Thick rubber walls - like Kong dog toys

Forum,

Can anyone provide some guidance on how thick TPU/TPE walled units with a large inner diameter are made? While thin wall rubber (like CV joint boots) can be air-expanded and pulled off, I don't believe things like a thick rubber Kong toy can be removed that way. Any help is appreciated.

MarthaAttachment 227Attachment 228

Is there a core that the part is molded around?

If the part is injection molded, it sure seems like there has to be a core. But it must be a 2-part core I believe. And that seems cost prohibitive for rubber toys. Possibly it's done in two halves that are glued/welded? -Martha