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A method and apparatus are provided for strengthening a portion of a blow molded bottle. The method includes directing a jet of cooled air at a preform before it is molded, causing the wall thickness in the cooled area to remain thicker after molding to strengthen that area of the blow molded articl

A method and apparatus are provided for strengthening a portion of a blow molded bottle. The method includes directing a jet of cooled air at a preform before it is molded, causing the wall thickness in the cooled area to remain thicker after molding to strengthen that area of the blow molded article. The apparatus includes a blow molding machine that is provided with a nozzle positioned to direct the cooled jet of air towards the preform. The nozzle is mounted in a standby station that is in between the existing heating station and blow molding station. In one embodiment, the cooled jet of air is directed at a location just below the neck of the preform to create a ring of increased thickness in the shoulder of the blow molded bottle, adding strength to the shoulder of the bottle. A conventional blow molding machine may be modified to rotate and cool the preform in the standby station.

대표청구항 ▼

The invention claimed is: 1. An apparatus for strengthening a blow molded article, wherein the blow molded article is molded from a preform, the apparatus comprising: a heater for heating the preform to a desired temperature; a blow mold including a mold cavity for receiving said preform, said mold

The invention claimed is: 1. An apparatus for strengthening a blow molded article, wherein the blow molded article is molded from a preform, the apparatus comprising: a heater for heating the preform to a desired temperature; a blow mold including a mold cavity for receiving said preform, said mold cavity defining a shape corresponding to a desired shape of the blow molded article, said blow mold capable of molding the preform into the shape of said cavity after the preform has been heated by said heater; a transport system for moving the preform through said heater and said blow mold along a path; and a nozzle positioned to direct a cooled jet of air towards a desired location on the preform, said nozzle fixed in position along said path between said heater and said blow mold, said cooled jet of air cooling said desired location on the preform to strengthen the preform in said desired location, wherein a wall of said preform maintains a greater thickness in said desired location than in the remainder of said wall after said preform is blow molded; wherein said nozzle is adapted to be selectively adjusted to vary the size of said cooled jet of air and to vary said desired location on said preform. 2. The apparatus of claim 1 wherein the preform includes a first end, a second end, a neck, and a shoulder region, said first end defining an opening and said second end being closed, said neck comprising a portion of the preform including said first end, said shoulder region comprising a portion of the preform proximate said neck, said cooled jet of air directed towards said shoulder region. 3. The apparatus of claim 1 further including an air flow meter, said air flow meter connected to said nozzle to adjustably control the pressure of said cooled jet of air. 4. The apparatus of claim 1 comprising a plurality of said nozzles. 5. The apparatus of claim 1 further including a carrier for transporting the preform along said path proximate said heater, said nozzle, and into said blow mold, said carrier including a grip for holding a portion of the preform, said grip being rotatable with respect to said carrier. 6. The apparatus of claim 4 further including a belt, said grip including a wheel in contact with said belt, said belt provided with motion to rotate said wheel proximate said heater and said nozzle. 7. The apparatus of claim 6 wherein said belt is driven about a first pulley and a second pulley, said pulleys located on opposite sides of said standby station, said belt providing rotation to said grips as said carrier moves past said nozzle. 8. The apparatus of claim 1 wherein said nozzle includes a first plate and a second plate, said first plate and said second plate spaced apart to form a gap therebetween for the passage of said cooled jet of air. 9. The apparatus of claim 8 wherein said gap defines a width, and wherein said first plate is slidable with respect to said second plate to control the distance of said width. 10. A method for strengthening a blow molded article, the article formed from a preform in a blow molding machine that includes a heating station and a blow molding station, the method comprising the steps of: transporting the preform in a carper along a path through the heating station and the blow molding station; heating the preform in the heating station; providing an air nozzle between the heating station and the blow molding station adjacent to the path of the preform and fixed in position with respect to the path; adjusting the size of the air nozzle to correspond to a desired location on the perform; rotating the preform as it is transported past the nozzle; directing a jet of air through the nozzle towards the preform, the jet of air being cooler than the preform to form a process ring on a selected portion of the preform; and molding the preform in the blow molding station, the process ring maintaining a greater thickness than the remainder of the preform and forming a strengthened and thickened region in the article. 11. The method of claim 10 wherein the process ring is formed proximate to a neck of the preform, such that the process ring thickens and strengthens a shoulder region of the article. 12. The method of claim 10 wherein the rotation of the preform includes contacting a portion of the carrier with a belt that is driven by a set of pulleys. 13. The method of claim 12 wherein two of said pulleys are located on opposite sides of the nozzle. 14. The method of claim 13 wherein the cater includes a grip that grasps the neck of the preform and rotates the preform with respect to the carrier. 15. The method of claim 14 wherein the grip is attached to a wheel that rotates with the grip and is contacted by the belt. 16. The method of claim 10 wherein the cooled jet of air has a pressure that is controlled by an air flow meter. 17. A method for modifying a blow molding machine to strengthen blow molded articles formed from preforms, the machine including a heating station, a blow molding station, a transport system for transporting the preforms from the heating station to the blow molding station, and a rotation mechanism for rotating the preforms, the method comprising the steps of: extending the rotation mechanism into a standby station between the heating station and the blow molding station to provide rotation to the preforms in the standby station; positioning a nozzle adjacent to the standby station; adjusting at least one of the size and position of the nozzle to correspond to a desired location on the preforms, the nozzle subjecting the desired location on the preforms to a jet of air in the standby station to cool and strengthen the preforms in the desired location; and molding the preforms into blow molded articles in the blow molding station after the preforms are subjected to the jet of air, wherein the preforms maintain a greater thickness in the desired location than in the remaining portions of the preforms after the articles are molded. 18. The method of claim 17 wherein the rotation mechanism is a belt drive system, and wherein the step of extending the rotation mechanism into the standby station includes extending a belt into the standby station. 19. The method of claim 18 wherein the belt extends around a number of pulleys, and the step of extending the rotation mechanism includes positioning a pulley such that said belt extends into said standby station. 20. The method of claim 17 including directing the jet of air at a location just below the neck of the preform, such that the blow molded article is strengthened in a shoulder region.