Experience injection molding with everyday objects! 1/2

Injection molding is not familiar to us in our everyday lives, as it is often associated with factories and laboratories. This time, we will introduce a way to experience what injection molding is all about by “duplicating” it using items sold at 100-yen stores!

*‘Duplication’ is the process of creating a new object with the same content and shape as the original one!

What to prepare

1) UV resin

2) UV-LED light

3) oyupla. Then decide on the item you want to duplicate.

This time, we decided on this item.

This item was originally made by injection molding. Therefore, there are PL (mold division lines) marks on the surface. Therefore, we would like to create our own “mold” using this PL as a reference.

Gates and PLs were determined in this way.

(i) Making the core mold.

Make a mold of the core side to match the PL above.

Soften the oyupla by dipping it in hot water of about 80°C.

The softened oil plastic is then pressed against the item.

It is important to note that the area to be gated should not be blocked. If the gate is blocked, the resin cannot flow through. Once the plastic is approximately pressed into place, cool it with water to harden the plastic.

If the mold cannot be pressed successfully, soak it again in hot water at about 80°C to soften it and start again. This completes the core mold.

(2) Making the cavi mold

Now make the mold for the other side. This one also uses oyupla.

(The color is changed so that the cavi-core is easily recognisable).

Cover the other side with softened oil plastic. Again, do not block the gate.

Using transparent oyupla allows air bubbles etc. to be seen and reduces pressing defects.

If there are no problems, cool the oyupla in water and harden.

(3) Mould release

After the oyupla has hardened, remove the item from inside the mold and check that it is properly pressed against the mold. If there are no problems, align the cavi-mold with the core mold again.

This will create a space in the mould that fits the shape of the item.

By pouring resin through the gate into this space, replication becomes possible.

In the next article, we would like to experiment to see if it is possible to mould the item by pouring resin (UV resin) through the gate.