US 5,618,365 A · Process for manufacturing a tube with a wall containing more than 60% of plastics material and having a skirt and a necked head and a corresponding tube

Abstract

The invention disclosure relates to a process for manufacturing a collapsible tube with a wall containing more than 60% by volume of plastic material from a substantially cylindrical, or tubular, blank. The inside and outside layers of the tubular blank are of polymeric plastic material, and the tube has a skirt and a necked head. In the process a shaping operation is performed where an end portion of the tubular blank is necked by bringing closer together inner and outer tools, thus producing crumpled folding of the end of the tube. Prior to the shaping operation the blank is heated in order to bring the portion of the end portion to be shaped to a temperature at the time of the shaping operation which is at least equal to the melting point of the polymeric plastic material forming of the layers the inside and outside surfaces of the wall of the blank. The polymeric plastic material is thus in a viscous molten state at the time of the shaping operation. By virtue of the shaping operation, the crumpled folds are formed by simply bringing closer together the inner and outer tools so that when the folds are fully crushed between the tools and the folds are completely welded to each other, thereby producing the necked head and shoulder integral with the remaining skirt portion of the previously tubular blank.

Claims27

Dependent claims

A process for manufacturing a necked collapsible tube (3) having an end portion defined by a wall containing more than 60% by volume of a plastic material and comprising a substantially cylindrical tubular blank (4) formed of a multilayer laminate having at least one intermediate layer and inner and outer layers, at least the inside and outside surfaces of the inner and outer layers of the tubular blank being of polymeric plastic material, said tube (3) having at least a skirt (40) and a necked head (7), said process comprising a shaping operation where an end portion (5) of the tubular blank (4) which is free of folds is necked by bringing closer together an inner tool (1) and an outer tool (2), said shaping operation producing crumpled folds (13) of said end portion (5), and wherein:

a) prior to the shaping operation only the inside and outside surfaces of the polymeric plastic material of the inner and outer layers of the end portion (5) are brought to a viscous molten state by heating;
and
b) in said shaping operation necking said heated end portion (5) to form crumpled folds (13) in said end portion (5) by bringing closer together inner and outer tools (1 and 2) wherein said end portion is crushed to form crumpled folds absent a separate folding step, said crumpled folds (13) being formed only by movement of the inner and outer tools toward each other wherein said heated end portion (5) is crushed between said tools (1 and 2), and wherein the folds (13) are welded to each other, thereby producing said necked head (7) and thereby also forming a shoulder (8) between the necked head (7) and the skirt (40).

A process for manufacturing a necked collapsible tube (3) having an end portion defined by a wall containing more than 60% by volume of a plastic material and comprising a substantially cylindrical tubular blank (4), at least the inside and outside surfaces of the tubular blank being of polymeric plastic material, said tube (3) having at least a skirt (40) and a necked head (7), said process comprising a shaping operation where an end portion (5) of the tubular blank (4) is necked by bringing closer together an inner tool (1) and an outer tool (2), said shaping operation producing crumpled folds (13) of said end portion (5), and wherein:

a) prior to the shaping operation the polymeric plastic material is brought to a viscous state by heating, said blank (4) to bring said end portion (5) to a temperature at the time of the shaping operation which is at least equal to a melting point of said polymeric plastic material forming at least an inside surface and an outside surface of the wall of said blank (4);
and
b) in said shaping operation necking said heated end portion (5) to form crumpled folds (13) in said end portion (5) by bringing closer together inner and outer tools (1) and (2), said crumpled folds (13) being formed by movement of the inner and outer tools toward each other wherein said heated end portion (5) is crushed between said tools (1 and 2), wherein the folds (13) are welded to each other, thereby producing said necked head (7) and thereby also forming a shoulder (8) between the necked head (7) and the skirt (40), and wherein in step (a) the tubular blank (4) is initially placed between said inner tool (1) which has a top part (101) providing a forming surface for defining an inner surface of said necked head (7) and a rigid sleeve (36) which surrounds the end portion (5) with slight clearance and passing upwardly beyond it, said end portion (5) of the blank (4) and said top part (101) of the tool (1) being in a top position, and then hot gas is used to heat the inside of said end portion (5) until it deforms to become an undulating necked portion (37) which has a molten end edge (38), and then said sleeve (36) is removed from said undulating necked portion (37), and step (b) then follows.

Dependencies are inferred from the claim text.

Process for manufacturing a tube with a wall containing more than 60% of plastics material and having a skirt and a necked head and a corresponding tube

Life of this patent

Process for manufacturing a tube with a wall containing more than 60% of plastics material and having a skirt and a necked head and a corresponding tube

Life of this patent

Abstract

Claims27