Dust leakage is the most common and most costly quality failure in sachet powder packaging. It shows up in three ways that every production manager recognises: pouches arriving at customers with powder residue on the outside, sachets that pass production inspection then fail on the shelf, and rejected batches where the seal has visibly broken down.<\/p>\n
All three are preventable. All three trace back to the same small set of root causes.<\/p>\n
This article gives you five actionable tips drawn from real production troubleshooting \u2014 for milk powder, probiotic powder, seasoning powder, pharmaceutical powder, and pesticide powder lines. Each tip identifies the failure mechanism, explains why it causes leakage, and tells you specifically what to fix.<\/p>\n
Most powder packaging engineers focus their troubleshooting on fill weight accuracy. That is important, but it is not where dust leakage originates. Leakage starts when airborne powder particles \u2014 generated during the filling drop \u2014 land on the film surface at the seal zone before the sealing jaw closes.<\/p>\n
Every time an auger releases a dose of powder into a forming tube, there is a brief pressure pulse. Fine particles become momentarily airborne. Where they settle depends entirely on the airflow patterns inside the filling chamber. If those patterns are uncontrolled \u2014 if there are gaps in the chamber walls, if the filling tube is not properly seated, if the powder drop height is too great \u2014 particles drift toward the film edges and the seal area. Once they are on the film, the sealing jaw will press them into the seal and create a contaminated bond.<\/p>\n
The fix begins with a sealed filling chamber design that controls internal airflow geometry to direct the powder drop cleanly downward, minimising lateral particle travel. On machines specifically designed for powder, like the BY-JLB160X and BY-JLB160P, this is built into the standard filling head. On general-purpose machines adapted for powder use, it is often not \u2014 and no amount of parameter adjustment will compensate for a fundamentally open chamber design.<\/p>\n
A practical diagnostic you can run on any machine: hold a sheet of clean white paper alongside the seal zone during a dry run with no film and no product. Run the machine for 30 seconds at normal auger speed. If you see powder deposits on the paper afterward, uncontrolled chamber airflow is your problem \u2014 and the fix is either a chamber modification or a machine upgrade, not a seal temperature change.<\/p>\n
The single most common cause of apparent leakage in sachet powder packaging is not actually a contamination problem at all \u2014 it is a sealing problem masquerading as one. The seal looks intact. It passes visual inspection. A light squeeze test feels fine. But under real-world transport stress \u2014 vibration, compression, temperature cycling in a shipping container \u2014 the seal peels because it was never fully bonded in the first place.<\/p>\n
This happens when sealing temperature is set below the minimum required for the specific film laminate being used. Every laminate structure \u2014 BOPP\/PE, NY\/PE, PET\/AL\/PE aluminium foil \u2014 has a defined sealing temperature window. Below that window, you get a cold seal: the sealant layers contact each other and look fused, but the molecular bond is shallow and the peel strength is low. Set temperature too far above the window and you overheat the sealant layer, creating brittleness and potential film burn-through at the seal edge.<\/p>\n
The correct sealing temperature range for your film is available from your film supplier as a heat-seal curve document. Get it before you set your machine parameters \u2014 not after you have a leakage complaint. Programme your machine to the midpoint of the recommended range, then conduct a peel strength test on every new film roll: grip the seal with both hands and pull sharply perpendicular to the seal line. A properly bonded seal on standard food-grade laminate should resist at least 15\u201320 N\/cm of peel force, with the film tearing before the seal separates.<\/p>\n
For pesticide powder packaging specifically, the chemical interaction between certain active ingredients and the film sealant layer can degrade seal bond strength over weeks, even when the initial seal was well within specification. Conduct an accelerated aging test \u2014 store sealed sample pouches at 40\u00b0C and 75% relative humidity for four weeks \u2014 before approving any new film and product combination for commercial production. A seal that passes day-one inspection but fails at week three in a distributor’s warehouse is a supply chain problem you do not want to discover after the product has shipped.<\/p>\n
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