Your Guide to Understanding Blow Molding

Blow molding is the process of forming hollow products by expanding a hot plastic parison against the internal surface of a mold. These cases and enclosures are usually manufactured from high-density polyethylene (HDPE) with a double-wall construction.

The exterior can have a smooth or textured finish to resist dents, cracking and scuffs. The shells are unaffected by a wide range of temperature fluctuation and are impervious to chemical attack. Further, blow-molded cases can meet US 94B specifications as an electrical insulator.

A Focus on the Extrusion Blow Molding Process

Different blow molding processes offer different advantages, based on the material used, performance requirements, production quantity and costs.

In the extrusion blow molding process (most commonly used in case production), the plastic parison is extruded from a hopper above the mold. The two halves of the case mold close, clamping the ends of the extruded plastic. The softened parison inside the mold is filled with air or other compressed gas. The parison expands against the sides of the mold cavity, forming a hollow object the size and shape of the mold. Finally, the part/case is ejected from the mold and the next cycle begins.


Features and Benefits of Blow Molding

  • Durable – impact resistant plastic
  • Molded from chemically resistant resin
  • Color – will not rub off surface
  • Multiple stock sizes can be easily and economically customized with mold-in place interiors
  • Custom sizes practical for quantities over 1,000 pieces

Blow-Molded Case Applications

  • Bulk containers for foods, chemicals
  • Industrial equipment
  • Fuel tanks
  • Lawn and garden
  • Medical equipment
  • Outdoor displays
  • Outdoor products

Talk to Cases By Source About Your Needs

Whether your custom case application requires extrusion blow molding or injection blow molding, Cases By Source is able to offer the process that is best suited for your application.

With access to the newest blow molding equipment, we will factor in the shot size and overall required dimensions of the case, and mold the best case to suit your needs. Our in-house design team will provide assistance and product design capabilities to complete the project. Further, we will design and build prototype and production tools and complete all secondary operations.

Cases By Source provides complete program management, guiding your case or enclosure from concept to production, and ensures the highest quality products.

Note: You can save money by using a stock mold and building a custom interior insert tool at a fraction of the cost of an entirely new mold.


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