Technical Specifications
- Material: Low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE)
- Thickness: 4.0 mil (0.004")
- Construction: Tubular with heat-sealed bottom
- Core size: 3" diameter with 1" diameter core plug holes
- Opening: Front slit for automatic loading
- Perforation: Back panel for easy bag separation
Compatible Packaging Equipment
Our pre-opened bags work with most automated bagging systems, including:
- Autobag® machines (AB 180, AB 255, etc.)
- PAC Machinery automated baggers
- Pregis systems
- Mini Pak'r and similar vertical form-fill-seal machines
Custom Options Available
Need something beyond our stock sizes? We offer custom pre-opened bags with:
- Custom sizes: Any width or length to fit your product
- Colors: Tinted or opaque films (blue, pink, amber, black, etc.)
- Printing: Up to 8-color process printing for branding
- Special features: Hang holes, headers, venting, zip closures
- Protective additives: UV inhibitors (UVI), VCI for corrosion protection
- Alternative materials: Anti-static, biodegradable, or specialty films
Custom orders typically ship within 4 weeks.
How to Order
- Select your size: Browse stock sizes above or request a custom size
- Choose quantity: Order by the case (quantities vary by size)
- Add to cart: Stock items ship within 24-48 hours
Frequently Asked Questions
What are pre-opened poly bags?Pre-opened poly bags are polyethylene bags wound on a roll with the front panel already slit open and the back panel perforated, so an automated bagging machine can index, load, and tear off each bag without an operator opening it by hand. They are also called auto bags, machine-ready bags, or bags on a roll. How thick is a 4 mil pre-opened poly bag and how much can it hold?A 4 mil bag is 0.004 inches thick — twice the wall of a standard 2 mil bag — and typically handles products in the 10 to 15 pound range. The extra thickness adds puncture and tear resistance for items with sharp edges, corners, or hardware, while staying clear enough to read a label through. What is the difference between pre-opened bags and regular poly bags?Pre-opened bags have a front slit and a back perforation and come on a roll for machine loading; regular lay-flat poly bags come flat in a case and must be opened and filled by hand. Pre-opened bags cost slightly more per bag but cut labor dramatically on any line running an automated bagger. Are 4 mil pre-opened poly bags food safe?Yes. These bags are made from FDA-compliant virgin polyethylene approved for direct food contact, which is why they are widely used for bakery items, produce, frozen foods, candy, and dry goods. What core size do these rolls use?Our standard roll uses a 3" diameter core with 1" diameter core plug holes, which fits most automated baggers. If your machine requires a different core diameter, we can produce the rolls to your specification as a custom run. Which bagging machines do pre-opened poly bags fit?They run on most automated bagging systems, including Autobag machines such as the AB 180 and AB 255, PAC Machinery baggers, Pregis systems, and Mini Pak'r style vertical form-fill-seal equipment. Match the bag width and length to your machine's film path and product size. How many bags come on a roll?Bag count varies by size because roll diameter is fixed. Smaller bags such as 4x6" can run 2,000 or more per roll, while larger bags such as 12x18" hold far fewer. The exact count per roll and per case is listed on each individual product page above. Can pre-opened poly bags be custom printed?Yes. We print up to 8 colors with your logo, product information, barcodes, or handling instructions. Custom printed pre-opened bags require a minimum order quantity and typically ship about 4 weeks after art approval. Who uses 4 mil pre-opened poly bags?E-commerce and fulfillment operations, hardware and fastener packagers, apparel and textile shippers, electronics assemblers, and food processors use 4 mil pre-opened bags. They are the standard choice when a lighter 1.5 or 2 mil bag will not survive the product or the shipping environment. Related Products
Looking for other automated packaging solutions? Check out our:
|
