6 golden rules in plastic product design: packaging

We list the 6 essential golden rules to be kept in mind in packaging design:

1. Keep the wall thickness uniform. The part design with non-uniform wall thickness may cause problems such as: shrinkage on cavities, stresses, voids and warpage. Parts with non-uniform wall thickness cool non-uniformly, thus causing the presence of stresses in the final part.

2. Foresee a correct demoulding for the parts.

3. Add ribs to gain strength. In many applications, part strength must be increased, adding filler to the composite material. But thinking on part design the easiest way of solving this problem is by modifying the part’s geometry, adding ribs.

4. Do through holes, not blind holes. In order to obtain them, it is needed to put rods inside the cavity.

5. Minimize welding lines. Injection speed and melt temperature are key factors that determine the presence of welding lines. They may be visible in the part, promoting aesthetic problems and decreasing the part’s mechanical strength.

6. Avoid sharp corners, since they increase the stress concentration, thus decreasing the part’s resistance and causing premature failures. They also affect to the plastic flow during the moulding stage causing problems during the filling process.

In order to have a good product processability and avoid part failures we need to bear in mind these six indications when designing packages.