Assembly Line

How syringes are made

A disposable syringe is three plastic and rubber parts molded by machines that run around the clock.

stations
7
things upstream
80
raw sources
23
steps from the ground
11

The short version

A disposable syringe has a clear plastic barrel, a plunger and a rubber tip that seals the two. Machines mold the barrel and plunger from polypropylene, print the volume scale, and fit the rubber tip. A hypodermic needle, drawn from stainless steel tube, is added before the sterilized syringe is sealed in its pack.

  1. Mold the barrel

    Polypropylene pellets are melted and injected into a steel mold cavity. The mold is cooled, opens and drops out a clear tube with a flange and a tip.

    Goes in
    Polypropylene

  2. Mold the plunger

    A second machine molds the plunger, a cross-shaped rod with a thumb pad on one end. Its shape resists bending while it slides.

  3. Print the scale

    Ink is applied to the barrel to mark volume, with a precision that clinicians depend on for dosing.

    Goes in
    Ink

  4. Make the rubber seal

    A rubber tip is molded so it fits the barrel wall with no gaps. A thin film of silicone oil coats the barrel so the plunger glides.

    Goes in
    Synthetic rubberSilicone

  5. Draw the needle tube

    Stainless steel tube is drawn through progressively smaller dies until it reaches the needle gauge. It is cut into lengths and the end is ground to a sharp bevel.

    Goes in
    Stainless steel

  6. Assemble the parts

    Robots push the seal onto the plunger, slide the plunger into the barrel, and fit the needle hub with its protective cap.

  7. Sterilize and seal

    Packed syringes are sterilized in their wrappers. Sealing them first means they stay sterile until opened.

    Goes in
    Plastic bag
End of the lineSyringe

Worth repeating

  • In 1853, Charles Pravaz and Alexander Wood independently developed syringes fitted with a needle fine enough to pierce the skin.
  • In 1951, Rothauser produced the first injection-moulded polypropylene syringes, a plastic that can be heat-sterilized.
  • Hypodermic needles are made from stainless steel or niobium tube, which is drawn through progressively smaller dies.

Back to the ground

Follow every input upstream and syringe starts as these 23 raw sources.

WaterSilica sandCrude oilSoybeansRapeseedClayAirTitanium oreIron oreSulfurCornSugarcaneNatural gasQuartzCoalTimberChromiteLimestoneNickel oreRock saltTronaSugar beetBauxite

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Canned soup 9 stations · 23 raw sources Pickles 6 stations · 16 raw sources Gelatin 7 stations · 4 raw sources Pasteurized milk 6 stations · 1 raw source Jam 6 stations · 10 raw sources Vinegar 6 stations · 8 raw sources

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Sources

Cite this page: "How syringes are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/syringe

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