WO2019203631A1

WO2019203631A1 - Method for manufacturing air-tight, suspended plastic containers

Info

Publication number: WO2019203631A1
Application number: PCT/MX2018/000091
Authority: WO
Inventors: Álvaro Fabián BRICIO ARZUBIDE; Juan Carlos ORTIZ MANZO
Original assignee: Active Financial, S.A. De C.V.
Priority date: 2018-04-17
Filing date: 2018-09-20
Publication date: 2019-10-24
Also published as: MX2018004716A

Abstract

This invention relates to an industrial method for moulding polymers which is used to produce suspended plastic containers, in other words, containers with an air-tight, moulded plastic covering that form a single part, with a space containing air, an atmospheric vacuum or any other material between said containers, and which are useful for protecting or insulating the substances contained therein.

Description

MANUFACTURING PROCESS OF SUSPENDED PLASTIC HERMETIC TANKS.

FIELD OF THE INVENTION

This invention relates to manufacturing processes for the manufacture of tanks made of synthetic or semi-synthetic polymers, either thermo-fixed or thermo-plastic, more in particular this invention relates to the manufacture of tanks or parts which have in its exterior one or more hermetic covers of the same or different form, and which are mainly used to isolate or protect the substances contained therein.

BACKGROUND OF THE INVENTION

Materials made up of a variety of synthetic or semi-synthetic organic compounds are called plastic, which have the property of being malleable and can therefore be molded into solid objects of various shapes. This property gives plastics a wide variety of applications. Its name derives from plasticity, a property of these materials, which refers to the ability to deform without breaking.

There are several industrial processes for the manufacture of parts in plastic or thermo-fixed and thermo-plastic polymers, in high or low pressure processes, pressure injection, rotational molding and blowing processes are just a few examples, we can briefly mention that:

Injection molding is a semi-continuous process that consists of injecting a polymer in a molten (or hollowed) state into a mold closed under pressure and cold, through a small hole called a gate. In that mold the material solidifies, beginning to crystallize in semi-crystalline polymers. The piece is obtained by opening the mold and removing the molded part from the cavity. Rotational molding or rotational molding is a process of forming plastic products in which a polymer is introduced in a liquid state or powder into a mold and this, when rotating in two axes perpendicular to each other, adheres to the surface of the mold, creating hollow pieces Blow molding is a process used to make hollow plastic parts thanks to the expansion of the material. This is achieved through the pressure exerted by the air on the walls of the preform, whether it is injection-blowing, or the Párison, if we talk about extrusion-blowing.

Currently, through these processes, parts, tanks and tanks of different sizes and shapes are made, with the purpose of containing countless substances in them.

Nowadays when in the industry it is required to obtain suspended hermetic tanks, that is to say one inside the other, with a separation space between them, it is done in cold, that is, the inner tank is manufactured by some conventional method, such as it can be the roto-molded, the injection under pressure or the blown, among others, to later manufacture the outer tank in two or more parts, thus, the initial piece is covered with the outer parts, these will be joined by heat, so mechanically or by an adhesive, between the inner and outer part there may be a space that can be filled with insulating material, protective material or simply air. The way to do it in cold is mainly due to the high temperatures that the molds operate in the manufacture of plastic parts, the pieces manufactured in these plastic materials change their physical or molecular state to a considerable increase in temperature, so it is not possible subject these products to new high temperature processes without them undergoing considerable molecular change. Documents US3094448, US20150079378A1, CA2868460A1, EP2830845A1,

EP1633546B1, US20050017409A1, US5922778A, CA2914166A1, US20170158789A1, US7332543B2, US20040116608A1, US2005017409A1 and US7736566 are a sample of patents granted where the process of broken-molding is described, no document of the state is mentioned by any document they could obtain concentric polymer tanks, US7736566 whose inventors are Rainer Pechtold, Russelsheim (DE); Ingo Hermann, Mainz (DE); Markus Lindner, Mainz (DE) describes a process of roto-molding on a tank, however it refers to a metallic tank and not to a tank made of polymers, as already noted, no document in the prior art mentions or The problem of producing polymer thermo tanks obtained in the same mold is approached in order to obtain elements in one piece.

A process is presented that consists of the molding of pieces with hermetic deposits or covers on the outside, these being the same or different way, made of polymer materials of high or low melting coefficient, and that allows to obtain at the end of the process a product of a single piece, since these, during the second molding process, are fused (together) in a single piece, thereby obtaining a product of high rigidity and tightness.

DESCRIPTION OF THE INVENTION

A novel manufacturing process of concentric tanks or tanks made of polymer is presented by means of which parts are obtained that have other bodies tightly connected to each other, there being a gap between them, this vacuum can be used to contain Another type of material, for example, can be insulating materials, protective materials, or substances that allow to react in the case of leaks (such as anti-inflammable, extinguishing or neutralizing substances), or also a combination of these.

This novel process consists in injecting a high flow of cooling fluid through a system of universal joints and joints, carried out during the elaboration of the workpiece, inside the part placed in the internal part of a broken-molding mold. outer cover, which is done through a process of broken-molding, this in order to molecularly stabilize the part placed inside and that it does not suffer effects on its properties, chemical or physical, due to the considerable increase in temperature during the process.

The time required to perform the rotational molding process is several minutes, the temperature inside the mold can reach 350 degrees Celsius, a high flow of refrigerant inside the tank allows the inner tank to remain rigid and without deformities , not so the materials placed in the points of support of both bodies as separators that will be fused, finally achieving a piece of great tightness and rigidity.

The cooling fluid can be air, water, oil or thermal liquids such as glycol which has a thermal absorption capacity greater than 400 degrees Celsius, or also a mixture or combination of these.

The tank cover can be of the same or different form and can be placed in any position within it in the same way, between these two deposits there will be a space which can be used to contain another type of material, it can be for example insulating materials, protective materials or substances that allow to react in the case of leaks.

DESCRIPTION OF THE DRAWINGS:

Fig. 1.- An example side view of a rotational molding mold incorporating this technique is shown.

Fig. 2.- A side view of a polymer tank or tank made by any plastic molding method is shown.

Fig. 3.- The example of the mold of roto-molded of Fig. 1 is shown cross-sectional where the position of the tank or tank (without sectioning) of Fig. 2 placed in its internal part, before placing it is shown a hermetic cover by this method.

i Fig. 4.- The cooling process of the inner tank during the rotational molding operation is shown schematically.

Fig. 5.- The product is shown once molded product of Fig. 3, cross-sectioned, which consists of the suspended tank of Fig. 2 (shown without sectioning) with the hermetic polymer outer shell.

PROCESS OPERATION.

Having described the nature of the present invention, it will now be described by reference to the attached drawings. However, those skilled in the art will appreciate that many variations and modifications can be devised without departing from the scope of the invention as described above.

A novel manufacturing process of deposits or tanks made of polymer is presented, through which parts are obtained that have other bodies of the same or different shape in their exterior, tightly connected to each other, there being a space between them.

The process requires the following elements:

1.- Mold assembly station, 2.- Baking station 3.- Cooling station. 4. Homo. 5.-Tank or inner part. 6.-Insulated refrigerant ducts. 7. -Universal duct joints. 8.-Inlet of cooling fluid to molds. 9.-Outflow of cooling fluid in molds. 10.-Chiller for cooling fluid. ll.-Rotary mold holder. 12. Pump or impeller of cooling fluids. 13.-Exterior Cover. 14, -Cold-molding mold. 15.- Straight supports

16.-Refrigerant fluid. 17.- Tubular supports. 18.- Airtight plastic tank suspended. 19.- Space between tanks or deposits.

And it consists of the following steps: 1.- Preparation of a hollow plastic part by a conventional method.

2.- Assembly of the part of step 1, inside the rotational molding mold for the elaboration of an outer cover.

3.- Start of the injection process of high flow of refrigerant fluid, through the system of universally articulated and thermally insulated ducts, to the internal part of the part of step 1.

4.- The process of broken-molding of the outer tank begins when this mold is introduced into the oven.

5.- The cooling of the mold is carried out. 6.- The mold is opened and the tank is removed.

This process begins in a first step with the manufacture of a tank or tank (5) Fig. 2-5, by any conventional method of manufacturing polymers (plastics), so that once this piece is obtained in a mold assembly station (1) be placed, in a second step, inside the rotational molding mold (14) Fig. 1.3, with the purpose of molding a cover -which can be of the same or different shape-, this piece is It may or may not be placed concentrically interchangeably through supports (15) Fig. 3-5, which may be of any type of metallic or polymeric material, which will be fused during the rotational molding process, in a third step. through a fluid pump (12) Fig. 4, and using coolant ducts (6) Fig. 4, and universal joints (7) Fig. 4, which through the fluid inlet points (8) Fig. 1, 3-5, and of tubular supports (17) Fig. 3-5, injected into the inner tank (5) Fig. 2-5, a f high regular and permanent luxury of cooling fluid (16) Fig. 4, to maintain the dimensional, physical and chemical stability of the tank (5) Fig. 2-5, during the rotational molding process, which is carried out in a step 4 , inside an oven (4) Fig. 4, in a temperature range that can vary from 220 to 400 degrees Celsius for several minutes, where the flow of this refrigerant fluid will not stop, which will be recirculating and will remain fried with the help of a fluid chiller refrigerant (10) Fig. 4, in a step five, the mold is removed from the oven (4) Fig. 4, for cooling, in a step six the mold is opened to remove the finished piece thus concluding the process.

Between the inner tank and the cover there will be a space (19) Fig. 5, which can be used to contain some types of materials that can be insulating, protective materials or substances that allow to react in the case of leaks (as they can be anti-flammable substances, extinguishers or neutralizers), or a combination of these.

Claims

CLAIMS Having sufficiently described my invention, I consider it as a novelty and therefore claim as my exclusive property contained in the following clauses:

1.- Manufacturing process of suspended plastic hermetic tanks comprising; in a first phase, the elaboration of a hollow plastic part (5) by a conventional molding method; in a second phase the assembly of this piece inside a rotational molding mold (14) for the elaboration of an outer cover (13); in a third phase, the beginning of the process of injection of refrigerant fluid (16) to the internal part of the inner part (5); in a fourth phase the molding process of the outer cover (13) by the method of broken-molding inside an oven (4); in a fifth phase the cooling of the mold (14); and in a sixth phase the opening of the mold and the extraction of the tank (18).

2. Manufacturing process of suspended plastic hermetic tanks as described in claim 1 wherein the assembly of the inner part (5), in the second phase of the process, is carried out through straight supports (15) and tubular supports (17).

3. Manufacturing process of suspended plastic hermetic tanks as described in claim 1 wherein the injection of refrigerant fluid (16), in the third phase of the process, is performed using a fluid pump (12), insulated ducts of refrigerant (6) and universal duct joints (7).

4. Manufacturing process of suspended plastic hermetic tanks as described in claim 3, wherein the cooling fluid (16) is cooled through chiller equipment (10).

5. Manufacturing process of suspended plastic hermetic tanks as described in claim 3, wherein through the tubular supports (17) the inlet and outlet of refrigerant fluid (16) is made to and from inside the internal tank (5) respectively.

6. Manufacturing process of suspended plastic hermetic tanks as described in claim 4, wherein the cooling fluid can be air, water, glycol, oil or a mixture thereof.

7.-Manufacturing process of suspended plastic hermetic tanks as described in all the preceding claims wherein the suspended hermetic plastic tank (18), product of the previously claimed process, is molecularly made in one piece.

8.-Manufacturing process of suspended plastic hermetic tanks as described in all the preceding claims, wherein the space (19) located between the inner tank (5) and the plastic cover (13), there is liquid, solid, gas, atmospheric vacuum, insulating material, protective material, anti-flammable material, extinguishing material, or some type of material that ensures the characteristics of the substance contained in the first deposit.