Fishy Blog

Stability Tests – Dye stability

In the second of two posts we’ll look at how our nylon takes an off the shelf synthetic dyestuff and how it reacts when put through real world tests.

You may remember us posting some dye tests on Twitter a few months ago. They worked really well with a strong and deep colour imparted by every different dye in the Rit DyeMore range.

This slideshow requires JavaScript.

But what happens when you wash the material after dying ?

We ran two different post dye wash tests on samples from these same swatches.

10 minute blitz – excess detergent, boiling water and microwave for 5 minutes followed by a 5 minute soak.

This slideshow requires JavaScript.

The process was repeated for every colour, except neutral & graphite, and the results were as follows;

We combined the boil test of the neutral & graphite to see if we got any bleed over. We did.

Neutral black in wash water

In each picture below the bottom samples are the original and the top are the boil washed samples.

This slideshow requires JavaScript.

As you can see all samples showed a diminution of colour saturation. The remaining water left in the bowls after each test confirmed that this was excess dye being removed from the surface rather than bleaching by the detergent.

The second round of tests on a fresh set of samples was carried out using a lower temperature (40C) conventional wash cycle but with added media to simulate wear (a bit like a stone wash). We bagged the samples together so that they would all get the same treatment and wouldn’t stick to the washing machine barrel.

This slideshow requires JavaScript.

The results were virtually identical to the 10 minute blitz test. Except that the neutral/graphite test didn’t show any dye transfer and some of the boiled swatches were a bit more curled than the ones washed at a lower temperature.

We repeated the 40C wash three times on the same swatches but saw no cumulative impact. Repeating the boil washes saw minimal discolouration left in the bowl but the colour saturation getting lower each cycle, suggesting that the detergent was having a bleaching effect.

This slideshow requires JavaScript.

Summary; cold water dying using Rit Dymore is effective and can provide attractive permanent colours in our nylon product. Though boil washing is not destructive mechanically it can re-mobilise dyes. No dyed product should be sent out unwashed, but a relatively low temperature conventional wash should be sufficient to remove excess dye remaining after the cold dying process.


Stability Tests – Long Term Mechanical

We’ve had a couple of queries in from designers considering the longer term stability of the Fishy Filaments recycled nylon product both in terms of use cases such as wet/dry cycles in water sports and for washability in wearables/fashion.

In the first of two posts we’ll look at some bodies that we printed a year ago and have kept in water since then. In the second we’ll look at some wash tests on dyed forms.

So first off, remember a year ago when we carried out some ‘short’ term (17 day) immersion and wash tests ? Well we kept those going over the last year. The forms shown below have been stored in water for almost exactly a year.

This slideshow requires JavaScript.

The aim was to see if interlayer bonding was effective or whether water ingress and algal action might prise the layers apart with time.

The clear glass jam jar was filled with fresh water so that we could ensure that we did get some algal growth but didn’t end up with a storage degradation issue. The rationale for the choice of storage vessel was that jam is not an inert substance and that its storage technology has been honed over many decades. As you can see we got a little rusting on the lid but the water was not otherwise contaminated.

I didn’t feed the algae (apart from that little bit of rust) and its apparent volume reached a maximum after a few months and then held despite regular and vigorous shaking at least once a month. Its a bit of a stretch scientifically but this might suggest that we did have a closed system and that the algae was not metabolising the nylon at any appreciable speed. This would seem to support the idea of nylon as a persistent material with a lifespan measured in centuries rather than years, but I’ll leave the often quoted 600 year figure to others to confirm.

Mechanically there was very little to choose between the long term soaked forms and the original shorter term soak test forms that we kept as a long term control. The original control forms from a year ago and stored in uncontrolled conditions, but that were never soaked, remained noticably stiffer. This seems to support the contention that nylon reaches an equilibrium with the amount of water it can absorb and release under normal environmental conditions, and that the elevated temperatures required to dessicate the polymer prior to printing (somewhere over 70C) are absolute ‘need to knows’ for anyone considering using nylon as a 3D printing material.

TIP – you cannot leave it to a silica dessicant pack to dry pure nylon 6 or to keep it dry, you have to heat it to between 70-80C and keep it there for several hours. Once you have driven off both surface and internal moisture from the polymer you have a limited time in which to use that filament and when you can expect optimum performance. How long that period is will depend very much on local conditions but a warm, dry storage system can extend that envelope very significantly and we recommend considering solutions such as Richard Horne’s heated drybox, ESun’s eBox or if you are a bit wealthier Mass Portal’s filament drying systems. Unheated options such as Polymaker’s Polybox are useful but have more limited application. It might feel like a bit of a hassle but stable 3DP materials are a rarity in the manufacturing world. Most materials (leather, metal, ceramics) need both pre and post manufacturing processes to make them stable over the longer term.

But once printed that ‘absorb and release’ process does not seem to degrade the 3D printed form, suggesting repeated immersion in water is not going to cause rapid degradation. This should give some reassurance to the several designers looking at wet/dry use cases, but of course we advise carrying out your own tests too.

After a quick rinse and scrubbing off the algae, we looked at the colour. The jar was kept on a window sill that gets direct sunlight year round. Of course two layers of glass severely limits the amount of UVB incident on the forms, but some UVA should still have got through. PA6 (our kind of nylon) is considered to have ‘Fair’ resistance to UV degradation. Also I think it is worth pointing out that some of the more obvious UV damage seen in low-end 3DP filaments is bleaching of cheap masterbatch pigments that manufacturers add to them rather than the underlying polymer itself.

Long Term Stability Tests
Left – 1 year fresh water soak. Centre – 1 year dry storage. Right – 1 year dry storage after 10x boil washes and 17 days immersion

The underlying colour of our nylon appears to have changed ever so slightly over the course of a year long soak in fresh water, but nowhere near as much as it did after repeated boil washes with detergent, and in a different way. On closer inspection the apparent muddyness of the long term soaked forms is due to algal growth into some of the layers at surface, and that scrubbing with a toothbrush did not dislodge. It is noticable that surface roughness is the primary determinant of the location of algal growth suggesting some interlayer penetration by the algae. We should note that these forms were all printed on a minimally modified Wanhao Duplicator i3 at a relatively coarse 0.3mm layer height.

So in summary; soaking in water over long periods does not seem to impact the mechanical properties of 3D printed nylon forms unduely but surface roughness does seem to promote algal growth. UVA does not seem to cause significant damage to our Nylon 6, but UVB cannot be ruled out by these tests as a possible source of degradation.

Hopefully this will help designers when evaluating material choices.

Next post will be on colour stability through various wash cycles.

New EU proposals on fishing net disposal

The new fishing net recycling proposals announced this morning by the EU as part of a larger package addressing plastics wastes have two main parts; EPR and net tagging.

EPR or Extended Producer Responsibility is the same instrument as used for plastic packaging whereby the producer of the plastic product must contribute towards infrastructure for its recycling or disposal. The means through which the EU is proposing to regulate that is a new version of the Ports Reception Facilities Regulations. Essentially this means that net producers (not fishers) will have to fund net waste collection and disposal infrastructure. Previously it has been normal for ports to charge for waste disposal, whether as a discrete charge or bundled with other harbour fees.

Net tagging is firmly aimed at fishers to enhance the existing responsibility to attempt lost net retrieval or report lost nets alongside fishing activity. There are already rules in the Fisheries Control Regulation that requires marking gear and carrying retrieval equipment on board. This proposal suggests a tightening of the implmentation of those rules, especially around reporting.

The EU says that the aim here is to address an incentive gap whereby fishers were being discouraged from managing end-of-life and lost nets in an environmentally optimal manner.

Our analysis is this;

The big change here is that ports will be able to get funding for new Port Recpetion Facilities through a new mechanism, effectively creating a new market for local recycling infrastructure.

The EPR on end-of-life nets puts our containerised recycling solution on the market as a new kind of self-sustaining port reception facility. There have already been enquiries from net producers. We now expect more. All the larger commercial fishing ports will have to manage end-of-life nets in a far more rigorous manner if/when the proposals become law.

Even ports that choose not to recycle within their own boundaries will have additional infrastructure challenges associated with end-of-life net management as tagged nets become assets/liabilities to be tracked.

There are, of course, both upsides and downsides to that but its difficult to see specific downsides for Fishy Filaments Ltd and its product lines.

BlueInvest 2018

Fishy Filaments was invited to attend the European Commission and EMFF’s first ever BlueInvest pitch event in Brussels on the 17th May 2018.

It was, nominally, a competitive pitch to a panel of professional investors but it was really more a structure to bring together actors in the Blue Economy, with most of the space in the Square Brussels Meeting Centre dedicated to short one-to-one meetings. Around 350 interested parties attended and event registration was closed early, so plenty of active interest in the maritime economy out there.

I had travel problems on the way so had a dissappointingly short time during the formal event to network but still made some useful contacts and it was, over all, well worth attending.

This slideshow requires JavaScript.


We seem to be running parallel to Nike’s R&D (with a lower spend and only a bit behindšŸ¤«)

A few weeks ago we showed some R&D that we’ve been doing on digital textiles, commenting about how aniostropy could be designed in or out of the 3D printing process when building flat objects.

FYI – Anisotropy is a measure of uniformity in a structure. Most 3D printing projects and technologies aim to make the mechanical properties of the final printed body uniform, mimicing established manufacturing technologies like injection moulding. That seems like a waste of an opportunity within 3D printing that designers are only now starting to get to grips with.

Well, it seems Nike are a bit further along that track than we knew, with their ‘Flyprint’ professional-level sports shoes. These shoes did the London Marathon with Eliud Kipchoge driving them


This is the first time that conventional ‘uppers’ have been 3D printed for a commercial (albeit bespoke) line of sports shoes. Previous 3D printed sneakers have been soles (Adidas/Carbon) and/or mid-soles/footbeds (Under Armour).

The semi-conventional pattern of the Nike Flyprint upper is built as a flat textile panel from TPU which is 3D printed on what seems to be, again, a fairly conventional Fused Filament-style 3d printer. Conventional textile uppers are cut and sewn by nimble hands.

From the vid the printer is pretty big, dimensionally, but otherwise nothing special. The special thing is the optimisation of where the upper has strength, where it has breathability and where it has flexibility. The structure is deliberately isotropic (has uneven properties). The data on where to put the 3D printed material and where not in order to achieve an optimised performance comes from analysis of the individual runner’s anatomy and running dynamics. That is Nike’s special sauce.

At $600 per pair they aren’t cheap and right now they are only being produced for Nike sponsored professional atheletes, but this is scalable technology. And this is a market that Fishy Filament’s recycled nylon material can service with the right partner.

Nike Flyprint

Nike Flyprint close-up

Nike Flyprint toe

We’re growing !

First hire, production units and equipment commissioned, sales enquiries coming in for our 100% recycled nylon

Some recent progress to report;

  • A significant grant win that should cover ~45% of the capital expenditure
  • First hire made and interviews conducted for second hire
  • Production units commissioned from Iso Spaces
  • Production equipment on order
  • Demo pieces delivered for display in New York
  • Sales enquiries now coming in regularly
  • E-commerce website under construction
  • Further technical advances made on the product and recycling process has allowed multiple blends to be successfully tested (Porthcurno, Longships and possibly a 3rd as yet un-named blend)
  • Independent test results now received and strongly suggest that the Longships blend will pass the safety requirements necessary for use as ‘packaging’. The ‘packaging’ use class includes some food contact applications.
Translucent base of Pineapple vase 0.3mm thick
Translucent base 0.3mm thick



Prepping for some long-lived demo pieces

We’re prepping some 3D printed demo pieces for a long-lived display in NYC. Initial result looking good

Ever been asked what item of yours that you’d want to put in a time capsule ?

Its a tricky one. That item will be everything that a 3rd party who sees that time capsule will have upon which to base an opinion of you, your impact and relevance to their lives at some remote point in space and time.

Do you put an idealised version of yourself, a ‘warts & all’ version of yourself or do you just busk it and see what happens ?

Fishy Filaments has been asked to place some demo pieces in a well known organisation based in New York City. While we will have the ability to replace them at some point in the future, those items will be viewed by opinion formers and decision-makers in coming months (and potentially years), so we’ve been working to try and deliver a polished but realistic representation of the state of the art.

Here are some of the test results.

This slideshow requires JavaScript.

This slideshow requires JavaScript.