Understanding Fill-Formats: Open Zipper End (OZE) vs. Zipper Tamper Evident (ZTE)

ZipSeal™ reclosable bags are widely used for packaging consumer goods, from food products to electronics to medical devices. Most are produced with a “tamper evident” feature that clearly indicates when the package has been opened. The most popular format is a tear strip intended to protect contents until removed by the end user.

Reclosable zipper bags come in two fill-formats: OZE and ZTE.


OZE drawing

OZE stands for Open Zipper End, meaning that the bag is produced with seals on three sides and an open zipper end (like a plastic sandwich bag). They are commonly seen in supermarkets and convenience stores as the packaging of choice for food products. During production, OZE pouches can be zipped closed to prevent contents from falling out prior to being heat sealed, whereas a ZTE bag needs to be heat sealed immediately to prevent product loss or contamination.

Considerations:

1.) OZE bags are not tamper evident until the heat seal is applied above the zipper.

2.) Contents must pass through the zipper opening to fill the bag. This can slow packaging time, and is not recommended for highly delicate items, which could be damaged by the zipper, or fine powders, which could become trapped in the zipper.

* The OZE style is used on Stand Up Pouches where the bottom gusset eliminates the option to fill through the bottom.

OZE bag

ZTE drawing

ZTE stands for Zipper Tamper Evident, meaning that the bag comes sealed above the zipper and on the sides, leaving the end opposite the zipper open. The open end must be heat sealed directly after filling. The end user must tear open the tamper-evident strip above the zipper to access the product within.

This is the more efficient fill format. The pouch is quickly filled through the open "bottom,” then sealed immediately. Because ZTE bags are quicker to fill, they are the preferred format for large scale packaging production.

Considerations:

  • Zipper Tamper Evident bags can be filled more quickly because the zipper does not hinder the fill process
  • They are the better option for packaging delicate contents and powders because they are not filled past the zipper
  • They must be heat sealed almost immediately to keep contents inside and prevent contamination
ZTE bag

Both styles should be heat sealed. Zippers are a value-added feature for the end user, and should not be used as the closing method by the packager. This is especially important for food and pharmaceutical applications, for which product safety is a paramount concern.

IMPAK produces both OZE and ZTE styles with a range of zipper profiles and materials. Contact us for the most appropriate format for your application.

Our ZipSeal™ Bags may be found here: ZipSeal™ Bags


More Options from IMPAK

Stand Up Pouches

Stand Up Pouches with ZipSeal

Stand Up Pouches, which have become a popular way to package food products, frequently feature ZipSeals™. These fall under the OZE zipper style because the pouch has to be filled through the top. Stand Up Pouches comprise a large portion of our custom orders and they can be produced in a range of sizes, with added features such as tear notches, windows, and spouts. See our Stand Up Pouches section for our stock items, or contact us for custom orders.

Heat and Vacuum Sealers

RapidSealer band sealer

IMPAK has a large selection of heat sealers and vacuum sealers. As a world leader in the industry, IMPAK supplies the highest quality sealers at affordable prices. Our band sealers can print lot codes or other critical information into the seal while achieving production throughputs of at least 1,000 pouches per hour. For a low cost/low volume solution, one of our dependable manually operated impulse sealers. See our Sealers page for more details and options.

ZipSeal™ is a trademark of IMPAK Corporation.