Vial Files: How Are Tubular Glass Vials Made?

In the age of 3D printing, it’s easy to handwave how certain items get made. If it isn’t printed, it’s injection molded or perhaps vacuum formed.

With so many simple concepts (sitting on top of immensely complex techniques) floating around, it’s no shock that glass vials come from mechanized glass blowing processes.

Glass can’t rest like some other products as it is essentially a slow-moving liquid and begins to settle even as it is being formed.

For anyone wondering how the glassware used in hospitals, vitamin shops, and dispensaries around the world gets made, this is the article to read.

Glass Vials

Vials are distinct from bottles in one direction. All vials are bottles, but not all bottles are vials.

Vials, in common usage, need to adhere to certain standards in terms of shape, size, and wall density. After all, the National Institute of Standards and Technology has pages of rules laying out rules for product labeling. Many of these rules protect consumers from receiving less than they advertised.

In medical applications, you certainly want the vial to contain the amount of material indicated. Vials come in many sizes and colors, learn more about the uses of each.

Tubular Glass

Glass vessels are produced through either a blown glass or tubing glass method. Industrial blown glass is more precise than the artisanal version you might picture, but not precise enough for proper glass vials with caps, markings, or made for cork stoppers.

Despite the name, blown glass uses molds to create shapes and those molds allow variations in wall thickness while also allowing materials to settle at the bottom.

Tubular glass maintains a constant temperature and motion to ensure that variations in wall thickness don’t occur.

Initial Process

The process for forming tubular glass starts with a furnace that melts down raw materials, mostly silica, into a molten, malleable form. From there it is fed into machines that shape and cut it utilizing one of two processes.


In this process, a long glass tube forms by flowing glass out of the furnace around a tapered mandrel. This vertical implement allows the glass to flow around it before dropping down into rollers that draw the glass at a set speed.

The rollers keep the outside moving while air pushed through the tip of the mandrel maintains the inner core.

Once formed, cutters chop the tubular glass at the end and press it flat with a stamp that indicates the manufacturer. The ‘top’ of the vial is formed with a lip through the application of blowers.


The Danner process utilizes a rotating mandrel to shape the glass as it flows down an incline. This gradual flow allows a stream of air to keep the walls separate and form a tube.

Once formed, the glass tube follows the rest of the manufacturing identically to the Vello process.

Quality and Testing

Once a vial exits the line, multiple cameras shine light through the vial to confirm the dimensions and to weed out impurities.

Find More

Like most manufacturing, glass vials are a product of simple physics and chemistry refined through decades of automation to arrive at a quality, affordable product.

If you’re interested in other insights into business, technology, and manufacturing check out our other offerings.

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