Mylar bags are multilayer polyester pouches made from BOPET, often laminated for barrier protection against oxygen, moisture, and light, and used widely in food, cannabis, and pet food packaging. They can include features like resealable zippers, child-resistant closures, and vacuum seals. Two digital printing technologies, liquid electrophotography and piezoelectric inkjet, are used to print on Mylar, each offering high-resolution printing, white underlays, and variable data capabilities. The digital printing process involves six key steps: substrate pretreatment, optional primer application, ink deposition, curing/fusing, protective lamination, and final converting/finishing. Digital printing offers major benefits, including short-run flexibility, fast lead times, variable data printing for traceability, and reduced prepress waste. It is ideal for applications like food, cannabis, nutraceuticals, cosmetics, and industrial packaging, particularly where SKU changes and personalization are frequent. Compared to traditional methods like flexo and gravure, digital printing reduces setup time and costs but has higher per-unit ink costs; break-even points typically fall between 5,000–25,000 units, depending on job complexity.
What are Mylar bags?
Mylar bags are flexible, multilayer polyester pouches that block oxygen, moisture, and light to protect products and extend shelf life. They are made from biaxially oriented PET (BOPET), often metallized or laminated to a heat‑seal layer such as LDPE; total laminate thickness commonly ranges 80–200 µm. Typical uses include food packaging, coffee bags, pet food bags, and child‑resistant cannabis pouches (examples: stand‑up pouches, flat heat‑seal pouches). Common features include resealable zippers, vacuum sealing, and optional child‑resistant closures; converters add accessories during pouch forming, such as zipper insertion, tear notches, and induction liners.
Which digital printing technologies apply to Mylar Bags?
There are two digital printing technologies that are applied to Mylar bags, which are electrophotographic liquid-toner systems and industrial piezoelectric inkjet systems.
1. Electrophotographic Liquid-toner
Electrophotographic presses deposit a liquid toner layer and fuse that layer by heat or radiant energy. They produce dense solids and consistent color across long runs. They run in roll-to-roll formats for flexible laminates such as metalized PET and foil laminates. The liquid toners contain high-opacity pigments and require white-ink management, including recirculation and scheduled white passes, to maintain opacity. Converters usually add a post-print lamination to restore barrier properties and to separate printed ink from product contact.
2. Industrial piezoelectric inkjet
Industrial piezoelectric inkjet presses use piezoelectric printheads and UV-LED inks in single-pass or multi-pass modes. They print at typical drop sizes of 4–30 pL and at resolutions commonly between 600 and 1,200 dpi. Printers lay inline white underlays under CMYK where they print on metallized or transparent films. These presses print variable data natively, for example, lot codes, QR codes, and serialized identifiers, which simplifies traceability and personalization.
Digital presses produce a range of bag types, for example, Mylar bags, coffee bags, kraft paper bags, pet food bags, vacuum-seal bags, compostable and recyclable pouches, and child-resistant bags. Printers select the digital method based on run length, color complexity, white-ink requirements, and finishing needs such as lamination, zipper insertion, or spout attachment.
What is the Process of Digital Printing for Mylar Bags?
Production workflow for digital printing on Mylar bags is a six-step roll-to-roll sequence: substrate pretreatment, optional primer, ink deposition, curing or fusing, protective lamination, and converting.
Substrate pretreatment
Increase surface energy to ≥38 mN/m using corona or plasma; remove oils, dust, and release agents by wipe or air‑knife, and log surface‑energy rea
dings before press load. Measure with a Dyne test or contact‑angle goniometer; target 38–46 mN/m for inkjet and liquid‑electrophotography substrates. Record pretreatment settings (power, web speed, electrode gap) for reproducibility across runs and across ASUWANT product lines, such as compostable, biodegradable, and recyclable bags.
Primer application (optional)
Apply a solventless or low‑VOC primer when adhesion or print uniformity is marginal; target coating weights of 0.5–3.0 g/m² depending on primer chemistry and substrate. Dry to specification and log dryer temperature and dwell time; verify adhesion via cross‑cut and tape tests on sample strips. Choose primers certified for compostability, if a compostable laminate is used, and include primer chemistry and lot number in the job ticket.
Ink deposition
Print with piezoelectric inkjet or liquid electrophotography; deposit white underprint as a separate spot channel beneath CMYK for metallized or clear films. Target 600–1,200 dpi and drop sizes 4–30 pL for photographic detail; schedule white‑pass recirculation and opacity checks and reduce speed, if opacity or dot stability falls below spec. For variable‑data jobs supply locked templates and test data to confirm registration of lot codes, QR codes and serialization fields.
Curing or fusing
Cure UV‑LED inks inline or thermally fuse liquid toners; confirm absence of surface tack with a thumb rub or tack test and measure cure energy with a radiometer. Adjust lamp output or line speed to correct incomplete cure and allow printed web to cool before lamination to avoid seal distortion. Document cure settings (LED mW/cm² or fusion temperature and dwell) and include cure‑check results in the press log.
Protective lamination
Apply wet adhesive, solventless, or extrusion lamination to isolate printed inks from product contact and to restore barrier and heat‑seal functionality. Select adhesive compatible with the ink and downstream sealant layer (examples: solventless polyurethane, water‑based acrylic) and verify laminate bond via peel tests (N/15 mm). Re‑measure OTR and WVTR on laminated samples to confirm shelf‑life targets and attach the barrier test report to the job file.
Converting and finishing
Slit, gusset, form pouches, insert zippers or spouts, and set heat‑seal parameters per sealant specifications; define slitting tolerances (±0.5 mm typical) and dwell/pressure values for each seal bar. Execute QC tests on pilot runs: adhesion cross‑cut, rub resistance (Crockmeter), seal‑strength (N/15 mm), and barrier sampling (OTR, WVTR). Archive converting parameters and QC results for each SKU so production settings reproduce across ASUWANT product lines, such as Mylar bags, coffee bags, and child‑resistant pouches.
What are the Benefits of Digital Printing for Mylar Bags?
Digital printing reduces time to market and enables SKU proliferation while imposing constraints on special-effect reproduction and per‑unit ink expense at larger volumes.
Short‑run flexibility
Digital printing supports short runs from ~100 to 25,000 units, making limited editions, seasonal SKUs, and test‑market batches practical. Converters can produce region‑specific artwork, promotional releases, and small batches of ASUWANT products (examples: compostable pouches, biodegradable coffee bags, recyclable Mylar samples) without plate setup; inventory and obsolescence decline.
Variable data and traceability
Digital printing prints unique serial numbers, QR codes, lot codes, and best‑before dates in the same pass. Submit CSV or database mappings and locked templates to print per‑unit serialization for anti‑counterfeit measures, supply‑chain tracing, and compliance panels (examples: serialized cannabis pouch lots, roast‑date coffee bags, batch‑coded nutraceutical sachets); this removes separate overprinting steps.
Faster lead times
Digital printing shortens lead time from weeks to days by eliminating plate and cylinder production. Proofs, press samples, and color adjustments move faster; SKU changeovers take minutes (examples: seasonal SKUs, regional SKUs) instead of hours, enabling quicker market tests and faster replenishment for small‑run ASUWANT product lines.
Lower prepress waste
Digital printing removes plate waste and cuts make‑ready sheet counts from the hundreds to single digits. Scrap material and plate disposal fall, lowering prepress cost and environmental impact for short runs (examples: small compostable bag runs, trial Mylar pouches); record reduced prepress cost per SKU and fewer landfill‑bound materials.
What applications and use cases suit digital printing on Mylar?
Digital printing on Mylar serves short- to medium-run packaging that requires frequent SKU changes, per-unit serialization, or rapid market tests.
Food packaging
Food packaging requires barrier protection, printed roast/best-by dates, and resealable features. Use metallized or laminated BOPET for oxygen and light barrier; apply white underprint for clear or metallized films. Typical run lengths range from ~100 to 25,000 units; examples of ASUWANT products include compostable and recyclable coffee bags.
Cannabis and edibles
Cannabis packaging demands child‑resistant closures, odor barriers, and compliant, serialized labeling. Print variable lot codes, QR links and multi‑language warning panels in-line. Converters use post-print lamination to separate inks from product contact and to meet regulatory traceability requirements.
Nutraceuticals and supplements
Nutraceutical pouches require batch codes, tamper-evident seals, and fast run changeovers for formulation shifts. Use high-opacity white and foil laminates for OTR control; print variable lot and expiration data directly to reduce separate overprint steps.
Cosmetics samples and single‑use pouches
Cosmetics samples demand photographic color, tight registration, and small-batch flexibility. Digital presses reach 600–1,200 dpi for photographic detail; apply UV-LED curing and thin laminates when product-contact safety requires it.
Pet food, vacuum-sealed, and industrial uses
Pet food and vacuum-seal bags require robust seals, high-opacity prints, and wide web handling. Use thicker laminates (80–200 µm) and verify seal strength (N/15 mm). ASUWANT lines include pet food bags and vacuum seal bags in recyclable and biodegradable formats.
Digital printing on Mylar reduces lead time and supports SKU proliferation across ASUWANT product families such as compostable, biodegradable, and recyclable bags.
Comparative analysis of digital vs. flexo/gravure/screen Printing
Digital printing removes plate setup and shortens lead times, trading higher per-unit ink cost for lower fixed setup costs; conventional methods incur higher make‑ready (plate/engraving) costs but lower incremental cost per unit at scale.
| Attribute | Digital (inkjet / L.E.P.) | Flexography / Gravure / Screen |
| Setup cost | Low (no plates); examples: immediate job changeover | High (plates/engravings); examples: plate production, cylinder engraving |
| Ideal run length | Short to mid runs (typical parity 5k–25k units) | Mid to long runs (economical above parity range) |
| Color fidelity | High photographic reproduction; extended-gamut tools available | High solids and spot-color accuracy; superior for large flat solids |
| Variable data | Native support (lot codes, serials, personalization) | Requires additional steps or overprinting |
| Metallics/specialty effects | Requires post-print foiling/varnish for true metallics | Direct metallic inks and in-line effects available |
| Turnaround | Days (no plate-making) | Weeks (plate-making and setup) |
Cost model and break-even considerations
Break-even between digital and conventional printing depends on fixed setup costs, variable ink/substrate costs, and finishing complexity; digital becomes cost-competitive for runs where plate and cylinder costs would otherwise dominate.
Total unit cost = (fixed setup cost + variable production cost) / run length. For conventional processes fixed setup includes plate/cylinder costs and press make-ready; for digital fixed setup is minimal, but variable ink cost per square meter is higher. Practical parity range commonly observed by converters lies between 5,000 and 25,000 units for flexible pouches, but actual break-even shifts with number of colors, required white ink passes, lamination requirements, and extensiveness of finishing (examples: foiling or embossing increases analog advantage for long runs).
