Heat and pressure-formed flexible containers

• US 6,361,642 B1
• Filed: 12/02/1997
• Issued: 03/26/2002
• Est. Priority Date: 12/02/1997
• Status: Expired due to Term

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Bellamy, David, Wolf, Ludwig Jr.
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Piazza, Gladys
• Application Number:
  US08/982,758
• Time in Patent Office: 1,575 Days
• Field of Search: 383/38, 264/545, 264/574, 264/573, 264/512, 264/516, 264/524, 264/535, 264/544, 264/572, 156/221, 156/222, 156/224, 156/292, 156/156, 156/245, 156/285, 156/287, 156/303.1, 156/306.6, 156/308.4
• US Class Current: 156/245
• CPC Class Codes: A61J 1/05 for collecting, storing or administering blood, plasma or medical fluids multiple bags systems for separating or storing blood components A61M1/0209; Infusion or perfusion containers
• CPC Class Codes: A61J 1/10 Bag-type containers
• CPC Class Codes: A61M 1/0209 Multiple bag systems for separating or storing blood components
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: B29C 49/0691 using sheet like material, e.g. sheet blow-moulding from joined sheets
• 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 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/133 Fin-type joints, the parts to be joined being flexible the parts to be joined being rigid B29C66/1312
• CPC Class Codes: B29C 66/242 said joint lines being closed, i.e. forming closed contours
• CPC Class Codes: B29C 66/53262 Enclosing spouts between the walls of bags, e.g. of medical bags
• CPC Class Codes: B29C 66/63 Internally supporting the article during joining B29C66/49 takes precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/712 the composition of one of the parts to be joined being different from the composition of the other part
• CPC Class Codes: B29C 66/81423 being concave
• CPC Class Codes: B29C 66/81427 comprising a single ridge, e.g. for making a weakening line; comprising a single tooth
• CPC Class Codes: B29C 66/81431 comprising a single cavity, e.g. a groove
• CPC Class Codes: B29C 66/81811 of the welding jaws
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/843 : Machines for making separate joints at the same time in different planes; Machines for making separate joints at the same time mounted in parallel or in series
• CPC Class Codes: B29K 2023/06 : PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/083 : EVA, i.e. ethylene vinyl acetate copolymer
• CPC Class Codes: B29K 2023/086 : EVOH, i.e. ethylene vinyl alcohol copolymer
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2027/12 : containing fluorine
• CPC Class Codes: B29L 2031/7148 : Blood bags, medical bags

Abstract

A flexible container comprises first and second flexible sheets of plastic material having peripheral edges, which have been sealed together along a plane to create an interior chamber in the container. At least one of the first and second flexible sheets includes a preformed, stress-relieved region, which is extended outside the plane and overlies at least a portion of the interior chamber.

Claims

1. A method for making a flexible container comprising the steps of

providing first and second flexible sheets of plastic material which softens in response to exposure to heat, the first and second flexible sheets having top, side and bottom peripheral edges,

forming a first seal region joining the peripheral side and bottom edges along a plane to create an interior chamber in the container, the peripheral top edge of the container being left unsealed,

locating a port tube body between the first and second flexible sheets in the unsealed peripheral top edge,

forming a second seal region joining the peripheral top edge along the plane and joining the port tube body within the peripheral top edge, the port tube body providing fluid flow communication with the interior chamber through the second seal region,

after forming the first and second seal regions, softening the first and second flexible sheets by exposure to heat, forming heat-softened first and second flexible sheets, and

applying positive pressure inside the interior chamber through the port tube body to form in the heat-softened first and second flexible sheets stress-relieved regions extending outside the plane and overlying the interior chamber.

2. A method according to claim 1

wherein the step of forming the first seal region includes the step of forming an interior seal joining the flexible sheets together along the plane to form first and second compartments in the interior chamber,

wherein the locating step includes locating first and second port tube bodies between the first and second flexible sheets in the unsealed peripheral top edge,

wherein the step of forming the second seal region includes the step of joining the peripheral top edge along the plane and joining the first and second port tube bodies within the peripheral top edge, the first and second port tube bodies providing fluid flow communication, respectively, with the first and second compartments of the interior chamber through the second seal region, and

wherein the step of applying positive pressure includes applying positive pressure inside the first and second compartments of the interior chamber through the first and second port tube bodies, respectively, to form stress-relieved regions that overlie each of the first and second compartments.

3. A method according to claim 2

wherein the interior seal includes an interruption providing fluid flow communication between the first and second compartments.

4. A method according to claim 1

wherein the plastic material is selected from a group consisting essentially of polyvinyl chloride, polyethylene, polypropylene, ethylene-vinyl-acetate, fluropolymers, or copolymers of these materials.