Reducing waste and costs with a new approach to production
Manufacturing techniques have long relied on subtractive processes – starting with a solid block of material and removing excess to leave the desired part. However, in recent decades a new approach has arisen: additive manufacturing, building up parts layer-by-layer. As the technology develops, evidence increasingly suggests additive techniques can reduce waste and costs compared to traditional subtractive methods.
What is Subtractive Manufacturing?
Subtractive manufacturing refers to machining, cutting, drilling and otherwise removing material to shape a part. It requires significant equipment, expert skills and has notable limitations:
- Machinery: subtractive processes need different specialized machines – lathes, grinders, cutters etc. This necessitates major upfront investment.
- Labor: operators of subtractive machining equipment have to be extensively trained to produce accurate outcomes. Significant manual skill is involved.
- Waste: up to [40% of material](https:// courses.lumenlearning.com/suny-tecmap2materials) can be lost as waste chips and swarf. Designs are also constrained by what can physically be cut or bored out of a block.
For simple parts like a 10cm rod, this can entail using separate machines for turning, cutting and finishing – plus expert staff to oversee each process stage.
What is Additive Manufacturing?
In contrast, additive manufacturing builds up parts by depositing material layer upon layer from a digital model. Often called 3D printing, key advantages are revealed when compared to subtractive techniques:
- Less Machinery: Highly-capable 3D printers can produce end-use parts in a huge range of plastics, metals, even biological tissue. No specialized tooling is required and a single device can create varied, complex geometries.
- Low Skill Needs: Operator training on an industrial printer is measured in days or weeks – a far cry from master patternmakers and machinists. Designers directly prepare digital CAD files guiding the additive system.
- Material Savings: With additive, no excess material chips away in the process. Only what is needed for the final part gets deposited, with reusability of some powders reaching over 95%.
Rather than taking blocks of metal and cutting, drilling and grinding away material, additive systems can fuse together fine metallic powders to near final shape.
Cost and Time Savings
Additive manufacturing machines may have higher upfront costs, but this is compensated by avoiding expenses later for tooling, fixtures, special-purpose machinery and extensive operator training. Efficiencies in design, materials use and labor time also quickly accumulate positive impact.
Parts made with additive can also be turned around extremely quickly – modifying digital files and re-printing a new design iteration takes just hours or days, versus weeks or months to alter physical tooling. Lead times fall from procurement of blocks of raw material to directly producing products on-demand.
Enabling New Design Freedoms
Traditional subtractive methods imposed design restrictions based on machining accessibility – interior cavities and complex lattices or organic shapes could simply not be easily produced by boring and drilling. Additive systems have no such limitations, enabling optimization of designs purely for functionality rather than manufacturability.
Lightweighting, part consolidation and high levels of customization can now be practically implemented, accelerating innovation. 3D printing permits customer co-creation of new designs before production – even economical bespoke manufacturing tailored to an individual.
Additive techniques will not wholly replace all subtractive methods but do promise less waste, lower costs and expanded design possibilities over traditional approaches. As the capabilities of 3D printing expand, companies adopting additive stand to gain clear competitive advantage through smarter production strategies and advanced product designs.