In the packaging industry, the core demands for food-grade packaging always lie in safety & compliance paired with practical adaptability. For 25kg food-grade plastic bags, this means ensuring not only safe transportation and storage but also maintaining the integrity of the food inside. Recently, we worked with a client who needed custom 25kg food-grade plastic bags. The entire negotiation process focused on requirement clarification, solution adaptation, sample validation
Case Details
. Initial Consultation
The client’s initial inquiry was straightforward: “We need PE plastic bags that can hold 25kg, Package salt. must be food-grade, and we need to know the best structure and thickness.” At first glance, this seems simple, but it hides two critical factors: food safety compliance and load-bearing stability. These became our primary negotiation focal points.
Instead of proposing solutions immediately, we used three key questions to uncover the client’s latent needs, avoiding misalignment caused by ambiguous requirements:
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"What kind of food are you going to package? Is it powder, granules, or blocks? Different food properties have different requirements for the bag’s sealing, moisture resistance, and leak-proof performance."
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"What is the usage scenario of the bags? Is it for in-plant turnover, long-distance transportation, or terminal retail? Will there be stacking and extrusion during transportation? This will affect the load-bearing design of the bags."
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"Are there any additional requirements? For example, do you need logo printing, or have special requirements for moisture resistance and air exhaust? Powdered products often have residual gas during filling, which may cause problems during palletizing."
Through in-depth communication, we learned that the client’s main purpose is to package
powdered salt. The key requirements are as follows: 1, the moisture resistance must be extremely high to prevent the powdered salt from absorbing moisture and caking, which will affect the quality of the salt; 2, during the filling process of powdered salt, residual gas will remain in the bag. If the gas cannot be discharged in time, the bags will be uneven when palletized, leading to slipping (pallet slipping), which is a major hidden danger in transportation; 3, the bag must have sufficient load-bearing capacity to withstand 25kg of weight and adapt to long-distance transportation and warehouse stacking, with simple product information printed on it and reasonable cost control.
Solution Communication: Targeted Proposal of Maze Exhaust Bag Structure
Bag Structure: Maze Exhaust Bag, Customized for Powdered Products
Aiming at the client’s needs of powdered salt—high moisture resistance, residual gas exhaust, and 25kg load-bearing, we first excluded the traditional single-layer common PE bag and composite double-layer bag. The traditional single-layer bag has poor moisture resistance and no exhaust function; although the composite double-layer bag has good load-bearing and moisture resistance, it cannot effectively discharge the residual gas in the bag, which will still cause pallet slipping during palletizing, failing to solve the client’s core pain points.
Combining the characteristics of powdered salt and the client’s key demands, we specially recommended the maze exhaust bag, which is customized for powdered products. The structure is a single-layer PE structure, but it is designed with a special maze exhaust channel. The core design concept is: "external air cannot enter, internal air can be discharged", which perfectly solves the client’s two major pain points of moisture resistance and air exhaust.
We explained the working principle and advantages of the maze exhaust bag to the client in detail:
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Food-grade compliance: The entire bag is made of food-grade PE material, which is odorless, non-toxic, and fully complies with the national food contact plastic packaging standard (GB 4806.7-2016), which can be directly in contact with powdered salt to ensure food safety.
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High moisture resistance: The single-layer PE structure is processed with a special moisture-proof coating, and the maze exhaust channel is designed with a one-way sealing structure. External air and moisture cannot enter the bag, which can effectively prevent the powdered salt from absorbing moisture and caking, ensuring the quality of the salt during long-term storage and transportation.
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Efficient air exhaust: During the filling process of powdered salt, the residual gas in the bag can be smoothly discharged through the maze exhaust channel. After filling, the exhaust channel will automatically seal under the pressure of the powdered salt, preventing external moisture from entering. This solves the problem of pallet slipping caused by uneven bags due to residual gas during palletizing, ensuring the safety of transportation.
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Load-bearing stability: Although it is a single-layer structure, the PE material we selected has high tensile strength and tear strength, which can easily bear the weight of 25kg, and is not easy to be damaged during stacking and transportation, meeting the client’s load-bearing needs.
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Cost advantage: Compared with the composite double-layer bag, the single-layer maze exhaust bag has a lower production cost while meeting all the client’s needs, which helps the client control the procurement cost reasonably.
The client raised a question: "Is the single-layer maze exhaust bag less load-bearing than the composite bag? Can it really withstand 25kg of powdered salt without damage?" We patiently explained: "The load-bearing capacity of the bag depends not only on the number of layers but also on the material quality and thickness. The PE material we use for the maze exhaust bag is high-strength food-grade PE, which has higher tensile and tear strength than ordinary PE materials. At the same time, we will match the appropriate thickness according to the 25kg load-bearing requirement, which can fully guarantee the load-bearing stability. In addition, we can provide samples for on-site testing to let you intuitively see the effect." The client expressed recognition of this after understanding the principle and advantages.
(II) Size and Thickness Recommendation: Adapt to Powdered Salt Filling and Load-Bearing
On the basis of determining the maze exhaust bag structure, we combined the characteristics of powdered salt (small particle size, easy flow, and need for compact filling) and the client’s 25kg load-bearing requirement, and recommended the appropriate size and thickness to the client to further ensure the practicality of the bag.
1. Size recommendation: According to the bulk density of powdered salt (about 1.2-1.3g/cm³), we recommended the size of 50cm × 80cm. This size can not only easily hold 25kg of powdered salt but also leave a proper space for exhaust during filling, ensuring that the residual gas can be fully discharged. At the same time, the size is suitable for palletizing (matching the standard pallet size), which can avoid uneven stacking and reduce the risk of pallet slipping.
2. Thickness recommendation: Considering the load-bearing capacity, moisture resistance, and service life, we recommended the thickness of the single-layer PE maze exhaust bag as 0.18-0.20mm. The specific thickness is 0.20mm, which is the most cost-effective choice: it can ensure sufficient load-bearing capacity to withstand 25kg of weight, has good moisture resistance and tear resistance, and can avoid the bag being punctured or damaged during filling, transportation, and stacking. It also controls the production cost within the client’s acceptable range.
To let the client have a more intuitive understanding, we prepared samples of maze exhaust bags with the recommended size and thickness, and demonstrated the air exhaust effect and load-bearing performance on the spot: we filled the sample bag with 25kg of powdered salt, and the residual gas in the bag was quickly discharged through the maze channel; after stacking 3 layers, the bag remained flat and intact, with no deformation or air leakage. The client was very satisfied with the effect after on-site observation.
For clients who have similar needs (packaging 25kg powdered food such as salt), we put forward the following suggestions:
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For powdered products with high moisture resistance and residual gas exhaust needs, priority should be given to the maze exhaust bag structure, which can achieve "one-way exhaust and moisture-proof", avoiding the problems of caking and pallet slipping caused by traditional bags.
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The size should be determined according to the bulk density of the powdered product to ensure that it can hold the required weight and leave a proper exhaust space.
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The thickness should be matched according to the load-bearing requirement. It is not necessary to pursue excessive thickness blindly. Choosing high-strength food-grade PE material can ensure load-bearing stability while controlling cost.
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Food-grade compliance must be confirmed. It is necessary to require the supplier to provide material certificates and third-party test reports to avoid food safety risks.
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Before bulk production, sample testing must be carried out, focusing on verifying the key performance (such as exhaust, moisture resistance, load-bearing) related to the characteristics of the powdered product to ensure that it meets the actual use needs.
If you also have procurement needs for food-grade plastic bags, whether it is 25kg load-bearing, or packaging powdered products such as salt, we can provide professional scheme design, sample verification, and bulk production services according to your specific needs, and fully guarantee that the products are compliant, practical, and cost-effective.
