Food Pallet

Rotational molding has been extensively used to the mold pallets because of its many advantages. Unfortunately most companies underestimate the structural requirements for pallets and the subtle details required for a well designed product. This case study will describe the design and development of a rotationally molded pallet for a company in India, M-Plast.

Our client described a pallet that would be smooth, devoid of any holes through the surface except for handles around the perimeter and attractive. They provided us with a 2D concept drawing created in AutoCAD as shown in this picture.

Although a pallet mold could have been constructed from the drawing provided it would have been significantly inferior to the final design generated from the CAD files shown in these pictures.

This design was attained after numerous iterations and subtle design improvements invested into many weeks of development. Some of these iterations are shown in the following pictures.

The difference between the original design and the final design is in the details which will be discussed in the following pictures.

The Autocad 2D design described a pallet with a flat surface compared to the final 3D design we developed which included a subtle crowned surface.

A crowned surface eliminated any chance of indeterminate warpage which is typical of rotationally molded flat surfaces.

Our design included numerous kiss-offs for added reinforcement which were carefully located to coincide with the grid pattern on the top surface. This attention to detail disguised any blemishes with these textured areas that would have otherwise been noticed on the top surface.

Kiss-offs were detailed to provide maximum heat transfer by providing a large surface area which funneled down to a point contact. This design assured us that the wall thickness would be uniform and surfaces would knit with minimum voids.

The Autocad design specified a simple foot which distributed loads to a much broader surface area that could easily collapse. 

Our design however, specified cored legs which transferred loads directly to the opposite surface with a generous kiss-off. The smaller surface area highlighted in yellow was all that contacted the floor.

This structure eliminated the bending moments and deformation problems associated with the earlier proposed design.

Draft and parting lines were defined for every feature, including the strap tie down openings around the perimeter. In these sections draft was split for each mold half.

These are only a few of the hundreds of details that make the difference between a quality pallet that works and one that will just looks like a pallet. The following photographs will show the mold and final production part. The cast mold pattern was cut directly from the CAD files you have just seen and has been a major success.