Mylar Heat Seal Bags

Mylar Heat Seal Bags with Optional Zip Reclosure

Start with how the pouch will be filled and opened. A flat heat-seal pouch may suit a product used in one go. For repeated access, choose a zipper design that leaves the zip usable after the first opening.

Agree whether your pouches will arrive top-open or bottom-open before ordering. Seams made during pouch production are separate from the final closure made after filling. The production drawing should identify both.

In a top-filled zipper pouch, the heat-seal area and tear path need to sit above the usable zip. Optional tear notches help customers start the opening at the intended point. Closing the zip afterwards does not restore the pack’s original sealed condition.

Film Choice Depends on the Contents

The material choices for custom Mylar packaging depend on what the product needs during storage and handling. Tell us if moisture, oxygen, aroma or light exposure is a concern. Sharp edges and handling demands also matter when selecting the film.

The name “Mylar” alone does not identify the pouch’s complete layer structure or sealing properties. Clear, black, white, metallic and kraft-faced appearances do not describe the full material either. Polyester film, metallised polyester and aluminium foil are different components; a metallic finish does not establish that a pouch contains foil.

Agree the full film construction and inner sealing layer, plus the total thickness of one pouch wall in microns, including the permitted variation. Thickness alone does not prove barrier performance. Claims about oxygen or moisture protection need evidence relevant to the specified material and finished pack.

For food use, provide the food type, filling temperature, expected storage conditions and contact duration. Suitability documents need to cover the actual construction, including relevant inks, adhesives and coatings.

Pouch Dimensions and Usable Fill Space

Specify width × height, adding gusset depth where applicable, and state the units. Confirm whether the gusset measurement means its full opened depth. External dimensions include areas that cannot be filled, such as seams, the zipper and the sealing header.

A 100 g powder and a 100 g snack can need different pouch volumes. Allow for settling, enough opening width for filling and clear space to make the final seal.

Where fit is uncertain, arrange a representative trial fill before committing to the dimensions. A trial fill checks capacity and loading; a separate sealing trial checks the proposed film on your equipment.

For upright shelf display, consider pouches with an expanding stand-up base. Side-gusset formats provide a different shape and do not automatically stand upright. Check the chosen format with its intended fill.

Sealing Settings Depend on Film and Equipment

Share your sealer details and packing method when discussing the specification. Equipment must suit the material, seal length and combined thickness of the layers being joined. An impulse, constant-heat or band sealer is not a guaranteed match simply because it can seal some plastic bags.

Establish settings with the pouch and equipment suppliers using the actual construction. Heat, pressure and sealing time work together; cooling time or conveyor speed may also matter. There is no single temperature setting for every pouch.

Keep powder, crumbs and oil out of the sealing area, and avoid folds or wrinkles between the jaws. A seal can look neat and still leak. Assess the filled pack under its intended handling and storage conditions; appearance alone does not establish seal performance or shelf life.

Print Placement on the Filled Pouch

We supply plain pouches and printed heat seal bags, including limited-colour and full-colour options. Specify your preferred matt or gloss appearance alongside the print requirements. On clear or metallic backgrounds, discuss whether a white ink layer is needed beneath the design.

The agreed pouch template sets the layout for your artwork. Keep text, barcodes and batch-coding areas clear of seals, zipper positions and gusset folds. Review how the layout will look when the pouch is filled.

Position any hanging hole in a header area outside the sealed product compartment, with enough surrounding material to support the filled pouch.

If you want a window, agree its material and location before finalising artwork. The window can change light and barrier protection, so assess visibility alongside the product’s storage requirements.

Artwork Approval, Production and Repeat Orders

List quantities separately for each size and artwork version. We offer a free artwork check. Upload reference images through the quote form, then email print-ready PDF, AI or PSD artwork to sales@healeypackaging.co.uk with your enquiry reference.

Keep the approved film, dimensions, opening and closure details with the artwork version for repeat orders. Retain the validated sealing settings with the machine details, and review them if the film construction or equipment changes. Agree any additional design work, tooling or sample costs in the quotation.

Production takes 7–10 working days after artwork approval; transit is separate. Delivery of your empty pouch order is free across the UK and USA, including all US states. Healey Packaging covers applicable import duties and taxes.