Process Advantages
Engineered blow molding offers a highly versatile process for fabricating parts. Effective designs for its blow molding take advantage of the inherent advantages of the process:

• “Hollow” aspect of design
• Strength-to-weight structural integrity
• Suitability for large shapes

Process Limitations
• Extent to which material can be stretched
• Degree to which complexity/detail can be reproduced
• Part length limitation by material melt strength

The design must also make economic sense compared to other processes and materials.

The design/processing relationship
Engineered blow molding forms parts by blowing a hollow parison outward to conform to the shape of the mold (Fig.1). Inherent to this process is stretching of the thermoplastic resin material. That stretching thins the walls. Forcing the material to stretch too much may make it impossible control wallsection thickness or even cause the parison to rupture/fracture.
...