spans 89 catalog models with body material rows including PE and PET. Trigger bottle components are recorded across PE, PP, and PET. That is the catalog-side foundation for any bottle conversation — material presence across three polymers and family-level anchors. Notably absent is any layer structure: no film construction, no tie-layer data, and no barrier grade appears anywhere in the register.
That absence is deliberate. The register records that these materials exist and where they are used; it does not describe wall architecture. Everything about how a specific construction behaves — its gas-barrier performance, its delamination resistance — is engineering knowledge acquired per project, not a registered property.
3.2 The EVOH boundary: a claim direction, not a registered layer
The boundary statement must be explicit: no EVOH material is recorded in the material register. An EVOH barrier layer — the common industry route to a low-oxygen-permeation wall — is therefore a claim direction, documented per project, not a catalog offering. This is structurally identical to the bio-based PE position: when a brief asks for a barrier bottle, the request lands one step earlier than the material record, at the layer construction and its source documentation.
Two statements the program will not make. We do not claim to supply EVOH layers as a catalog position, and there is no material record on which baked-in barrier copy could sit. What a project can do is establish the evidence chain per project: the layer construction as specified, the feedstock and supplier documentation, and a project record that the delivered wall matches the specification. Only then does the barrier conversation become real — and it is a per-project conversation.
3.3 OTR: a materials-science subject without numbers
Oxygen transmission rate — OTR — is the materials-science measure of how much oxygen passes through a wall of a given thickness and area over time. As industry knowledge the mechanism of a barrier layer is broadly understood: certain high-barrier resins slow oxygen permeation dramatically compared with straightforward polyolefin walls, which is why barrier structures matter for oxygen-sensitive contents in personal care. That description is directional engineering guidance — no OTR values and no permeation rates are published here, because none are recorded in the program.
The practical consequence is the same discipline used everywhere in this program: barrier behavior is confirmed per project, not assumed per construction name. An oxygen-sensitive application gets its wall evaluated per project — the layer arrangement, the wall geometry, and the acceptance level are the project's, and the result is recorded per project.
3.4 Delamination and recycling-oriented state: independent confirmation per project
Multi-layer walls introduce interfaces, and interfaces introduce a distinct failure mode: delamination — the separation of coextruded layers under stress or handling. As industry methodology, delamination susceptibility depends on the pairing of a specific construction — layer materials, tie chemistry, and processing — with the stress history of the filled part. It is inherently a per-project trial subject, observed on real filled samples under the project's conditions, with findings recorded per project.
The recycling-oriented side follows the same discipline written elsewhere in this program for PCR: any recycled-content percentage is defined per project, and no unconditional recycling claim is made. Layered walls get exactly the same scrutiny as any other material phrase — the reclamation or disposal route is defined by the project and independently confirmed against the actual construction before any recycling-oriented statement is made.
3.5 The verification flow that closes a multi-layer conversation
A complete barrier conversation resolves in a fixed order:
- Anchor on the recorded side: PET, PE, and PP as registered bottle materials, with the dropper (73 catalog models, glass and PET bodies), airless (89 catalog models, PE and PET body rows), and trigger (PE/PP/PET components) families;
- Classify the claim: EVOH barrier (no record — claim direction requiring layer-construction evidence) versus recorded single-material wall (engineering verification);
- For a barrier direction, establish the layer documentation per project before part work;
- For performance, route OTR-type evaluation, delamination trials, and recycling-oriented confirmation per project, with criteria configured per project;
- Release the part per project, recording the claim evidence and the test results together.
That flow keeps the two evidence layers clean: wall architecture is evidenced per project by documentation, part behavior is evidenced per project by testing, and the catalog record supplies only the foundation.
<pre class="language-mermaid"><code>flowchart LR
A[Single-material bottle<br/>family recorded] –> B[EVOH multilayer claim<br/>no record,<br/>claim direction]
B –> C[OTR subject<br/>project verification]
C –> D[Delamination + recycling<br/>per-project confirmation]
D –> E[Drop + compatibility<br/>verification per project]
E –> F[Release per project]
</code></pre>
What: Verified Program Data and the Verification Hooks
- Bottle materials (recorded): PET, PE, and PP are the registered bottle materials;
- Dropper family (recorded): 73 catalog models with glass and PET bottle bodies;
- Airless family (recorded): 89 catalog models with body material rows including PE and PET;
- Trigger anchor (recorded): trigger bottle components are recorded across PE, PP, and PET;
- EVOH boundary (recorded): no EVOH material is recorded in the material register — multi-layer barrier is a claim direction requiring per-project material and layer-structure evidence;
- Quality hooks (capability-level): the drop test and the compatibility test are registered capabilities of the quality program; parameters and criteria are set per project;
- What is not claimed: no OTR values, no permeation rates, no layer thicknesses, no delamination propensity, and no EVOH supply.
Gotchas
- No EVOH material is on record. No EVOH material is recorded in the material register — copy implying a barrier layer or EVOH supply would be a claim without an evidence base.
- Wall architecture and behavior are different evidence. Layer documentation proves what the wall is; OTR-type trials and delamination observation prove what it does — one never substitutes for the other.
- OTR has no numbers anywhere. No OTR values, permeation rates, or layer thicknesses exist in the program; an OTR-type evaluation is a per-project construct with the project's own conditions.
- Recycling-oriented claims are per-project and independently confirmed. Any recycled-content percentage is defined per project, and no unconditional recycling claim is made — the same discipline applied to PCR discussions.
- Delamination is a pairing, observed per project. A specific layer construction with a specific stress history; findings are recorded per project on filled samples, never as a catalog property.
- Drop testing is capability-level. The drop test is a registered hook with no published parameters; the height, conditioning, and pass criteria are the project's.
- Keep the families straight. Droppers (73 catalog models, PET bodies), airless (89 catalog models, PE and PET rows), and trigger components (PE/PP/PET) are the recorded scopes; bottle copy must stay within them.
Related Resources
- Categories: Bottles · Droppers
- Related insight: Bio-Based PE vs. Fossil HDPE · PCR Decontamination & Traceability · PCR Resin Processing · The 12-Test Lab Matrix
- Quality & Testing Capabilities — drop and compatibility testing · Customization — per-project barrier evidence and verification criteria