# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DZAeiZiAsNA
- **Gondola URL:** https://gondola.cc/posts/66312623-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/4f20eb9c8b.jpg
- **Posted:** 2026-05-31T15:06:42.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

Lay dry fiber into a mold, seal it under a plastic film, and let the atmosphere do the work. Vacuum infusion turns the 101 kPa of pressure sitting on top of all of us into a precision manufacturing tool.

The setup is deceptively simple. Dry reinforcement (glass, carbon, or aramid) is stacked in the mold, then covered with a stack of consumables: peel ply, a distribution mesh, spiral feed tubing, and a vacuum bag sealed to the tool with tacky tape. A pump evacuates the air. Once the bag pulls down hard and holds vacuum, a feed line is opened and degassed resin is pulled through the preform by the pressure differential alone.

That flow is not random. It obeys Darcy’s law:

	•	Q = (k·A/μ)·(ΔP/L)
	•	k is the permeability of the fiber stack
	•	μ is the resin viscosity
	•	ΔP is the pressure drop driving the front

This is why infusion resins are formulated with low viscosity and long pot life. The resin has to travel the full length of the part before it gels, and the engineer controls that race by tuning flow media placement, feed line geometry, and inlet timing. Get it wrong and resin races along an edge faster than it wets the core, leaving dry spots that no amount of pressure can fix once cured.

Why bother over hand layup?

	•	Fiber volume fractions of 50 to 70 percent, versus 30 to 40 for wet layup
	•	Far lower void content and tighter, repeatable laminate thickness
	•	A closed process, so styrene and other VOCs stay contained
	•	Excess resin is drawn into a catch pot, not left as dead weight

The payoff is strength-to-weight. Wind turbine blades, race car monocoques, and large marine hulls all lean on infusion because atmospheric pressure is free, perfectly uniform, and never gets tired.

#stemantics #composites #materialsscience #engineering #manufacturing

## Stats

- **Views:** 34,295
- **Likes:** 302
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- **Comments:** 2

## Tags

engineering, materialsscience, composites, manufacturing, stemantics

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