"PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT

AS OBTAINED"

The present description refers to the Certificate of Addition of Invention of PI 0301765-6, under the title "PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED".

FIELD OF APPLICATION: The present "PROCESS TO OBTAIN AXIAL

REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED" has the purpose to obtain axial reinforcement in plastic flask and plastic flask with axial reinforcement as obtained, pertaining to the field of plastic products, more precisely plastic flasks for packing and which have been developed to overcome inconveniences as noticed in the state of the art.

BACKGROUND OF THE ART:

As known, numerous products, be them liquid, pasty or solid (powder), such as: cleaning products, personal cleansing, beverages and others, are packed in plastic flasks. These flasks should meet various specifications, such as: appropriately pack a given volume of product, be neutral over the product, be practical while the product is used, support numerous efforts to which they may be submitted through their working life, have a selling- appellant appearance, be low-cost so not to increase the final cost of the product to undesirable levels and others.

Said packs are usually obtained by blowing. According to this process, a blowing machine provided with a mouth and core set is initially previewed, forming a plastic parison; followed by a molding machine containing a mold formed by halves moving between two positions: an open position, into which an appropriate path of the parison is introduced by gravity between the parts of the mold; and a closed position, in which the halves of the mold are closed around the parison path, cutting their ends and wherein the parison is blown and inflates until abutting the walls of the mold and taking their shape.

The pack as obtained is comprised by a hollow plastic body provided with a cap-receiving neck usually releasing product, being said body usually provided with external embossments acting as decoration and reinforcement. Through its working life, this kind of pack may be submitted to various efforts, including axial efforts. When these efforts are higher than the resistance of the pack, they make their walls curved towards inside or outside (they become stuffed). To overcome that, the pack should be provided with thick walls and/or external embossments selected to absorb these efforts. However, these solutions are not always ideal, since, as already stated above, it is desirable that said packs consume the least possible quantity of raw material. On the other hand, to provide external embossments with axial reinforcement characteristics may be an undesirable condition. Said external embossments with reinforcement function may also present difficulties to label the product. Furthermore, said external embossments may require relatively complex and expensive

molds.

Therefore, to provide plastic flasks as used as packing of elements particularly absorbing axial efforts has been a constant difficulty for the manufacturers of said kind of packing. Therefore, the object of the patent of invention PI

0301765-6 is to provide a "PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED" constituting an advantageous option over others. Bearing in mind, therefore, the above referenced problems and with the purpose to overcome them and aiming to meet the object as mentioned, we have developed the "PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED" object of the patent of invention PI 0301765-6, essentially consisting in providing the plastic parison from which the flask will be formed with internal lengthwise ribs, formed by means of corresponding grooves included in the molding surface of the core of the set of mouth and core of the blowing head of the blowing machine responsible to form the parison. The flask obtained from this process is therefore comprised by a hollow body provided with a cap-receiving neck and a wall provided with internal lengthwise reinforcement ribs.

This form of embodiment solves difficulties to provide axial reinforcement for a flask, since by using the internal axial reinforcement ribs as mentioned, the wall of the flask may have its thickness considerably reduced. Experiences show that a flask

containing internal reinforcement ribs and 60 g weight has kept the same axial resistance of an equal flask with no ribs and 70 g weight. This shows a considerable reduction of raw material consumption.

On the other hand, by using internal axial reinforcement ribs, the external surface of the flask, if desired, may be completely plain. If, however, an external embossed surface is desired, these may be projected to act solely as a decoration element, not having to necessarily work as a reinforcement. Said aspects may result in facilities to label packs. Also, said form to obtain the flask may result in a simpler mold.

SUMMARY OF THE INVENTION: The present Certificate of Addition of a "PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED" uses the same principle as disclosed by the Patent of Invention PI 0301765-6, but has the purpose to provide a better weight/resistance ratio and not only axial but also radial resistance, i. e. a plastic flask through its working life is submitted to various efforts in all directions, being one of the most worrying ones the axial direction, since sometimes, depending on the model of the flask, it suffers axial pressure e. g. when it needs to pressure-couple a cap or during storage, when flasks need to be piled up. But the radial direction also worries, since that flask, both while being stocked and transported and during its use, suffers radial pressure, and should also be sufficiently resistant not to crush or crack during said effort, also providing better resistance when pressed otherwise.

We have also noticed that the best result, depending

on the form of the plastic flask to be obtained, depends on the formation of the plastic parison, formed by the mouth (bush) and core (pin) set of the blowing machine, as well as on the temperature and pressure at which it is made. We have therefore concluded that we may obtain other types of internal ribs (folds) as reinforcements and not only straight lengthwise ribs formed by means of corresponding external parallel grooves lengthwise as included on the molding surface of the core of the set of the mouth of the blowing machine, but said core could have inclined or even curved grooves and, considering the memory of the molten plastic material forming the parison, we may obtain completely different effects, according to the plastic flask to be obtained, its use and application, so to better improve the resistance/weight ratio, both axially and radially, by means of conformation of internal straight, diagonal and curved ribs.

We can also, by turning or swinging the core, according to the desired path, obtain various helix effects according to the speed of movement, or wavy or zigzag shapes, as desired.

By means of various tests and studies, we have also verified that not only the core may have grooves for the conformation of internal reinforcement ribs, but also the mouth (bush) may have internal grooves, thus forming external ribs (folds) which, working jointly with the core (pin), may reach various effects between the conformation of external and internal ribs (folds), which may be interspersed or crossed so to form a lattice effect.

We have also concluded that up and down movements of the core (pin) matching a male fitting at the mouth (bush) added

to its conformation also generates different and interesting effects, i. e. if the core has at its end the grooves to form ribs (folds) on the flask, but said core (pin) has a straight part following said grooves, said core (pin) has a straight part, which at the end of parison extrusion may clean the internal part of the neck, making it become plain with no internal ribs (folds). With that up and down movement of the core (pin), we may also obtain thicker or thinner regions on the flask with larger or smaller ribs, or even with no ribs.

The present Certificate of Addition of Invention of PI 0301765-6, "PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED" is therefore constituted, so to reach the objects as mentioned above and offer large reliability, therefore aiming to obtain a flask with truly innovative technical and functional features and great performance, providing large enhancements, promoting, personalizing and highlighting itself over the state of the art.

BRIEF DESCRIPTION OF DRAWINGS:

However, to better understand and explain the detailed description that follows, illustrative figures are attached, to which it makes reference, so that:

- Figure 1: shows a scheme covering the first step of molding of a plastic parison from which a flask is formed and simultaneous molding of internal axial reinforcement ribs;

- Figure 2: shows the second stage of introduction of a path of the plastic parison into the flask molding machine;

- Figure 3: shows the third stage of flask molding by blowing from the plastic parison path as introduced into the mold;

- Figure 4: shows an enlarged "AA" cut, as shown by Figure 1, in which the molding mouth and core set is seen;

- Figure 5: shows an example of a flask in side view with lengthwise straight ribs;

- Figure 6: shows a crosswise "BB" cut as per an example of flask of Figure 5; - Figure 7: shows a front view of a core (pin) model with appropriately distributed straight and lengthwise grooves on its conical end and a mouth (bush), in which it has a male fitting to form the plastic parison to obtain a flask with internal lengthwise straight ribs (folds); - Figure 8: shows a front view of a flask model obtained by the core (pin) with lengthwise straight grooves as shown by Figure 7;

- Figure 9: shows a front view of a core (pin) model which conical end has a higher straight and lower band with appropriately distributed lengthwise straight grooves to form the plastic parison by means of a male fitting at the mouth (bush), and a flask with internal lengthwise straight ribs (folds) as per the body of the flask as represented or with no ribs at given points is obtained, as per the neck of the flask as represented; - Figure 10: shows a front view of a flask model with the internal part provided with ribs (folds), except on the neck, which internal part is straight, obtained by the core (pin), as shown

by Figure 9, and its axial movement;

- Figure 11: shows a front view of a core (pin) model with sloped grooves in parallel to obtain a flask with diagonal ribs (folds); - Figure 12: shows a front view of a flask model obtained by the core (pin), represented by Figure 11, forming sloped ribs (folds) in parallel;

- Figure 13: shows a front view of a core (pin) model with curved and sloped grooves in parallel which, jointly with the turning movement of the core, is obtained from a flask with helix ribs (folds);

- Figure 14: shows a front view of a flask model obtained with helix ribs (folds) obtained by the core (pin) with curved and sloped grooves as shown by Figure 13; - Figure 15: shows a front view of a core (pin) model with curved and sloped grooves in parallel which may work jointly with a mouth (bush), also provided with internal grooves, thus obtaining a flask with internal and external grooves;

- Figure 16: shows a front view of a flask model obtained by the set of core (pin) and mouth (bush) of Figure 15, thus obtaining a kind of formed lattice between internal and external ribs (folds);

- Figure 17: shows a front view of a core (pin) model with appropriately distributed straight and lengthwise grooves on its conical end, suffering male fitting at the mouth (bush) and bilateral half-turning to form the plastic parison to obtain a flask with internal ribs (folds) in wavy or zigzag form;

- Figure 18: shows a front view of a flask model obtained by the set of core (pin) and mouth (bush) as per Figure 17, provided with internal grooves in wavy or zigzag shape; BASICS OF THE INVENTION: According to the illustrations and details, the

Certificate of Addition to PI 0301765-6, under the title "PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED" as proposed herewithin, constitutes a process to obtain axial reinforcement and also promote the enhancement of radial resistance in a plastic flask (F), obtained by means of the usual blowing machine (1), provided with a blowing head, formed by a mouth (2) and core (3) set; and a molding machine (4) formed by a two-half mold (5), effecting inversely opposed movements between two positions, being the open position intended for loading and the closed position for molding. Therefore, the blowing machine (1) by means of molten plastic extrusion at a given temperature and over given pressure forms the plastic parison (6), passing between the mouth (2) and core (2) set and remaining vertically located by gravity between the parts of the mold (5), so that, when the plastic parison (6) reaches the lower internal part of the mold (5), it gets closed around it and blowing starts, causing its expansion until abutting the internal walls of the mold (5), thus assuming its shape. Axial reinforcement, also improving radial resistance, and process to obtain it as claimed herewith is comprised by molding ribs (7) on the plastic parison (6) itself, be them internal

or external, and are formed by the set of mouth (2) and core (3).

To obtain reinforcemenet ribs (7) inside the flask (F), the core (3) is provided with ribs (9) on the external part of its conical end (8), which may be straight lengthwise, sloped or curved, appropriately distributed or not, which quantity, position and size will depend on the model of flask and the need of axial reinforcement and improvement of radial resistance to be thus obtained, as required, and, by the usual movement as already existing in the core (3) over the mouth (2), various kinds of ribs (7) may be formed, which go from the lower part (10) to the higher one (11) of the flask (F), including up to the neck (12), if so desired.

Therefore, we may, through the core (pin) with appropriately distributed straight and lengthwise grooves on its conical end and a mouth (bush), which has a male fitting to form the plastic parison, obtain a flask with internal lengthwise straight ribs.

If the internal part of the neck (12) is preferably straight, or even some internal part of the flask (F) with no ribs (7), the conical end (8) of the core (3) may be provided with a straight higher band (13) which, according to its axial movement over the bush (2), may form straight parts of the plastic parison (6), thus obtaining parts of the flask (F) as desired, with no ribs

(7). If a reinforcement is desired through diagonal ribs

(7), it may be effected by positioning sloped external grooves (9), also located on the conical part (8) of the core (3) and, according

to pressure and temperature as used to make the plastic parison (6) as added to the memory of the material itself, this will form diagonal ribs (7) from the lower part (10) to the higher part (11) of the flask (F). Another different reinforcement result may also be obtained by means of the core (3) as provided on its conical part (8) with external sloped and curved grooves (9) which, by turning the core (3), added to the memory of the material constituting the plastic parison (6), forms helix ribs on the flask (F). That process added to the mouth (2) also provided with small internal lengthwise straight grooves (9a) form between internal ribs (7) made by the core (3) and the external ribs (7a), made by the mouth (2), a lattice, despite, with the blowing process, the external part loses its shape as an apparent rib (7a) when abutting the mold, but it provides better reinforcement to the flask wall, only visible when made in translucid material and therefore not impairing the external flask (F) printing or labeling process.

There is also another way to make internal ribs (7) by means of a core (3) provided with external grooves (9) at its conical part, so that, while the extrusion of the plastic parison (6) is made, it interspersedly makes bilateral semiturning movements, thus obtaining a wavy or zigzag effect to the internal ribs (7) of the flask (F). Therefore, by means of the mouth (2) and core (3) set, as per the ribs (9) existing on them and turned to the extrusion area of the plastic parison (6), thus considering the

memory of the material conforming it and/or the movement of the core (3) over the lengthwise or turning bush (2), obviously also working the pressure as used for the extrusion of the plastic parison (6) and the temperature of said material/ we may reach numerous results with number, location and kind of ribs (7) which, according to the flask to be obtained, will provide better axial and radial resistance and material savings between 30% and 40%, i. e. a better flask (F) weight/resistance ratio to be obtained.

The present description dealt with a new conception of a "PROCESS TO OBTAIN AXIAL REINFORCEMENT IN PLASTIC FLASK AND PLASTIC FLASK WITH AXIAL REINFORCEMENT AS OBTAINED", presenting, as we can show from the effected analysis and the figures as shown, numerous advantageous as a function of the differences over the existing and used conventional methods, besides constructive and functional technical characteristics as fully new before the state of the art.

Having therefore disclosed and illustrated the best way of embodiment as currently contemplated to embody the present invention, numerous modifications and variations in its form of embodiment may be promptly introduced by the experts in the art. For example: we may use this process to obtain an internal reinforcement not only with the intention to reinforce the flask, but also as a decorative effect, mainly in transparent or translucid plastic materials, or by means of coextrusion. However, it should be understood that the present invention is not limited to the practical aspects of the currently preferred embodiment as shown and disclosed and that each and

every modification and variation should be considered as being covered by the spirit and scope of the invention.

For the offered advantages and also for having truly innovative technical characteristics, they fulfill all requirements of originality and novelty in the field, thus assembling all required conditions to deserve the privilege.