Help identifying (1 Viewer)

[Radams1970]

Sorry, I’m looking for a nice set and found these. They feel like clay but look plastic and off there’s about 500. Kinda hoping someone can talk me out of getting them!

 

[allforcharity]

Mermaid mold. BLIMP. Avoid.

 

[SpaceMonkey420]

Plastic injection spots are my favorite.

 

[Colquhoun]

Plastic injection spots are my favorite.

And these have not just 1...but 4!

 

[Radams1970]

Thanks guys.... I think!

 

[ekricket]

Do you have a picture of the edges? Those are some funny looking injection marks. Too precise and they are textured in the bottom. No discoloration either. They just look funny, but they probably right, these most likely not the best.

 

[CrazyEddie]

Those round dots are ejection marks, not injection marks. They’re where the ejector pins in the injection mold pushed against the still-cooling plastic to eject the chip from the mold.

It makes sense that they’d be textured. The pins normally lie flush with the surface of the mold, so it makes sense that they’d have the same texture as the rest of the mold.

These types of marks are also called “witness marks”. Some are ejection marks, like these; others are injection marks, where the plastic entered the mold through what are called “gates”. The injection witness marks are rough, blobby, and pointy; the ejection witness marks are clean, smooth (usually, but these are textured), and round and flat.

 

[CrazyEddie]

I don’t recall noticing marks like this on the other mermaid chips I’ve seen. It’s possible these used a different mold (but clearly intended to be a copy of the others), or maybe these came from a batch where the marks are more pronounced. The press operator has some degree of control over the final appearance of the chips that come out of the mold by adjusting parameters like temperature, pressure, and time. Ejecting the chip while the plastic is still cooling vs after it’s gotten very firm would change how deep an impression the pins make on the chip.

 

[ekricket]

textured. The pins normally lie flush with the surface of the mold, so it makes sense that they’d have the same texture as the rest of the mold.

They have enough force to push hot material that far into the chip, yet they don’t deform the hot textured dimples? I have a hard time with this.

 

[CrazyEddie]

A fair point. I’m not an expert, I’ve just watched a few videos.

 

[ekricket]

Look at these ejection marks. Bits of plastic left, discoloration around some marks, etc.... the ones in the OP just look different, not like any I’ve seen before. Especially the white ones

 

[ekricket]

Picture of edges or other colors might help

 

[CrazyEddie]

On those top hat chips, one side has three evenly-spaced clean round depressions and the other side has a single rough bump. I suspect the clean depressions are ejection marks and the rough bump is an injection mark. It makes sense that the plastic would be injected on one side of the mold and then the ejector pins would be on the other side of the mold; that matches what I’ve seen in videos showing injection molds in use.

But I agree the chips in the OP look unusual, and different from other mermaid examples I’ve seen. It’s entirely possible those indentations were a deliberately molded feature. They’re just weird.