Why does new Ikea furniture (Kallax) make a liquid sound when moving?

Question

Does anyone know the cause of Kallax furniture (and perhaps more Ikea pieces) making a liquid "wooshing" sound when you move/turn over the furniture?

I purchased two Kallax bookshelves from Ikea (Nov 2015). When I flipped the bookshelves over while moving each of them, they each made a "wooshing" sound as though there was liquid inside of the furniture. Could be unrelated, but I also noticed that the furniture had holes on the top, as though to let the furniture "ventilate" (the holes served no functional or design purpose). I could replicate the sound each time I flipped the bookcase over.

Note, I drove the piece from Ikea to back home and put it together as soon as I got home.

Answer 1

Yes, it can be very true indeed that the 'wooshing sound' that you are talking about is the result of the scrap material that was left unchecked during the production of the furniture. Many a times when hollow parts/ material (like the bamboo arms for wooden chair) are used for designing the furniture, the fine particles of wood dust or scraps resulting from the use of chisel or any other tool may get accumulated into these cavities. I have been working as a furniture repair guy at the Austin Furniture Repair where I have a lot of these cases. So, rest assured as it might not really be that big a problem. Hope it helps!

Answer 2

My guess is that there is a small amount of sawdust/wood particles inside the hollow pieces from the manufacturing process. I wouldn't worry about it.

I can't see how or why there would be liquid inside but if there are holes at one end it should be easy to verify by tipping that end down.