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EP-4735228-A1 - A METHOD OF PRODUCING PLASTIC CONTAINERS

EP4735228A1EP 4735228 A1EP4735228 A1EP 4735228A1EP-4735228-A1

Abstract

A method of producing containers is disclosed herein, wherein the container has reinforcing ribs on its inner wall. The method comprises extruding one or more layers of molten thermoplastic around a mandrel; forming a parison with combination of circumferential & longitudinal grooves; and blowing compressed air into the formed parison to form the container with combination of circumferential & longitudinal reinforcing ribs on an inner wall of the container. The container produced from the said method has a greater compressional strength and is applicable for variety of purposes.

Inventors

  • AGARWAL, VINOD

Assignees

  • Creative Propack Ltd.

Dates

Publication Date
20260506
Application Date
20230928

Claims (20)

  1. 1. A method of producing containers comprises extruding one or more layers of molten thermoplastic around a mandrel; forming a parison with combination of circumferential & longitudinal grooves, wherein said longitudinal grooves correspond to plurality of indentations inscribed on a mandrel and said circumferential grooves correspond to plurality of circumferential indentations formed during parison programming; and blowing compressed air into the formed parison to form the container with combination of circumferential & longitudinal reinforcing ribs on an inner wall of the container.
  2. 2. The method as claimed in Claim 1, wherein the longitudinal indentations are present in range of 4 to 64.
  3. 3. The method as claimed in Claim 2, wherein the longitudinal indentations are in the range of 20 to 40.
  4. 4. The method as claimed in Claim 1, wherein the adjacent longitudinal indentations are spaced apart at a distance ranging from 0.5 mm to 10 mm.
  5. 5. The method as claimed in Claim 4, wherein the adjacent longitudinal indentations are spaced apart at a distance ranging from 0.7 mm to 1.5 mm.
  6. 6. The method as claimed in Claim 1, wherein the longitudinal indentations have depth of 0. 1 mm to 10 mm.
  7. 7. The method as claimed in Claim 6, wherein the longitudinal indentations have depth in the range of 0.2 mm to 1 mm.
  8. 8. The method as claimed in Claim 1, wherein the longitudinal indentations have width of 0. 1 mm to 10 mm.
  9. 9. The method as claimed in Claim 8, wherein the longitudinal indentations have width of 0.4 mm to 1.5 mm.
  10. 10. The method as claimed in Claim 1, wherein the circumferential grooves are present in range of 1 to 15.
  11. 11. The method as claimed in Claim 10, wherein the circumferential grooves are present in range of 2 to 6.
  12. 12. The method as claimed in Claim 1, wherein the circumferential grooves are spaced apart in range of 1 mm to 500 mm
  13. 13. The method as claimed in Claim 12, wherein the circumferential grooves are spaced apart in the range of 20 mm to 300 mm.
  14. 14. The method as claimed in Claim 1, wherein the circumferential grooves have depth of 0. 1 mm to 10 mm.
  15. 15. The method as claimed in Claim 14, wherein the circumferential grooves have depth of between 0.2 mm to 1 mm.
  16. 16. The method as claimed in Claim 1, wherein the circumferential grooves have width of 0. 1 mm to 10 mm.
  17. 17. The method as claimed in Claim 16, wherein the circumferential grooves have width of 0.4 mm to 1.5 mm.
  18. 18. The method as claimed in Claim 1, wherein the thermoplastic material is selected from High Density Poly Ethylene (HDPE), Low Density Poly Ethylene (LDPE), Linear Low Density Poly Ethylene (LLDPE), Polypropylene (PP), their blends, PCR and such.
  19. 19. The method as claimed in Claim 1, wherein compression strength of the container is increased in range of 10% to 50%.
  20. 20. A container comprising a neck, and a body made of thermoplastic material; wherein an inner surface of the body is provided with a combination of circumferential & longitudinal reinforcing ribs.

Description

A METHOD OF PRODUCING PLASTIC CONTAINERS FIELD OF INVENTION: [001] The present invention relates to making containers, and more particularly, to producing the plastic containers with patterns on inner surface. BACKGROUND OF THE INVENTION: [002] Plastic containers are widely used for number of commercial purposes. The containers may be in the form of cylindrical bottles for storage of liquid and solids. In most of the uses, the strength of the container is critical. Smart selection of material of construction takes care of the strength factor. However, to provide further strength to the container, reinforcing ribs are structurally included around the body of the container. Most typically, such reinforcing ribs are included at the outer surface of the body of the container. However, with this, the outer surface becomes uneven, and not so adaptable for labeling and decoration purpose. [003] To overcome said issue, some selected producers started the practice of incorporating the reinforcing ribs at an inner surface of the container. The current applicant is one such producer and has been granted patent IN403144. In the said patent, wherein the container & a method of forming the same is disclosed, the current applicant has demonstrated that the inclusion of reinforcing ribs on the inner surface has increased the compression strength of the container for the constant volume and weight. [004] The applicant herein proposes a method by which plastic containers having further greater compression and hoop strength may be produced effectively. SUMMARY OF INVENTION: [005] It a primary object of the invention to provide greater compression and hoop strength to the plastic container. [006] It is an object of the invention to provide a method by which the plastic container having patterns on its inner wall may be produced. [007] The method of producing the container comprises steps of: extruding one or more layers of molten thermoplastic around a mandrel; subjecting the layers for programming; forming a parison with combination of circumferential & longitudinal grooves; and blowing compressed air into the formed parison to form the container with combination of circumferential & longitudinal reinforcing ribs on the inner wall. [008] The longitudinal reinforcing ribs on the inner wall of the container correspond to plurality of longitudinal indentations provided on a mandrel, whereas the circumferential reinforcing ribs correspond to circumferential grooves provided during processing (e.g. parison programing). For example, during parison programming, the gap between die and mandrel may be changed to change the thickness of the parison. [009] In an embodiment, the longitudinal indentations on the mandrel are present in range of 4 to 64. The adjacent longitudinal indentations are spaced apart in range of 0.5 mm to 10 mm. Each of the longitudinal indentations has depth of 0. 1 mm to 10 mm, and width of 0. 1 mm to 10 mm. [010] In the same embodiment, the circumferential grooves are present in range of 1 to 15, wherein adjacent circumferential grooves are spaced apart in range of 1 mm to 500 mm. Each of the circumferential groove has depth of 0.1 mm to 10 mm, and width of 0. 1 mm to 10 mm. [Oi l] The thermoplastic material is selected from High Density Poly Ethylene (HDPE), Low Density Poly Ethylene (LDPE), Linear Low Density Poly Ethylene (LLDPE), Polypropylene (PP), their blends, PCR (Post-Consumer Recycled Material or Post Consumer Resin) and such. [012] The present invention also discloses a container which is produced by the method and the apparatus disclosed above. [013] The said container comprises a neck, and a body made of thermoplastic material. The container has an inner surface provided with a combination of circumferential & longitudinal reinforcing ribs. [014] The longitudinal reinforcing ribs are present in range of 4 to 64. The adjacent longitudinal ribs are spaced apart in range 2 to 50 mm. Each of the longitudinal indentations has depth of 0.05 mm to 8 mm, and width of 0.3 mm to 30 mm [015] The circumferential ribs are present in range of 1 to 15, wherein adjacent ribs are spaced apart in range of 5 to 300 mm. Each of the circumferential ribs has depth of 0.05 mm to 8 mm, and has width of 0.3 mm to 30 mm. [016] The container described above show increased compression strength in range of 10% to 50%. BRIEF DESCRIPTION OF DRAWINGS: [017] Following figures illustrate various aspects of the present invention. Figure 1(a) shows a divergent mandrel with longitudinal indentations. Figure 1(b) shows a convergent mandrel with longitudinal indentations. Figure 2 shows a parison forming with circumferential grooves. Figure 3 represents an example of the finished container, in the form of bottle. DETAILED DESCRIPTION OF THE INVENTION: [018] Accordingly, the present invention discloses a method and an apparatus for producing containers. While describing the invention, certain terms and expressions are recognised and