Cracking issues in expanded food packaging are typically not due to insufficient bag thickness, but rather due to misalignment in several steps from material discharge to packaging. The proportion of broken particles deteriorates separately in the packaging section and the transportation section, with different causes and solutions for each. This article follows the on-site investigation sequence, targeting bagging, filling, and quality control personnel, explaining what to check, how to verify, and the interdependencies between improvement actions for each section.
From which section does the debris start to increase?
First identify the positions where the ratio of debris changes from 0 to 1, then discuss the reasons. The ratio of debris in the same batch of products varies unevenly from packaging and line-off to shipment: if the ratio is high in the sampling at line-off, the issue is in the packaging stage; if the ratio is normal at line-off but high upon delivery, the issue is in the packing or transportation stage.
Segmented statistics can be simple: take samples and weigh them at three locations—bagging machine exit, packaging completion, and upon arrival at the unloading point—and record the corresponding production speed and inflation settings. By combining these three data points, it becomes clear where the deterioration occurred.
Key Points
- First locate where the debris is increasing, then decide on the adjustment direction.
- The falling height of the material and cleaning before sealing are the two easiest areas to improve in the bagging section.
- The inflation volume must be reconfirmed based on the bag type, packaging method, and stacking height, and cannot be carried over from the previous model.
- Transport validation must use the fully packaged shipping unit after packing; bare package tests cannot represent the condition upon delivery.
Bagging Section: The drop height and clamping are the first points to check.
When the drop height is too high, the product impacts the bag bottom at a higher speed, increasing the instantaneous force and compression between the product and the bag bottom. This section typically does not require changing the material: reducing the drop height, adding buffer guides, and optimizing the shape of the bag mouth on the forming tool can all reduce the amount of debris at the end of the line.
The second point is in the same section. Shavings and seasoning powder fall inside the bag opening and are enclosed in the sealing edge during cross sealing, forming a channel for slow pressure release inside the bag. As the bag body softens, its cushioning ability decreases, leading to an increase in the breakage rate during transportation. Cleaning of the sealing area should be managed as a whole section.
Why can’t the inflation volume be copied directly from the previous product?
The inflation level is a parameter that is established together with packaging. When the bag type, single bag weight, or packaging arrangement changes, the bag thickness and stack height under the same inflation level will also change. Copying the settings from the previous model often leads to results such as the outer box not being able to accommodate the contents, or being able to accommodate them but causing long-term stress on the sealing edges.
Confirm the sequence as follows: first determine the allowable thickness range of the bag based on the net weight per case and the number of stack layers, then find the inflation setting that can stably fall within this range, and finally check if the sealing edge deforms under stacking conditions. For the trade-off between outer box and stacking, refer to the comparison.Candy Snack Packaging SolutionsConfirm the approach of categorizing by scenario.
What are the signs of insufficient cross-sealing cooling?
Inadequate cooling is easily identifiable: the edge sealing appears normal at the end of the production line, and it doesn’t tear easily when pulled by hand. However, after being packed and left for some time, it starts to show signs of wrinkling, opening, or slow leakage. The cause is that the edge sealing hasn’t stabilized yet and is pulled by subsequent operations, or continues to deform under stacking pressure.
To confirm this, it must be observed under normal production speed rather than at a reduced speed during trial runs. After increasing the production speed, the same temperature and pressure leave less cooling time for the sealing, which is the most common cause of samples passing inspection but production abnormalities. The matching of heat sealing parameters with the material can be referenced as follows:Heat Sealing Temperature and Sealing Layer Settings。
How to schedule offline gas leakage detection?
Offline inspection is not about picking out defective products, but rather determining whether the current settings are stable at full speed. It is recommended to take samples at fixed intervals, perform integrity checks on finished bags before packaging, and record the production speed, inflation settings, and film roll batch numbers for the shift. Data accumulated per shift provides a more accurate reflection of trends.
Common practice is to separate the appearance inspection from the internal pressure test: the former checks for wrinkling, foreign material inclusion, and misalignment of the edges, while the latter checks whether the bag remains full after pressure application. If both pass but leakage is found upon arrival, the issue is likely to occur during packaging and stacking processes.
Why does the outer box fail earlier than the bag?
The stacking pressure is ultimately borne by the outer box, while the cushioning capacity of the bag only applies when internal pressure is maintained. When the number of stacked layers is too high, deformation of the lower outer boxes will squeeze the inner bags, compressing the internal space and reducing the cushioning effect. This is unrelated to whether the sealing edges are intact, which is why situations like “the bags are not leaking but the products are still broken” can occur.
The improvement directions are three: reduce the number of stacked layers, adjust the packaging arrangement to make the bag body force distribution more even, and enhance the outer box’s pressure resistance. All three aspects need to be verified based on the actual condition after packaging.
How to correlate test results from the transportation process with production line data
The value of transportation testing lies in converting road risks into repeatable actions and measuring results with the same set of criteria. For exampleASTM D4169 Practice for Performance Testing of Transport PackagingProvide a test sequence based on package type and transportation method to help determine which set is suitable for your product.
The key to corresponding production line data is consistency in recorded items: the proportion of debris is statistically measured at the same location and under the same weighing criteria before and after the test, and the single-case load and stacking layers are recorded. The test subject must be a complete packaged unit after boxing.
How to statistically track the arrival fragment rate meaningfully
Inconsistent data collection standards can obscure real changes. It is recommended to fix four aspects: sampling location, weighing method, judgment criteria, and corresponding production speed and packaging parameters. Only after these four aspects are fixed can data from different shifts be compared.
The packaging structure can also affect the statistical results. For the same product, changing the bag type will alter the distribution of debris. A baseline should be established before and after the change. The failure location at the structural level and the judgment method can be combined withFailure Dimension Analysis of Potato Chip and Expanded Food PackagingLet’s take a look.
Conclusion
Fragment control should be done in segments: the bagging section should control falling impact and seal contamination, the boxing section should control the matching of inflation volume and stacking, and the transportation section should validate the complete packaged units after boxing. The statistical caliber for all three segments must be consistent; otherwise, improvements cannot be proven. When making changes, only one variable should be altered at a time, and confirmation should be done under normal production speed.
Common Questions
What should be the breakage rate for expanded food packaging?
The breakage rate of expanded food packaging has no universal standard; it should be determined based on the specific production line and distribution channels. The degree of fragmentation, bag type, packing method, and transportation distance all affect the results. Comparing directly between different factories in the same industry has limited practical significance. A more practical approach is to first measure the current level, then set an acceptable range based on the distribution channels. Each adjustment should be retested using the same criteria. For specific product structure selection, it can be combined withFood Grade Packaging Film with Custom PrintingLet’s confirm together.
Is a larger inflation volume safer?
Increasing inflation will enhance the cushioning space inside the bag, but it also occupies more volume in the outer box and increases the continuous pressure on the sealing edges. A decrease in load will raise the number of stacked layers, and deformation of the lower outer boxes will compress the internal space of the bags, significantly reducing the cushioning effect in the latter part of transportation. The proper approach is to determine the inflation level as a packaging parameter, coordinating it with the single-box load, stacking height, and sealing condition.
Is the wrinkling on the heat seal caused by temperature issues or pressure issues?
First check pressure and time, then check temperature. Wrinkles are usually caused by uneven force applied between the film layers during sealing. Common causes include uneven pressure distribution, insufficient sealing time, or the bag opening not being fully flattened before sealing. High temperature can also make the sealed edge brittle and cause contraction wrinkles, but this typically comes with the bag opening being easily torn. The troubleshooting order is to first observe the location and direction of wrinkles at full speed, then check if the sealing time and pressure are stable, and finally adjust the temperature.
What factors affect the breakage rate during incoming material or finished product inspection?
The main aspects are three: material toughness, sealing condition, and packaging method. Material toughness determines the bag’s ability to resist sharp corners and folding. The sealing condition determines whether the internal cushioning space can be maintained. The packaging method determines the degree of compression the bag undergoes during transportation. Incoming material inspection should confirm the surface condition of the film roll, thickness uniformity, and static electricity status. Finished product inspection should confirm the integrity of the sealing edge and internal pressure retention. The packaging process should record the quantity per box and the number of stacked layers.