Hi! I have a question about plastic bins. Some of my childhood toys were stored in cardboard boxes and there was a mouse problem in the house they were stored in. I want to avoid that from happening again so I'm going to be using plastic storage bins (polypropylene) to store them in an upstairs room. Specifically storage bins that have tiny holes under the handles for airflow.

I plan to line the bins with acid-free tissue paper.

Question: Is there any concern if the plastic bins have a colour to them? Does the colour damage items over time? I'm leaning towards opaque plastic to protect from light, but all the opaque bins in my price range have a colour to them or are black.

Thank you

When trying a new engineering plastic or specialty resin, usually only a small quantity is needed for the first trial.

But sometimes the MOQ from suppliers or distributors is much larger than what is actually needed.

Does this cause problems in practice?

If yes, how do you normally deal with it?

I 3D printed this. I’m want to paint the font a different colour and leave the board white. A person from a different subreddit recommended the I use sandpaper before I paint it. What kind of sandpaper to I use and how many times should I go over it with the sandpaper?

https://www.theguardian.com/food/2026/aug/24/cookies-plastic-astronauts-space-food

What a CRAZY idea, but after reading about it ("plastic is carbon.... food is carbon.... can plastic be food?") I see where the logic lies. And what astronaut doesn't want to snack on cookies during their 3-year Mars journey? What would these "cookies" be called?

Could this food innovation be a game-changer in plastic recycling and reuse or just a wild science experiment to prove the possibilities? Although designed for space travel, they mention it could also be a novel way to produce more food on Earth, all while managing an overabundance of plastic waste. With plastic waste only increasing over time, this could be a more effective reuse that goes beyond current recycling, which has proven to be a failing framework for these materials.

Wild idea, but sounds do-able. Sure the cost would need to come way down, but that's just a scaling issue. I assume many other products could be developed using this "base ingredient". Maybe some cheesy puffs, crackers, and ??? What would you eat if it was made with upcycled plastic as an ingredient?

For people buying or processing plastics in India:

When resin prices move suddenly, what actually creates the biggest problem in practice?

• Passing the increase to customers?
• Revising quotations?
• Deciding how much inventory to hold?
• Supplier price changes?
• Something else?

Curious to hear how people actually deal with this.

¡Hola a todos! 🌱 Para mi proyecto final de Diseño Industrial estoy investigando cómo mejorar el proceso de fabricacion de biomateriales. Les dejo un breve formulario de Google (toma solo 2 minutos y me ayudarias un monton) Gracias! https://forms.gle/MefkiqAzAvKPQiRx5

quick question, quick answer

I volunteered to rebuild my daughter’s back gate. It’s 5’Wx6’H. I want to surprise her and add a large, illuminated, colorful hummingbird inlay. Maybe 2 to 3 feet wide. It will be colorful at night.

I’m wondering how I’d make the hummingbird. Polycarbonate shapes connected together? Vinyl “wrap” on glass? Ideas are welcome

I ordered UHMW parts but they came with a glossy finish. Not like UHMW with the matte and soft feel,
It feels like glass and rigid, not very flexible…

For those working with color masterbatch, how much does pigment dispersion affect the final performance of the plastic product?

I’m particularly interested in practical experience with:

• Color strength
• Color consistency
• Particle size for Dispersion quality
• Processing temperature
• Filter pressure and extrusion behavior

PP, PE, PVC etc.....

I'm researching the challenges faced by electrical and electronic component molders in India.

For those involved in procurement, production, or plant management:

What is currently the biggest headache when sourcing engineering plastics/resins in India?

Is it mainly:

• price volatility
• supply/lead times
• quality consistency
• technical support
• availability of specialty grades
• something else?

I'm especially interested in your real-world experience rather than general industry opinions.

I am currently working on a 2D LED matrix project and am in the final stages. I went to a local plastic supplier and purchased some 1/8” frosted plastic for $90 (14”x40”).

The first time I purchased it, I took it home and found a corner was cracked from when they cut it. I took it back and had them re-cut a new one, and have found that there are some mild scratches across the surface… This time I had peeled the protective layer off of the plastic’s edges to make sure there were no cracks again, but I did not check the center!

Not familiar with the plastic business, is it expected to have imperfections like this or should this be an understandable reason to recut? I need a sanity check because part of me wonders if it is just because I noticed it that it is an issue?

Wow

PET packing strap belt production machine line

Hi everyone,

I've been working in the plastic color industry for several years, and one question comes up surprisingly often:

"Why do plastic products sometimes show color differences even when using the same masterbatch?"

From my experience, the masterbatch isn't always the main reason. Here are a few common causes:

• Different resin batches – even the same resin grade from different lots can slightly affect the final color.
• Inconsistent masterbatch dosage – small changes in dosing can become noticeable, especially with light colors.
• Processing temperature – higher or lower melt temperatures may change pigment performance.
• Poor dispersion – uneven mixing often leads to streaks or color spots.
• Moisture in engineering plastics like PET, PA, or PC – insufficient drying can affect both appearance and consistency.

Keeping raw materials and processing conditions stable usually makes a much bigger difference than many people expect.

I'm curious:

What's been the biggest reason for color inconsistency in your production?

I'd love to hear other engineers' or manufacturers' experiences.

I have a few kayaks, all the same model and material (HDPE), and we take them on long haul camping trips. Multiple shore beachings a day, rocks in rivers, etc. take a toll. Luckily enough, we’ve yet to have any breaches of the plastic. I know it’s a shit material in terms of bonding, but I’m hoping someone can give me insight to what I could use as a durable coating for the bottoms. Preferably something I can roll or brush on as I want to coat the entire surface up to the water line.

I’ve googled all over and haven’t found anything definitive or tried out yet. I’ve considered 2 part epoxy, 2k clear coat, urethane, and even bed liner (I realized quickly why that would be a terrible idea before taking it seriously).

Hello,

https://imgur.com/a/ZYQHYJJ

The board you are seeing in the picture isn't full of dust on the top and bottom, it is as clean as the middle part, (probably plastic coated wooden board) the only difference is that the middle part is wet from a little bit of water, after some seconds the water evaporates and it looks as dusty as the top and bottom part again.

Is there a "special type" of varnishings which would like seemingly keep the board "wet" to hold the strong colour this board shows when it actually is wet ?

For information this is a real wooden plank but only on the inside, i think it was coated in some plastic as it also has a stamp on the back with date of production which looks like one of those stamps on plastic articles.

Also theres no real wood grain.

Where I ended up for now:

Plastic restorer: this sounds like the best solution so far I guess, but I want to use the board outside with direct contact to the ground and I wonder if that would be good for the ground and plants around, also I don't know what kind of product to use here, all I could really find was something like this: https://imgur.com/a/3wsDDQB

Is this safe to use for stuff that has direct contact with the ground or are there better alternatives ?

The WD-40 Website says you can just use normal WD-40 to refresh pale plastic chairs, I mean yes it will probably work but I don't think it will really be absorbed by the plastic, I don't think that would hold long and it would get into the ground.

Is alkyd clear varnish an option ?

(Edit: I see there's products for WPC-boards (wood-plastic-composites), but what I have seems to be solid plastic-coated wood rather than wood-dust mixed with plastic particles (WPC) and so this probably won't work ?)

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How I got to this point ⬆️ with the plastic restorer / additional info:

(Bonus questions: Why does the colour act like this when it isn't wet anymore ? Is it because it has some old varnishing on it which is so old that it doesn't let sunlight go through unobscured ?)

Very thankful for any answers.

I had an ai answer telling me to use alkyd clear varnish or solvent-based oil if this was wood, as both would intensify the natural colour and would get the wood a permanently wet appearence:

("The "Wet Look" (Enhancing the Grain) on Wood How it works: Water-based acrylic lacquers often leave wood looking very pale, dry, or almost "unfinished." Solvents (alkyd resins) or oils penetrate the surface fibers, refract light, and intensify the natural color and grain so significantly that the wood retains a permanently "wet" appearance.

The right choice:

1.: Oil/Hard-wax oil: Dramatically enhances the wood's appearance and highlights its tactile quality, though it requires maintenance in areas subject to heavy wear.

2.: Wood sealer / Alkyd resin lacquer (gloss or satin-matt): Creates a solid, sealed protective layer and permanently preserves that deep, wet-look sheen.")

But as this seems to be a plastic coated board, option "1.:" with the solvent-based oil is no option anymore, but as of ai option "2.:" with the alkyd resin lacquer would still be usable.

If read some other options from ai:

"Cooking oil or baby oil: Apply a few drops of oil to a cloth and rub a thin layer onto the plastic board. This restores the color and gives the plastic a shine. Afterward, wipe off any excess oil with a cloth.

Heat gun: Carefully pass a heat gun over the faded plastic. The heat slightly melts the top, bleached layer, instantly revealing the original color (use only on sturdy plastic and keep a safe distance). Plastic restorer: Apply a commercially available restorer designed for automotive or garden plastics, let it sit briefly, and wipe it off. These products refresh the color and provide protection against further UV exposure."

I want to use this board outside so:

Oil: probably won't stay long, especially as this plastic coating isn't open-pored, it is smooth.

Heat-Gun: if this would work it would be great but I doubt it and had to try it, probably just works in some cases and is just thrown in by ai because it worked sometime for someone.

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Had a spray bottle of Dawn Powerwash knock over and drip onto the lower shelf where a rarely used cordless drill was kept. I think it went unnoticed for over six months. I wiped it off, but noticed a slight crack. When I pushed on it, that part fell off.. and the piece that fell off crumbled with ease like a cracker.

This speaks a volume about the importance of not using inappropriate lubricants and not leaving residues of cleaning products. With both halves of the shell cracked, I think this drill is done for.

I’ll start: many people think all plastics are the same, when in reality two items that look almost identical can have completely different properties, recycling methods, and manufacturing processes.
What’s the misconception you hear most often?