BG61335B1 - Container for the storage and distribution of water-containing aromatized or perfumed product - Google Patents

Abstract

The container is used in the specialized production of liquid, creme- or paste-like products, and its content is fully and evenly distributed. The container (C) has an upper part for distribution, fixed to a multilayer flexible body containing one intermediate layer of polymer having a barrier effect (20) to oxygen, aromas and perfumes. The layer is sensitive to humidity and on each of its side there is one or more polymer layers (1, 12, 14, 10) based on polyolefins. All layers are interconnected in a continuous manner, and the integrity of the layers fitted on the internal side of the intermediate layer having barrier effect (1, 21) has total density between 40 and 150 micrometers intended to ensure the satistisfactory storage of the aroma or the perfume of the product stored in the container.

Description

TECHNICAL FIELD

The invention relates to a tube for storing and dispensing a product, usually liquid, creamy or pasty, which allows the aroma or perfume of the product contained therein to be well preserved.

BACKGROUND OF THE INVENTION

It is known from patent application EP-A084 922 and patent US 4 626 456, a tube for storing and dispensing a product containing water, for example, flavored or perfumed, having a dispensing tip fixed fixedly on a flexible multilayer body comprising an intermediate layer, which acts as a barrier with respect to oxygen and fragrances or perfumes but is sensitive to moisture so that on each of the surfaces of said intermediate layer there are one or more polymer layers based on polyolefins interconnected. The product contained in the tube is, for example, toothpaste, and the intermediate layer that acts as a barrier is, for example, EVOH (copolymer of ethylene and vinyl alcohol). The construction of a body without an intermediate metal layer, comprising layers of mainly polypropylene, sprinkled with, for example, powdered calcium carbonate, mica, or talc, allows the tube to be well kept from bending cracks.

However, there are two major disadvantages to this decision. As is known from U.S. Patent No. 4,407,897, EVOH is very sensitive to moisture. A toothpaste, usually containing 20 to 30% by weight of moisture, placed in a tube with a barrier layer of EVOH, loses much of its aroma. It is also known that protecting the tube from local cracks in bending will, in turn, make the tube more difficult to empty.

It is known from patent application GB-A-2 048 209 for storage of a product, such as toothpaste, the body of which is made of multilayer plastic material and can be deformed under successive pressures and bending and has increased resistance to adhesion of layers . This body includes 5 at least one layer that acts as an oxygen barrier, for example from EVOH or PA (polyamide), one layer of olefins and one adhesive layer of modified olefins located between the two mentioned layers. The adhesion of the layers in said body is avoided by a suitably selected elasticity of the adhesive layer that is lower than that of the barrier layer and higher than that of the olefin layer. At the same time, the thickness 15 of the olefin layer is greater than the sum of the thicknesses of the barrier layer and of the adhesive layer and the body of the tube, depending on the thickness of the olefin layer, has a marginal elasticity of 7 to 170 kg / cm. This improves the ability of the tube to recover after each push and bend. However, this source did not mention how to avoid the aroma loss of the product contained in the tube.

SUMMARY OF THE INVENTION

The invention relates to a tube which provides the best preservation of the aroma or 30 perfumes of the product contained therein, enabling its useful and more complete distribution.

In particular, the invention relates to a tube, of the type known from the patent cited above, 35, characterized in that the set of layers located on the inner surface of said layer, which acts as a barrier, has a total thickness in the range of 40 to 150 μ, which gives a better preservation of the aroma or perfume of the product contained or contained in the tube.

When the thickness of the layers located on the inner surface of the layer 45 acting as a barrier is less than 40 gm, the moisture from the product passing through said layers rapidly destroys the layer that acts as a barrier with respect to oxygen and fragrances, or perfume, and in this way the product can completely lose its aroma.

When the thickness of the layer 2 in question is greater than 150 μητ, the moisture does not penetrate to the layer which acts as a barrier, but the aroma and perfume of the product are absorbed to a considerable extent by said layers. Since fragrances and perfumes are substances present in the product in the form of an aqueous solution, their evaporation and absorption are followed by a first approximation of the evaporation and absorption of the water, which ensures the humidity of the product.

Patent application GB 2 048 209, cited above, does not dwell on such problems, despite their importance, nor does it contain any indication of the thickness of the layers located on the inner surface of the barrier layer.

When the thickness of the layers disposed on the layer acting as a barrier is in the range of 55 to 140 µm, preferably between 65 and 130 µm and preferably between 70 and 120 µm, further improved results are achieved with respect to preserving the aroma or the perfume of the product contained in the tube.

Polyolefins, in particular of the polyethylene group, which are economically advantageous and result in excellent adhesion of the layers between them, may be used for the construction of the tube according to the invention. The body of the tube according to the invention consists of polymer layers based on polyolefins comprising a finite inner layer of low density polyethylene or linear low density polyethylene having a specific gravity of 0.86 to 0.93 g / cm ³ and other layers which are either of low density polyethylene with a specific gravity of 0.90 to 0.93 g / cm ³ or of high density polyethylene with a specific gravity of 0.935 to 0.97 g / cm ³ .

The tube according to the invention, in addition to better preserving the aroma or perfume of the product stored therein, also exhibits a less tendency to crack under pressure, due to the increased elastic resistance of the body of the bending tube. This is due to the fact that the polyethylene layers forming the body of the tube include one or more layers of polyethylene / high density, with a total thickness greater than or equal to 90 pm. Tests have shown that when the total polyethylene / low density thickness increases from 84 to 125 pm, the elastic resistance of the bending body increases more than twice. When the thickness of the body is from 260 to 380 pm, for example in toothpaste, 5 the total thickness of said layers of polyethylene / high density is preferably 100 to 140 pm, the end layers being preferably polyethylene / low density or the inner layer is of linear polyethylene / 10 low density. In fact, the outer outer layer of the body is required to have good plasticity combined with resistance to compression, while the outer inner layer is required to be resistant to micro-splitting. The above 15 boundaries for the total thickness of the polyethylene / high density layers are recalculated depending on the thickness of the body if it is outside the specified limit. These calculations should take into account the indicated increase in the elastic resistance of the bending body, the influence of the barrier layer and its characteristics, which are higher than those of a polyethylene / high density layer with the same density. thickness. For the thickness of the body mentioned above, the condition that the sum of the doubled thickness of the interlayer acting as a barrier and of the total thickness of the polyethylene / high-density layers 30 is preferably included within the limits of 130 to 180 µm, the former condition relating only to the total thickness of the polyethylene / high density layers may or may not be met.

In order to facilitate the production of a body with the desired total thickness of the polyethylene / high density layers, in the presence of the final inner and outer outer layers of the above-mentioned type, i. usually polyethylene / low density, preferably one or the first (first) intermediate layer of polyethylene / high density is inserted between the first layer of polyethylene / low density and the first 45 bonding layer, which in turn borders the inner surface of the intermediate layer acting as a barrier; or one (second) intermediate layer of polyethylene / high density sandwiched between a second intermediate layer 50 of polyethylene / low density, and a second bonding layer which in turn borders the outer surface of the intermediate layer, act3

61335..

as a barrier.

Said first and second layers of high density polyethylene / high density are generally used simultaneously to facilitate the production of the body, with thicknesses ranging from 10 to 50 pm and from 60 to 140 pm respectively.

Said polyethylene / high density layer (s) are in a state of "continuous bond" with the layers between which they are incorporated, and since they are made of fusion-compatible materials, excellent adhesion is achieved between the layers during production. In the cross-section of the tube body according to the invention, one layer of polyethylene / high density may be different from the other layers only by means of measuring the microhardness, but not by the appearance of the structure. This result is obtained either by co-extrusion of the body, or by gluing overlapping the edges of a multilayer workpiece obtained by one or more coats and joining the layers with subsequent extrusion coated polyethylene coating.

The first and second intermediate layers of polyethylene are usually each adjacent to one of the surfaces of the intermediate layer, which serves as a barrier and is connected to one of the bonding layers, which are most commonly of EAA (a copolymer of ethylene with acrylic acid ) or from EMA (a copolymer of ethylene with methacrylic acid). The five layers in question are usually in the form of a preform workpiece in which the intermediate layer, which acts as a barrier and is sensitive to moisture, is relatively well protected in this respect.

The materials used for the interlayer, which acts as a barrier and is sensitive to moisture, may include: EVOH and PVOH (polyvinyl alcohol), the degradation of which under the action of moisture is described in the aforementioned patent of U.S. Pat. No. 4,407,897, as well as polyamides and modified polyamides, e.g., polymethaxylyl adipamide (MXD6), which have a lower degree of sensitivity to moisture. One such intermediate layer, which acts as a barrier, is usually in the thickness of 0.01 to 0.05 mm. In some cases, a plurality of such intermediate layers may also be used, which act as a barrier, provided the condition that the overall thickness of the assembly is within the above preferred range is met.

In order to facilitate the distribution of the product stored in the tube and to achieve its full utilization, a second variant solution is provided that can be used alone or in combination with the first requiring a minimum thickness of polyethylene / high density layers in the body of the tube to be greater than 90 pm.

According to the variant solution, there is a ring that can be pressed between the body and the tip of the tube. The arm of the known tubes, depending on the method of their production, is rigid and forms a kind of wall, where a part of the product is retained, which is usually pasty or creamy. Due to the production method, which is the subject of patent application FR No. 9301065 of 27.01.1993, from the same applicant, it is preferable to obtain a tube in which the distribution head includes a nozzle with a diameter smaller than that of the body and annular arm connecting the nozzle to the body, said arm being smooth and having a thickness ranging from 0.9 to 1.35 times, preferably 0.8 to 1.25 times less than the thickness of the body and with it forms a continuous structure. Said arm is made of pressed folds, glued together, and can be easily pressed sideways. Said arm and at least part of the nozzle of the tube include the barrier or barrier layers of the body of the tube in the form of elongated, tapered, folded and pressed folds that are glued together. The nozzle may be provided with a ring of polyethylene glued to it, keeping at least half its ability to squeeze laterally.

This variant solution provides at the same time the possibility of easier and complete distribution of the product contained in the tube and improved preservation of its aroma or perfume at the level of the head of the tube. The thin folds of the barrier layer in the shoulder generally together fulfill the preferred condition that the overall thickness is from 0.01 to 0.05 mm.

The manufacturing method providing this variant solution for refining the tube according to the invention is briefly disclosed in the examples described below.

The advantages of the invention are that, in addition to being a very economical body structure, it provides an opportunity to better preserve the aroma or perfume of the product contained in the tube; in addition, it allows, in the preferred embodiment, to reduce the local 10 cracking of the bent tube, with the force distributed over most of the tube and reduced; alternatively or in combination with the main solution, the invention provides the possibility of side squeezing of the tube arm, thereby facilitating the ejection of the product at the end of the tube use.

EXAMPLE 20

An explanation of the attached figures, of which:

Figures 1 to 3 represent a section of the bodies of three tubes, the first of which is outside the scope of the invention (Fig. 1 is given for comparison), and the other two (Figures 2 and 3) illustrate tubes according to the invention.

Figure 4 is a cross-sectional view of the distribution of the values of the elastic 30 bending resistance of a tube body, made in accordance with the first solution according to the invention, for easier and more complete displacement of the product contained in said tube. 35

Figure 5 - in the aroma loss test, the graphical dependence of the weight loss of body samples as a function of the total thickness of the interlayers that serve as a barrier to oxygen. 40

Figure 6 is a graphical change in the flexural strength of a body as a function of the total thickness of the polyethylene / high density layers entering the structure of said body. 45

7 to 10 show the embodiment according to the invention for improved distribution of the product contained in a tube with a side pressure arm. Figure 7 is an outside view of a tube obtained 50 at room temperature molding and is for comparison purposes.

Figure 8 is a partial section along the axis of a tube with a side squeeze arm obtained according to the invention.

Figure 9 is a partial section along the axis of a tube with a side pressure arm provided with a polyethylene annular frame that encloses the outer part of the tip of said tube according to the invention.

Figure 10 is a micrograph of a top view of the arm of said tube and the attachment of that arm to said annular frame in axial section.

DETAILED EXPLANATION OF THE FIGURES

1) Structure of the tubular bodies according to figures 1 to 3.

The structures of said three tubes include one intermediate layer 20 which acts as a barrier and is of EVOH 0.02 mm thick, bonded through two adhesive layers 21 and 22 of copolymer EMA (copolymer of ethylene with methacrylic acid). 0.01 mm thick each with layers of polyethylene, these adhesive layers 21 and 22 may be in contact with polyethylene / low density with a specific gravity of 0.92 g / cm ³ of layer 1 or of intermediate sublayers 11 or 12. between layers of different types are marked with continuous lines, while the invisible border me du undercoats of polyethylene / low-density polyethylene / high density obtained as a result of their connection, at least on the surface, in the step of melting is indicated by a broken line.

The term "sublayers" is here used to refer to such layers, the boundary between which is indistinguishable visually, but in terms of the overall technical functions examined according to the invention, they exist and act as separate layers. Said sublayers can only be distinguished by measuring microhardness.

In Figures 1 to 3, it can also be seen that the polyethylene / high density sublayers 13 and 14 with a specific gravity of 0.95 g / cm ³ are each included on their own, between the intermediate sublayer already mentioned above. polyethylene / low density 11 or 12 and one end inner layer of linear polystyrene / low density 100 or one end outer layer of polyethylene / low density 10.

Starting from the axis of the body through the juice outwards, the sequence of the thicknesses of the layers is given below, with the details of the sublayers in parentheses.

Tube (A) (Figure 1): low density polyethylene / low density layer 1, 0.035 mm thick; layer 21 of EMA, 0,01 mm thick; layer 20 of EVOH 0.02 mm thick; 0.01 mm thick EMA layer; layer 12 + 14 + 10 of polyethylene 0,215 mm thick (layer 12 of polyethylene / low density 0,082 mm thick; layer 14 of polyethylene / high density 0,0105 mm thick and layer 10 of polyethylene / low density, outer outer, with a thickness of 0.023 mm).

Tube (B) (Figure 2): inner layer 100 + 13 + 11 of polyethylene 0.09 mm thick (layer 100, inner inner, linear polyethylene / low density, 0.01 mm thick; layer 13 of polyethylene / high density, 0.02 mm thick and polyethylene / low density layer 0.06 mm thick); the sequence of the layers of EMA, EVOH and EMA, as well as their thickness, is as indicated for tube (A); and a layer of 12 + 14 + 10 of 0.215 mm thick polyethylene of the same construction as noted above for tube (A).

Tube (B) (Figure 3): inner layer 1! of polyethylene / low density 0.215 mm thick; the sequence of the layers of EMA, EVOH and EMA, as well as their thicknesses, is as indicated above for tubes A and B; layer 12 + 14 + 10 of polyethylene 0,175 mm thick (layer 12 of polyethylene / high density 0,073 mm thick; layer 14 of polyethylene / low density 0,084 mm thick and layer 10, outer outer, of polyethylene / low density 1 s thickness 0.018 mm).

The bodies of tubes A, B and B are obtained by winding and gluing multilayer blanks with the above structures and thicknesses of the individual layers, after which the heads of the tubes are cast on the bodies.

2) Aroma loss test

Circular test specimens 50 mm in diameter from the three tubes A, B and B described above in accordance with Figures 1 to 3 are impregnated from the inner surface of the body - these are respectively the inner inner layers 1 or 100 with a standard toothpaste containing

25% water and menthol, then kept in a chamber at 38 ° C for 4 weeks. At the end of the period mentioned above, toothpaste is washed from the surface. The weight loss of each sample is determined taking into account the loss of water and aroma.

In this test, it is desirable that the weight loss per unit inner surface be 10 less than 1.2 mg / cm ² and preferably lower than 0.66 mg / cm ² . The body of tube A meets the broader requirement but does not meet the preferred lower limit. The results of this test are presented in Table 15 of Figure 1 and also in Figure 5.

Explanation of test results. There is no test pattern where the intermediate layer of EVOH acting as a barrier is stripped from the inside of the body - at 20 such a position the layer of EVOH would be completely destroyed by moisture during the production of the respective multilayer blank. In such a case, in fact only theoretical, in FIG. 5, a 25 weight loss would be observed due to the easy passage of moisture through the EVOH layer and the absorption of this moisture from the layers above the EVOH layer.

When the thickness of the layers 30 located on the inside of the EVOH is 0.02 mm, a significant weight loss of more than 2.5 mg / cm ² is still observed. However, weight loss rapidly decreases when the thickness of the layers located on the inside 35 of the EVOH exceeds 0.03 mm. The portion of the graph in figure 5 corresponding to this point is straight and steeply increasing, on it is located the point A corresponding to the absorption with destruction of the layer of EVOH of 40 moisture, which then passes through the layer of EVOH together with the aromas and the water and fragrances are also well absorbed from the layers 12, 14 and 10, located above (on the outside) of the EVOH layer, and from the layers 45 and 21 and 1, located below (on the outside) of the EVOH. The steep decrease in the rights from point A to point B corresponds to the prevailing protection effect exerted by the EVOH layer 20 from the increasing 50 thickness of the inner to the EVOH layers. The steep increase in entitlements from point B to point B corresponds to the prevailing one

61335, influence of absorption of water and aromas from the inner to EVOH layers by their thickness. When the barrier layer of EVOH is sufficiently protected, the ability of the inner layers to absorb moisture and aromas increases.

3) Test for pressure or flexural strength of the body

According to FIG. 4, sample 15 of the body is machined to form a reproducible semicircular cylindrical vault 16 with a diameter of 25 mm and a length of 100 mm, and a rigid rod of 3 mm diameter is exerted on it by a linear forming 18 on the top of said vault. The trace marked with the broken line 19 corresponds to the shape perceived by the vault 16 as the pressure of the rod 17 increases.

Apparatus (not shown in the drawing) measures the resistance exerted by the arch 16 or 19 on the rod 17 and thus determines the maximum value of the flexural strength of the body. When said counteraction is of high value, the body of the respective tube is better suited to pressure and its bending remains, at least in part, within the range of elasticity, thereby avoiding local tightness, contrary to what is indicated in the EP -A 0 084 922.

The test results are shown in Table 2 and Figure 6. Points A, B and B are arranged in a single line in Figure 6. In the absence of a layer (s) of polyethylene / high density in the body of the tube, i. when the body is made entirely of polyethylene / low density, with the exception of the EVOH layer and the two fine adhesive layers 21 and 22 enclosing the EVOH layer on both sides, the flexural counteraction is very low positive (point Z in Figure 6 ), and as shown in the graph with the increase in the thickness of the polyethylene / high density layers, the bending resistance of the body increases, increasing rapidly between 40 and 70 pm (the portion of the curve, ZX, marked with a broken line). line).

For the 90 µm thickness mentioned above as the minimum total thickness of the polyethylene / high density layers, the effect of increasing the flexural strength is graphically confirmed. The tube B according to the invention has a bending-resistant body, while tube B has no satisfactory performance in this respect. Tube A, which does not satisfy the moisture and flavor loss requirements and which is not included in the scope of the invention, satisfies the flexural strength requirement.

4) Tube with side pressure arm according to the variant solution for easier and more complete distribution of the product contained in the tube according to the invention (Figures 7 to 10).

The method of manufacturing the tube is that one end of the tubular workpiece, of length greater than the length of the body, is knocked out and only that end is heated at a temperature lower than the melting temperature of the surface layers of the workpiece , preferably at temperatures in the range of 140 and 220 ° C, in the case where said surface layers are polyethylene. The edges of said part are then torn apart with the help of suitable tools, formed by creasing folds, and the folds formed thus are glued to each of the two surfaces, thus producing a shoulder with very smooth surfaces.

Figure 7 shows a tube with a shoulder formed at room temperature. Double folds, such as 31 and 32, as shown in the figure, correspond to folding of the curved edges to the inside of the tube 31 or to the outside of the tube 32.

When molded upwards, as described above, the compression of the folds mainly affects the barrier layer 20 included inside the wall. In this way, a shoulder smaller than that of the wall of the body can be obtained. 8 shows a threaded tip tube 34 according to the invention, wherein the tip is obtained directly by molding upwards while forming a thread cut 35 at the end of the tip narrowing between the inner and outer annular elements of the tube manufacturing device. Figure 9 shows a tube 36 of the same type, obtained by molding hot and then covered with an outer annular frame 37 of polyethylene, with which the tip of the tube ends. This frame 37 is perfectly soldered to the outside and to the upper end ¹ of the tubular head 36 formed above. In this case, the frame is secured by molding a polyethylene annular billet heated to a temperature of 160 ° C by paste molding at 5 higher than the melting point. Attachment of the annular frame can also be accomplished by injection molding or by ultrasonic soldering. Each of the tubes 34 and 35 has a body type B with a thickness of 0.345 10 mm, which is not modified when forming the head upwards, and an annular arm 38 with a thickness that meets the requirements (between 0.3 and 0.4 mm). Figure 9 shows a tube 36 in which the annular frame 37 occupies less than half the width of the annular arm 38, and the latter can still be pressed laterally in a manner sufficient to enhance the displacement of the annular frame 38. tube product. 20

The cross-section of the tube 36, including the point of attachment of its arm 38 to the annular frame 37 (Fig. 10), illustrates the efficiency of pressing and brazing the folds of the nozzle, as well as the excellent 25 soldering of the annular frame 37 to the arm 38:

The double crease 39 of the barrier layer 20 has a termination 40 which disappeared upon folding and layering of the crease, 30 said double crease 39 being followed by two very thin creases 41;

The second part 42 of the partition layer 20 belongs to a fold jointed with a double fold comprising the double fold 39 of the partition 35 layer 20;

. 61335 ....... .. ..,. · ... . . ··, ... · ...... · ..

On the right end 40 of the double crease 39 is a frame 37 which is made of polyethylene, as well as the surface layers of the tube 36;

The continuity of adhesion between the folds as well as between the folds forming the shoulder and the annular frame is excellent. The section clarifies the laterally adhesive layers, such as 21, but no break in the polyethylene layer is observed which surrounds the described elements.

The achieved thinning is surprising, it can be controlled if desired by selecting the molding temperature upwards and by adjusting the distance between the elements of the device used to shape the head of the tube.

INDUSTRIAL APPLICABILITY

Tubes according to the invention with a flexible plastic body provide better preservation of the aroma or perfume of the product contained therein and can be used to store and distribute liquid, creamy or paste products, flavored or perfumed as desired. Tubes according to the invention also provide easier and better distribution of the product contained therein. With these qualities, the tubes according to the invention can find application, in particular in the manufacture of cosmetic, pharmaceutical, hygiene, food and maintenance products.

Table 1

Weight loss of test tubes impregnated for 4 weeks with flavored toothpaste

Tube The thickness of the layers located on the inside of the EVOH layer Weight loss mg / cm ² A / for comparison / 45 gm 0.83 B / according to the invention / 100 gm 0.12 B / according to the invention / 135 gm 0.59

Table 2

Maximum strength of bending tube bodies (Figure 4)

Tube Body thickness / in Hg / Total thickness of polyethylene / high density / in ppm / Total polyethylene thickness / high density +2 EVOH thickness / in ppm / Maximum strength / N / A / for comparison / 290 105 145 6.6 B / according to the invention / 345 125 165 8.7 B / acc the invention / 340 84 124 4.2

Claims

Claims (14)

Claims A tube (B, C, 34, 36) for storing and distributing a water-containing product, for example, flavored or perfumed, including a dispensing tip (38 and 35), fixedly attached to a flexible multilayer body comprising a polymeric intermediate layer (20) , which acts as a barrier against oxygen, fragrances and perfume and is sensitive to moisture, adhesive layer (21) and one or more polymer layers (1, 100, 13, 11 and 12, 14, 10) based on polyolefins, bound in a continuous manner between each other, respectively, on each side of said boundary Inner layer, characterized in that the set of layers (1, 21 and 100, 13, 11 and 21, respectively) located on the inside of the intermediate layer acting as a barrier has a total thickness in the range of 40 to 150 μπι . Tube according to claim 1, characterized in that said total thickness of the layers (1, 21 and 100, 13, 11, 21 respectively) disposed on the inside of the intermediate layer acting as a barrier is within the range of 55 to 140 pm, preferably 65 to 130 pm. Tube according to claim 1 or 2, characterized in that said polyolefin-based polymer layers include, on the one hand, a polyethylene / low-density inner layer (1) or linear polyethylene / low-density linear layer (100). with a specific gravity in the range of 0.85 to 0.96 g / cm ² and, on the other hand, layers of polyethylene / low density with a specific gravity in the range of 0.90 and 0.93 g / cm ² or of polyethylene / high density with specific gravity in the range of 0.935 and 0.97 g / cm ² (13 and 14). 4. Tube (B, 34, 35) according to claim 3, characterized in that the layers of polyethylene comprise one or more layers of polyethylene / high density (13, 14) with a total thickness of at least 90 pm. Tube according to claim 4, characterized in that the sum of the thicknesses of the polyethylene / high density layers (13, 14) is in the range of 100 to 140 pm, with the thickness of the body being in the range of 260 to 380 pm. Tube according to claim 4, characterized in that the sum of twice the thickness of the intermediate layer acting as a barrier (20) and the thickness of the layers of polyethylene / high density (13, 14) is in the range from 130 to 180 pm and body thickness ranges from 260 to 380 pm. Tube according to any one of claims 3 to 6, characterized in that the polyethylene layers include a first layer of high density polyethylene (13) which is inserted between the end inner layer (100) and the first intermediate layer of low density polyethylene (11), the latter bordering the inside of the intermediate layer, which 9 .... 6.1335 .. it acts as a barrier (20). Tube according to any one of claims 3 to 7, characterized in that the polyethylene layers include a second layer (14) of high density polyethylene, which is placed between the outer outer layer (10) of polyethylene / low density and a second polyethylene / low density intermediate layer (12), the latter adjacent to the outside of the intermediate layer acting as a barrier (20). Tube according to claim 7 or 8, characterized in that the first layer (13) of polyethylene / high density and the second layer of polyethylene / high density (14) are or are melted without interruption with said layers of polyethylene / low density (100, 11 and 12, 10, respectively), among which are or are located. Tube (B, 34, 36) according to claim 8, characterized in that the thicknesses of the first and second layers (13, 14) of polyethylene / high density are in the range from 10 to 50 pm and from 60 to 140, respectively. pm. Tube (B, 34, 36) according to claim 10, characterized in that the first and second intermediate layers (11, 12) of polyethylene / low density are individually connected to the respective side of the intermediate layer, which acts as a barrier ( 20) by an adhesive layer (21, 22) of EAA (ethylene-acrylic acid copolymer) or EMA (ethylene-methacrylic acid copolymer). Tube according to any one of claims 1 to 11, characterized in 5 that the intermediate layer acting as a barrier (20) is of a material selected from the group of EVOH (copolymer of ethylene and vinyl alcohol), PVOH (polyvinyl alcohol), PA (polyamide), modified poly10 amide and having thickness from 0.01 to 0.05 mm. Tube (34, 36) according to any one of the preceding claims, characterized in that the dispensing head (38 and 35) includes a nozzle (35) with a diameter, 15 smaller than the body, and an annular arm (38) that connects the nozzle (35) to the body, said arm having a thickness of 0.9 to 1.35 times the thickness of the body and forming an integral part of the structure 20 of said body, made up of elongated, pressed and glued between them folds of the layers forming the body. 14. Tube (36) according to claim 13, characterized in that it is compressed 25 and the folds of said arm glued between them include the elongated and pressed folds (39, 41) of the barrier intermediate layer (20).