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United States Patent m
[in 3,959,431  May 25, 1976
[ 54] METHOD AND APPARATUS FOR MAKING MULTIPLE-LAYERED SHEETS
 Inventor: Frank R. Nissel, Ambler, Pa.
 Assignee: Welex, Incorporated, Blue Bell, Pa.
 Filed: Dec. 19, 1974
 Appl. No.: 534,428
Related U.S. Application Data
(63] Continuation of Ser. No. 287,509, Sept. 8, 1972, abandoned, and a continuation-in-part of Ser. No. 264,387, June 19, 1972, Pat. No. 3,833,704, which is a continuation-in-part of Ser. No. 118,410, Feb. 24, 1971, abandoned.
[521 U.S. CI 264/171; 264/176 R;
264/177 R; 425/133.5
[51 ] Int. CI.2 B29D 7/04; B29F 3/00
[581 Field of Search 264/171, 176 R, 177 R;
425/131.1, 133.5, 461, 462, 463; 18/12 DS,
 References Cited
UNITED STATES PATENTS
2,900,708 8/1959 Pond 425/131
2,985,556 5/1961 Rowland 264/171
3,223.761 12/1965 Raley 264/171
3,400,190 9/1968 Donald 264/171
3,415,920 12/1968 Lee et al 425/131
3,432,588 3/1969 Breidt et al 264/171
3,494,993 2/1970 Breidt et al 264/171
Primary Examiner—Willard E. Hoag
A rod of heat-plastified material is extruded and passed through an adaptor section, during delivery to a sheet extruder. In the adaptor section, another material or substance is fed into the interior of the justextruded rod, such that, upon the rod subsequently being expanded in one direction, and reduced in thickness in another direction, in a sheet-extruder, a multiple-layered laminate may be provided, in that the substance introduced into the rod may differ from the material of the rod. Variations may be made in the manner of introduction of other material into the rod, in order to obtain various numbers of layers, and desired distributions of introduced material through the rod.
8 Claims, 8 Drawing Figures
U.S. Patent May 25, 1976 Sheet 1 of 2 3,959,431
U.S. Patent May 25, 1976 Sheet 2 of 2 3,959,431
METHOD AND APPARATUS FOR MAKING
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation of application Ser. No. 287,509, filed Sept. 8, 1972 and now abandoned. This is also a continuation in part of co-pending application Ser. No. 264,387, filed June 19, 1972, now U.S. Pat. No. 3,833,704, which in turn is a continuation in part of copending application Ser. No. 118,410, filed Feb. 24, 1971, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to providing laminated sheets of thermoplastic, or thermoplastic sheets of multi-layered construction.
In the manufacture of various products, it becomes highly desirable to utilize multiple-layered thermoplastic sheets, of laminated construction. For example, there are various articles of manufacture, wherein it becomes highly desirable to utilize layers having different characteristics. Specifically, in the manufacture of plastic cups, it may be desirable to utilize a thermoplastic material having high impact strength, such as butadiene-styrene. However, such a material generally has a dull, matte finish which does not have the attractive appeal associated with other types of thermoplastics, such as crystal polystyrene, which may have a high gloss finish. Accordingly, it may be desirable to utilize one type of material for strength or structural characteristics, and another for its aesthetic characteristics. Even further, it may be desirable to utilize various types of thermoplastics, laminated together, for various applications, with one laminate or layer providing strength in one direction, another providing strength in another direction, and with an intermediate layer perhaps providing bulk, and with outer layers being preselected according to aesthetic characteristics of materials which comprise the outer layers, for example. It will be noted that these instances in terms of product possibilities are merely suggested for purposes of example, it being understood that this invention encompasses the lamination or multi-layer construction of various types of materials, of various numbers of layers, for covering a myriad of uses.
In the past, multiple-layered thermoplastic layers, or laminates have been constructed, but generally such involves the use of a plurality of sheet extruders, for laminating one sheet to another subsequent to the extrusion of each sheet, by using various co-extrusion processes having complex dies and other apparatus. Often, such apparatus is considerably expensive.
THE PRESENT INVENTION
This invention is directed toward providing a method for extruding multiple-layered constructions, or laminates, which does not require duplication of the sheet lamination functions, and which does not require inordinate expenditures for apparatus.
In its specific form, this invention is adapted for modifying existing sheet-extrusion apparatus of the type that first extrudes a thermoplastic rod, and which then feeds the rod into a sheet extruder, whereby its dimensions are reduced in one direction while being elongated into another, in order to effect sheet formation. The present invention is thus addressed, in one respect,
to the zone, or path of delivery of the rod between the rod extruder, and the sheet extruder. In accordance with this invention, various modifications to the outlet of the rod extruder, and/or the path of delivery be
5 tween the rod extruder and the sheet extruder are contemplated, and preferably in the form of providing adaptors in a family, which may be used, either one, or in a series, for introducing various substances intermediate of the rod, for delivery to the sheet extruder as a
10 component of the rod, which, after extrusion in the sheet extruder will result in a multiple-layered construction, or laminate.
Thus, this invention contemplates selectivity with regard to the type and form of the adaptors to be dis
15 posed between the rod extruder and sheet extruder, depending upon the particular nature, thickness, placement, and number of layers to be desired in the finallyformed laminate. Also, with the apparatus of the present invention, it is possible to modify existing appara
20 tus quickly, and relatively inexpensively, in order to provide various types of laminates, thereby achieving an element of universality with equipment that has previously been limited generally to specific constructions.
25 Also, the present invention contemplates the provision of novel overall apparatus, specifically adapted for accommodating the various laminate-selection features of this invention, in being adapted to receive various quantities and types of adaptors, depending upon the
30 particular application desired.
SUMMARY OF THE INVENTION
A laminate is provided by the use of novel method and apparatus, by the adaptation of an extruded ther35 moplastic rod prior to feeding the rod to a sheet-forming die, by introducing other substances and materials into the rod from laterally of its path of flow between the rod extruder and the sheet-forming die or extruder.
Accordingly, it is a primary object of this invention to 40 provide a novel adaptor for use between a rod extruder and a sheet die or extruder.
It is a further object of this invention to provide a novel method of forming a laminated sheet.
It is another object of this invention to provide a 45 laminated sheet formed in accordance with the method of this invention.
It is another object of this invention to provide a novel apparatus adapted for interchangeability between the point of rod extrusion and the point of entry 50 of the rod into the sheet-forming die, in order to accommodate various pre-selected variations in the final formed laminated sheet.
It is a further object of this invention to provide novel apparatus and techniques for introducing materials and 55 substances into a thermoplastic substance being delivered to a sheet-forming die.
It is another object of this invention to accomplish the above objects, while providing interchangeability of dies.
60 It is another object of this invention to provide a method and apparatus for making multiple-layered thermoplastic constructions, by laterally feeding the substance that is to form one of the layers, into the just-formed rod.
65 It is another object of this invention to accomplish the objects set forth immediately above, in multiple stages, for the provision of greater numbers of layers in the laminate to be formed.