This custom flat bottom pouch with zipper is made from 150-micron compostable film. It has a flat rectangular base, folded side gussets and a resealable zipper top. We make it to your size and print your artwork on it. The minimum order is 1,000 pieces. Most customers use it for coffee, snacks, pet food and herbal products. BioPouches supplies custom packaging to brands around the world.

Flat Bottom Construction and Zipper

A flat bottom pouch has five parts: the front panel, the back panel, two folded side gussets and the base. The base lets the filled pouch stand on a flat surface. The gussets open as the pouch is filled. The corners are the difficult part. Several layers of film fold together there, and the seal has to cover the change in thickness. If the panels or folds are not aligned, the pouch comes out crooked.

Wrong dimensions are a common problem. Fill weight alone does not tell you the size, because the same weight of product can take up different space. We ask for the product and the fill weight, then check the dimensions before production.

The zipper has to sit in the right place. If it is too high, it gets in the way of the top seal. If it is misplaced or badly attached, the pouch does not close properly. The zipper does not keep the product fresh by itself. The film barrier and the seals matter more.

Material and Custom Printing

The film is compostable and listed at 150 microns. Compostable film usually has a narrower heat-seal window than normal PE-based film. Its oxygen and moisture barrier is usually lower than a high-barrier laminate. So seal settings need more attention, and shelf life has to be tested with your product. Coffee needs protection from oxygen and moisture, and the aroma must stay in. Freshly roasted coffee often needs a degassing valve, and a valve is not included unless you ask for it. Our coffee packaging page shows the coffee options. Snacks and nuts are mostly about moisture and fill volume. Pet food needs enough capacity and puncture resistance for the product shape. Herbal products need moisture and aroma protection. If you are not sure which film fits, read choosing the right food packaging.

Keep artwork away from the folds and the seal areas. Text too close to a fold gets distorted once the pouch is filled. Text too close to a seal can be cut or covered. We print by gravure, digital and flexographic printing, with equipment up to 10 colors, and which method suits a compostable film is confirmed for each order. Our article on the flexible packaging printing process explains the methods.

Manufacturing and Quality Checks

We cut the film first, and every fold and seal after that depends on the cut. Then the gussets are folded, the base is formed, the zipper is applied and the seals are made. Heat sealing depends on temperature, pressure and dwell time. The flat bottom corners need the closest control, because that is where a weak seal is most likely.

Production follows SOPs. Our QC team checks samples and finished pouches. The lab has an electronic tensile tester for film strength and a heat-seal tester for seal strength. It also has a coefficient of friction tester, which shows how the film slides on filling equipment, a leak and seal-integrity instrument, a temperature-controlled oven and a whiteness meter.

Inspection covers dimensions, base and corner alignment, zipper operation, seals and print registration against the approved sample. We also look for wrinkles and contamination on the surface. Visitors to the production area wear shoe covers and head covers and pass through an air shower. Equipment is cleaned daily. You can see the equipment in our factory photographs.

Specifications and Custom Orders