Method for the production of caps with a heat shrinkable skirt and caps obtained according to the method
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
B29C-061/02
B29C-055/22
출원번호
US-0595764
(2004-11-08)
등록번호
US-8226867
(2012-07-24)
우선권정보
FR-03 13193 (2003-11-10)
국제출원번호
PCT/FR2004/002862
(2004-11-08)
§371/§102 date
20060510
(20060510)
국제공개번호
WO2005/046969
(2005-05-26)
발명자
/ 주소
Granger, Jacques
Luciani, Andre
출원인 / 주소
Alcan Packaging Capsules
대리인 / 주소
Dennison, Schultz & MacDonald
인용정보
피인용 횟수 :
0인용 특허 :
4
초록▼
The method comprises a) an extrusion stage wherein a extruded tube made of a thermoplastic material is formed by extrusion with the aid of an extrusion die having a diameter D0, a slit width E0 and a section S0; b) a stage wherein the extruded tube is radially expanded in order to form a radially ex
The method comprises a) an extrusion stage wherein a extruded tube made of a thermoplastic material is formed by extrusion with the aid of an extrusion die having a diameter D0, a slit width E0 and a section S0; b) a stage wherein the extruded tube is radially expanded in order to form a radially expanded tube having a diameter D2, a thickness E2 and corresponding section of area S1; c) a truncating stage wherein the expanded tube is broken down into tube portions; d) a stage in which the tube portions are formed in such a way that a heat-shrinkable cap is obtained and in which an axial drawing stage is incorporated, between extrusion stage a) and expansion stage b), at the output of the extrusion die, in order to obtain an axially drawn tube having a diameter D1 which is typically smaller than D0 and D2, and a thickness E1 which is typically lower than E0, such that S0/S1 typically ranges between 2 and 10. The advantages of the invention are as follows: it is possible to obtain caps which are economic, easily heat-shrinkable and which have a stable axial dimension, thereby avoiding any axial distortion, i.e. any axial distortion of the impression.
대표청구항▼
1. A method for the production of caps having a heat shrinkable skirt comprising: (a) extruding a thermoplastic material to form a tube having a first diameter D0, a first thickness E0, and a first cross-sectional area S0;(b) drawing the tube in an axial direction, the axially drawn tube having a se
1. A method for the production of caps having a heat shrinkable skirt comprising: (a) extruding a thermoplastic material to form a tube having a first diameter D0, a first thickness E0, and a first cross-sectional area S0;(b) drawing the tube in an axial direction, the axially drawn tube having a second diameter D1 less than the first diameter D0, a second thickness E1 less than the first thickness E0, and a second cross-sectional area S1, the ratio of the first cross-sectional area to the second cross-sectional area between about 2 and 10;(c) providing a cooling assembly and cooling the drawn tube in the cooling assembly;(d) providing a radial expansion assembly having an annular vacuum chamber and increasing the diameter of the drawn tube in the radial expansion chamber to form a radially-expanded tube having a third diameter D2 greater than the first and second diameters;(e) passing the radially-expanded tube through an axial tension assembly;(f) segmenting the radially-expanded tube into portions of desired length;(g) forming a cap blank by heat shrinking one of the portion on a mandrel; and(h) providing a head on the cap blank to form a cap having a head and a skirt. 2. The method according to claim 1, in which a cooling zone is provided subsequent to drawing the tube in an axial direction, the axially drawn tube at a first temperature T0, the cooling zone having a cooling assembly to lower the temperature of the axially drawn tube to a second temperature T1, the second temperature being: (a) about equal to at least the glass transition temperature Tg or the melting temperature Tf of the thermoplastic material, wherein the diameter of the axially drawn tube at the second temperature is subsequently increased or (b) low enough to interrupt the axial drawing step and to fix the diameter of the axially drawn tube at a generally predetermined diameter. 3. The method according to claim 2, in which the thermoplastic material is extruded at an extrusion temperature and the change in temperature from the extrusion temperature to the second temperature is between about 30° to 150° C. 4. The method according to claim 2, in which the thermoplastic material is extruded at an extrusion temperature and the change in temperature from the extrusion temperature to the second temperature is between about 45° to 100° C. 5. The method according to claim 2, in which the cooling apparatus includes an external air or water projection. 6. The method according to claim 2, in which the cooling apparatus comprises a ring cooled with air or water. 7. The method according to claim 6, in which the ring includes a part with diameter equal to about D0 so as to form a calibration ring from which a tube having a diameter of about D0 exits. 8. The method according to claim 2, in which the cooling means includes air or water projection provided inside the axially drawn tube. 9. The method according to claim 2, in which the diameter of the drawn tube is increased using a radial expansion assembly that includes a radial expansion chamber provided with an inner wall having a diameter equal to about D2 and an expansion area for increasing the diameter of the axially drawn tube from D1 to D2. 10. The method according to claim 9, in which the radial expansion device includes an entry ring with diameter of about D1 to provide the axially drawn tube with a diameter D1 before radial expansion of the axially drawn tube. 11. The method according to claim 10, in which the entry ring forms an annular chamber with an inner surface having an inner diameter D1, the inner surface comprising a plurality of orifices for providing a vacuum, the annular chamber being put under a pressure Pa less than atmospheric pressure P, wherein the axially drawn tube is pushed into contact with the inner surface. 12. The method according to claim 1, in which the diameter of the drawn tube is increased by (a) maintaining the inside of the drawn tube under pressure or (b) maintaining the outside of the drawn tube under negative pressure. 13. The method according to claim 12, in which the diameter of the drawn tube is increased by maintaining the drawn tube under a vacuum. 14. The method according to claim 13, in which the inner wall of the radial expansion assembly is a tubular metallic wall capable of allowing air to pass through. 15. The method according to claim 13, in which the inner wall of the radial expansion assembly is surface treated. 16. The method according to claim 1, in which the increase of the diameter from D1 to D2 is at least about 10 mm, and the increase of the diameter occurring over a distance L1 less than about 250 mm. 17. The method according to claim 1, further including cooling the radially-expanded tube in an auxiliary cooling assembly to a temperature T2 between 10° C. and 60° C. 18. The method according to claim 1, in which the thermoplastic material is extruded using a die having a diameter D0 between about 20 mm to 50 mm and thickness E0 between about 0.5 mm to 3 mm. 19. The method according to claim 18, in which the thermoplastic material passes through the die at a rate of about 10 kg to 100 kg per hour. 20. The method according to claim 1, in which the diameter D1 of the axially drawn tube is between about 5 mm to 20 mm and the thickness E1 is between about 0.2 mm to 0.6 mm, the ratio of D1/D0 being no more than about 0.6 and the ratio of E1/E0 being no more than about 0.6. 21. The method according to claim 1, in which the diameter D2 of the radially-expanded tube is between about 20 mm to 50 mm and the thickness E2 is between about 0.05 mm to 0.35 mm, the ratio D2/D1 being no more than about 2 and the ratio of E2/E1 being no more than about 0.6. 22. The method according to claim 2, in which a radial expansion assembly is positioned at a distance L from a die for extruding the thermoplastic material, the radial expansion assembly being generally free to move in an axial direction, the distance L selected to provide a sufficient degree of axial drawing and cooling of the axially drawn tube. 23. The method according to claim 22, in which the cooling assembly is positioned at a distance L0
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이 특허에 인용된 특허 (4)
Okabe Mitsuo (Yokohama JPX) Hyakutome Kimiaki (Sayama JPX) Akiba Hideto (Sayama JPX), Container with metallic cover and method of manufacturing the same.
Reed Leonard W. (Wantage GB2) Barr Robert M. S. (Faringdon GB2) Dick David A. (Wantage GB2), Process of forming a biaxially oriented thermoplastic tube including the formation and severance of a bubble forming a r.
Levine Herbert R. (Dover NH) Gerrato Stephen G. (Greenland NH) Poulin Benoit L. (Hudson NH), Texturized heat shrinkable tubing having radial and longitudinal shrinkage memory.
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