Balloons are commonly used for toys and decorations, and in widespread use as such. A balloon, as the term is used here, refers to an inflatable article, typically made of a latex rubber material, that, upon being inflated, stretches to a larger size relative to its uninflated size. The most common balloon shapes are that of a spherical or ovoid/pear shape, and the elongated cylindrical shape. These balloons are generally created on a simple mold form by dipping the mold form in liquid latex rubber, creating a layer of latex rubber over the mold form. Upon curing, the formed balloon is removed from the mold form by a combination of air pressure at the nozzle end of the balloon and suction at the distal end of the mold form. The pressurized air separates the cured latex rubber from the mold form, which allows the suction to pull the balloon off the mold form.
The pressure/suction form of mass manufacture limits the shapes of balloons that can be produced using this technique. A major limitation is that there cannot be any portion of the mold form that extends outward from the mold form at a substantial angle. So, for example, forming a balloon to resemble a human figure with outstretched arms (e.g. at about a 90 degree angle to the mold form) can't be achieved because of the limitation of having to stretch the nozzle over such features of the mold form. Other types of inflatable articles that are not intended to stretch (e.g. that are made with vinyl-based materials) are produced in all manner of shapes. These can be made in halves that are joined together. Hollow articles made of rubber or similar materials can also be made on mold forms with various features to resemble recognizable shapes, but these are removed from the mold form by means other than a pressure/suction method.
Balloons can be made in a variety of shapes, with some limitations, on mold forms that cannot be used in the pressure/suction method of mass manufacture, requiring removal of the balloon by hand. Techniques for creating a mold form to achieve a desired shape of a balloon when inflated, taking stretching of the material into account, are described in U.S. Pat. No. 9,056,404. The method described therein uses a sophisticated computational approach to determine a rest shape from an inflated shape. However this approach fails to take into account the limitations of the pressure/suction method of mass manufacture.
Therefore, a need exists to overcome the problems with the prior art as discussed above.