WO2016046844A4

WO2016046844A4 - Process for manufacturing of aluminium alloy cheese tube, cheese pipe or bobbin for woven sack

Info

Publication number: WO2016046844A4
Application number: PCT/IN2015/050113
Authority: WO
Inventors: Bhagwat Ramanbhai PATEL; Prashant Ramniklal GANDHI
Original assignee: Siddhi Engineers
Priority date: 2014-09-25
Filing date: 2015-09-17
Publication date: 2016-08-11
Also published as: IN2014MU03077A; WO2016046844A3; WO2016046844A2

Abstract

The present invention relates to a process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for woven sack. The present invention provides light weight, strong and accurate product made from specific aluminum alloys (i.e. 6082 or 6061) duly cold drawn and heat treated to achieve very high strength to weight ratio. The primary billets of aluminum alloys are subjected to a porthole extrusion process sequentially it is subjected to cold drawn for reducing the cross sectional area of the tube. After cold drawn, tubes are further solution treated by special quenching of fog or water. Solution treated porthole extruded aluminum alloy tube can also be used as feed stock. After successive cold drawing, the tubes are straightened on the straightening machine to relieve stress and subsequently the age hardening is carried out to achieve desired tensile strength and percentage elongation in the product.

Claims

14 AMENDED CLAIMS received by the International Bureau on 25 May 2016(25.05.2016) We Claim,

1. A process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for woven sack comprising following steps: a) manufacturing porthole extruded aluminium tubes from billets formed by aluminium alloy;

b) cold drawing said extruded aluminium tubes at a room temperature to reduce the cross section area and thickness of said extruded aluminium tubes; c) straightening the cold drawn aluminium tubes at a room temperature to remove stress generated during step b);

d) carrying out artificial age hardening treatment to further improve the mechanical strength and percentage elongation (ductility) in straightened aluminium tubes;

(Support found in Original claim 6) wherein step (d) is carried out 165 °C for 6-18 hours.

2. The process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for woven sack as claimed in claim 1 wherein aluminium alloy is selected from alloy 6061 and alloy 6082.

3. The process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for woven sack as claimed in claim 1 or 2, wherein, at step (a) extruded porthole aluminium alloy tube is solution treated (T4 condition) or without solution treated (M condition).

4. The process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for woven sack as claimed in any of claim 1 to 3 wherein for M condition 15

porthole extruded aluminium alloy is sequentially solution treated by fog or water quenching after straightening the cold drawn aluminium tubes.

5. The process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for woven sack as claimed in claim 1 wherein the step (c) is carried out by hyperbolic 6 roll machine.

6. The process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for woven sack as claimed in claim 1 wherein weight reduction in product is 40%.

7. The process for manufacturing of aluminium alloy cheese tube/ cheese pipe or bobbin for Woven Sack as claimed in claim 1, wherein the mechanical properties includes improvement in tensile strength and percentage elongation, reduction in cross section area, reduction in weight and achievement of the precise dimensional tolerance includes tolerance on internal diameter and uniform thickness of the aluminium tubes.

16

Statement under Article 19 (1)

Dl teaches method of extruding aluminum base alloys for increasing tensile strength and high electrical conductivity with respect to base alloy. The prime object of Dl is to provide a method which minimizes the occurrence of the chatter cracking in aluminum alloy and optimization of the strength and electric conductivity in the same. On contrary, present invention provides high tensile strength, in the range of 330-335 Mpa, aluminum alloy 6061 or 6082 with excellent ductility and proof stress. It is to be noted that Dl disclose the difficulty in extrusion associated with the alloy 6061 (Column 2, L: 29-33) and doesn't discloses the crucial step of straightening and age hardening at 165 °C which provides tensile strength in range of 330-335 Mpa. The process rendered by Dl provides tensile strength in the range of 235 Mpa while present invention takes the same tensile strength for further improvement through present innovative process that provides tensile strength in the range of 330-335 Mpa. D2 provides process for making an essentially lead free screw machine stock alloy. The process step of D2 mainly includes homogenization, cooling, cutting and extrusion (Reference: claim 1). Consequently, D2 provides the tensile strength in rod or bar while' the present invention results the tensile strength in the range of 330-335 Mpa in tube or bobbin. It is to be noted that present invention provides bobbin or tube with accurate and precise high tensile bobbin made up of 6082 and 6061 which is not disclosed by the D2. It is to be observed that ISR (Please refer box No. V of Written Opinion) cited by the examiner states that D2 provides idea about straightening of cold work tube which is not supported with the disclosure made by D2, that relates to manufacturing of bar or rod further D2 doesn't provides the age hardening temperature 165 °C. Moreover, the objection raised by Examiner regarding inventive step with respect to prior art D1-D2 (Please refer supplemental box of box No. V of Written Opinion) is respectfully objected because neither of cited documents provided from examiner discloses process of manufacturing aluminum alloy bobbin with exceptional properties like high tensile yet light weight, precise and excellent ductility while comparing the base alloy and which can withstands pressure generated by winding panel of woven sack.