Applications and development of stand-up pouches in the flexible packaging industry, a must-read!

People's purchasing power for fast-moving consumer goods Continues to grow, and the fast-moving consumer goods market is developing rapidly of also drove flexible packaging industry's rise. Today, packaging bags types and uses are very extensive, and good packaging can also establish product of high-quality image, improve product of competitiveness, thus promoting product sales.

I. Types and application advantages of stand-up pouches

Stand-up pouches for clothing packaging

Stand-up pouches for hardware packaging

Stand-up pouches for food packaging

product packaging classification there are many ， If classified by technology, they can be divided into: moisture-proof packaging, waterproof packaging, mildew-proof packaging, fresh-keeping packaging, quick-frozen packaging, breathable packaging, microwave sterilization packaging, aseptic packaging, inflatable packaging, vacuum packaging, deoxygenation packaging, blister packaging, close-fitting packaging, stretch packaging, retort pouch packaging, etc. The above of various packaging bags are all made of different composite materials, and their packaging characteristics correspond to different product requirements, and can effectively maintain product its own quality and stable functions.

Stand-up pouches are considered a classic of modern packaging, and also a relatively novel form of packaging. In terms of enhancing product grade, strengthening visual effects on shelves, light carrying, ease of use, waterproof, moisture-proof, oxidation-proof and sealability, are occupies certain advantages. Stand-up pouches in types can be divided into ordinary stand-up pouches, spout pouches, stand-up zipper pouches, imitation spout pouches, and special-shaped stand-up pouches. 。 Mainly used in juice drinks, seasonings clothing and apparel, hardware and electronics, cleaning supplies cosmetics and other products 。

Products packaged in stand-up pouches are very convenient for consumers because it is plastic packaging ， bags, it has light weight and not easy to damage characteristics 。 In addition, with zippers /bone-shaped of stand-up pouches can be reused, spout stand-up pouches make food easier to pour out, and exquisite printing can help product attract consumers' attention.

Stand-up pouches are generally made of PET/ FOIL /PET/PE laminated structure, and can also have 2 layers 、 3 layers or other specifications and materials 。 Depending on the different products to be packaged, an oxygen barrier layer can be added as needed to reduce the oxygen permeability and extend the shelf life of the product.

Ordinary stand-up pouches and general stand-up pouches use a four-side sealing method, which cannot be resealed and reopened; stand-up pouches with spouts are more convenient for pouring or sucking out the contents, and can be resealed and reopened, which can be considered a combination of stand-up pouches and ordinary bottle mouths; imitation spout stand-up pouches combine the convenience of stand-up pouches with spouts and the low cost of ordinary stand-up pouches, that is, the function of the spout is achieved through the shape of the pouch itself, but imitation spout stand-up pouches cannot be resealed; special-shaped stand-up pouches are based on the traditional pouch shape according to product needs, various shapes of new stand-up pouches are produced through changes, such as waist design, bottom deformation design, handle design, etc.

II. Stand-up pouches often encountered three quality problems

Common sizes of stand-up pouches

1. Stand-up pouch leakage

The main reasons for leakage in stand-up pouches are the selection of composite materials and the heat sealing strength.

1. Material Selection

The selection of materials for stand-up pouches is crucial for leak prevention. The goal is to improve the peel strength between the outer layer and the intermediate barrier layer, and between 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 should be adjusted. In particular, it is necessary to explore the heat sealing temperature of different structured pouches, because different types of plastic films have different melting points and 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, which reduces the sealing strength. In addition, the four-layer sealing part 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 should be determined after sufficient experimental verification.

In actual production, leakage tests should be conducted on stand-up pouches according to the different requirements of the contents. The simplest and most practical method is to fill the bag with a certain amount of air, heat-seal the bag opening, place it in a basin of water, and squeeze different parts of the bag by hand. If no bubbles escape, it indicates that the sealing of the bag is good; otherwise, the heat sealing temperature and pressure of the leaking part should be adjusted in time. Stand-up pouches containing liquids should be treated with more caution. The squeeze and drop methods can be used to detect whether there is any leakage. For example, a certain amount of water can be filled into the bag, the mouth sealed, and the pressure resistance test method in GB/T1005-1998 can be used for detection. The drop test method can also refer to the above standard.

2、 Uneven Pouch Shape

Flatness is one of the indicators to measure 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 heat sealing temperature, too high heat sealing pressure, or too long heat sealing time will cause the composite film to shrink and deform. Insufficient cooling will cause insufficient setting after heat sealing, unable to eliminate internal stress, causing wrinkles in the bag, so the process parameters should be adjusted, and the normal operation of the cooling water circulation system should be ensured.

3、 Poor Symmetry

Symmetry not only affects the appearance of stand-up pouches but also affects 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 hole may deform or wrinkle due to mismatch with the main material tension, resulting in reduced heat sealing strength. When the bottom hole deforms, the material feeding tension should be appropriately reduced, and the waiting time should be increased during heat sealing to correct it, so that the four layers of the bottom can be fully heat-sealed. In addition, asymmetrical pouch shapes can also be related to photoelectric tracking, material feeding, cursor design, roller balance, and synchronization of stepper motors or servo motors. This problem should be solved during specific operations according to different products and different bag-making equipment.

III. Two Examples of Stand-Up Pouch Applications

1、 Irregular Shape Stand-up pouches Successful Application

Zipper /The function of the bone strip is also to facilitate multiple openings. However, the difference is that the method of repeated sealing is the zipper/bone strip, so this type of design is not suitable for sealing liquids, but for packaging some dry goods, such as: clothing, hardware accessories, candy, dried fruit, chocolate, biscuits, jelly, tea, etc.

Shunxingyuan Packaging is a supplier of hardware packaging bags for famous sub-brands such as Masco's LIBERTY, BRAINERD, and HOME DECORATORS COLLECTION. Shunxingyuan Packaging can deeply explore customer needs and reasonably design specific solutions for product packaging upgrades, truly enabling enterprises to achieve more convenient and safe product use, reduce costs, improve efficiency, enhance product aesthetics, and meet more environmentally friendly needs. Ultimately, customers are very satisfied with the hardware supporting packaging delivered to them.

2. Spout Stand-up pouches Successful Application

Now, people's living standards are constantly improving, and more and more people are accustomed to using laundry detergent instead of laundry powder for washing. Because laundry detergent is convenient and quick, it does not require repeated cleaning, saving time, effort, and water. Laundry detergent packaging mainly includes bag packaging and can packaging. ， Bagged laundry detergent packaging requires higher standards than ordinary soft packaging. The bag is strong degree ，resistance to liquid corrosion and penetration, and pressure resistance from heavy objects bearing capacity, drop resistance and scratch resistance properties ，transportation safety, and shelf display effect etc., are more stringent. 。

Laundry detergent packaging bags are color-printed composite structures, the most common specification 2 kg, there are the following two common structures:

PET12/PA15/PE120

PET12/PA15/FOIL5/PE100

For the above composite structure film material selection, biaxially oriented polyester PET and biaxially oriented nylon PA specifications and performance are standardized. Polyethylene PE is the key to the quality of laundry detergent packaging bags. A well-known brand of laundry detergent packaging bags uses Borstar bimodal polyethylene formula, which, compared with traditional polyethylene products, has the characteristics of high strength, burst resistance, impact resistance, good barrier properties, good rigidity and ability to stand upright, stress cracking resistance, and good sealing.

Most bagged laundry detergents use stand-up pouches. Adding a capped low-pressure polyethylene (HDPE) spout ， forms a bag with a spout. In addition to the advantages of easy opening and multiple sealing like bottled products, ， it also has the advantages of low packaging material consumption, high printing and packaging level, low packaging storage and transportation costs, and small garbage disposal volume. ， It is known as environmentally friendly packaging. According to statistics, compared with the same capacity, the material consumption of bags is lower than that of bottles Reduction of more than 30% in packaging, warehousing and transportation costs ， Reduction in garbage disposal volume More than 5 times 。