Signaling arrangements employing molded thermoplastics
AssigneeDigimarc Corporation
InventorsTomas Filler, Vojtech Holub
Life of this patent
Estimating the term…
Abstract
A thermoplastic resin is molded to define a container bearing a surface 2D code signal, such as a digital watermark pattern. In some arrangements, the mold dimensions are tailored, and process parameters are selected, so that an indentation in the mold gives rise to a corresponding indentation—rather than a corresponding protrusion—in the shaped plastic. In other arrangements, a metal mold is provided with a patterned resin on its surface to define the 2D code signal. The resin may take the form of a rigid or non-rigid insert that can be removed or re-worked to change the code signal without changing the metal mold. A variety of other improvements and arrangements are also detailed.
Claims22
A method comprising:
- introducing plastic into a mold that defines plural cavities, and removing from the mold a shaped item that has plural indentations, rather than protrusions, at locations corresponding to said plural mold cavities.
A method comprising:
- introducing plastic into a mold that defines plural cavities, and removing from the mold a shaped item that has plural indentations, rather than protrusions, at locations corresponding to said plural mold cavities, wherein the cavities include cavities having opening dimensions of 160 microns or less, and said cavities having opening dimensions of 160 microns or less span, in aggregate, a majority of total surface area spanned by all cavities.
A method comprising:
- introducing plastic into a mold that defines plural cavities, and removing from the mold a shaped item that has plural indentations, rather than protrusions, at locations corresponding to said plural mold cavities, wherein the plural cavities correspond to a 2D code comprised of marks at locations within an N×N array of locations, wherein the cavities are placed at positions corresponding to between 5% and 20% of said N×N locations.
A method comprising:
- introducing plastic into a mold that defines plural cavities, and removing from the mold a shaped item that has plural indentations, rather than protrusions, at locations corresponding to said plural mold cavities, wherein:
- the plastic comprises HDPE or LDPE;
- the cavities include cavities having opening dimensions of 100-160 microns, and said cavities having opening dimensions of 100-160 microns span, in aggregate, a majority of total surface area spanned by all cavities of said mold;
- and
- the method comprises extrusion blow molding, with a blowing pressure of 3-6 bars.
A method comprising the acts:
- introducing plastic, other than polyethylene terephthalate (PET) or polypropylene (PP), into a mold, said mold having a mold surface that defines plural mold cavities having opening dimensions of 240 microns or less, the mold surface having a surface roughness of less than 1.6 microns, the method including urging the plastic against the mold surface with a molding pressure of 1.5-10 bars, and removing from the mold a molded item having an item surface that faced the mold surface, said item surface having plural indentations, rather than protrusions, at locations corresponding to said plural mold cavities.
Dependencies are inferred from the claim text.