How Machines Build 3D Objects Layer by Layer from Melting Plastic

This patent describes a method and machine for creating three-dimensional objects by precisely depositing melted material, layer by layer, from a movable nozzle onto a base.

What it covers

This patent describes an apparatus that builds a three-dimensional object by sequentially depositing multiple layers of solidifying material. It uses a movable head with a dispensing outlet, or nozzle, that releases material in a fluid state, such as melted plastic (Claim 1). This material then solidifies at a specific temperature. A mechanical system moves the dispensing head and a base member relative to each other along X, Y, and Z axes (Claim 1). This movement allows the machine to precisely place each layer, building up the object slice by slice. For example, a computer-aided design (CAD) program can create a 3D model, which is then converted into instructions for the machine to deposit material for each layer (Claim 11).

What it doesn't cover

• —Does not cover 3D printing methods that do not involve depositing material from a dispensing head, such as laser sintering of powder or stereolithography using light to cure liquid resin.
• —Does not cover processes where the material does not solidify after being discharged from the nozzle, as Claim 1 specifies a 'supply of material which solidifies at a predetermined temperature'.
• —Does not cover methods that build objects without forming 'multiple layers' sequentially, as described in Claim 1.
• —Does not cover systems where the dispensing head and base member do not move relative to each other in three dimensions along 'X,' 'Y,' and 'Z' axes.
• —Does not cover 3D printing techniques that do not meter the discharge of material from an orifice at a predetermined rate, as required by Claim 1.

The clever bit

The core innovation was precisely controlling the deposition of a material that changes state (from fluid to solid) in successive, thin layers. By moving a dispensing head and base member in three dimensions, and carefully metering the material, complex shapes could be built up automatically, layer by layer, with controlled thickness.

Why it matters

This patent is foundational to Fused Deposition Modeling (FDM), one of the most widely used 3D printing technologies today. It laid the groundwork for how many modern 3D printers operate, enabling the creation of physical prototypes and functional parts directly from digital designs. The company Stratasys, founded by the inventor, commercialized this technology, making 3D printing accessible for various industrial and, eventually, consumer applications.

Real-world examples

• 1.Stratasys FDM 3D printers
• 2.Ultimaker desktop 3D printers
• 3.Prusa Research 3D printers
• 4.Creality Ender series 3D printers
• 5.Most consumer-grade 3D printers that use plastic filament