Four-Side Sealing Packaging Process

Four-Side Sealing Packaging Process

Four-Side Sealed Packaging is a type of three-dimensional flexible packaging bag with four vertical sealed edges. The bag body consists of front, back, and two pleated side panels. After packaging, the overall appearance is square and upright, offering good structural support, capacity performance, and display effectiveness on shelves.

What is four-sided sealing packaging?

Four-side sealed packaging （four-side-seal-packaging）This packaging process involves folding composite film material into a bag structure using a bag-making machine, and then heat-sealing the four vertical corners of the bag body to form a stable three-dimensional support structure.

It’s not an ordinary flat bag, nor a traditional one.Eight-Sided Flat Bottom BagThe four-sided sealed bag has the following characteristics:Four side seams are clearly sealed, the left and right pleats naturally unfold, and the bag body appears square or rectangular after filling.This structure ensures better stiffness and three-dimensional shape retention of the packaging after filling with coffee beans, tea, nuts, pet food, or powder products.

Advantages of Four-Side Sealing Packaging Process

The bag has a square body, offering good display effect.

Four-sided sealed bag packaging offers a neat appearance after packaging, with the bag body less prone to collapsing, making it suitable for shelf display, e-commerce product presentation, and brand packaging upgrades. The front offers a focused visual effect, and product information can also be displayed on the sides. 

Four-sided sealing, more stable structure

The four vertical edges of the bag body are heat-sealed, enhancing the package’s structural support and compressive strength. Compared to ordinary back-seal bags, four-sided sealed bags are more suitable for filling heavier or bulkier dry goods.

Better capacity performance

The side flaps of the winders can increase the thickness and capacity of the bag, making it suitable for packaging products such as coffee beans, tea, nuts, pet food, freeze-dried food, powders, and granules.

Multi-sided printed display

Four-sided sealed bags feature multiple display areas on the front, back, and both sides, allowing for printing of brand logos, product names, key selling points, nutritional information, barcodes, usage instructions, and more, making them suitable forBrand Packaging Design。

Can be combined with multiple functions

Depending on product requirements, additional features such as resealable zipper, easy-tear notch, one-way exhaust valve, transparent window, hanging hole, matte film, localized gloss varnish, and foil stamping can be added to enhance packaging functionality and brand sophistication.

Four-Side Sealing Packaging Parameters Introduction

The following are the common technical parameter ranges for four-side sealing packaging. They can be customized according to your product requirements.

Parameter Dimensions Specification Range / Options Description
Dimensions Specifications
Bag Width (Front Width) 60 – 300 mm Customizable based on net weight, filling volume, and front display requirements
Bag Height (Front Height) 100 – 450 mm Suitable for packaging coffee, tea, nuts, pet food, powders, and dried goods.
Side Panel Width 30 – 100 mm The side flaps of the winders determine the thickness and capacity of the bag, which can be adjusted according to the load.
Four-side sealing width 5 – 15 mm Four vertical heat-sealed edges enhance bag body support, making the packaging more square and upright.
Bag body thickness 80 – 180 μm Select different thicknesses based on product weight, moisture barrier requirements, and transportation strength.
Material Combinations
Economic Type PET/PE、BOPP/PE、BOPP/CPP Suitable for packaging ordinary snacks, dried goods, powders, and lightweight products, with relatively low cost.
Standard Barrier Type PET/VMPET/PE、BOPP/VMPET/PE Suitable for moisture-proof and light-protected products such as coffee, tea, nuts, freeze-dried foods, etc.
High barrier type PET/AL/PE、PET/AL/NY/PE Suitable for packaging of food and powder products with high requirements for moisture-proofing, oxygen barrier, light protection, and aroma preservation.
Puncture-resistant PET/NY/PE、PET/PA/PE Suitable for products with high packaging strength requirements such as pet food, granulated food, nuts, freeze-dried food, etc.
Textured Type Matte film/AL/PE, kraft paper/AL/PE, kraft paper/VMPET/PE Ideal for packaging coffee, tea, nuts, and premium food products, enhancing brand sophistication
Printing and Surface Finishing
Printing Process Offset Printing, Digital Printing Offset printing is suitable for large-scale production, while digital printing is ideal for small batches, multiple designs, and proofing tests.
Print Color Count 1 – 10 Colors Customizable printed colors based on brand design, product series, and packaging style.
Print Area Front, back, left and right sides Four-sided sealed bags offer multi-angle display space, allowing full presentation of brand information and product features.
Surface Treatment Matte, Gloss, Partial Gloss, Gold Stamping, Aluminum Foil, Paper-like Finish Choose different textures based on packaging positioning for coffee, tea, pet food, or premium snacks.
Functional Accessories
Zipper / Self-adhesive Strip Optional Suitable for multiple-opening packaging of coffee, tea, nuts, pet food, and powder products
Easy-tear notch Optional (U-shape / V-shape / Straight) Enhances consumer opening experience, often used in conjunction with zipper structures
One-way Exhaust Valve Optional Suitable for coffee bean packaging, allowing release of internal gas and reducing entry of external air
Clear Window Optional (Round / Rectangle / Irregular Shape) Suitable for packaging of products that require product visibility, such as tea, nuts, grains, pet food, and snacks.
Mounting hole Optional Suitable for small retail packaging and hanging display scenarios
Applicable Scenarios
Coffee Packaging Coffee Beans, Coffee Powder, Single-Serve Coffee Filters Outer Bags Can be paired with high barrier materials and one-way exhaust valves to enhance aroma retention and display appearance.
Tea Packaging Tea, Flower Tea, Bagged Tea Outer Packaging Optional aluminum foil or metallized composite film can enhance moisture-proof, light-blocking, and aroma-retaining effects.
Food Dry Goods Packaging Nuts, snacks, freeze-dried foods, grains, and miscellaneous grains The bag has a square body and excellent capacity, making it suitable for e-commerce and supermarket shelf displays.
Pet Food Packaging Pet treats, freeze-dried pet food, pellet food Optional puncture-resistant composite film can enhance packaging strength and transportation stability.
Powder Packaging Protein powder, meal replacement powder, seasoning powder, nutritional powder Can be paired with a zipper and high barrier material, allowing for multiple uses and reducing moisture exposure.
Business Parameters
Minimum Order Quantity (MOQ) Offset: 5,000 – 10,000 pieces; Digital: 500 – 1,000 pieces Minimum order quantity will be adjusted based on size, material, printing process, and order quantity.
Sample lead time Digital proof: 3 – 5 days; Print proof: 5 – 7 days Recommend confirming the bag structure, capacity, sealing effect, and print color before mass production.
Delivery Lead Time First order: 15 – 25 days; reorder: 10 – 15 days The specific cycle is determined by the order quantity, material inventory, printing process, and production schedule.
Customization Instructions Customize based on provided designs, samples, or dimensions We can provide packaging solutions based on product weight, capacity, shelf life requirements, and brand design.

Common applications of four-side sealing technology

Coffee Packaging

Four-sided sealed bags are suitable for packaging coffee beans and coffee powder. The bag has a square shape, offering good display effects. It can be paired with a one-wayVentilation valve and high barrier composite film, helping to preserve coffee aroma and enhance brand display effects.

Tea Packaging

Tea has high requirements for moisture-proofing, light protection, and aroma preservation. Four-sided sealed bags can be used with aluminum foil or metallized composite films, making them suitable for packaging loose tea, flower tea, and tea bags.

Nut and Snack Packaging

The four-sided sealed bag offers excellent capacity performance with a firm and upright bag body, making it suitable for packaging nuts, dried fruits, freeze-dried foods, expanded snacks, candies, and other snacks. It can be paired with a transparent window to display the contents.

Pet Food Packaging

Pet food is typically heavy, and granular or freeze-dried products require certain packaging strength. Four-sided sealed bags can choose puncture-resistant composite films such as PET/NY/PE to enhance packaging stability and transportation safety.

Powder and Dry Goods Packaging

Protein powder, meal replacement powder, seasoning powder, nutritional powder, grains, and mixed grains can be packaged using four-sided sealed bags. The bag has a square shape, stable capacity, and can be paired with a zipper structure for convenient multiple openings and storage.

Difference Between Four-Side Sealed Bags and Other Bag Types

Bag Type Structural Features Suitable Products
Four-sided sealed bag Four vertical side seams, flapped sides on both sides, square and upright bag body Coffee, Tea, Nuts, Pet Food, Powder, Dried Goods
Eight-Side Sealed Bag Flat-bottom self-standing, with more complete front, back, side, and bottom structures Coffee, pet food, freeze-dried food, premium snacks
Ziplock Bag A longitudinal seal is located in the center of the back, commonly used for automatic packaging. Candies, bread, ice cream, small hardware items, daily necessities
Three-side sealed bag Three-sided heat seal, flat bag body, non-stand-up Seasoning Packs, Masks, Wet Wipes, Small-Sized Food Products
Stand-up pouch Bottom standable, with optional zipper or suction cup Snacks, liquids, personal care products, pet food

Four-Side Sealed Packaging Case