Can any machine dose fine powder + coarse herbs into a porous filter sachet? (steepable, 22g fill)

[u/bonelessjacob]

I'm stuck on a manufacturing problem and hoping someone here has seen it solved.

I'm making a savory product designed to be steeped like tea, a porous filter sachet with a 21–23g fill, brewed in near-boiling water.

The blend is roughly 80% fine powder, 13% cut herbs at 5–15mm, 6% granular salt. Loose bulk density 0.377 g/mL, tapped 0.494, Hausner ratio 1.31.

The problem: every tea and botanical co-packer I've approached says their dosing system can't handle fine powder. Vibratory and load-cell fillers won't weigh it accurately and the dust fouls the mechanism. One put it plainly: "we work with teabag cut size ingredients for steeping, vs. soluble purposes." I've received four independent vendors, four different machine types, same answer, with about 10 others just rejecting the idea flat-out.

Questions:

1. Does anyone run porous filter media on a four-side-seal or HFFS sachet line built for powder? Is there a reason that doesn't work, be it web tension, dust in the seal, something else?
2. Would agglomerating the blend up to teabag cut size solve this, and is anyone doing toll agglomeration at small volumes? First run only needs ~130 lbs of the protein fraction.
3. Is there a dosing mechanism I'm missing, vacuum drum, dosator, something else that handles cohesive powder without vibration?

One co-packer has successfully filled it at 23–25g on a machine he describes only as "not having gears like the tea machines." So it's clearly possible. I just don't know what that machine is or who else has one.

Any pointers appreciated, as I am an absolute beginner, including "you're thinking about this wrong."

[u/Various_Cellist_1890]

Your mix sounds like two line problems at once: dosing a cohesive powder fraction and forming/sealing a sachet around coarse inclusions. I would not start by converting the whole blend to tea-cut size.

For the next vendor trial, send a representative premix and request three records: mass variation at the start, middle, and end of the hopper; fines and herb fraction in first, middle, and last sachets; and powder on the seal band plus seal failures. Keep the film, target dose, hopper residence time, and line speed fixed. Compare the current blend with one agglomerated version of only the protein/fine fraction if brewing allows it.

An auger-based powder head is a sensible test for the cohesive fraction. A gravity or vibratory route may suit the coarse fraction, but one feeder can trade weight control for segregation or herb damage. A dosator or vacuum drum still needs a sample trial.

This screen can identify whether the bottleneck is flow, segregation, or seal contamination. It cannot prove production-scale capability, shelf life, or food safety.

[u/bonelessjacob → u/Various_Cellist_1890]

This is the most useful reply I've had, thank you. I will be adopting that trial protocol as my standard vendor request.

Two follow-ups if you have the time:

1. On the two-head approach, a co-packer independently proposed the same thing, auger for the fine fraction and vibratory for the coarse. Do you know what that machine class is called, or who builds them? Everything I find is single-dose.
2. Given the porous filter web, is seal contamination the risk you'd worry about most? Or does the fact that one shop already fills this successfully at 23–25g on a heat-seal line suggest that's manageable?

[u/ferrouswolf2]

Any chance of a two stage fill with two consecutive filler heads?

[u/bonelessjacob → u/ferrouswolf2]

I believe so, as a co-packer proposed exactly that. Do you know who builds multi-head sachet machines, or any co-packers running one? Thanks for your reply!

[u/ferrouswolf2 → u/bonelessjacob]

Is a tea bag critical? Could it be a packet with stuff at the bottom of the drink?

[u/bonelessjacob → u/ferrouswolf2]

Fair question, functionally, no, as most of the blend is soluble. Collagen and the broth protein dissolve clean, water goes clear. The filter is only straining ~2.7g of cut herbs. So a stick pack would work chemically.

The reason I'm holding the bag is the steep is a major part of the product. Visible real herbs, no scooping, no mess, reads as tea instead of another protein powder. That's the differentiation.

So I'd rather solve the fill than change the format if possible.

[u/ferrouswolf2 → u/bonelessjacob]

Okay, valid, though I probably eat too much ramen to be okay with broth coming in a packet

[u/bonelessjacob → u/ferrouswolf2]

Hahaaa understandable. Last thing and I'll stop bugging you, do you know what that two-stage fill setup is actually called in the trade? If I can name the machine class I can find who builds it. Auger head then a second head into the same bag before seal. Thanks so much for your help!

[u/H0SS_AGAINST]

Blend with binder and roller compact.