Old PLA filament not sticking to bed

[Lez0]

Hi everybody.
This is a new one.
I was doing a simple print, a disc 1g of filament.
I thought it was a good way to use up some old filament as the colour didn't matter.
The first print was a blob of plastic stuck to the nozzle.
After 3 more failed attempts to print, re-leveling the bed, cleaning with alcohol, to make sure all is OK etc. the filament just would not stick to the bed.
I changed the filament, same make and colour, and hey pesto a perfect print that I had to use a knife to get it off the bed, it was well stuck.
So it was the old filament that was the problem of not sticking to the bed.
Has anybody else had this problem?
Lez

[LePaul]

Is it dry? is it brittle?

I've run into some filament that should wouldn't stick too Just ball up around the nozzle

What material? What print temp?

[Roberts_Clif]

I have used many miscellaneous bed surfaces on occasions when 3D Printing with some 6 year old filaments.
My bed surfaces have been Vinyl transfer paper and plastic tape, various self adhesive bed surfaces.
Never had a filament that I could not get a good 3D printed model.

Note : My Filament is always in a sealed plastic container with fresh dollar store Moisture Eliminator or Charcoal Moisture Eliminator.
I think that this allows my older filaments to maintain a like new characteristic about it, allowing me to print perfect models

I have a sealed heated chamber that helps brittle filament to become pliable allowing it not to break during printing.

[Lez0]

Hi
Filament was good, I tested it by trying to break it, but it bent, so not brittle.
I keep all my filaments well wrapped up and if they are brittle I bin them.
I use a vinyl cover for the bed, it normally works very well as I normally have the problem of getting the parts off the bed, I have to use a sharp Stanley knife and I sometimes break the blade getting parts off!
I use PLA PETG & TPU filaments, all stick well to the vinyl.
I am more curious as to why the old filament didn't stick as the roll was almost done.

Lez

[Roberts_Clif]

I am more curious as to why the old filament didn't stick as the roll was almost done.

Lez

I would really like to know why myself, as the forum is for learning this innovative new hobby.

[LePaul]

I can only suggest your thoroughly clean the build surface, something like 91% IPA and if it still won't stick, maybe an adhesion promoter like hair spray (extra hold Aqua Net seems popular)

[Lez0]

I did try and clean it with IPA but the old filament didn't stick, really odd!
Usually I have the problem of getting the part off the bed, and never any problem with it sticking.
Lez

[LePaul]

Time for some new filament then!

[Roberts_Clif]

I would not get rid of the filament yet, instead purchase a new roll to see it the problem continues on new filament roll,

[Lez0]

Hi
As I said in my original post, I used a new roll of the same make and colour and it printed no problem, it stuck really well, in fact I had to use a knife to get it off the bed.

[LePaul]

Get a wham bam surface, those flex beds are great!
(And save 10% using WNIC2022)

[Lez0]

Thanks LePaul

[Adrian_S]

Just a thought, have you checked the diameter of that old filament? If it's less that the 1.75 nominal then your first layer might not be getting enough squish with the amount being extruded. If that's not the issue I'd try playing around with the extrusion temperature, raising it 5 degrees at a time, to see if that made any difference.