Blow Molding

By December 1, 2017Articles

Blow Molding Requires Precision Molds to Assure the Highest Standards of Quality

Blow Mold Noble PrecisionIn the most basic of terms, blow molding is a process used in the manufacturing of hollow plastic parts.  This production method is a successor, in a manner of speaking, to the art of glassblowing, and it has permitted the replacement of heavier and/or breakable glass parts with lighter and more durable items or components.

Regardless of the specific parts or items to be produced, the general blow molding process remains consistent throughout.  It begins by melting the plastic and forming it in a parison (or hollow plastic tube) that has a hole in one end to allow compressed air to pass through.  The parison is placed in the mold and pressurized air is applied through the hole to push or force the melted plastic to take the shape of the mold; once that plastic has cooled and hardened, the mold is opened and the part/component is removed or ejected.

There are in fact three main types or variations of the blow molding process; these include:

Extrusion Blow Molding – this is essentially the general process described above, as it is derived directly from glass blowing techniques.  In this case, a metal blow pin is inserted in the opening of the parison and the melted plastic is forced, or extruded, into the mold using compressed air.  This is considered the simplest method of blow molding; it is also time-effective and cost-effective and hence is commonly used for high-volume production runs.  

Injection Blow Molding – in this method, the parison is formed around a core pin using Injection Molding then the injection mold is opened and the parison is transferred to the blow mold for the production of the part/component using the extrusion process.  Because this practice often has a lower production rate, it is the least-used method of blow molding, often reserved for small medical vials and single-serve bottles.

Injection Stretch Blow Molding – in this particular process, the injection molded parison is stretched before it is transferred to the blow mold.  This allows for the production of parts or items that are more rigid, less porous, and have higher transparency and better impact resistance; it is therefore a favoured method for producing bottles/containers for carbonated beverages.

Blow molding is applied in the manufacture of a wide range of products; a sampling of such items would include containers or bottles for:

  • Drinking water
  • Juices and sodas
  • Liquid soaps/detergents
  • Motor vehicle engine fluids
  • Household cleaning supplies
  • Medicinal and cosmetic products

In order to produce such vessels, etc., with the volumes, efficiencies, and quality/tolerances demanded by their customer base, manufacturers will need blow molds (and in some cases injection molds too) that are very precise in their design; it would be unfathomable to think that distributors of drinking water or sodas would accept plastic bottles that are malformed and/or prone to leaks or rupture.

Therefore, manufacturers who employ blow molding within their production methods would be well-advised to consult with the precision mold-making experts from Noble Precision as a means of assuring the highest standards of quality for their specific products/outputs.

Precise Blow Molds to Help Manufacturers Attain the Highest Possible Efficiencies

High-performance 5-axis CNC machining centreNoble Precision has the capacity to design/produce precise blow molds for the production of parts/components in a wide variety of shapes and sizes.  This expertise is reinforced by Noble Precision’s considerable financial investments in state-of-the-art technology, notably the latest in 5-axis simultaneous CNC machines and CAD/CAM software; this commitment allows their clients to benefit from the most advanced and accurate machining methodology.

The Precision Blow Molds produced by the Noble Precision team can help their clients attain the highest possible manufacturing efficiencies, including:

  • Cost savings
  • Time savings
  • High tolerances
  • Waste reduction

For additional information on the Precision Molding services available from Noble Precision, please go to our Mold Making page. 

For precise blow molds to support the high-quality and high-tolerance production of plastic parts or components, call the mold-making specialists at Noble Precision at 647-499-7569 or contact us to schedule a no-obligation consultation.