Keeping the lint out of final mechanical assembly? - Page 1
Forum section: electronics / general

author: rich
author_rank: Frequent Contributor
timestamp: April 07, 2016, 05:33:03 pm
content: I'm wondering if there are any top-tips for getting rid of lint, fibres and hairs eradicated from mechanical assembly.The issue I am fighting is that I my ABS enclosures come back from CNC machining already a bit swarfy and beginning to attract collecting dust etc. I then fit the PCB, LCD and self-adhesive graphic overlay with clear window.Occasionally after fixing the overlay, then there are a few specs of dust or a white fibre waving at me through the window. (Only once have a had an eyelash in there). This all fails my own QC and I scrap the overlay and start again.I've started using adhesive tape to pick up stray dust/fibres but this feels like a hack. Not sure what direction to try next - Compressed air? Some other sticky pickup tool?Thanks.

author: AF6LJ
author_rank: Unknown
timestamp: April 07, 2016, 05:43:06 pm
content: Try this;Wash the enclosures in soapy water and dry with a paper towel, do not rinse the enclosure the soapy film left will keep static from attracting dust and lint.

author: rich
author_rank: Frequent Contributor
timestamp: April 09, 2016, 03:17:30 pm
content: Thanks for the tip. I will try a soapy experiment on a single unit and see if it attracts less dust etc. I would guess that I'd need to IPA that film away or else the overlay wouldn't stick quite so well.I reviewed the full process in greater detail this morning. One of the wipes I use doesn't shed lint but it does produce fine white dust. A friend suggested a domestic air purifier could reduce the overall level of dust in my home lab - I think these are just a big fans with a hepa filter and don't seem massively expensive so might be worth a shot I need to do more research on them.

author: AF6LJ
author_rank: Unknown
timestamp: April 09, 2016, 04:49:05 pm
content: Quote from: rich on April 09, 2016, 03:17:30 pmThe air purifier removes the dust by placing a negative charge on the air that enters the unit the dust sticks ti the internal filter media and the anode plate internal to the unit.The thin soap film may not effect your decal.Give it a try.

author: Farley
author_rank: Regular Contributor
timestamp: April 09, 2016, 10:27:46 pm
content: Keeping dust and specs out of assemblies like that can be a battle. In the past I've had laminar flow hoods installed at the assembly workstations and had the operators wear lint free gloves. It also helps to have compressed air and a nozzle/blower at the station. In my experience, it's inevitable that you will still have a few escapes.

author: IconicPCB
author_rank: Super Contributor
timestamp: April 10, 2016, 12:22:45 am
content: Alongside soapy surface try a mild solution of fabric softener. A ( better than soap) anti static finish.

author: apelly
author_rank: Unknown
timestamp: April 10, 2016, 03:14:24 am
content: Quote from: rich on April 07, 2016, 05:33:03 pmWatchmakers use some sort of bluetack stuff. Found this link by googling sticky stuff - warning; dangerous google termhttp://watchmakingblog.com/2008/08/19/rodico-premium/Might give you somewhere to start

author: SeanB
author_rank: Super Contributor
timestamp: April 10, 2016, 10:08:10 am
content: Safe to search with Duckduckgo though.......

author: janekm
author_rank: Unknown
timestamp: April 10, 2016, 10:40:04 am
content: Quote from: rich on April 07, 2016, 05:33:03 pmThe small workshops fitting replacement screens / protective overlay glass in China use first contact cleaner with lint-free (cleanroom) wipes followed by sticky tape (seems to be a particular type though, avoiding residue I presume) so it's a common technique at least.

author: SeanB
author_rank: Super Contributor
timestamp: April 10, 2016, 11:11:28 am
content: Blue light tack painters tape works for that, removes the lint and leaves no residue.

author: rich
author_rank: Frequent Contributor
timestamp: April 11, 2016, 12:49:54 am
content: Thanks for all the really good suggestions. I'm not sure I can stretch to building a laminar flow hood where I am now, but I will try out all the others suggestions and report back with any interesting progress.

author: ChunkyPastaSauce
author_rank: Unknown
timestamp: April 11, 2016, 01:10:05 am
content: Pretty easy to buildup a static charge on plastic parts. Doing stuff like trying to brush away dust, can actually build a charge on the part making dust immediately cling back to the part. There are a bunch of static control methods used for dust control on plastic parts. See static eliminators, anti-static air gun, anti-static capacitive gun

author: tggzzz
author_rank: Super Contributor
timestamp: April 11, 2016, 11:57:27 am
content: Quote from: ChunkyPastaSauce on April 11, 2016, 01:10:05 amAnd ESD precautions

author: charlespax
author_rank: Regular Contributor
timestamp: April 13, 2016, 12:50:05 pm
content: Here's a pro tip for trying surfaces without leaving any lint behind: Use newspaper. Seriously. It works great on mirrors and glass, so I assume it would work on ABS too.

author: DTJ
author_rank: Super Contributor
timestamp: April 13, 2016, 01:02:15 pm
content: Paper towel is a great source of abrasive lint.Perhaps something like these dusting cloths would work:https://www.google.com.au/search?q=swiffer&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwipltuk1YvMAhVH3mMKHQL6D2EQsAQIJw&biw=1366&bih=628#tbm=isch&q=pledge+grabit++dusting&imgrc=XfV6R-Luqc5tkM%3AThey do a great job of cleaning dust from screens and furniture. Maybe clean up all nearby surfaces prior to assembly tasks.

author: IconicPCB
author_rank: Super Contributor
timestamp: April 13, 2016, 10:07:52 pm
content: Do NOT use paper.As already pointed out it is too abrasive and will scratch the surfaces.

author: janekm
author_rank: Unknown
timestamp: April 17, 2016, 09:13:29 am
content: Quote from: IconicPCB on April 13, 2016, 10:07:52 pmIndeed, dolomite and talc are common fillers in paper manufacture...

author: rich
author_rank: Frequent Contributor
timestamp: April 17, 2016, 03:20:56 pm
content: Newspaper on glass works great as glass is hard. Plastics not so much.I had too look up dolomite on wikipedia (calcium magnesium carbonate) as I guessed it probably wasn't one of these

author: rich
author_rank: Frequent Contributor
timestamp: April 17, 2016, 05:22:17 pm
content: Inspired by the suggestions in this thread, I bought some new items to try this week: Dust blower, Foam swabs, Gloves, Alternative clean room wipes. Results below:Instead of dusting/wiping the abs enclosures, I washed, rinsed and left them to dry naturally. Soap residue was minimal to none. All particles removed and abs enclosure doesn't seem to attract for fresh dust now.Result: SuccessOf new buys, the dust blower is the star of the show: high speed air jet and targeted thanks to the metal nozzle. 4 - 5 blasts before removing the LCD protective covering and affixing the graphic overlay eliminates the need for swabs or wipes except in rare circumstances.Result: SuccessFoam tipped swabs - IPA wiped front panel for better overlay adhesion. The swab size perhaps causes less ambient dust swirl than the larger IPA wipes I used previously.Result: Inconclusive(but keeping with swabs as more agile than wipes)Gloves - The intent was to eliminate skin oils but the fit was so poor they were unusable. Also I don't think these aren't the correct type as material is a simple mesh so when you grip a part it's easy for skin to contact with the part.Result: FailClean room wipes -Result: Not tested(as swabs did a good job)

author: DTJ
author_rank: Super Contributor
timestamp: April 18, 2016, 02:22:11 am
content: Good feedback, useful information for others.For the cotton gloves try lint free cotton assembly gloves. I saw some the other day for $0.40 /pair in a flyer I received. Here's an example:http://www.boc.com.au/shop/en/au-boc-industrial-store/cotton-gloves/boc-white-interlock-cotton-gloveI'm sure somewhere local to you will sell them. They are sometimes used in mechanical workshops for precision assembly work and are treated as a disposable item.