Thermoformed hollow plastic body and method for producing it

• US 9,676,516 B2
• Filed: 10/18/2013
• Issued: 06/13/2017
• Est. Priority Date: 10/19/2012
• Status: Active Grant

• Current Assignee: Dr. Doll Holding GmbH
• Original Assignee: Dr. Doll Holding GmbH
• Inventors: Doll, Theo
• Primary Examiner(s): Tucker, Philip
• Assistant Examiner(s): Slawski, Brian R
• Application Number:
  US14/057,547
• Publication Number:
  US 20140113092A1
• Time in Patent Office: 1,334 Days
• Field of Search: 156 60, 156196, 156210, 156212, 156242, 156245, 156292, 156297, 156298, 1563031, 1563082, 1563084, 1563096, 1563099, 156322, 428 357, 428 365, 108 5726, 108 5727
• CPC Class Codes: B29C 49/20 of articles having inserts or reinforcements ; Handling of inserts or reinforcements
• CPC Class Codes: B29C 51/00 Shaping by thermoforming , i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor blow moulding of tubular preforms B29C49/00, deforming of tubular or hollow preforms B29C67/0014
• CPC Class Codes: B29C 51/12 of articles having inserts or reinforcements
• CPC Class Codes: B29C 51/267 Two sheets being thermoformed in separate mould parts and joined together while still in the mould B29C49/0691 takes precedence
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/065 HDPE, i.e. high density polyethylene
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2055/02 ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0097 Glues or adhesives, e.g. hot melts or thermofusible adhesives
• CPC Class Codes: B29K 2623/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2625/06 PS, i.e. polystyrene
• CPC Class Codes: B29K 2715/003 Cellular or porous
• CPC Class Codes: B29L 2031/7178 Pallets
• CPC Class Codes: B65D 19/0028 and each contact surface having a discrete foot-like shape
• CPC Class Codes: B65D 19/18 made wholly or mainly of plastics material
• CPC Class Codes: B65D 19/385 Frames, corner posts or pallet converters, e.g. for facilitating stacking of charged pallets
• CPC Class Codes: B65D 2519/00034 Plastic
• CPC Class Codes: B65D 2519/00069 : Plastic
• CPC Class Codes: B65D 2519/00139 : Plastic
• CPC Class Codes: B65D 2519/00174 : Plastic
• CPC Class Codes: B65D 2519/00208 : Plastic
• CPC Class Codes: B65D 2519/00273 : made of more than one piece
• CPC Class Codes: B65D 2519/00288 : made of one piece
• CPC Class Codes: B65D 2519/00323 : made of more than one piece
• CPC Class Codes: B65D 2519/00338 : contact surface having a discrete foot-like shape
• CPC Class Codes: B65D 2519/00437 : on the load supporting surface
• CPC Class Codes: B65D 2519/00562 : chemical connection, e.g. glued, welded, sealed
• CPC Class Codes: B65D 2519/00592 : by means of hinges
• CPC Class Codes: B65D 2519/0091 : whereby all side walls are hingedly connected to each other
• CPC Class Codes: Y10T 428/1352 : Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1376 : Foam or porous material containing

Abstract

A thermoformed hollow plastic body, which is formed by two plastic shells welded to one another around the periphery, with at least one hollow chamber, into which at least one dimensionally stable plastic body is placed, and a method for producing such a thermoformed hollow plastic body wherein a first sheet of plastic is thermoformed into a first plastic shell while forming at least one open hollow chamber.

The outer contour of the plastic body is made to match an inner contour of the hollow chamber and is connected by its surface in full area contact and with a material bond to neighboring inner surfaces of the plastic shells.

Claims

1. A method for producing a thermoformed plastic pallet comprising the steps of:

thermoforming a first sheet of plastic into a first plastic shell having a base wall defining a lower terminal surface and a plurality of supporting feet projecting downwardly from and beyond the lower terminal surface in spaced-apart relation with one another to form respective areas for supporting the plastic pallet on a support surface, the first plastic shell having a hollow chamber formed interiorly of each of the supporting feet;

inserting a dimensionally stable plastic body into each of the hollow chambers, each plastic body having an outer contour matching an inner contour of the corresponding hollow chamber;

thermoforming a second sheet of plastic into a second plastic shell;

placing the second plastic shell onto the first plastic shell and the plastic bodies;

welding a periphery of the second plastic shell to a peripheral region of the first plastic shell; and

connecting each of the plastic bodies at respective surfaces thereof in a material-bonding manner to corresponding neighboring inner surfaces of the first and second plastic shells.

2. The method according to claim 1, further including forming each plastic body as a foam plastic body or as an injection-molded plastic body.

3. The method according to claim 1, further including forming each plastic body as a foam plastic body, wherein the step of thermoforming the second sheet of plastic includes forming the second plastic shell with a hollow chamber, and forming each foam plastic body so as to be oversized with respect to the corresponding hollow chamber of the first plastic shell and with respect to the hollow chamber of the second plastic shell.

4. The method according to claim 3, further including welding the foam plastic bodies to the inner surfaces of the first and second plastic shells.

5. The method according to claim 4, wherein the step of inserting includes inserting each foam plastic body into the corresponding hollow chamber in a heated state of the first plastic shell.

6. The method according to claim 5, wherein the step of placing includes placing the second plastic shell in a heated state and under pressure onto the first plastic shell and the plastic bodies, and the step of welding includes welding the second plastic shell both peripherally to the first plastic shell and in full area contact to the foam plastic bodies.

7. The method according to claim 1, wherein the step of thermoforming the second sheet of plastic includes forming the second plastic shell with a hollow chamber, and outer dimensions of each plastic body match inner dimensions of the hollow chambers of the first and second plastic shells, the step of connecting further including providing the surfaces of the plastic bodies with a bonding layer of adhesive to form a material-bonding connection between the plastic body and the corresponding neighboring inner surfaces of the first and second plastic shells.

8. The method according to claim 7, wherein at least the hollow chambers of the first plastic shell are cooled before the inserting step.

9. The method according to claim 7, including incipiently melting each plastic body adjacent an outer contour thereof before the inserting step to provide a smooth surface on the plastic body.

10. The method according to claim 1, further including inserting a reinforcing profile arrangement into the first plastic shell before the step of placing.

11. The method according to claim 1, wherein the plastic bodies are interconnected to one another to form a one-piece body, the method further including inserting a reinforcing profile arrangement into the one-piece body before the step of placing.

12. the method according to claim 1, wherein the plastic bodies are interconnected to one another to form a one-piece body, and the step of inserting includes inserting the one-piece body into the first plastic shell such that each plastic body of the one-piece body is located within one of the hollow chambers.