--- title: "Pre-opened bags on a roll for autobag machines: when and why | JMP" description: "Pre-opened LDPE bags on a roll for autobag machines on automated assembly lines — how they differ from an ordinary polybag, when they make sense, and why they're custom." url: "https://jayamandiripackaging.com/en/articles/pre-opened-bags-on-a-roll" language: "en" alternates: - { language: "id", url: "https://jayamandiripackaging.com/id/artikel/pre-opened-roll-bag-untuk-mesin-autobag" } --- 1. [Home](https://jayamandiripackaging.com/en) 2. [Articles](https://jayamandiripackaging.com/en/articles) 3. [Polybag](https://jayamandiripackaging.com/en/articles/category/polybag) # Pre-opened bags on a roll for autobag machines: when and why By Ezra Andhika · Operational Director, PT Jaya Mandiri Packaging · July 8, 2026 ![A JMP pre-opened roll bag pulled from the roll — the perforation and the already-open mouth an autobag machine needs.](https://jayamandiripackaging.com/photos/moments/roll-bag-2024/02.webp) If your assembly line bags thousands of parts a shift, an operator opening each bag by hand is waste you don’t see — until you count the seconds per bag and multiply by daily volume. That’s where an **autobag machine** (auto-bagger) comes in. It picks, opens, fills and seals bags automatically. But an autobag machine can’t run ordinary polybags. It needs **pre-opened bags on a roll**: bags already open at the mouth and joined in sequence on a roll, so the machine can pull them one after another with nobody opening anything by hand. ## How they differ from an ordinary polybag An ordinary polybag arrives as separate loose bags with the mouth closed — right for manual packing. A pre-opened roll bag is built differently: * **Already open** at the mouth, ready for the machine to fill. * **Joined on a roll** with perforations, so the machine can pull and break off one bag at a time. * **Dimensionally exact** to the machine’s spec — width, length, thickness and perforation pitch all have to be right, or the machine jams. That is why pre-opened roll bags are almost always **custom**: made for one machine-and-part combination, not picked off a stock size. ## When it makes sense * An automated line with high volume and consistent parts. * Bagging speed you need without adding operators. * Packaging consistency that has to survive an automotive customer’s audit. If your volume is small or your parts vary a lot, ordinary manual polybags are still cheaper. Pre-opened roll bags only win once automatic speed and consistency are a real requirement. ## Why the source matters In Indonesia most plastic bag makers produce ordinary roll bags — the tear-off type for waste or retail — not pre-opened bags for autobag machines. What is usually left is importing: from the autobag machine brand itself, or an exporter abroad. JMP is among the few makers in Indonesia producing **pre-opened LDPE plastic roll bags locally**, built to your machine and part spec. ## Autobag systems we supply We produce pre-opened roll bags for a range of Autobag® systems, from tabletop to high-speed: * **Autobag® PaceSetter PS 125™ and PS 125 OneStep™** — tabletop baggers for hand-load applications: simple, flexible, suited to medium volume. * **Autobag® Brand 500** — high-speed automatic filling and sealing. Bag sizes from 2″×2.5″ up to 12″×20″ (to 36″ unsupported). * **Autobag® Brand 550** — high-speed with printing capability. Bag sizes 2″×5″ to 12″×20″, running up to **45 bags per minute**. Every roll bag is matched to your machine’s width, length, thickness and perforation pitch, so the machine runs without jamming. The full spec sheet is on the [pre-opened roll bag product page](https://jayamandiripackaging.com/en/products/polybag/pre-opened-roll-bag). Making them locally means two practical things: shorter lead times than importing, and specifications you can adjust without a container-load minimum. If your line runs an autobag machine and you have been relying on imported bags, there is a local option worth re-costing. Want to know whether your part and machine are a fit? [Send us the spec](https://jayamandiripackaging.com/en/contact) — we’ll help settle the material, thickness and perforation dimensions. Source: PT Jaya Mandiri Packaging (JMP) — carton box & polybag manufacturer for the automotive industry since 1990\. jayamandiripackaging.com Need a quote? Send your part spec or a photo — we price it first. [10-minute chat · WhatsApp](https://wa.me/6281384833969) JMP · automotive packaging since 1990 Share article [ WhatsApp ](https://wa.me/?text=Pre-opened%20bags%20on%20a%20roll%20for%20autobag%20machines%3A%20when%20and%20why%20%E2%80%94%20https%3A%2F%2Fjayamandiripackaging.com%2Fen%2Farticles%2Fpre-opened-bags-on-a-roll) ![A JMP operator working a corrugated sheet.](https://jayamandiripackaging.com/photos/hands-work.webp) Have a part to package? ## Send a spec — we price it first. A photo of the part and a rough monthly volume is enough to start. No technical drawing needed. [ 10-minute chat · WhatsApp ](https://wa.me/6281384833969) [‹ Previous](https://jayamandiripackaging.com/en/articles/ev-supply-chain-tkdn-packaging-checklist) — Joining the EV/TKDN supply chain: a packaging checklist for component suppliers [Next ›](https://jayamandiripackaging.com/en/articles/carton-box-flute-guide) — Carton box flute guide: B, C, E, and BC — how to choose ## See also [Custom PE/PP polybags](https://jayamandiripackaging.com/en/products/polybag) (Product) — 5–100 cm wide, 30–120 micron, flexo printed — MOQ is counted by the kilogram, not by the piece. [How to choose a polybag factory (and what to specify)](https://jayamandiripackaging.com/en/articles/how-to-choose-a-polybag-factory) (Polybag) — Not every supplier calling itself a polybag factory extrudes its own film. Three questions that separate them, and the spec you should have ready before you request a quote. [Polybag MOQ, and how many bags you actually get per 100 kg](https://jayamandiripackaging.com/en/articles/polybag-moq-per-kilogram) (Polybag) — Polybag MOQ is measured by weight: 300 kg unprinted, down to 100 kg for common specs, 200 kg printed. Plus the arithmetic for converting a tonnage into pieces. ## About JMP PT Jaya Mandiri Packaging has manufactured corrugated carton box and PE/PP polybag for the automotive industry since 1990 — with the Flex-Stock (VMI) program. ISO 9001:2015 certified; ISO 14001 in progress. [Flex-Stock (VMI) program](https://jayamandiripackaging.com/en/automotive-vmi) · [Products](https://jayamandiripackaging.com/en/products) · [About JMP](https://jayamandiripackaging.com/en/about) Have a question about your needs?[Get in touch](https://wa.me/6281384833969). --- Source: https://jayamandiripackaging.com/en/articles/pre-opened-bags-on-a-roll — Markdown rendering of the HTML page, generated at build time. 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