US2296752A - Process of manufacturing embossed articles - Google Patents

Description

p 1942- E. s. WHETZEL PROCESS OF MANUFACTURING AN EMBOSSED ARTICLE Filed June 11, 1941 FIEl. 2

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Patented Sept. 22, 1942 UNITED STATES PATENT OFFICE PROCESS OF MANUFACTURING EMBOSSED ARTICLES Application June 11, 1941, Serial No. 397,551

4 Claims.

This invention relates to a process of manufacturing an embossed article. The process is particularly adapted for the manufacture of decorated advertising displays, containers and the like but may be used for other purposes as well.

Many useful articles may be made from sheets of plastic materials by shaping the sheet under heat and pressure. In the shaping of the article, parts of the sheet are compressed and other parts are stretched and the thickness of the sheet is correspondingly increased or decreased. Cellulose acetate plastics have proven particularly satisfactory in this shaping process.

Many articles shaped in this manner require colored decorations. For quantity production with high grade printing materials, fiat sheet printing is the most economical and satisfactory means of applying the design, and the screen stencil method of flat printing is best adapted for many articles. The screen stencil method, however, has heretofore had only limited use except when the finished article presented substantially fiat surfaces. On irregularly curved portions of the article, a different and. more expensive method has ordinarily been required.

One object of the present invention is to provide a method by which articles of extremely irregular shape may be produced with decoration applied to the irregular portions as well as to the fiat surfaces as simply and economically as has heretofore been possible by fiat sheet printing. In the preferred form of the invention, this object is attained by the use of lacquers having substantially the same physical characteristics as the sheet itself and applying the lacquered design to the fiat sheet before shaping. In the shaping operation, the several parts of the design under- .gO the same degree of compression and stretching as the sheet itself and must withstand the internal stresses and the necessary heating without breaking or separation from the sheet and without substantial alteration of the coloring.

The shape of the design is altered in the forming process in the same manner as the shape of the sheet from which the article is produced. For that reason the design is applied in a distorted form so that when the shaping operation is complete, the design assumes a desired final form. To produce a given final design requires a careful and accurate study of the deformation occurring in the shaping process and a corresponding control of the original distorted form of the design.

will be understood from the accompanying drawing and the following description and claims:

Fig. 1 is a plan view of a sheet of material having a design stencilled thereon in a distorted form. Fig. 2 is a front elevational view of an embossed article formed from said sheet. Fig. 3 is a plan view of the upper end of said article.

In the drawing, the use of the invention is illustrated as applied to the formation of an advertising display in the form of a half section of a bottle. preferred form, the design is first applied by a screen stencil to a fiat sheet of a cellulose acetate plastic material. One or more such stencils may be used, depending upon the number of colors represented in the design. Parts of the design may be opaque, translucent or transparent, as desired. The lacquered sheet is then placed in a press having forming dies adapted to produce the desired shape of the finished article, Said dies are ordinarily heated to a temperature in the range of 250 Fahrenheit and the pressure and temperature are maintained for a matter of several seconds. In the case of the article illustrated in the drawing, the upper and lower portions l l and I! of the sheet are compressed to form the top and bottom of the bottle-shaped article respectively, while the central portion indicated at I3 is considerably stretched. Accordingly, the design in these parts must be distorted to provide the final desired form. In this connection, attention is called to the line H at the upper part of the design. In the flat sheet this line is in the form of a half elipse. In the finished article the same line takes the form of a half circle. Similarly, the lettering appearing in the central part of the design must be horizontally compressed in the initial form in order to provide the desired final shape when the central portion of the sheet is stretched.

' In developing the process as described above, considerable experiment was necessary to find a suitable printing material which could be used in the process. I have found that the most satisfactory printing material is a lacquer having a cellulose acetate base. Such a lacquer, when used with a cellulose acetate sheet and with a proper plasticizer in the proper proportion can be given approximately the same physical characteristics as the sheet itself. A cellulose acetate lacquer applied to a cellulose acetate sheet has good adhesion to the sheet and does not break away from the sheet in the forming operation. Moreover, a suitable choice of solvents renders lacquers of Other objects and features of the invention this type eminently suitable for screen stencilling.

In carrying out the process in its article having a design whichmay be continuous irrespective oi the shape oi. the several portions of the finished article and which may be conveniently applied by the use of a screen stencil.

The use of a. cellulose acetate lacquer with a cellulose acetate sheet and the proper plasticizer and solvents gives to the lacquer substantially the same plasticity characteristics and resistance to heat as the sheet itself. When used with a transparent sheet, the cellulose acetate lacquer iilm colored with suitable pigments gives a pleasing design which is particularly desirable in a lighted advertising display.

The invention has been described in one of it preferred forms, the details of which may be varied by those skilled in the art without departing from the scope of the invention as defined in the appended claims.

The invention claimed is:

1. A process of manufacturing an embossed, decorated article comprising applying to a flat sheet of a cellulose acetate plastic material a distorted design formed by a cellulose acetate lacquer having at least as great a plasticity as said sheet, embossing said sheet, and thereby changing the design from the original distorted form to a ilnal desired form.

, 2. A process of manufacturing an embossed, decorated article comprising applying to a flat sheet of a cellulose acetate plastic material a distorted design formed by a cellulose acetate lacquer having approximately the same plasticity characteristics as said sheet, embossing said sheet under heat and pressure and thereby changing the design from the original distorted form to a final desired form.

3. A process of manufacturing an embossed, decorated article comprising applying to a list sheet of a cellulose acetate plastic material a distorted screen stencilled design formed by a cellulose acetate lacquer having approximately the same plasticity characteristics as said sheet, embossing said sheet and thereby changing the design from the original distorted form to a ilnai desired form.

4. A process of manufacturing an article comprising applying to a flat sheet of a cellulose acetate plastic material a design formed by a cellulose acetate lacquer having approximately the same plasticity characteristics as said sheet, and then simultaneously changing the shape of said sheet and the lacquer coating under heat and pressure.

EUGENE S. WHETZEL.

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