Method for stretch-blow moulding a container, including measuring the movement of the stretch rod during a boxing operation

Patent metadata

Field	Value
Publication number	US-9744712-B2
Application number	US-201314646148-A
Country	US
Kind code	B2
Filing date	Nov 14, 2013
Priority date	Nov 20, 2012
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

Disclosed is a method for manufacturing a container ( 2 ) from a blank ( 3 ) made of plastic material, in a stretch-blow molding unit ( 7 ) including: a mold ( 11 ) provided with a wall ( 13 ) and a mold base ( 14 ) which is axially movable relative to the wall ( 13 ) between a low position and a raised position; a stretch rod ( 22 ) which is axially movable relative to the mold ( 11 ) between a high position and a low position; the method including: a phase of inserting the blank ( 3 ) in the mold ( 11 ); a phase of stretch-blow molding; a phase of boxing; a phase of determining the start and end of the boxing phase, respectively, by detecting the movement of the rod ( 22 ) from the low position thereof and the stopping of the rod ( 22 ) at the raised position thereof.

First claim

The invention claimed is:

1. Method for producing, from a blank ( 3 ) of plastic material, a container ( 2 ) having a body ( 4 ) and a base ( 6 ), in a stretch-blow-molding unit ( 7 ) comprising:
a mold ( 11 ) provided with a wall ( 13 ) having the shape of the body ( 4 ) of the container ( 2 ), and with a mold base ( 14 ) having the shape of the base ( 6 ) of the container ( 2 ), the mold base ( 14 ) being movable axially relative to the wall ( 13 ) between a low position and a raised position;
a stretch rod ( 22 ) that is movable axially relative to the mold ( 11 ) between a high position in which the rod ( 22 ) is outside of the mold, and a low position in which the rod ( 22 ) locally presses the blank ( 3 ) against the mold base ( 14 ) in the low position;
this method comprising:
a phase for introduction of the blank ( 3 ) into the mold ( 11 );
a stretch-blow-molding phase, during which a fluid under pressure is injected into the blank ( 3 ) and the stretch rod ( 22 ) is moved from the high position to the low position;
a boxing phase, during which the mold base ( 14 ), initially in low position, is moved to the raised position, and during which the stretch rod ( 22 ), accompanying the mold base ( 14 ), is moved from the low position to a raised position corresponding to the raised position of the mold base ( 14 );
wherein the method comprises the determination of the start of the mold base ( 14 ) from the low position by detection of the movement of the rod ( 22 ) from the low position, and the determination of the arrival of the mold base ( 14 ) at the raised position by detection of the stopping of the rod ( 22 ) at the raised position.

2. Method according to claim 1 , further comprising determining the instantaneous position of the mold base ( 14 ) between the low position and the raised position by detecting the instantaneous position of the rod ( 22 ) between the low position and the raised position.

3. Method according to claim 1 , further comprising an operation for adjustment of a movement order for the mold base ( 14 ), when the start of the mold base ( 14 ) does not correspond to a predetermined theoretical start.

4. Method according to claim 1 , further comprising an operation for adjustment of the flow rate of a solenoid valve ( 19 ) connecting an actuator ( 17 ) carrying the mold base ( 14 ) to a source ( 18 ) of fluid under pressure, when the actual arrival of the mold base ( 14 ) does not correspond to a predetermined theoretical arrival.

5. Stretch-blow-molding unit ( 7 ) for producing, from a blank ( 3 ) of plastic material, a container ( 2 ) having a body ( 4 ) and a base ( 6 ), this stretch-blow-molding unit ( 7 ) comprising:
a mold ( 11 ) provided with a wall ( 13 ) having the shape of the body ( 4 ) of the container ( 2 ) and with a mold base ( 14 ) having the shape of the base ( 6 ) of the container ( 2 ), the mold base ( 14 ) being movable axially relative to the wall ( 13 ) between a low position and a raised position;
a stretch rod ( 22 ) that is movable axially relative to the mold ( 11 ) between a high position in which the rod ( 22 ) is outside of the mold, and a low position in which the rod ( 22 ) locally presses the blank ( 3 ) against the mold base ( 14 ) in the low position;
the stretch-blow-molding unit ( 7 ) further comprising means ( 23 ) for detecting at least movement of the rod ( 22 ) from the low position, and stopping of the rod ( 22 ) at a raised position corresponding to the raised position of the mold base ( 14 ), and a central processing unit ( 10 ) designed to deduce the start of the mold base ( 14 ) from the low position, and the arrival of the mold base ( 14 ) at the raised position.

6. Stretch-blow-molding unit ( 7 ) according to claim 5 , wherein the detecting means appear in the form of an optical sensor ( 23 ).

7. Stretch-blow-molding unit ( 7 ) according to claim 6 , wherein the optical sensor ( 23 ) is a laser sensor.

8. Stretch-blow-molding unit ( 7 ) according to claim 6 , further comprising a frame ( 20 ), wherein the stretch rod ( 22 ) is mounted on a carriage ( 21 ) that is mobile relative to the frame ( 20 ), and wherein the sensor ( 23 ) is attached to the frame ( 20 ) and points toward the carriage ( 21 ).

9. Method according to claim 2 , further comprising an operation for adjustment of a movement order for the mold base ( 14 ), when the start of the mold base ( 14 ) does not correspond to a predetermined theoretical start.

10. Method according to claim 2 , further comprising an operation for adjustment of the flow rate of a solenoid valve ( 19 ) connecting an actuator ( 17 ) carrying the mold base ( 14 ) to a source ( 18 ) of fluid under pressure, when the actual arrival of the mold base ( 14 ) does not correspond to a predetermined theoretical arrival.

11. Method according to claim 3 , further comprising an operation for adjustment of the flow rate of a solenoid valve ( 19 ) connecting an actuator ( 17 ) carrying the mold base ( 14 ) to a source ( 18 ) of fluid under pressure, when the actual arrival of the mold base ( 14 ) does not correspond to a predetermined theoretical arrival.

12. Method according to claim 4 , further comprising an operation for adjustment of the flow rate of a solenoid valve ( 19 ) connecting an actuator ( 17 ) carrying the mold base ( 14 ) to a source ( 18 ) of fluid under pressure, when the actual arrival of the mold base ( 14 ) does not correspond to a predetermined theoretical arrival.

13. Stretch-blow-molding unit ( 7 ) according to claim 7 , further comprising a frame ( 20 ), wherein the stretch rod ( 22 ) is mounted on a carriage ( 21 ) that is mobile relative to the frame ( 20 ), and wherein the sensor ( 23 ) is attached to the frame ( 20 ) and points toward the carriage ( 21 ).

Assignees

• Sidel Participations

Inventors

• Letestu Mickael
• Protais Pierrick

Classifications

• B29C2049/4892

  Mould halves consisting of an independent main and bottom part · CPC title

• B29C49/36

  rotatable about one axis · CPC title

• B29C49/783

  blowing pressure · CPC title

• B29C49/541

  having a recessed undersurface · CPC title

• B29L2031/712

  Containers; Packaging elements or accessories, Packages (closures therefor B29L2031/56; ink or toner cartridges B29L2031/7678; squeeze tubes B29L2023/20; suitcases B29L2031/7418) · CPC title