Injection bonded articles comprised of a rigid core and secured together with an elastomeric material network which also forms seals and encapsulates at least a portion of the rigid core. The elastomeric material is selected to be compatible with the material comprising the rigid core to create a chemical and mechanical bond therebetween. Injection bonding and over-molding techniques are used to fabricate an electrodeionization apparatus spacer comprised of mated rigid segments secured by a unitary elastomeric material network that also forms internal and external seals that fluidly isolate one or more of inlet ports, resin cavities, and outlet ports as well as throughports. Injection bonding and over-molding techniques can also be used to fabricate other articles comprised of multiple segments.