Overview #
Flat pouches and sachets serve a wider range of product categories than most brand teams realize — and the specification requirements shift significantly depending on what goes inside. A single-serve coffee sachet and a cosmetic sheet mask pouch may look similar on a shelf, but their laminate constructions, seal integrity requirements, and print surface treatments are fundamentally different. This guide walks through four industry verticals where we regularly produce flat pouches and sachets, covering the structural parameters, print specifications, and production decisions that matter most for each. If you’re briefing us on a new pouch project, this is the technical context our team works from.
Food & Beverage: Barrier Performance and Seal Integrity #
Food applications drive the most demanding specifications we work with on flat pouch lines. For dry goods — ground coffee, protein powder, snack seasonings — we specify a minimum oxygen transmission rate (OTR) of ≤5 cc/m²/day and water vapor transmission rate (WVTR) of ≤3 g/m²/day, measured per ASTM F1927. These values require a foil-laminate or high-barrier EVOH construction; standard BOPP/PE structures won’t hold.
Our standard food-grade laminate for dry single-serve sachets is a 3-layer structure: 12µm PET (outer print layer) / 7µm aluminium foil (barrier) / 60µm PE (heat-seal layer), with a total caliper of approximately 79µm. For wet or oil-based contents — sauces, condiments, liquid flavourings — we increase the PE seal layer to 80–100µm to handle the additional stress on the bottom seal during filling.
Seal strength is non-negotiable for food. We target a minimum peel strength of 25 N/15mm on all food pouch seals, tested per ASTM F88. Our heat-seal parameters for PET/foil/PE laminates run at 160–180°C, 0.3 MPa, 1.0–1.5 seconds dwell time. Brands that come to us with pre-designed pouches from a non-food background often underspecify the seal layer — we’ve seen 40µm PE seal layers fail at the bottom gusset under normal filling-line pressure.
All food-contact laminates we supply comply with FDA 21 CFR 177.1520 (polyolefins) and EU Regulation 10/2011 on plastic materials in food contact. For markets requiring GB/T compliance, we reference GB 9683 for composite food packaging.
| Laminate Structure | OTR (cc/m²/day) | WVTR (g/m²/day) | Typical Application |
|---|---|---|---|
| PET 12µm / PE 80µm | 80–120 | 8–15 | Non-barrier dry goods |
| PET 12µm / VMPET 12µm / PE 80µm | 8–15 | 1.5–3.0 | Moderate barrier snacks |
| PET 12µm / Al foil 7µm / PE 80µm | ≤1.0 | ≤0.5 | High-barrier coffee, powder |
| PET 12µm / EVOH 15µm / PE 80µm | 0.5–2.0 | 2.0–4.0 | Foil-free high-barrier option |
Personal Care & Cosmetics: Surface Finish and Tactile Brand Expression #
Cosmetic flat pouches — sheet masks, single-use serums, travel-size skincare sachets — are primarily a brand expression vehicle. The product inside is often water-based and low-aggression, so barrier requirements are moderate (WVTR ≤10 g/m²/day is typically sufficient). The specification challenge shifts to print quality and surface finishing.
We run cosmetic pouch artwork on 10-colour rotogravure presses with a repeat length of 300–800mm. Our register tolerance on gravure is ±0.15mm, which is critical for fine-line cosmetic artwork with tight colour breaks. For brands requiring Pantone-matched brand colours, we target ΔE ≤1.5 against the Pantone reference under D50 illuminant — our colour management workflow is G7-calibrated.
Surface finishing options we regularly apply to cosmetic pouches include:
- Matte OPP lamination (1.8–2.2µm coating weight): the most common choice for premium skincare; reduces gloss to 10–20 GU (60° geometry)
- Soft-touch coating: applied at 3–5 g/m² dry weight, gives a velvet tactile feel; adds approximately 3–4 working days to production
- Spot UV on matte base: we apply UV varnish at 6–8 g/m² to selected design elements; cure energy 120–160 mJ/cm²
- Hot stamping foil: registered to ±0.3mm on our flat-bed foil units; available in gold, silver, holographic and custom pigment foils
One common mistake we see from cosmetic brands: specifying a full-bleed matte lamination and then adding a large spot UV panel that covers more than 40% of the pouch face. At that coverage level, the differential tension between laminated and UV-coated zones causes curl on the finished pouch — it won’t lay flat in a display tray. We guide brands to keep spot UV coverage below 35% of total face area, or switch to a full gloss lamination base with selective matte coating instead.
Nutraceuticals & Supplements: Compliance, Child-Resistance and Dosage Accuracy #
Single-serve supplement sachets — electrolyte powders, collagen peptides, pre-workout blends — sit at the intersection of food and pharmaceutical packaging requirements. For US-market products, we work to FDA 21 CFR Part 111 GMP documentation requirements, and for EU brands we reference the relevant provisions of Regulation (EC) 1925/2006 on food supplements.
The structural specification for supplement sachets typically uses a 3-layer laminate: 12µm BOPP / 12µm VMPET / 60µm PE, total caliper 84µm. Fill weights for single-serve sachets in this category typically run 5–30g, and the seal geometry must be designed to ensure the sachet tears cleanly at the notch without spilling powder. We cut tear notches at 45° to the seal edge, with a notch depth of 2.0–2.5mm — shallower than that and the tear propagates unpredictably across the print panel.
For brands selling into markets with child-resistant packaging requirements (PPWR in the EU, 16 CFR Part 1700 in the US), we can integrate a peel-and-reseal child-resistant closure into flat pouch formats. This adds approximately 0.08–0.12 USD per unit to the component cost and requires a minimum pouch width of 80mm to accommodate the closure mechanism.
Dosage accuracy is a brand and regulatory concern: we recommend brands specify fill-weight tolerance at ±2% of target fill weight, and confirm this with their filling-line supplier before finalising the pouch opening width.
Industrial & Household Products: Chemical Resistance and Functional Sealing #
Flat pouches for household chemicals — detergent pods, descaling sachets, single-use cleaning concentrates — require a fundamentally different laminate approach. Aggressive surfactants and oxidising agents will attack standard PE seal layers over time. For these applications, we specify a CPP (cast polypropylene) seal layer at 50–80µm rather than PE, as CPP offers better resistance to surfactant migration and maintains seal integrity at temperatures up to 121°C.
REACH compliance (Regulation EC 1907/2006) is mandatory for any pouch in contact with household chemical products sold in the EU. We maintain REACH compliance documentation for all laminate components and can provide full material declarations on request.
Print specifications for industrial pouches are typically simpler — 4–6 colour flexo or gravure, no premium surface finishing — but the functional requirements are more demanding. We specify a minimum burst strength of 200 kPa (tested per ASTM D3786) for pouches containing liquid concentrates, and all seals are 100% inspected on our inline vision systems for seal voids above 0.5mm².
Specification Notes for Brand Partners #
When you brief us on a flat pouch or sachet project, the first things we need are: product type and fill weight, target markets (for regulatory compliance routing), and any existing laminate specification or barrier data from your product team. If you don’t have barrier data yet, tell us the product category and shelf-life target — we’ll recommend a laminate construction based on our experience with similar products.
The most common brief mistake we see is brands sending us a visual design file without a dieline, then asking us to “fit it to a standard size.” Flat pouches don’t have a universal standard size — the pouch dimensions are determined by fill volume, filling-machine jaw width, and display requirements. We develop the dieline first, then the artwork is adapted to it, not the other way around.
Our typical process: structural dieline and laminate recommendation in 3–5 working days, digital colour proof in 5–7 working days, physical sample in 12–15 working days, production lead time 20–28 working days after sample approval. MOQ for rotogravure-printed flat pouches is typically 50,000 units per SKU.
Frequently Asked Questions #
Q1: What OTR value do I need for a ground coffee sachet, and which laminate achieves it?
A: For ground coffee, you need OTR ≤1.0 cc/m²/day to protect flavour over a 12-month shelf life. We achieve this with a PET 12µm / aluminium foil 7µm / PE 80µm laminate — the foil layer is the key barrier element. EVOH-based foil-free structures can get close (0.5–2.0 cc/m²/day) if your brand requires recyclability, but we’d want to validate against your specific shelf-life target before committing.
Q2: What is your MOQ and lead time for flat pouches with rotogravure printing?
A: Our standard MOQ for rotogravure-printed flat pouches is 50,000 units per SKU. Production lead time after sample approval is 20–28 working days. If you’re running multiple SKUs with the same laminate structure and only changing the artwork, we can sometimes consolidate cylinder costs — worth discussing at the brief stage.
Q3: Do your food-contact laminates comply with FDA and EU food contact regulations?
A: Yes. All food-contact laminates we supply comply with FDA 21 CFR 177.1520 for polyolefin components and EU Regulation 10/2011 for plastic materials in food contact. We maintain full material declarations and migration test reports for our standard laminate constructions, and can provide these as part of the sample approval package.
Q4: Can I get a soft-touch finish and spot UV on the same cosmetic sachet?
A: Yes, but with a coverage constraint. We apply soft-touch coating at 3–5 g/m² dry weight as the base, then register spot UV at ±0.3mm over selected elements. To avoid curl from differential tension, we recommend keeping spot UV coverage below 35% of the total face area. If your design requires higher UV coverage, we’ll recommend switching the base to gloss lamination with selective matte coating instead.
Q5: What causes seal failures on powder sachets during filling, and how do you prevent them?
A: The most common cause is an undersized PE seal layer — we see this frequently when brands source laminates specified for display rather than filling-line use. For powder sachets filled on vertical form-fill-seal (VFFS) equipment, we specify a minimum 60µm PE seal layer and run heat-seal parameters at 160–180°C, 0.3 MPa, 1.0–1.5 seconds. We also validate seal strength at ≥25 N/15mm per ASTM F88 on production samples before approving a new laminate for a filling-line run.
Planning a flat pouch or sachet project? Contact our team to request a complimentary specification review and sample quote.
We had seal failures on a 12µm PET / 7µm Al foil / 60µm PE sachet run for a single-serve protein powder client — about 3–4% of units were failing peel tests at the bottom gusset seal, well outside the ≤1% threshold we’d agreed on. Took us almost two weeks to isolate it: the PE sealant layer had been substituted mid-production run by the converter without notification, slightly different melt index, and our dwell time hadn’t been adjusted to compensate. The foil construction was fine, barrier numbers were clean — it was purely a thermal bonding issue that the OTR/WVTR specs couldn’t catch.
The 7µm foil callout is accurate but doesn’t mention how brittle that gauge gets on tight corner radii — we had a run of 50ml single-serve spirit sample sachets where the foil was delaminating at the bottom seal corners after about 3 weeks in ambient storage, and it traced back to the bend radius on our pillow-pouch former being too aggressive for anything under 9µm.
Switched our single-serve collagen sachet from BOPP/PE to the PET/foil/PE construction about 18 months ago after a humidity issue in our 3PL warehouse in New Jersey was causing seal failures. Our Shenzhen supplier had to recalibrate their heat-seal dwell time from 0.8s to 1.1s to get consistent bonds on the thicker laminate — took four sample rounds but WVTR came back at 0.3 g/m²/day on the final validation, which finally put the issue to bed.
The 80µm PE seal layer in that table is fine for most powder applications but we found out the hard way it’s not enough for oil-based hot-fill — running a 85°C chilli sauce sachet on our Totani FBM60, the seal layer was softening under dwell pressure and we were getting weak seals on roughly 6% of units. Had to move to a 100µm cast PP heat-seal layer before the line stabilized.
Ran into a structural issue that wasn’t barrier-related at all — we were producing 8ml single-serve whisky taster sachets for a distillery client in Speyside, and the 12µm PET outer layer we’d spec’d was developing micro-cracks along the score lines after about 3 weeks in cold storage at the fulfilment centre (around 4°C). The print layer was separating with it, so by the time units reached consumers the front panel looked like cracked varnish. Turned out the PET we’d pulled from stock had been sitting since a previous run optimised for ambient-fill, and nobody had flagged the flexural fatigue risk at low temp for a pouch with that aspect ratio.
Worth noting on the PE seal layer thickness — we moved from 60µm to 75µm on a single-serve instant soup sachet (approx. 8g fill weight, fine particulate) after seeing burst pressure failures drop below our internal 300 mbar minimum on roughly 2% of pouches off a Totani BH-60. The extra 15µm made a measurable difference; burst averages came back up to 380–410 mbar with no other changes to the line settings.
Does the 60µm PE seal layer hold up on liquid or oil-based single-serve fills at elevated fill temperatures, or do you spec a different sealant resin — mLLDPE or ionomer — when the contents aren’t a dry powder?