Clean look
No stitch lines, needle holes or frayed edges, so the bag looks neat and your print stands out.
As a supplier, EcoLeaderPack supplies high-volume, stitch-free ultrasonic packaging from fully automated ultrasonic welding lines, with ultra-low unit costs and rapid global fulfillment.
Ultrasonic heat-sealed non-woven bags are made from spunbond polypropylene (PP) fabric. Instead of sewing, the machine uses ultrasonic heat and pressure to weld the side seams, bottom and handles. The result is a clean, flat edge with no needle holes and no loose threads.
Because the whole process runs on automated lines, these heat-sealed polypropylene carrier bags suit bulk orders well, from D-cut flat bags and W-cut vest bags to 3D box bags and laminated bags. The smooth, thread-free surface also gives your logo a clean area to print on.
No stitch lines, needle holes or frayed edges, so the bag looks neat and your print stands out.
Welded seams have no needle holes for water to seep through. Add lamination, and the whole bag wipes clean.
Automated lines keep size and seam quality steady across large orders and keep the unit cost low.
Welded seams spread the load along the edge, which helps stop the bottom and handle area from splitting in daily use.
EcoLeaderPack supplies five ultrasonic bag styles, all available in custom sizes, colors and prints. Start with what the bag will carry and where it will be used.
EcoLeaderPack prints ultrasonic non-woven bags with four methods. The right one depends mainly on two things: how many bags you need, and how detailed your artwork is. Ultrasonic sealing is how the bag is built, not how it is printed, so the welded body works with every method below.
Your artwork is printed on the inside of BOPP or CPP film first, then the film is heat-bonded to the fabric. Because the ink sits under the film, the print stays bright, does not fade, and wipes clean of water and oil. The film also makes the bag stiffer and steadier when loaded.
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The design is printed on transfer paper, then pressed onto the fabric with a heated roller at about 200°C. No plates are needed, and full-color photos and gradients come out clearly.
Quote Heat Transfer Printing
Send your artwork as a vector file (AI, PDF or EPS) with Pantone color codes. We confirm the print method, print area and number of colors before sampling.
Send Artwork for Review
EcoLeaderPack supplies both heat-sealed and sewn non-woven bags. The better choice depends on your budget, order size and how much weight the bag needs to carry.
| Heat-sealed | Sewn | Combined | |
|---|---|---|---|
| How it is made | Welded with ultrasonic heat, no thread or glue | Sewn with thread | Heat-sealed body, stitched handle base |
| Seams | Flat welded edge, no needle holes | Stitch line with needle holes | Welded body seams, stitched handle base |
| Cost | Lowest on large orders | Higher, more labour | In between |
| Load | Daily retail loads, about 5–10 kg depending on style and GSM | Heavier loads | Stronger handles than heat-sealed alone |
| Best for | Vest bags, takeaway bags, promotional and laminated bags | Special shapes, heavy-duty and long-life totes | Retail totes that need a clean look and strong handles |
A few simple checks help you avoid the most common quality problems with heat-sealed bags.
Some low-cost laminated bags are laminated first and then printed on top of the film. The ink sits on the surface, so the print can rub off after a few touches or wipes.
EcoLeaderPack prints on the inside of the film first, then laminates it to the fabric. The ink is sealed under the film, so it does not rub off or fade.
The point where the handle meets the bag takes most of the weight. If the bag will carry heavy items, ask for thicker, reinforced welds at the handle base; otherwise the handle can tear away at the root.
For heavier loads, EcoLeaderPack adds a folded, welded top hem and extra weld points at the handle base, and can add stitching there when needed.
Good virgin PP non-woven fabric has no sharp smell and no formaldehyde, which matters for bags that touch food or cosmetics. Fabric made from low-grade recycled material often smells, and can turn brittle and crack over time.
EcoLeaderPack uses virgin spunbond PP. We hold BSCI and OEKO-TEX Standard 100 certification; ask us for the certificate scope if your market needs it.
PP non-woven bags are reusable and can be recycled where local facilities accept polypropylene, but they are not biodegradable. Some markets also set a minimum fabric weight or a reuse rule for carrier bags.
Tell us your destination market, and we will match the GSM and documents to it.
Looking for full-color laminated totes or heavy stitched totes? Explore Custom Laminated Non-Woven Bags, Custom Non-Woven Tote Bags, or browse all styles in Custom Non-Woven Bags. If you need a bag that folds flat for shipping, see our foldable non-woven bags. For insulated styles, see our Custom Insulated Non-Woven Bags; for recycled-content styles, see our Custom RPET Non-Woven Bags; and for rigid structured styles, see our Custom Box Non-Woven Bags.
EcoLeaderPack's ultrasonic bags are produced on automated lines, in these steps:
With the right GSM, an ultrasonic seam handles everyday retail loads well. For heavy, long-life totes, a sewn or combined build is still the better choice. Tell us the load, and we will recommend the right build.
The D-cut opening is punched with rounded edges through a folded, welded top hem, and a higher GSM makes the handle area stronger. Let us know the load when you ask for a quote, so reinforcement can be agreed before sampling.
Automated lines need set-up time and material for calibration and knife alignment. The MOQ is 3,000 pcs for most styles and 5,000 pcs for W-cut vest bags.
Yes. Laminated printing suits full-color artwork on large orders, heat transfer suits full-color designs on small orders, and screen printing suits simple 1–4 color logos. See Custom Printing Options above.
No, PP non-woven is not biodegradable. It is made to be reused and can be recycled where facilities accept PP. D-cut and W-cut bags are widely used at supermarket checkouts, but whether they meet a market's carrier bag rule depends on its thickness or reuse requirement, so check it before ordering.
Both names are used for vest-style bags with built-in handles and side gussets. We supply them as one style.
Tell us the bag style, size, GSM and quantity, and we will reply with a quotation. All fields marked with * are required.