Colloid Mill Add-on: Hopper Enclosure, Feed Regulator and Ventilation

colloid mill add-on top view

colloid mill add-on bottom view

colloid mill add-on top view

This contraption does three things.

1) Regulate the in-feed of cacao nibs inside mill. Just turning the motor on and filling in the hopper with nibs to capacity won’t work. It runs for few seconds, slows down, clogs and stops. It is actually a homogenizer designed for liquid materials. However, regulating the feed to some point make it usable for grinding cocoa nibs.

2) Prevents nibs from flying out of the hopper. The spiral drive just above the rotor was designed to suck liquid in. However, the material I am trying to grind is somewhat similar to corn grits. Some are sucked in successfully some are not and end jumping out. It is so frustrating to see the nibs I worked hard for are just flying off to ground.

3) Inject air inside hopper. It helps cool down the mill a bit and facilitate escape of evaporating acids. In absence, it condenses on sides of hopper and my diy contraption. It is so messy.

Still made of thin plywood, pvc pipe scrap, HDPE plastic sheet and screws. Revising as needed and plans on building a stainless steel version once finalized. It is not in the near future, I think.

Various Tests on PET Peanut Jar

peanut jar with cocoa nibs

I did a few tests on this packaging material before, the peanut jar. Leak test, failed. Half-filled the jar with water and shook it. Water droplets were spilling out. It was not conclusive, however, I never used appropriate bottle seal.

Appropriate seal? The jar lid should be sealed using induction sealer with appropriate seal for this plastic. This PET perhaps so the seal should be made specifically for it.

Lukewarm water test. The bottle can hold itself well. Fair enough, barely hot water can never harm human skin, what less to a PET type plastic.

Hot water from a thermos. There was a slight deformation after few minutes. And that modest is unforgivable. It might affect the lid resulting to faulty seal. Disruption to structure might have also caused migration of plastic molecules to contents.

The last was hot water steam test. Held the bottle with the lid facing down the rushing steam. It shrunk so suddenly to unusable state, just like a flattened canned softdrink. It won’t budge if it was heat set.

So I concluded. It cannot be used for hot-packing products, but very much suited if allowed to cool to acceptable level. However, I found something interesting recently. The cocoa nibs that I packed in, tasted and smelled like plastic. It was faint, but may not in senses of sensitive buds. For me, it was awful, masking the original delicate flavors.

peanut jar with cocoa nibs

I bought samples of this PET jars to package our product cocoa nibs. We ended using the clear stand-up pouches. The latter is cheaper, look as good, easy to seal with impulse sealer and easier to handle.