Method for producing a foam body having an internal structure

A foam body having an internal structure, wherein the internal structure comprises a first polymeric material and wherein the foam body comprises a second polymeric material and the first polymeric material of the internal structure is distinct from the second polymeric material of the foam body wherein all surfaces of the internal structure contact the foam body, and wherein the internal structure is a spring having a loading direction and that upon stressing of the foam body at a location at which the internal structure is present and along a stressing direction of the internal structure a determined compressive strength is ≥10% to ≤10,000% higher than a compressive strength of the foam body at a location at which no internal structure is present as determined according to DIN EN ISO 3386-1:2010-09 using 40% compression.

The foam body having an internal structure of claim 1, wherein the first polymer material comprises a plurality of different materials.

The foam body having an internal structure of claim 1, wherein the foam body comprises a flexible foam having a compressive strength of ≥10 kPa to ≤100 kPa according to DIN EN ISO 3386-1:2010-09 using 40% compression and a density of ≥10 kg/m3 to ≤100 kg/m3.

The foam body having an internal structure of claim 1, wherein the second polymeric material is a polyurethane polymer.

The foam body having an internal structure of claim 1, wherein the internal structure alters a deformation behavior of the foam body under tensile load, compressive load, shear load, or a combination thereof, such that upon deformation under a load a foam body volume element that encompasses the internal structure undergoes a change in volume of ≥10% relative to a volume of the foam body volume element that comprises no internal structure.

The foam body having an internal structure of claim 1, wherein the spring comprises a leaf spring, a spiral spring, an elliptical spring, a parabolic spring, a wave spring, a leg spring, a rod spring, a coil spring, a disk spring, or a combination thereof.

The foam body having an internal structure of claim 1, wherein the internal structure comprises a plurality of internal structure volume elements comprising non-interconnected spherical volumes, non-interconnected elliptical volumes, non-interconnected rod-shaped volumes, interconnected spherical volumes, interconnected elliptical volumes, interconnected rod-shaped volumes, or a combination thereof.

The foam body having an internal structure of claim 7, wherein the plurality of internal structure volume elements have individual volumes of from ≥10 μL to ≤1000 mL.

The foam body having an internal structure of claim 1, wherein the first polymeric material is a polyurethane polymer.

The foam body having an internal structure of claim 1, wherein the internal structure is formed in the foam body by:

• introducing an injection means at a predetermined location inside the foam body and injecting via the injection means a predetermined amount of a melt of the first polymeric material or predetermined amount of a reaction mixture that reacts to afford the first polymeric material at the predetermined location, wherein the predetermined amount corresponds to an internal structure volume element, and wherein injecting the predetermined amount destroys and/or displaces a portion of the foam body at the predetermined location;
• and
• repeating the introducing step for further predetermined locations inside the foam body corresponding to further internal structure volume elements until the internal structure is formed.

The foam body having an internal structure of claim 10, wherein a plurality of injected melts or a plurality of injected reaction mixtures become at least partially interconnected to afford a common internal structure volume element.

The foam body having an internal structure of claim 10, wherein a plurality of injection means differing in their mechanical construction are employed to introduce the predetermined amount.

The foam body having an internal structure of claim 10, wherein a plurality of introducing steps are performed simultaneously.

The foam body having an internal structure of claim 10, wherein the injection means is a cannula and the end of the cannula is moved to the predetermined location of the foam body for injection of the predetermined amount wherein an end of the cannula is performed such that the first polymeric material already present in the foam body is not contacted by the cannula.

The foam body having an internal structure of claim 10, wherein formation of the internal structure is followed by performance of a material-removing after treatment step.