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

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.

The invention relates to a process for manufacturing a tube with a wall 
containing more than 60%, by volume of plastic material(s). From a 
substantially cylindrical tubular blank, the inside and outside surfaces 
of this blank being made of polymeric plastic material(s) and said tube 
having a skirt and a necked head, said process comprising a shaping 
operation where an end portion of the blank is necked by bringing closer 
together inner and outer tools, said shaping operation producing crumpled 
folds on said portion. 
A process and tube such as these are known from the patent U.S. Pat. No. 
A-3,823,850=AU-A-477254. According to that patent the shaping operation of 
the necked head of the tube, where the wall preferably comprises a metal 
barrier layer between layers of plastic material(s), is carried out 
mechanically without heating between an outer tool and fingers which move 
pivotally through the tool, producing an undulating structure which is 
preferably stabilised by heating the inside of the tube. The undulating 
structures are then deformed by rotation into a series of uniform 
uni-directional rigid folds. 
The folded head is then preferably introduced into a tool inside which the 
plastic material(s) is injected which coats the outside of the folded head 
and which becomes stuck to the folds. In this operation, the head can be 
clamped in such a way that the piled up rigid folds become bonded together 
by the effects of the heat from the injected plastic material(s) and the 
clamping. 
This process is complicated. It is only possible to obtain rigid folds on 
the necked head before the plastic material(s) is injected by having a 
wall with a metal barrier layer, since the walls which are polymeric or 
elastic. A good bond between the folds is only produced after said 
injection operation. 
The Applicant has tried to realise a process which avoids the 
afore-mentioned drawbacks. 
DESCRIPTION OF THE INVENTION 
The invention is concerned with a process for manufacturing a tube with a 
wall containing more than 60% by volume of plastic material(s), from a 
substantially cylindrical tubular blank, the inside and outside surfaces 
of the blank being made of polymeric plastic material(s), and said tube 
having a skirt and a necked head, said process comprising a shaping 
operation where an end portion of the blank is necked by bringing closer 
together inner and outer tools, said shaping operation producing crumpled 
folds on said portion, the process being disclosed in the cited document. 
The process is characterised in that: 
a) prior to said shaping operation said blank is heated in order to obtain 
for said portion a temperature at the time of the shaping operation which 
is at least equal to the melting point of each of said polymeric plastic 
material(s) forming the inside and outside surfaces of the wall of said 
blank, these materials being thus in a viscous molten state at the time of 
the shaping operation; 
b) according to said shaping operation, the crumpled folds are formed by 
simply bringing closer together the tools, these folds being crushed 
between said tools, and the folds being completely welded to each other, 
thereby producing said necked head which comprises at least one shoulder 
thus shaped. 
In the present description, the term "fold" means "part of a wall turned 
back on itself and forming a double thickness" and "folded region" relates 
to the line or narrow folded back zone or folding of a "fold" of this 
kind. 
The process of the invention is perfect for manufacturing tubes which have 
walls of varying structure: for example, in one single layer, or 
multi-layered without an intermediate layer providing a significant 
barrier effect to oxygen, dampness, flavourings and smells, or, depending 
on the problem posed, multi-layered comprising an intermediate layer 
providing an important barrier effect, the layer typically being of small 
thickness--0.01 to 0.05 mm--at the level of the tubular blank, whether 
that layer is metal or made of a polymeric plastic material(s). Whereas 
plastic material(s)s can be deformed through elongation, they cannot be 
reduced in length unless the products involved are ones which are 
heat-shrinkable. The Applicant has had the surprising idea of starting 
with a tubular blank which is internally and externally of polymeric 
plastic material(s) and which is brought to a temperature which is at 
least equal to the melting point of that/those plastics material(s) and to 
shape a portion of the blank into the necked head of the tube between the 
inner and outer tools defining the geometry of the desired tube. The neck, 
defined by the ratio of the maximum external diameter (that of the skirt) 
and the minimum diameter which is typically greater than 1.25, and, more 
typically greater than 1.4, is produced with crumpled folds produced by 
simply bringing closer together inner and outer tools, and the shaping 
operation which produces the neck produces a necked head which is 
perfectly welded within its thickness and over its inner and outer 
surfaces. 
The following significant and surprising effects are produced: 
the crumpled and crushed folds between the tools which have been brought 
together become perfectly welded to each other on each face of the necked 
head, they are re-arranged and thinned out variably in the thickness of 
the necked head; 
the faces are smooth, the crushed foldings of the folds are scarcely 
visible, or not visible at all; 
by virtue of the temperature of the shaping operation, the successive 
layers of the wall of the blank, particularly its intermediate layer(s) 
providing the barrier effect, are folded and crushed becoming thinner, and 
this happens without any breakage; 
the folding and thinning flattening mechanism is used typically to obtain a 
head with an annular shoulder, which, in thickness, is close to the 
thickness of the skirt, the shoulder thus being easy to crush laterally, 
thereby facilitating emptying of the tube by the end consumer. 
The selection of the temperature at the time of the shaping operation is 
made such that despite the crumpled folds a wall of a necked head is 
produced which has the same qualities of use as a wall without folds. 
It should be remembered that the reel ting point of plastic material(s)s 
corresponds to the melting of its crystallites or crystalline phases, and 
that after that melting point the material is in a viscous molten state 
whose viscosity which is first of all high decreases with temperature, the 
temperatures and viscosities which are appropriate for the injection 
moulding operation being for example more than 100.degree. C., above the 
fusion point. 
The shaping temperature which makes the polymeric plastic material(s) into 
a "viscous molten state" should be clearly differentiated from 
temperatures which give soft states which are used, for example, for 
heat-shaping and which are below the melting point. 
The process is very simple, and it merely comprises a heating operation and 
a shaping operation by crushing which give perfect welding of the necked 
head obtained. On a micrograph it is only possible to distinguish the 
individual folds by their intermediate barrier folds when present. The 
shaping operation and quality of the tubes obtained depend, in the same 
way, on the various qualities of the tubes: entirely polymeric with a 
barrier without layers, or polymeric with more than 60% by volume with a 
metal barrier layer. 
Usually, in the process where the folds are crushed and welded together, an 
exudate of plastic material(s) is produced of said folds on each face of 
the shaped shoulder which forms a glaze on that face. Said folds are 
advantageously crushed in such a way as to obtain a thickness of said 
shoulder shaped which is less than 1.35 times the thickness of the skirt 
of the tube. The shoulder can thus be crushed laterally, and this enables 
the tube to be emptied more thoroughly, particularly when its skirt is 
less than 0.7 mm in thickness. 
Of the methods of heating the end portion to be shaped into a necked head 
the following mode of operation which is particularly advantageous for 
large scale production: in step (a) the tubular blank is first of all 
placed between said inner tool which has a top part defining the inside of 
said necked head and a rigid sleeve which surrounds the end portion with 
slight clearance and which passes upwardly beyond it, said end portion of 
the blank and said top part of the tool being in a high position, and then 
hot air heats the inside of said portion until that portion becomes 
deformed into an undulating necked portion which has a molten end edge. 
Then, said sleeve is removed from said undulating necked portion, and step 
(b) follows. 
The air could be replaced by another gas or mixture of gases. 
The above-mentioned heating arrangement which can be summarised as: "top 
position+heating the inside of the end portion+sleeve beyond it" is of 
utmost importance: 
without a sleeve the heated end becomes deformed into an outer corolla 
(FIG. 16) 
with the sleeve, and only if it passes upwardly beyond the end portion, an 
initial necking is obtained in a reproducible manner with undulations 
(FIG. 18), the reduction to the mean diameter of the end then typically 
being 3 to 8 mm and being accompanied by a molten end edge which shows 
that the desired temperature for the shaping operation (b) has been 
exceeded. 
The sleeve thus prevents outward deformation of the end portion, and it 
appears to retain a cloud of hot air which envelopes the end of the 
portion and surprisingly causes it to become inflected inwardly. It also 
appears to play a part in controlling the heating of the inside of the end 
portion, somewhat like a radiator. A low position would not allow such a 
result since air or gas rises and since the end portion is drawn downwards 
by gravity. 
The initial necking thus obtained with the molten edge permits good control 
of the heating operation and prepares the necking by rapid crushing 
performed during the shaping operation. 
The first heating method is carried out in accordance with the following 
preferred features: 
the inside of said end portion is heated by introducing a nozzle into it 
which radially ejects air heated to at least 250.degree. C. through 
lateral orifices, comprising orifices which are provided for the heating 
operation at a level between half way up the end portion and 3 mm below 
the end of said portion; 
preferably, heating up of the top part is reduced by the use of a deflector 
and insulating clement fixed under the nozzle; 
preferably, to improve the homogeneous nature of the temperature of the end 
portion during the shaping operation, the outer tool is heated between 
100.degree. and 150.degree. C. and is provided with an inner, non-stick 
coating. 
A second heating method is advantageous in that it simplifies the process 
and device used: steps (a) and (b) merge since the end portion is heated 
by the outer tool which is heated to between 150.degree. and 300.degree. 
C. during the flattening of said crumpled folds. However, the surface of 
the necked shoulder is then slightly granular in appearance, even when 
there is an inner non-stick coating on the inside of the outer tool or 
die. 
The temperature at the time of the shaping operation is preferably more 
than 10.degree. to 100.degree. C. than the melting point of each of the 
plastic material(s) on the surface of the wall. If the temperature is 
closer to the melting point, the welding of the folds to each other is 
likely to be imperfect. If the temperature is more than 100.degree. C. 
more than the melting point of the material in question, the less viscous 
plastic material(s) is likely to no longer retain a good hold on the face 
through wetting and is likely to run off. 
To facilitate temperature control at the time of the shaping operation, 
when heating up is done, for example, to 10.degree. or 20.degree. C. more, 
it is preferable that the two plastic material(s) on the surface of the 
wall of the blank have close melting points, which differ by 40.degree. C. 
at the most. This makes it possible to have fairly similar viscous molten 
viscosities and consistencies at the selected temperature, which, when the 
folds are welded together, give the same results on the inside and outside 
of the necked head. 
For the sake of economy and quality of the welding of the folds together it 
is preferable to select materials for the surfaces of the blank wall from 
the group comprising the following 5 families: 
polyethylenes (PE) including linear polyethylenes; 
polypropylenes (PP); 
polyamides (PA); 
modified polyamides; 
polymeric alloys such as PE/PA and PP/PA; 
and saturated polyester comprising PET (polyethylene terephthalate) and PBT 
(polybutylene terephthalate). 
It is not obligatory, but is highly preferable, that the plastic 
material(s) comprising the surface of the blank wall both belong to one 
and the same family. Then, at the time of the shaping operation, they will 
have a comparable viscosity and will be similarly easy to crush. 
In particular, the family of polyethylenes is used including linear 
polyethylenes with a temperature at the time of the shaping operation 
which is preferably between 150.degree. and 220.degree. C. On the inside 
it is possible to use as an alternative an ionomer resin with a 
polyethylene base, such as SURLYN (registered trade mark for a group of 
thermoplastic ionomer resins). In particular, the family of polypropylenes 
is used with a temperature at the time of the shaping operation of between 
210.degree. and 270.degree. C. 
As already stated, the blank can have a wall which is made of one single 
polymeric material which is then combined with the materials of which the 
wall surface is made according to the foregoing description. 
A second instance which is particularly advantageous is that where the 
polymeric plastic material(s) of which the blank wall is made respectively 
form the inner surface layer and the outer surface layer of said wall, 
this wall being multi-layered and comprising between said surface layers 
at least one intermediate layer which provides a barrier effect, and which 
is bonded to the surface layers. 
The intermediate layer(s) therefore extends/extend continuously, and each 
is in one single piece from the bottom of the skirt of the tube to the top 
of the necked head. Their folds inside the crumpled folds of the wall make 
the barrier protection still more effective at the level of the necked 
head. In most cases, the wall of the blank is 0.2 to 0.9 mm in thickness, 
and said intermediate layers which provide a barrier effect have a total 
thickness of between 0.01 and 0.05 mm and are made of a material which 
belongs to the group formed by: modified EVOH (ethylene and vinyl alcohol 
copolymer), PVDC (vinylidene polychloride), PAN (polyacrylonitrile), PVDF 
(vinylidene polyfluoride), PA (polyamide), modified PAs including MXD6 (6 
metaxylene diamine), vinyl chloride and vinylidene copolymer ("saran") and 
slightly alloyed aluminium, usually called "aluminium" in such instances 
of usage. 
Each intermediate layer providing a barrier effect can also be made of one 
of the materials from the group constituted by PE and polyesters, this 
layer being coated with a deposit comprising silica and/or alumina and/or 
amorphous carbon. 
As far as the configuration and structure of the necked head are concerned: 
it typically comprises a neck which is less in diameter than the skirt and 
an annular shaped shoulder which joins the neck to the skirt; 
in the shaping process of the invention, the folds are crushed in such a 
way as to obtain for said shoulder a thickness that is less than 1.35 
times the thickness of said skirt, which can typically be between 0.9 
times and 1.25 times said thickness of the skirt and preferably less than 
or equal to 0.6 mm for ease of lateral crushing; 
the neck above it can be shaped directly into a bottle-neck of the tube. 
The outer tool of the process can thus comprise annular members which are 
contracted, i.e., moved radially inward when the blank is raised by the 
inner tool, the annular members having inner relief which form fixation 
reliefs for fixing a stopper on the outside of the bottle neck. 
In order to obtain a bottle-neck of the desired size, it is also possible 
to fix to the necked head an annular rim made of plastic material(s) which 
thus constitutes the outside of the bottle-neck of the desired tube. The 
rim can be made in several ways: 
by compression moulding onto the necked head an annular blank which has 
been pre-heated to between 60.degree. and 150.degree. C., and preferably 
at least 70.degree. C., and up to about 140.degree. C. above the fusion 
point of the material of the outer surface layer of the tube, with the 
inner tool being in place; it is thus a question either of deforming a 
blank, with moulding, in a softened state, or of compression moulding a 
blank in a viscous molten state; 
by sticking or welding a connected rim, as illustrated in the examples; 
by injection moulding onto the necked head. Particularly when the skirt is 
already decorated, the outer surface of the necked portion retains the 
memory of the effects of electric discharges which were applied prior to 
decoration in such a way that the rim is fixed there less reliably, and it 
is possible to improve fixture inside the bottle-neck by means of moulded 
straps which end under the shoulder (see examples). 
For all the fixing methods described hereinabove, apart from the sticking 
method, the plastic material(s) of the annular rim is preferably 
compatible, when it fuses, with the material of which the outside of the 
shaped tube is made, so that the rim is perfectly welded to the necked 
head. 
To reinforce fixture of the afore-mentioned annular rim to the necked head 
of the tube it is possible to provide it with a base which is widened on 
the outside and which fits the shaped shoulder of the tube. To obtain a 
tube shoulder which is able to be crushed to a large extent, it is 
preferable to restrict the width of the annular base along a radial 
generatrix of the shoulder, to less than half the width of the shoulder, 
or to limit its thickness to less than 0.4 mm outside the half-width 
dimension of the shoulder. 
The shoulder of the tube obtained, or the "finished shoulder" is the 
frustoconical part which extends from the foot of the bottle-neck to the 
join between the shoulder and the skirt. In order that the shoulder is 
able to be crushed laterally, its total thickness is preferably less than 
1 mm mid point of the finished shoulder and less than 0.8 mm at said 
joinder. 
All the above-mentioned methods for fixing the annular rim can be employed 
by using as the inner tool which holds the shaped tube the inner hot 
shaping tool, or an identical tool, which is advantageous. It is also 
possible to use moulding methods to form an annular rim which is provided 
not only on the outside of the neck of the tube shaped, but also on the 
inside thereof, provided that the plastic material(s) of the rim is 
compatible in terms of its melting properties with the plastic material(s) 
of which the outside and inside of said tube are respectively made, in 
order to obtain perfect welding of the rim to the two faces of the tube, 
and thus by using an inner tool which defines a narrower bottle-neck than 
the inside of the neck of the tube. These methods are those which require 
the melting point of the plastic material(s) of the rim to be exceeded, 
namely moulding, typically by injection, and compression of the annular 
blank into a molten state which is still sufficiently viscous and which is 
obtained by a preheating operation between the melting point and that 
melting point +140.degree. C. 
The invention also relates to a tube with a wall containing more than 60% 
plastic material(s), the inside and outside surfaces of the wall being of 
polymeric plastic material(s), said tube having a skirt which is between 
0.2 and 0.9 mm in thickness and a necked head comprising an annular 
shoulder which is shaped in such a way that it is between 4 and 20 mm in 
width, the necked head having crumpled folds which are piled up and bonded 
together inside and outside said wall, characterised in that the folds are 
of variably reduced thickness and are perfectly welded together, and that 
each face of the shoulder is glazed by an exudate of the plastic 
material(s) of which the surface of said face is made, this plastic 
material(s) having come away from the folds in the molten state and having 
been spread out and smoothed, and in that said shoulder comprising said 
folds is in thickness less than 1.35 times said thickness of the shirt and 
is easily able to be flattened laterally. 
This tube has a wall which preferably contains an intermediate layer which 
provides a barrier effect and a necked head which comprises a neck of 
smaller diameter than that of the skirt and an annular shoulder which 
joins the neck to said skirt, the shoulder comprising said crushed and 
welded folds and being between 0.9 times and 1.25 times the thickness of 
the skirt, and said intermediate layer extends in one single piece from 
the bottom of the skirt to the top of the shoulder, with the folds of 
reduced thickness being included in said folds of the shoulder. 
It should be noted that the outer and inner faces of the shoulder are each 
glazed by an exudate of plastic material(s) which has come from the 
crushed folds and which has been spread out and smoothed by the tools. The 
neck and shoulder of the tube are often surmounted by an annular rim of 
plastic material(s) which is joined to the neck and to the shoulder and 
which forms the outside of the bottle-neck of the tube. The rim thus plays 
no part at all in perfectly welding the folds of the necked head, coming 
from the heat shaping operation of the head. 
Further features of the tube will emerge from the description of the 
process and/or examples. 
Typically, the skirts of the tubes according to the invention are between 
13 and 55 mm in diameter. The tubes which have barrier layers are 
particularly advantageous for storing liquid products, or flavoured or 
scented creams or pastes, since the barrier protection is in one piece and 
is reinforced at least at the level of the shoulder. 
ADVANTAGES OF THE INVENTION 
The production, in one single heat shaping operation, of a tube with a 
necked head which is perfectly well welded over its entire thickness, from 
one single tubular blank; 
A tube with a continuous barrier layer, the necked head containing 
superposed folds which enhance the barrier effect: 
The addition of an outside of the bottle-neck of a plastic material(s) by 
selecting simple methods which employ the inner heat-shaping tool. 
A tube with a shoulder which can be crushed laterally which is of an easily 
controlled thickness.

1) PRINCIPLE OF THE INVENTION 
FIG. 1 shows an inner tool or mandrel 1 and an outer annular tool 2 which 
respectively form the inside and outside of the tube to be produced 3. 
The cylindrical tubular blank 4, of external diameter 35 mm, is wrapped 
around the mandrel 1 and an upper portion 5 passes beyond it. The blank 5 
is rolled and welded and comprises inner and outer surface layers of low 
density polyethylene (PE.BD). The portion 5 was heated with a nozzle with 
hot air 6 to 190.degree. to 200.degree. C. before the tool 2 was reclosed 
by axial displacement relative to the mandrel 1, on the portion 5 and 
before clamping it to the mandrel, giving the tube 3 which is heat-shaped 
according to the invention and which comprises a skirt 40 which is the 
unmodified part of the blank 4, and a necked head 7 which comprises a 
shoulder 8 and a neck 9. 
The tube was then ejected from the mandrel 1 by pressurised air through one 
or more conduits such as 10. 
It is seen that only the portion 5 of the tube needs to be heated. The 
necked head 7 made from crushed and perfectly welded folds has smooth 
inner and outer surfaces which are glazed by the molten PE which has come 
away from the flattened folds and has spread out when it made contact with 
the smooth surfaces of the tools. 
2) TESTS ON A FIRST TYPE OF MULTI-LAYERED BLANK 
This first type of cylindrical tubular blank is obtained by rolling and by 
compression welding the weld of a multi-layered film of 0.31 mm in 
thickness, comprising an intermediate layer of A1 which is 37 micrometers 
in thickness and which is bonded by adhesive layers of EAA to surface 
layers of PE.BD, namely an outer layer charged with white pigment and 70 
micrometers in thickness and an inner transparent layer of 90 micrometers. 
FIG. 2 shows a tube 11 shaped from a blank of this type with the device of 
FIG. 1, without heating the portion to be necked. The necked portion 12 
which is obtained 12 consists of a type of shoulder 12 which is placed 
below the skirt 40, and clearly shows the result of the necking operation: 
during this operation undulations are made towards the outside and inside 
which are flattened into folds such as the fold 13 which comprises an 
outer portion 131 encased by two folded regions 132 and two rear portions 
133 partly enclosing the fold 13. The folds have become loose by elastic 
return. This comparative sample 11 better illustrates the efficiency of 
the process according to the invention. 
FIG. 3 shows a tube 3 which is shaped with the same device and by the same 
clamping effect between the tools 1 and 2. However, this time the first 
type of blank is subjected to a heating operation at 190.degree. to 
200.degree. C. The shoulder 8 and the neck 9 of the necked head 7 are very 
smooth. The shoulder 8 is 0.35 mm in thickness and it has a transparent 
bottom (FIG. 7), and, like with the tubes in FIGS. 3 to 6, allows the 
arrangement of perfectly welded folds 13 to be seen which are in a 
rosework design in correspondency with the folded regions 132 of varying 
size. The outer face of the shoulder 8 is semitransparent, and looking 
through its smooth surface of PE it is possible to see some subjacent 
"phantom" folded regions. 
FIG. 4 shows the tube 3 which is surmounted by an annular rim 14 which 
forms the outside of the bottle neck 15. The rim of PE has been injection 
moulded by using the inner shaping tool 1 as the inner tool 1 which 
extends below the neck 9 for joining purposes. The rim 14 is welded in 
perfect continuity with the necked head 7, and its base 16 of increased 
width terminates with a thickness of less than 0.3 mm beyond the 
half-width of the annular shoulder 8. 
FIG. 5 shows a tube 3 which is identical to that of FIG. 3 and which is 
surmounted by an annular rim 140 made of moulded PE and which is welded in 
perfect continuity with the inside and outside of the necked head. The 
internal diameter of the bottle neck 15 thus defined is 2 mm less than the 
internal diameter of the neck 9, and an inner tool was used for the 
moulding operation which was different from the inner shaping tool. 
FIG. 6 shows another tube 3 on which an integrally formed bottle-neck with 
a double skirt is moulded, and which comprises an annular rim 14 on the 
outside of the neck 9 of the tube 3 and an inner skirt 17 which comprises 
grooved and ribbed through openings 18 for product in accordance with the 
patent FR-B-2 622 542=EP-B-315 554=U.S. Pat. No. A-4,942,981 for the 
Applicant. The annular gap between the rim 14 and the inner skirt 17 is 
covered over its entire height by the neck 9 with barrier layer 19 of Al. 
3) TESTS ON A SECOND TYPE OF MULTI-LAYERED BLANK (FIGS. 8 TO 12) 
This second type of tubular blank was obtained by rolling and welding a 
multi-layered film of thickness 0.325 mm and comprising an intermediate 
barrier layer 20 of thickness 20 micrometers made of EVOH, and bonded by 
adhesive layers to the PE layers. A tube 3 was obtained with an annular 
shoulder which is 0.37 mm in thickness in accordance with the technique 
described with reference to FIG. 1, and an annular rim 14 of PE, similar 
to that of FIG. 4, was moulded onto the necked head. FIGS. 8 and 10 show 
micrographic representations in axial section of the tube wall, showing 
respectively the part close to the rounded portion of the start of the 
shoulder and at the level where the top of the shoulder is joined to the 
rim 14. To simplify the description, FIGS. 9 and 11 show the main parts of 
FIGS. 8 and 10 respectively. 
In FIGS. 8 and 9 it is possible to see that the layer 20 of EVOH has 
substantially retained its initial thickness and is slightly undulating 
within the thickness due to the difference in the plasticity properties 
due to the effects of heat of EVOH in comparison with PE. The adhesive 
layers 21 are marked by dots in FIG. 9. 
FIGS. 10 and 11 give information on the process and its results: 
a double fold 22 of the barrier layer 20 shows an end 23 which differs very 
little in thickness from the initial thickness, and which has doubtless 
escaped from the superposition and flattening of the folds, followed by 
two folds 24 of greatly reduced thickness; 
a second portion 25 of a barrier layer 20 which belongs to a fold which was 
welded with the double fold containing the double fold 22 of the barrier 
layer; 
on the right-hand side of the end 23 and of the double fold 22 is the rim 
14 of PE in the form of the surface layers of the tube 3; 
the continuity of the weld between the folds, and between the folds forming 
the shoulder and the annular rim is perfect. The sectional drawing shows 
the adhesive layers 21 in places, but there is no other discontinuity in 
the PE encasing the afore-described elements; 
the reduction to thickness obtained is surprising, and it can be controlled 
as required by selecting the hot shaping temperature and by clamping the 
tools 1 and 2 (FIG. 1). 
FIG. 10 shows that the local thickness of the barrier layer and of the 
folds themselves vary according to a ratio of more than one (24,25) over 
two (23) layer in the shoulder shaped due to the fact that they are piled 
up irregularly in the process of the invention. 
FIG. 12 shows a tube 3 which is obtained from a second kind of blank, whose 
necked head 7 is surmounted by an annular rim 140 made of moulded PE both 
on the inside and outside of the head 7. The rim 140 has a narrower 
opening 26 than the internal diameter of the neck 9, and under the orifice 
there are 3 to 5 straps 27 which extend under the shoulder 8 and which are 
perfectly welded to the inside of the tube 3 which is also made of PE. 
FIG. 12 shows the inner tool used, comprising grooves 28 which easily make 
it possible for straps 27 to be obtained from the molten plastic 
material(s) forming the top of the bottle neck with its narrower orifice 
26. This fixing solution is particularly advantageous if the skirt of the 
tube has already been decorated after surface treatment by electric 
discharges (corona effect). FIG. 12 also shows the outer tool and the 
upper tool with injection passages. 
4) OTHER METHODS OF FIXING AN ANNULAR RIM MADE OF PLASTIC MATERIAL(S) TO 
THE HEAD OF A TUBE 
FIG. 13 shows the heating operation, which is carried out here with hot 
air, of an annular blank 29 made of PE and of suitable geometry, followed 
by compression thereof between the neck 9 and the shoulder 8 of the tube, 
on the one hand, and an outer tool 30 comprised of a segmented annular 
tool, one segment of which is shown. The tube 3 has surface layers which 
are compatible on melting with the PE. 
The blank 29 is heated between 150.degree. to 160.degree. C. with hot air. 
It is in a pasty state, that is to say it is in a very viscous molten 
state. The axial compression of the blank 29 into an annular rim 14 
produces a moulding which results in perfect welding outside the tube 3 
and contours 31 for engagement with a stopper when the tool 30 fills the 
contours hollowed out. 
FIG. 14 shows a welding arrangement for an annular rim 14 prepared 
beforehand with an annular bottom face 32 bearing perfectly on the 
shoulder 8 of the tube 3. The materials thus in contact are PE. The rim 14 
is welded with an annular ultrasonic transducer 33. Thus, annular welded 
fixture is produced of the rim 14 to the shoulder 8. 
FIG. 15 shows an arrangement for induction welding an annular rim 14 
prepared beforehand, like that in FIG. 14, which is applied perfectly by 
an axial force F to the shoulder 8 of the tube 3 which has been shaped, 
according to the invention, from a first type of blank, that is to say 
with an intermediate barrier layer of Al. The induction loop 34 heats this 
layer and also the surface layers of the shoulder 8 and of the rim 14 
which are in contact, and produces a weld between these PE layers of 
perfect continuity. The head of the tube 3 bears on an inner tool 35 made 
of a hard insulating material during this operation, possibly replacing 
the top of the tool 1 in FIG. 1. 
5) TESTS OF AN INDUSTRIAL NATURE 
These tests have been carried out on many thousands of cylindrical tubular 
blanks 4 of external diameter 35 mm, of two types: 
co-extruded multi-layered blanks of 0.5 mm in thickness which are 
constituted by an intermediate barrier layer of 20 micrometers in 
thickness and made of EVOH and bonded by adhesive layers to the surface 
layers of PE (third type); 
laminated multi-layered blanks which are rolled and welded longitudinally 
and which are 0.32 mm in thickness, which are also made of EVOH 20 
micrometers bonded by adhesive layers to surface layers of PE (second 
type). 
There were 3 working positions with the inner tool which supports the 
tubular blank moving rapidly from one position to the next: heating 
position; heat shaping position giving the necked head; compression 
moulding position of an annular rim onto the necked head. 
The tubular blanks 4 used were more than 150 mm in length, and, in the 
working position, each one embraced the inner tool 1 in such a way that 
only an upper end portion 5 of length 12 mm passed beyond the tool 1 (FIG. 
17). 
5.1) First Heating Arrangement 
Tests were carried out on the third type of blank. A nozzle blowing hot air 
of 320.degree. C. through a plurality of lateral orifices 61 of diameter 
0.8 mm was introduced into each portion 5, the lateral orifices 61 being 
in the upper half of the portion 5 and disposed at least 3 mm from the 
upper end 50 of that portion. 
After less than 1.5 seconds the heating operation systematically resulted 
in the deformation of the upper end 50 of the portion 5 and in the 
neighbouring region becoming an irregular outer corolla 39 (FIG. 16). This 
shape was not that desired for the necked portion, and since it became 
reduced in length was unacceptable for large scale production. 
Compared with the satisfactory device of FIG. 17, with this first device 
there was heating of the inside of the portion 5, but no sleeve 36, and no 
deflector and insulating element 62 fixed under the base 60. The nozzle 
had a seal-tight non-insulating bottom made of sheet metal which did not 
extend outside lateral wall. 
5.2) Second Heating Arrangement 
A rigid sleeve 36 made of stainless steel 5 mm thick is provided, which 
slides vertically around the blank 4, as indicated by the arrows 63, In 
the top position (FIG. 17), it surrounds the portion 5 with a diametral 
clearance which is less than 1 mm and it passes upwardly beyond it by at 
least 5 mm. 
The extent to which it passes beyond it was set at 20 mm for the series of 
longer tests, each test being carried out on a few hundred blanks 4. 
With this arrangement, inversion of the direction of bending of the upper 
end 50 of the portion 5 and its closeness relatively to the tests (5.1) 
was noted systematically. The bending is inward, and, after a constant 
period of time of blowing hot air inside the portion 5, an undulating 
necked portion 37 is obtained which has an undulating orifice edge 38 of 
mean diameter 27 to 30 mm, that is to say 4 to 7 mm less than the internal 
diameter of the blank 4, and has a molten end edge 39. 
The sleeve 36 here plays an important and reproducible part. It appears to 
retain the hot air to above the end 50 and produces an initial necking 
which is surprising. The edge of molten appearance and which is typically 
between 0.5 and 2 mm in thickness is testimony that the maximum 
temperature attained is much higher than the melting point of the surface 
layers of the portion 5, at least 30.degree. C. more than said melting 
point, and the neck 37 shows that the portion itself has reached a similar 
temperature. 
In the tests, the good quality of the heating, marked by the necking 37 
hereinabove and its molten end edge 38 was verified by the quality of the 
necked and crushed heads produced in the heat-shaping operation which 
followed said heating operation after a period of time of between 2 and 3 
seconds. The shaping operation is carried out after the nozzle 60 has been 
removed to the top and after the sleeve 36 has slid downwards. 
After the shaping operation, the welding of the folds 13 in the thickness 
of the shaped shoulder 8 is perfect, as in the tests carried out on blanks 
4 of the second type (FIGS. 8 to 12). The thickness of this shoulder 8 was 
0.6 mm. Each face of the shoulder 8 is shaped continuously by a PE exudate 
and is smooth and glazed. The outer faces of a few shoulders 8 reveal, 
when they are viewed on a slant, locally "embossed" regions which can 
result from the folded regions 132 (FIG. 2) close to the surface such as 
the "phantoms" mentioned in the tests on the first type of blank. 
The problem relating to appearance thus still exists in a more discrete 
manner. 
Another problem is apparent: after a couple of dozen tests (heating 
operation followed by shaping operation), it becomes difficult to eject 
the tubes 3 from the inside tool or mandrel 1 (FIG. 1), since the necked 
head adheres to the top part 101 of the tool 1. 
5.3) Second Improved Arrangement (FIG. 17) 
The bottom, made of sheet metal, of the nozzle 60 was replaced by an 
outwards extending ceramics cup 62 forming a deflector element which 
thermally insulates the main part of the top part 101 during the heating 
operation. 
The ejection difficulties disappeared. 
5.4) Heating the Portion 5 by the Outer Shaping Tool 
The outer tool or matrix 2 is clad internally with a non-stick 
product--TEFLON.RTM. (a registered Trademark for polytetrafluoroethylene, 
PTFE)--and heated to 210.degree. C. Necked heads of the tubes 3 were thus 
obtained which were as good in quality as the previous ones, except for 
the granular state of the surface of the outer face of the shoulders 
shaped which were in contact with the matrix 2. 
The shaping time had been increased, but it was still less than 2 seconds. 
The surface state of the upper face of the shoulder makes it desirable to 
cover it with the base of a bottle-neck fixed to the necked head. 
5.5) Compression Moulding of an Annular Blank on the Necked Head 
An annular rim of PE was then compression moulded onto the necked head 7 on 
a large number of tubes 3 which had originated from hot shaping treatments 
carried out in accordance with procedures defined under (5.3) and (5.4), 
the moulding operation being carried out either after the shaping 
operation (less than 4 seconds afterwards) or during a subsequent 
operation. There is very little difference between the results of the 
moulding operations for these two different time intervals. 
An annular bead 29 of molten PE at 220.degree. C. is placed on the shaped 
shoulder 8, that is to say which is at 90.degree. to 100.degree. C. above 
its melting point. The PE of the bead 28 is thus sufficiently viscous for 
the bead 29 to keep its annular shape and to become moderately oval in its 
cross-sectional shape when it bears on the shoulder 8 (FIG. 19). 
The bead 29 was compressed and moulded between the necked head 7, on the 
one hand, and the top portion of the inner tool 1 which passed beyond the 
neck 9 of the head 7, and, on the other hand, an outer tool made of 
extension pieces which cart move apart and which contract for moulding the 
threaded bottle-neck 15 and its base 16. 
FIG. 20 shows the structure obtained. 
The annular rim 14 made of PE is perfectly welded to the necked head 7. It 
comprises the bottle-neck 15 and its annular base 16 which extends to less 
than 1 mm from the join 80 of the shoulder 8 and the skirt 40. The base 16 
becomes progressively thinner from less than 0.4 mm at the mid point 81 of 
the shoulder 8 to less than 0.15 mm at its periphery 160. The bottom 16 
has the following thicknesses: 
0.7 mm at the foot of the bottle-neck 15, 0.37 mm at the half-width 
dimension of the shoulder 8, and periphery 160 merged with the start of 
the join 80. 
Since the shoulder 8 is 0.6 mm in thickness, the shoulder (8+16) of the 
tube obtained is particularly well able to be crushed laterally from its 
half width dimension. 
The bottle neck 15 extends the inner surface of the neck 9 and is perfectly 
welded to it. 
For the sake of economy, the neck 9 was reduced in height to 1 mm in some 
of the tests, giving a continuous inner surface of the bottle neck without 
any flaw. The neck 9 can be suppressed, the shoulder shaped 8 being 
complete, that is to say going as far as the upper axial portion of the 
tool 1. 
The base 16 gives a uniform appearance to the shoulder of the tube 3. It 
masks any undesirable appearing defects. 
5.6) Tests on Blanks of the Second type, Thickness 0.32 mm 
A few hundred blanks were subjected to tests similar to those described 
hereinabove (5.3), (5.4) and (5.5). The results are satisfactory and show, 
together with the foregoing results, that the shaping operation which is 
carried out above the fusion point is very reproducible. 
APPLICATION OF THE TUBE ACCORDING TO THE INVENTION 
For storing various products, foods, cosmetics, pharmaceutical products, 
hygiene products and maintenance products, particularly for products which 
are to be distributed more completely since the shoulder of the tube is 
able to be crushed, and for products which are to be protected from the 
effects of oxygen and water or humidity, whilst preserving their flavour 
or scent.