Custom T shirt Bags

T-shirt Plastic Bags Wholesale

T-shirt zipper bags are a widely used packaging product, named after their unique zipper closure design. Thanks to their convenient opening and closing mechanism and excellent sealing properties, they have significant applications in various industries.

Materials:

Common materials for zipper bags include polyethylene (PE), polypropylene (PP), and polyester (PET). PE is soft and flexible, often used for packaging food and daily necessities; PP has a higher hardness and better transparency, suitable for products requiring higher aesthetic standards; PET offers excellent barrier properties and strength, commonly used for products requiring long-term preservation or those with high demands for moisture and oxidation resistance.

Applications:

Zipper bags can be used for packaging food, such as nuts, candy, coffee beans, etc., effectively maintaining the freshness and flavor of the products. They are also used for daily necessities packaging, such as cosmetics, toiletries, and more. Additionally, they can be used for industrial products, stationery, and other items, meeting various customer needs.

Zipper Pull Zipper Bags

Zipper bags come in various shapes, including three-side seal zipper bags, four-side seal zipper bags, and stand-up zipper bags. The three-side seal zipper bag is the most common, with three sealed sides and a zipper on top. The four-side seal zipper bag seals all four sides, providing a larger space. The stand-up zipper bag features a special bottom structure that allows it to stand upright, making it easy to display and store.

Zipper Bag Manufacturing Process

- Co-extrusion Blown Film Process:

This method uses a multi-layer co-extrusion blown film machine to extrude different plastic materials simultaneously, creating a multi-layer film. This process improves the overall performance of zipper bags, such as barrier properties, strength, and flexibility. For instance, the outer layer may use a material with good printability, while the inner layer may be made from a material with excellent heat-sealing properties.

- Solvent-Free Lamination Process:

For zipper bags requiring multi-layer structures, the solvent-free lamination process is commonly used. This process bonds two or more films using a solvent-free adhesive at room temperature. Compared to traditional solvent-based lamination, this method is more environmentally friendly and results in better peel strength and hygiene performance of the laminated film.

- Zipper Injection Molding Process:

For high-end zipper bags or those with specific zipper performance requirements, the zipper injection molding process is used. In this process, plastic pellets are injected into molds to form the zipper, which is then integrated with the edges of the bag, ensuring a more secure attachment and stable zipper performance.

- Laser Cutting Process:

During bag production, laser cutting can be used to precisely trim the edges of the bags, making the cut edges neater and smoother. This also reduces thermal deformation of the film, improving the overall bag quality.

Key Points in Bag Production

1. Ensure that the raw material film is free from leaks to avoid distortion of the heat-sealed edges after bag production, which could affect the bag’s appearance.

2. Choose the appropriate heat-seal settings, ensuring clean sealing areas and checking the heat-seal knife and insulation fabric for proper condition.

3. Adjust key process parameters, including temperature, pressure, and time (speed), to achieve optimal heat sealing results. These are crucial for ensuring strong and secure seals.

Throughout production, it’s essential to continuously check the quality of finished products. In addition to inspecting dimensions and visual appearance, checks for seal strength and sealing performance should also be conducted. Problems should be promptly addressed, and detailed records should be kept.

For three-side seal zipper bags, the following should be checked:

- Bag dimensions, smoothness, appearance quality, alignment of the front and back, and compliance with any additional customer specifications, such as tear notch placement.

- The alignment of the zipper, especially at the connection section.

- Seal performance, which can be checked by spraying a dye solution into the seal area to see if it penetrates, or by filling the bag with water and hanging it upside down for 24 hours to check for leaks.

- Zipper alignment at the sealing area.

Heat-sealing technology is a simple process, but many factors can affect its quality. These include the peel strength of composite films, the heat resistance of printed inks, the migration of additives in the heat-seal layer, the width of the heat-seal, and the uniformity of the composite film’s thickness. These factors should be carefully considered during production to ensure the final product's quality.

For custom zipper bags, it's essential to work with a reliable, high-quality manufacturer to ensure your packaging is up to standard, minimizing after-sale issues. Partnering with a reputable zipper manufacturer will save you time, effort, and money! LIJIE in China is your best choice.