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Comment by PlunderBunny | Hacker News Reader

I think the results of soft plastic recycling are highly dependant on the country doing it. In New Zealand, soft plastics are mostly recycled into fence posts, which last 50+ years and are every bit as good (or better) than treated timber [0].

I’m not saying that we shouldn’t reduce our soft plastic use, but - like all recycling - you need to do a bit of research and think about it, instead of adopting a “recycling is good”/“recycling is a myth” mentality.

0. https://www.futurepost.co.nz/

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Plastic recycling is a drop of water in an ocean of plastic.

> In New Zealand, soft plastics are mostly recycled into fence posts

The latest (2025-01) official report[^1] I could found states that the recycling of plastics in NZ is poorly known. On page 135, it mentions the report "OPMCSA plastics research (2019)" as the reference in the domain.

According to that 2019 study[^2], the plastics used each year weight more than 700k t. Much more, because this ignores packaged imports, construction and agriculture. 31% of plastics imported are LDPE (so around 170k t), which is mainly used for producing soft plastics.

Out of those 600+k t/year, 380k t go to landfill waste, and 45k t are collected for recycling. Assuming generously that 50% of those intended for recycling are actually recycled, I'd estimate that 1.7 to 3% of the yearly NZ plastics are recycled.

Here's a quote about soft plastics:

    In 2017, 365 tonnes of soft plastics were recycled – but a lack of recycling market for these plastics meant that in the following year, plastic was stockpiled whilst new onshore markets were developed and a percentage of non-conforming plastic was landfilled.

365 t of soft plastics recycled out of 170k t of LDPE!

[^1]: https://environment.govt.nz/assets/publications/New-Zealand-...

[^2]: https://www.pmcsa.ac.nz/topics/rethinking-plastics/quantifyi...

My wording was poor - I meant to write "most soft plastics that were recycled, were recycled into fence posts". Not that most soft plastic was recycled.

I'm not disagreeing with any of what you have posted.

For reference, the 52 posts that I have on my property are constructed from more milk bottles and soft plastic than I will ever consume in my lifetime. It's a drop in the bucket, but it's significant to me.

Making fenceposts out of a mystery plastic sludge isn’t recycling, it’s downcycling

The plastics used aren't a mystery - the outer parts of the posts (the bit that's exposed) are made from milk bottles. The resulting product is something that is useful to me and to the other people that buy it. Without it, I'd buy a treated timber post, which also has an environmental cost (different trade-offs). Is it down-cycling when the resulting product is more useful that the products it was composed of?

Just a clarification: in NZ most soft plastics are sent to landfill, regardless of what happens to most of the plastic that is actually recycled. We're pretty bad for general recycling and really bad for plastic recycling. Most soft plastics here are from agriculture so it's probably a more solvable problem than if it was weighted towards domestic waste, but farming often manages to lobby their way out of regulation.

Sorry - yes. What I meant to say was "most soft plastics that are recycled, are recycled into fence posts".

>which last 50+ years

So it takes 50+ years for UV, rain and wind to turn it into microplastic mush? Sounds like a great product!

No one (including the manufacturer) knows how long it will last - 50 years is as far as accelerated aging can test to. You're assuming they split or break apart. The posts themselves are recyclable, so maybe in 50 years someone can pull them out of the ground and recycle them?

The point is that we know the weathering process will shed microplastics.

https://magazine.hms.harvard.edu/articles/microplastics-ever...

Absolutely, and they admit this themselves. From their FAQ:

"the rate of degradation is very, very slow – untreated plastics of the type used in Future Posts degrade in the environment by 1.3um to 22um (0.0013mm/year to 0.022 mm/year for HDPE and LDPE respectively). For the mix of plastics typically in a Future Post, that means the post will degrade at a rate of around 10% of thickness of a hair every year"

Think about what you’re writing and compare that to your experience with any non-uv stabilised plastic that has spent its life in the sun. For someone who implores for people to “think about it” you sure seem extremely easy to convince with a bit of marketing fluff

I'm not convinced - I'm still thinking about it even now! The plastics, treatments, geometry etc make the posts quite different from the kind of plastics we find falling apart on the roadside etc.

Yes, very dependent on the market. In some East African markets that don't have much history of recycling, Kubik [0] has a neat model of employing folks to recover plastic waste from landfills which are then used to creating building materials

0. https://www.buildkubik.com/

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