RogueRose - 8-6-2016 at 22:09
I have heard of people using toilet paper as filters by removing the inner cardboard. Kind of like an oil filter setup. I was thinking of making
something similar with paper towel rolls. There are a few types of paper towels, the ones for kitchen use ("quilted") and the cheap thin type that is
more akin to regular paper - like the kind in institution bathrooms, gyms, gas stations etc. I think the latter would be better for what I'm
planning.
I want to filter a number of different liquids so I'd need a different filter for each liquid. Oils act differently than water and the temp may
effect the filter efficiency and strength.
The first thing to do is remove the cardboard inner roll. I'll then find a container that the roll will fit into, something like an old food
container, just deep enough to hold 1/4" (or a little more) of an epoxy. Mix the epoxy and place the tightly rolled paper towel into the epoxy mix
and allow to dry. Hopefuly it doesn't soak up very far into the roll (any ideas how to prevent this) as this is just meant to seal the bottom and
hold the towels together. The same thing should be done to the top of the towel roll.
Now you have a sealed paper towel roll and you need to put a hole in one of the ends. Hardware stores have many types of threaded plastic or brass
hose attachments which would be perfect for this. I've drilled and reamed the hole in the epoxy, screwed in the hose barb and then sealed with some
epoxy. (if you use a brass barb you can re-use it by burning the epoxy off when finished).
Now when a hose is attached to the barb and liquid pumped through it has to pass through all the layers of paper towel.
Depending on how fast you need to filter (pressure) and the liquid to filter, it may be beneficial to add some reinforcement to the outer layer of the
paper towel by either wrapping with wire (sometimes anchored into the epoxy at the beginning) or with pipe clamps. I'd like to hear of other ideas if
anyone knows of a better method for this.
wg48 - 9-6-2016 at 05:53
Usually that type of filter has the flow from the outside to the center. With the center fitting closely to a pipe with holes in it.
The outside having a larger surface area improves the flow and the filter material is in compression against the inner tube so it is less likely to
fail. If the tube is a good fit in the paper and the first holes are at least the thickness of the roll from the ends no gluing of the ends is
required.