Volume element printing system with an object insertion device

1. A volume element (voxel) printing system for printing a three-dimensional object, the system comprising:

a first printhead group having a plurality of first printheads configured to print a first voxel layer on a substrate;

at least one second printhead group having a plurality of second printheads downstream from the first group, the second group configured to print a subsequent voxel layer on at least part of the first layer;

an object insertion device configured to insert an object into a cavity defined by the voxel layers;

a conveyor to operatively convey the substrate past the printhead groups; and

a control system to control and monitor the printhead groups, the object insertion device and the conveyor.

2. The printing system of claim 1 , wherein the printhead groups are configured not to print on predetermined parts of a preceding layer to define the cavity for receiving the object from the object insertion device.

3. The printing system of claim 1 , wherein each printhead includes a plurality of micro-electromechanical nozzle arrangements configured to operatively eject a voxel therefrom, said voxel selected from the group consisting of a polymer, a metal, a metal alloy, a wax, an evaporative drying material, and a compound.

4. The printing system of claim 1 , wherein the printhead groups are configured to print simultaneously such that a plurality of different layers are simultaneously printed as the substrate is conveyed past the printheads.

5. The printing system of claim 1 , wherein the printheads extend transversely across the conveyor relative to a conveying direction.

6. The printing system of claim 1 , having at least one curing assembly interspersed between the printheads to perform a curing process, said curing process selected from the group consisting of evaporative drying, freezing of voxels, ultra violet curing, printing of reagents, printing of catalysts, and printing of polymerization initiators.