Looking for lens recommendations product photography

You should read up on macro photography.

A few tips: Use a small aperture, i.e., large f-stop number, say f/8 or f/11. Try to line-up the focal plane with what you are photographing, as the area that is in focus is a "plane". The thickness of the 3d space in focus is related to the f-stop number (aperture), The wider the aperture (say f/1.8) the smaller the depth of field and only a thin slice of the 3d space is in focus. The narrower the aperture (say f/11) the larger the depth of field and the thicker the slice the 3d space is in focus.

You should be looking for a macro lens for this application. I great (and relatively low budget) macro lens is the Canon 100mm f/2.8 (the non-L, non-IS verstion).

You can also look into getting extension tubes for your current setup. That will allow you to focus closer to the subject. The third-party ones can be found relatively cheap and can be found even cheaper (say $30-40) in the used market. I prefer the ones that support AF. Extension tubes + small aperture + align the camera with the plane you want in focus should allow you to get what you need out of your current system.

The last trick is to use focus stacking, this is a bit more cumbersome and involves taking several images with the focus varying from close to far and then using focus stacking software to extract the portions in focus from each image to form a combined image.

I'd try (in order):

1. smaller aperture and careful alignment to see it is good enough
2. get the extension tubes
3. get the macro lens (shop around, there are various options)
4. focus stacking as a last resort