There are many rotational molding companies that can offer the right kind of molding services you need. Infusion molding is the driving of liquid plastic into a forming cavity. http://www.blue-reed.com/
A freelance product designer, as other product designers must hold a substantial degree or confirmation to take up customer activities or work in this field. http://www.blue-reed.com/ Slideshow 7479063 by bluereedllc
Rotomolding as a process is typically thought of as a means of creating large hollow parts. Rotational Molding, like all extra plastics processing techniques, has its very own wonderful conveniences, downsides and element-layout wishes.