DE1729108A1 - Process for the production of closed and open containers and molded parts from plastics and containers and molded parts produced in this way - Google Patents

Description

Method for producing closed and open Be @@ @ @n and molded parts made of plastics and containers and molded parts produced in this way The invention relates to a method for producing closed, open containers and molded parts made of plastics in the melting process and also by this process closed or open containers or molded parts produced in the melting process Plastic.

Closed and open containers and molded parts made of plastic, that is more or less pronounced hollow bodies have so far been produced in such a way that that its wall is single-layer or double-layer. The manufacture of single-layer Containers are known in many types, e.g. B. by blowing, spraying, vacuum drawing or rotational molding. The latter becomes a melted one in a melting process Layer of plastic spread out. The invention relates to this latter method.

Single-walled containers are temperature and strength-wise only resilient to a certain extent. Accordingly, you can they can only be produced up to a certain size. The invention lies in the The task is based, in particular, to produce large-volume hollow bodies or molded parts, which up to now could not be manufactured seamlessly in one piece. In this size comparable containers are said to be higher in terms of both temperature and strength become resilient.

Attempts have already been made to produce hollow bodies with double-layer walls manufacture by first making a single-layer hollow body and then another layer is applied in a further operation. Disadvantageous is here because # this double-layer production is a further step which is very difficult, especially with regard to the individual types of material is to be carried out. Furthermore, there is a perfect connection between different types of plastics not given when the first layer is completely formed and only then the second Layer is applied. The mechanical and temperature properties of such Containers and moldings are also inadequate. Furthermore, it is known that Difficulties due to distortion in cooling and poor shape retention, poor accuracy due to the shrinkage. These difficulties are known both with the single-layer as well as the double-layer plastic parts produced in the manner described above available.

In order to achieve the task at hand, there is a method according to the invention for making g closed and open Containers and molded parts Made of plastics in the melting process, characterized in that in one operation by means of layered distribution of melted plastic after melting from plastic to a first layer (outer wall) a second (middle) plastic layer formed with the addition of a propellant and seamless and homogeneous with the first Layer (outer wall) is fused, whereupon a third plastic layer (inner wall) formed and fused seamlessly and homogeneously with the second (middle) layer will. The middle layer is expediently in the wall is designed to be stronger than the outer and / or inner wall.

The distribution of the plastic in layers is essential in the invention in one operation during a z. B. container closed except for pipe socket is manufactured in the melting process, that is, by means of a rotation process. Through this that the individual layers are formed in one operation and are homogeneous and merge seamlessly with one another, the result is an excellent connection that leads to excellent temperature and strength properties. Further it is thus possible to produce large-volume bodies that were previously seamlessly integrated into one Piece could not be manufactured, z. B. Tanks with a Fassungsvermbgen up to to 50,000 1.

By changing the additives in the plastic in relation to a layer on the other layers during the layer-by-layer distribution of the individual amounts of plastic, so z. B. by adding a propellant to the plastic of the middle layer, there are also excellent insulation advantages. Different Wall thicknesses and different material compositions lead within the scope of the invention too many possibilities. Tests showed that in the Wise manufactured parts, that is from several homogeneously and seamlessly with one another consist of fused layers, withstand temperatures of -40 ° C, and also none Showed cracking and stress. Impact and drop tests could damage the inner wall do not destroy. The same occurred at a temperature of + 70 ° C. The cold and Warm tests were carried out for 24 hours each. Preferably in the middle layer an insert made of steel, polyamide or glass fiber fabric melted down. As a result, the values of the cold, warm and impact tests were significantly improved. It is important here that the middle layer has a different thickness than the outer or Has inner wall.

Pressure tests on large-volume bodies produced according to the invention yielded 125% better properties than the known single-layered ones. or have the two-layer container described at the outset. the Compressive strength tests were carried out up to 10 atm.

It is essential that, according to the invention, the various layers have their own temperature and strength values.

Blown, injection-molded, vacuum-drawn and manufactured in round molding single-layer containers and molded parts and also in the manner described above Manufactured double-layer parts withstood the aforementioned cold, heat, impact and Printing tests comparable to those produced by the process according to the invention Containers withstood, not withstood.

The invention is applicable to the manufacture of containers and molded parts of all types made of plastic or plastic compounds. In a preferred embodiment the outer wall of polyethylene, the middle layer of polyethylene with Propellant and the inner wall made of polyamide. Outward protruding screws, Tabs, lialterings, hinges made of metal or polyamide are expedient only melted into the outer wall and the middle layer. To that extent are Connections plastic-metal-plastic or metal-plastic possible. The embedding of metal parts, fittings, etc. in the middle layer has the advantage that then these parts through the respective outer insulation, which is through the outer or. Interior wall is formed, protected from all influences: are.

Another major advantage of the invention is the savings in material. The same wall thickness made of single-layer material would weigh 120% more. The same wall thickness made of two-layer material as described above other procedures would weigh 80% more.

Due to the layering according to the invention, in that the inner and outer sheaths are solid, homogeneously melted walls and the middle layer is a foam-like one If there are structures, the walls produced according to the invention have greater strengths than two-layer one produced by the other method described at the beginning Material. Tensile and shear tests show an improvement of over 100%.

Further details and advantages of the invention emerge from the The following description of exemplary embodiments shown schematically in the drawing of containers produced by the method according to the invention.

In the drawing: Fig. 1 shows a first embodiment in longitudinal section, FIG. 2 shows a cross section along line II-II in FIG. 1, FIG. 3 shows a second embodiment in longitudinal section, FIG. 4 shows a cross section along line IV-IV in FIG. 3, FIG. 5 shows a third embodiment in longitudinal section, FIG. 6 shows a cross section along line VI-VI in Fig. 5, Fig. 7 a fourth embodiment in longitudinal section, Fig. 8 a cross section according to line VIII-VIII in Fig. 7, 9 shows a fifth embodiment in longitudinal section, FIG. 10 in side view of a sixth embodiment, and FIG. 11 a seventh embodiment on average.

In Figs. 1 and 2, the first embodiment is an integrally formed except for one Nozzle 5 closed container shown, the wall of three homogeneous and layers fused together seamlessly in one operation, namely an outer wall 1 made of polyethylene, with a middle layer made of polyethylene Propellant, which is stoker in the wall than the outer wall 1, and one Inner wall 3 made of polyamide. The individual layers are not in the drawing shown with separate hatching, as they merged homogeneously and seamlessly are.

In the embodiment according to FIGS. 3 and 4, there is also an up to a connection piece 5 of closed container is shown, which consists of such three layers 1, 2, 3 consists. In the middle layer 2 there is an insert 4 made of steel, polyamide or glass fiber fabric melted down, i.e. firmly connected to the middle layer 2. In a manner not shown, the middle layer 2 can also optionally be parallel or glass fibers not lying parallel to be penetrated.

In Fig. 5 and 6, a closed container is shown, which also the layers 1, 2, 3 formed in the manner according to the invention. In the middle layer 2 and in the outer wall 1 are tabs 6 made of metal or Polyamide melted down, the inner wall 3 not being perforated. In the same Screws, retaining rings, hinges made of metal or polyamide can be melted down be.

The embodiment according to FIGS. 7 and 8 is also involved around a closed container, the walls of which contain the layers according to the invention 1, 2, 3. There is a heat-resistant piece of glass throughout all three layers 7 melted down.

Fig. 9 shows a closed container, in the invention & ße multilayer wall a nozzle 8 is melted, and also continuously through all three layers 1, 2, 3. In a similar way, wear and tear, pipe connections, Lid, inlet and outlet connections with or without flanges made of metal or polyamide melted down and optionally with a closable opening to influence the The inside of the container must be provided.

In the embodiment according to FIG. 10, there are openings in the container wall 9 that go through all three layers 1, 2, 3.

In the embodiment of FIG. 11 are on the entire container or Molded part ribs 10, wherein the wall is also made of the inventive Layers 1, 2, 3 consists. Similarly, grooves, depressions and ridges can be used be molded.

In a manner not shown, in containers or fittings in the middle layer 2 and inner wall 3 reinforcements be melted, the can also protrude through the outer wall 1 and inner wall 3. The grain sizes of the various materials for the layers 1, 2, 3 according to the invention be even or uneven.

The invention is not limited to the lierstellung in the Embodiments shown in the drawing. There are all kinds of embodiments into consideration such as containers, furniture, boats, refrigerators, petrol tanks, bltanks, dashboards, Electrical cabinets, surf boards, buoys, radio and television housings, stacking containers, Pressure vessels, chairs and armchairs, suitcases, canisters, garbage cans for larger garbage trucks, complete caravans, car bodies, heat boilers, rocket parts, aircraft fuselages, Airplane wing, components, building blocks, machine housings, machine stands, machine frames, Motor housing, complete insulation for Eseiz and cooling devices, thermal insulation Parts and vessels for the chemical industry that are simultaneously pressurized are.

Claims (11)

Claims 1. Method for producing closed and Open containers and molded parts made of plastics in the melting process, characterized in that that in one operation by means of layered distribution of melted plastic after the plastic has fused to form a first layer (outer wall) a second (middle) plastic layer formed with the addition of a propellant and is fused seamlessly and homogeneously with the first layer (outer wall), whereupon a third plastic layer (inner wall) is formed and seamlessly and homogeneously with it the second (middle) layer is fused. 2. The method according to claim 1, characterized in that the middle Layer is formed stronger than that in the wall with the help of the propellant Outer and / or inner wall. 3. The method according to claim 1 or 2, characterized in that # the Outer wall made of polyethylene, the middle layer made of polyethylene with propellant and the inner wall are formed from polyamide. 4. The method according to any one of claims 1 to 3, characterized in that that in the middle layer an insert made of steel, polyamide or glass fiber fabric is melted down. 5. The method according to any one of claims 1-4, characterized in that that outwardly protruding screws, straps, retaining rings, hinges made of metal or polyamide only melted into the outer wall and the middle layer will. 6. The method according to any one of claims 1-5, characterized in that that a heat-resistant piece of glass or nozzles, closures, pipe connections, Lid, inlet and outlet connections made of metal or polyamide throughout three layers (outer wall, middle layer and inner wall) melted down will. 7. Closed or open container produced in the melting process or molded part made of plastic according to the method according to any one of claims 1-6, characterized in that characterized in that it has an outer wall (1) made of polyethylene, one in one operation homogeneous and seamlessly fused middle layer (2) with thick walls, Consisting of polyethylene with propellant, and one homogeneous in one operation and has an inner wall (3) made of polyamide that is seamlessly fused therewith. 8. Container or molded part according to claim 7, characterized in that there is an insert (4) made of steel, polyamide or glass fiber fabric in the middle layer (2) melted down. 9. Container or molded part according to claim 8, characterized in that because # the middle layer (2) with either parallel or non-parallel lying Is interspersed with glass fibers. 10. Container or molded part according to one of claims 7-9, characterized in that screws, straps (6), retaining rings, hinges made of metal or polyamide are only melted into the AU (1) and the middle layer (2) and leave the inner wall (3) uninterrupted. 11. Container or molded part according to one of claims 1-10, characterized marked as # a heat-resistant piece of glass (7) or stub (8), closures, Pipe connections, covers, inlet and outlet connections made of metal or polyamide melted in all three layers (outer wall, middle layer and inner wall) are. L e r s e i t e