Three common problems with stand-up pouches, and how Shunxingyuan solves them

Stand-up pouches are now widely used in packaging for clothing, fruit juice drinks, sports drinks, bottled drinking water, suckable jelly, and condiments, among other products. Beyond the clothing and food industries, their use is also gradually increasing in products such as detergents, daily cosmetics, and pharmaceuticals. A stand-up pouch is a flexible packaging bag with a horizontal support structure at the bottom, allowing it to stand upright without any support, whether opened or unopened. However, stand-up pouches are prone to various quality issues during production, affecting not only product quality but also sales. Below, Shunxingyuan Packaging, a professional flexible packaging manufacturer, will discuss the various problems that can occur with stand-up pouches.

There are three common problems with stand-up pouches: leakage during use, uneven pouch shape during bag making, and asymmetrical bottom sealing.

1. Stand-up Pouch Leakage

The main causes of stand-up pouch leakage are the choice of composite materials and the heat sealing strength.

（ 1 ） Material Selection

The choice of materials for stand-up pouches is crucial for leak prevention, aiming to improve the peel strength between the outer layer and the intermediate barrier layer, and the barrier layer and the heat-sealing layer, as well as the heat-sealing strength of the pouch. Therefore, the surface tension of the composite surface of the film must be greater than 38 dyn/cm; the low-temperature heat-sealing performance of the inner heat-sealing film must be good, and the surface tension of the heat-sealing surface must be less than 34 dyn/cm; in addition, inks with good bonding properties, high-solid-content, low-viscosity adhesives, and high-purity organic solvents should be selected.

（ 2 ） Heat Sealing Strength

Low heat sealing strength is also a major factor affecting leakage in stand-up pouches. When heat sealing, the matching relationship between heat sealing temperature, heat sealing pressure, and heat sealing time must be adjusted. It is particularly important to explore the heat sealing temperature for different pouch structures, as different types of plastic films have different melting points and therefore different heat sealing temperatures; the heat sealing pressure should not be too high, and the heat sealing time should not be too long, to avoid macromolecular degradation and the heat sealing layer being sheared by the heat sealing knife in the high-temperature molten state, reducing the sealing strength. In addition, the four-layer sealing at the bottom of the stand-up pouch is the most critical part, and the heat sealing temperature, heat sealing pressure, and heat sealing time must be determined after sufficient testing.

In actual production, leakage tests should be conducted on stand-up pouches according to the requirements of the contents. The simplest and most practical method is to fill the bag with a certain amount of air, heat-seal the mouth of the bag, place it in a basin of water, and squeeze different parts of the bag by hand. If no bubbles escape, the sealing of the bag is good; otherwise, the heat sealing temperature and pressure of the leaking part should be adjusted immediately. Stand-up pouches containing liquids require even more careful attention. Leakage can be tested using squeezing and drop methods. For example, a certain amount of water can be filled into the bag, the mouth sealed, and then tested according to GB/T1005-1998 pressure resistance test method. The drop test method can also refer to the above standard.

  2. stand-up pouches Uneven Pouch Shape

Flatness is one of the indicators for evaluating the appearance quality of packaging bags. In addition to material factors, the flatness of stand-up pouches is also related to heat sealing temperature, heat sealing pressure, heat sealing time, and cooling effect. Too high a heat sealing temperature, too high a heat sealing pressure, or too long a heat sealing time will cause the composite film to shrink and deform. Insufficient cooling will result in insufficient setting after heat sealing, failing to eliminate internal stress, causing wrinkles in the bag. Therefore, the process parameters should be adjusted, and the normal operation of the cooling water circulation system should be ensured.

  3、 Poor Symmetry of Stand-up Pouches

Symmetry not only affects the appearance of stand-up pouches but also their sealing performance. The most common asymmetry in stand-up pouches is often found in the bottom material. Due to improper control of the bottom material tension, the bottom circular hole may deform, or wrinkles may occur due to mismatching with the main material tension, reducing the heat sealing strength. When the bottom circular hole deforms, the material feeding tension should be appropriately reduced, and the waiting time should be increased during heat sealing to correct the deformation, so that the four layers at the bottom of the bag can be fully heat-sealed. In addition, asymmetrical pouch shape can also be related to photoelectric tracking, material feeding, cursor design, roller balance, and the synchronization of stepper motors or servo motors. This problem should be solved during specific operations according to different products and different bag-making equipment.

Dongguan Shunxingyuan Packaging Products Co., Ltd. is a professional flexible packaging manufacturer with strong R&D, design, and production capabilities. Our products are widely used in the clothing, food, chemical, home gifts, and hardware electronics industries. We have advanced production equipment and 19 years of rich experience in flexible packaging production. Our customers are located in many countries around the world. ADIDAS, AAPE, IZZUE, IT, and BRAINERD are some of our well-known partners. The company's main business scope includes the professional production of various types of plastic bags for the clothing, food, chemical, home gifts, and electronics industries. Such as color-printed multilayer composite center-sealed bags, three-side sealed bags, eight-side sealed three-dimensional bags, kraft paper bags, and other food packaging bags; clothing and apparel inner packaging bags; anti-static packaging bags; vacuum nylon bags; retort pouches; food roll film; aluminum foil bags; shampoo bags; ink cartridge bags; bone-attached zipper bags; stand-up zipper bags; composite header bags; PE/PP/PO plastic bags; PP/PE film packaging bags; stand-up pouches, and various other packaging products. Shunxingyuan Packaging undertakes various packaging bag orders and custom packaging bag designs. We also offer free design services. We sincerely welcome your inquiries, discussions, and guidance, and look forward to sincere cooperation with you! Custom order hotline: 135-4929-7179

Custom Order Notice

1. The minimum order quantity for custom-made packaging bags is 10,000 pieces. The larger the order quantity, the lower the unit price of the product;

2. Customers need to provide us with detailed information, such as the material, materials, size, and thickness of the packaging bag, so that we can provide an accurate quotation;

3. If customers need custom designs, they need to provide the manufacturer with design drawings (PDF, AI format). If no custom design is needed, Shunxingyuan Packaging, a professional flexible packaging manufacturer, can provide free design services for customers;

4. Production Time: Generally, the production time for orders less than 500KG is 3-5 days. For larger orders, the time will be negotiated based on the order quantity.

5. Sampling Fee: Packaging bag sampling generally takes 2-3 days. Customers with samples can send them directly to the factory, and the cost will be borne by the customer.

6. After-sales Service: For any packaging bags produced by Shunxingyuan Packaging, any quality issues will be resolved through mutual consultation.

7. Special requirements must be stated in advance (such as packaging and transportation methods).

Shunxingyuan Packaging produces Stand-up Pouches Exquisite workmanship, clear printing, superior quality, worthy of your trust!

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