DE1273799B - Process for the production of a tubular container from thermoplastic material as well as a device for carrying out the process - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

ι EDITORIAL

Int. CL:

B29d

German class: 39 a3- 23/00

Number: 1273 799

File number: P 12 73 799.4-16 (T 22556)

Filing date: August 3, 1962

Opening day: July 25, 1968

The invention relates to a method of manufacturing a tubular thermoplastic container Plastic, in which in the end of a prefabricated pipe made of thermoplastic plastic introduced a disc made of thermoplastic material and at its edge with the end of the Tube is welded, as well as a device for performing this method.

Recently, containers made of plastic, both solid and flexible plastic, have been replacing little by little soft metal containers, glass tubes or the like, at least for certain purposes, such as for storing cosmetics, medical Preparations, paints and the like, because the manufacturing cost of such packaging is low lie. Such packaging made of flexible plastic is particularly favorable. For the manufacturer this means but any such packaging involves a considerable expense, all the more so as the containers are often more expensive than that are good contained in them.

It is already known to manufacture tubular plastic containers by placing a cold, in an essentially rigid washer body made of plastic material is slipped onto the end of a dome, who carries a plastic pipe. The end of the dome is then placed in a die or mold, which is heated so that the plastic washer to melt by moving the Domes is brought into engagement with the open end of the plastic tube. The washer must here be inserted over a pin extension of a dome and have an opening for this purpose. This requires that no complete closure for the pipe can be achieved, at least in one operation, because the hole, albeit a small one, has to be closed again. But the well-known method is effective to increase the cost, as described above, for the packaging container.

The method mentioned at the beginning can be carried out much cheaper and faster if according to the invention, the tube inserted into a hole cutting punch and this against the tube a plate made of thermoplastic material lying on a base and heated up to the melting temperature Plastic is pressed to punch the disc out of the plate and in doing so into the end of the tube to push in.

According to a further feature of the invention, it is advantageous immediately after welding to the Washer applied pressure to shape it into a specific shape.

It is particularly advantageous if the invented method for producing a tubular
Container made of thermoplastic plastic
and device for performing the
Procedure

Applicant:

Rexall Drug and Chemical Company,

Los Angeles, Calif. (V. St. A.)

Representative:

Dr.-Ing. H. Fincke, Dipl.-Ing. H. Bohr
and Dipl.-Ing. S. Staeger, patent attorneys,
8000 Munich 5, Müllerstr. 31

Named as inventor:

Myron H. Downs, Caldwell, N.J. (V. St. A.)

according to the disc with slight crimping on the inner edge of the welded joint by a Punch is pressed into a die.

Characterizes an advantageous device for carrying out the method steps according to the invention according to the invention by an annular, inside receiving the tube made of plastic Hole cutting punch with a cutting edge, the longitudinal axis of which is perpendicular to a base serving plate is aligned.

Here, according to the invention, the cutting edge of the punch can taper towards the inside in a wedge-shaped manner.

According to the invention, it is expedient to leave sufficient within the hole cutting punch Clearance in the radial direction for the plastic tube is a form dome relative to the hole cutting punch slidably guided, the end of which in particular in a manner known per se corresponding to the Inner profile of the container edge to be produced is formed, and one in or under the as a base Serving plate arranged, cooperating with the form dome and the outer shape of the container edge adapted die provided.

It is particularly advantageous if, according to the invention, the mandrel is composed of two coaxially arranged one to the other Parts is formed, the inner part is provided with a head serving as a stop and opposite the outer part is supported by a spring.

The invention enables rapid and economical large-scale production of such containers Number of items reached. With the simplest of equipment you can

809 587/526

3 4

a large number of slices melted unless there are certain color differences of Plastic can be punched out quickly. Tube 7 and washer 10 can be selected. After about It has been shown that a precisely formed 5 seconds can be welded to the pane 10 Butt joint between the pipe and the disc at the pipe 7 can be removed from the device, forms according to the invention. The reason for this- 5 To ensure that the disc 10 during for is not known, but it is assumed that the cooling is not tense, but rather in the If the molten plastic is liquid enough to remain essentially flat, either air will be underneath to enter the end of the tube without applying the latter to appropriate pressure or relative to the punch 5 deform. Likewise, the flat mandrel 13 which can be moved back and forth is likely to be insufficient Transfer heat to the front end of the tube, as shown in FIG. 1 with sufficient radial play in the inmit this could be deformed. nere of the tube 7 introduced, which the disc 10 to It is particularly advantageous that the production of the pad 9 presses, the end of this Blank by cutting out, the introduction of the dome 13 according to the inner profile of the herzu-blank is formed in the pipe end and the welding with the container rim. Since the practically simultaneously with the pipe. When 15 thorn 13 has room temperature, the same takes The heat of the disc 10 is welded in the cut blank, so that a or the thermal energy present in the pane flat, even end of the face for use in art; it does not matter whether the container makes a fabric container.

at the end completely closed or with a through-When punching the disc 10 from the heated

opening is desired. 20 plate 8 must have a relatively high force of

The invention is described below with reference to the z. B. act about 70 kg on the punch 5 when

schematic drawings for exemplary embodiments, the base 9 is made of metal and environmental

explained. In the drawings shows temperature. However, this force can

Fig. 1 the sectional view of a device to be considerably reduced to about 2.5 kg if

production of a container according to the invention, 25 a layered plastic base from a

FIG. 2 shows a sectional view similar to FIG. 1, material of low thermal conductivity with a das

however, at a later date in the container-melt preventing agent used, if so

manufacture, may be necessary to avoid sticking

F i g. 3 one of the F i g. 2 corresponding sectional dar- should. The pressure can also be reduced by

position to explain a further work 30 that a metallic base 9 is placed on a temperature

step in container manufacturing, keeping temperature closer to the melting temperature of the

Fig. 4 is a sectional view for a material of the plate 8 is opposite.

F i g. 2 modified embodiment of the invention. The device shown in Figure 2 is similar training, designed as the device according to Fi g. 1; she ent-F ig. 5 shows a partial section for the representation of a 35 only additionally holds a die 14, which with the head follows a further working stage of the container production. end of a mandrel 16 cooperates. By F i g. 4 and this training, it is possible with the art-Fig. 6 is a side view of a finished, one-sided fabric tube 7 connected disc 10, while it is from open tubular plastic container, which is still hot after the connection process, a geder Device according to FIGS. 4 and 5 produced 40 to give the desired shape. There is a die for this has been. 14 is provided, the cavity of which has a cross-section pro-F i g. 1 shows an annular, metal perforated fil that corresponds to the desired outer profile of the cutting punch 5 z. B. made of brass or steel with a front end for the finished container, a cutting edge 6, which is wedge-shaped pointed towards the inside. The punch 5 with inserted tube 7 and on runs in. The inner diameter of the punch 5 is so 45 the same welded disc 10 is in this dimensioned that he used a preformed tube 7 die with a snug fit until the edge of the cutting edge 6 on made of thermoplastic material, e.g. B. polyethylene, a shoulder 15 of the die 14 is seated. Then it will be can accommodate. Around the end face of a tubular mandrel 16 with a suitably rounded one To form gene container, the cutting edge 6 end face 17 within the tube 7 is gedes down Hole punch 5 with inserted tube 7 presses below 50, so that the end face 17 of the dome 16 the Applying a suitable pressure through a still hot, but already at the edge 12 with the Plate 8 made of thermoplastic suitable tube 7 welded disc 10 down into the Thickness pressed, the cavity of the die 14 presses into it from the desired end shape. Since the ma ^ of the container. This plate 8 lies on the trize 14 and the dome 16 on one of the ambient temperature Pad 9, e.g. B. od metal such as steel. Like., 55, the deformed hot disk 10 is quickly on, to which the longitudinal axis of the hole cutting is cooled and hardened, taking the shape of the stem feed S is aligned vertically, and is retained up to the die cavity (FIG. 3). This occurs their melting temperature of about 200 ° C is heated. However, there is no destruction and weakening of the Cutting edge 6 of the punch 5 punches a welding point at the edge 12, so that there is always a ^ Washer 10 from the plate 8, which at the same time remains in the 60 tight fixed connection. The only tough one The end of the tube 7 is pressed. Because the "table moment in the above-described manufacture Disk 10 while still essentially melting a tubular container is in the duration of the temperature, the edge 12 is the same immediately between the punching out of the disc 10, the With the adjacent edge of the tube 7, inserting the punch 5 with the contents 7, 10 into the hole Melting the inner peripheral surface of this 65 trize 14 and applying pressure to the mandrel The end of the pipe is welded together, which makes it so homogeneous The connection results in that after welding, the heat loss of the disc 10 due to heat does not occur sharply delimited junction is visible, line to the die 14 and the dome 16 a

such cooling that the disc 10 can only be deformed with considerably greater pressure. If too great a cooling has occurred, I will not let it through any more, even if | ioch such high pressure to balance out the plasticity To achieve a perfect shape of the disk 10 for the production.

In the embodiment of FIGS. 4 and 5, a two-part mandrel is used. Maintain However, in this case too, a metallic hole cutting punch 5 is wedge-shaped with an inwardly tapered cutting edge 6 for punching out a disc 10, the edge 12 of which with the inner peripheral region of one end of a plastic pipe 7 is welded. The mandrel is made from a hollow outer part 20 with an end open at the end and from a full inner part 22, which is under the return pressure of a helical spring 27 and back and forth coaxially within the outer part is movable. After this two-part mandrel 20, 22 has been inserted into the one received by the punch 5 and pipe 7 welded to the disc 10, these parts are made using Pressure on the upper end of the mandrel inner part 22 under the spring tension in this way Die 24 introduced so that this disc 10 adapts to the profile of the die cavity, which consists of step-shaped paragraphs of decreasing diameter and a threaded piece 19 with a pin attachment consists.

If the downward movement of the punch 5 is stopped by a shoulder 25 of the die 24, then sets the two-part mandrel 20, 22 together with the tube 7 and the welded disc 10 the Downward movement into the cavity of the die 24 continues until the end face of the disc 10 on the Central axis tapering wall area of the die cavity is reached. At this time touches the flange 26 of the stronger shaft part of the mandrel outer part, which is guided in the punch cavity itself 20 the upper edge of the punch 5, so that a further downward movement of the tube 7 and the Form mandrel outer part 20 is prevented. However, if the pressure is maintained, there will be a downward movement of the mandrel inner part 22 against the pressure of the return spring 27, so that the desired Design of the disc 10 according to the cavity of the die 24 and thus the in F i g. 6 shown finished container 18 results.

In this embodiment of the invention, the disc 10 is slightly crimped on The inner edge (at 12) of the welded joint is pressed into the die through the mandrel. This arises from the fact that the distance between the stepped end of the mandrel inner part 22 and the trains-ordered Steps of the die cavity is so large, fit at the high temperature of the disc 10 and (With the pressure applied, the molten material of the disc 10 flows between the mandrel inner part 22 and the walls of the Matrizenhohl-Jraumes enters. This slight ripple is then ! Run for the tube 7 and the disc 10 material different color selects, clearly visible, as shown in FIG. 5 is indicated. This is with The result is a particularly reliable weld with a high degree of probability. Apparently you can get through Changing the distance between the mandrel ends, the pressures applied and the relative movement the two mandrels achieved a variety of types of training of the connection areas will.

The method according to the invention is particularly suitable for the mechanization of the production of Containers of the type mentioned. B. od a turntable. Like. Can be used in a variety of positions in which the successive operations, such as the introduction of the Tube 7 in the punch 5, punching out the hot disc 10 from a continuous substantially molten plate material 8 supplied, the welding of the disk 10 with the tube 7, the shape of the disc 10 to the respective end of the container through Back and forth movement of the mandrel or mandrels within the punch 5 and removal of the finished container, can be carried out quickly and easily. Since the working speed and the dwell time in each working position can be set precisely, the aforementioned critical Easily control the process of cooling the disc 10. By applying mechanization not only the manufacturing costs for plastic containers are significantly reduced, but also the finished product also has a particularly uniform, with the container tube solid and practically invisible connected forehead part.

Claims (7)

Patent claims: 1. A method for producing a tubular container made of thermoplastic material, in the one in the end of a prefabricated pipe made of thermoplastic material Disc made of thermoplastic material introduced and at its edge with the end of the Pipe is welded, characterized in that the pipe is in a hole cutting punch used and this with the pipe against a lying on a base, heated up to the melting temperature plate made of thermoplastic Plastic is pressed to punch the disc out of the plate and in doing so in push in the end of the tube. 2. The method according to claim 1, characterized in that immediately after welding pressure is applied to the disc to shape it into a specific shape. 3. The method according to any one of the preceding claims, characterized in that the Washer with slight crimping on the inner edge of the welded joint by a punch in a die is pressed. 4. Device for performing the method according to one of the preceding claims, characterized by an annular hole-cutting punch which receives the plastic tube on the inside (5) with a cutting edge (6), the longitudinal axis of which is perpendicular to a base serving plate (9) is aligned. 5. Apparatus according to claim 4, characterized in that the cutting edge (6) of the The stamp tapers towards the inside in a wedge-shaped manner. 6. Apparatus according to claim 4 or 5, characterized in that within the hole cutting punch (5) leaving sufficient clearance in the radial direction for the pipe Plastic a mandrel (13, 16, 22) relative to the Hole cutting punch (5) is guided displaceably, the end of which, in particular, in a manner known per se, corresponding to the inner profile of the one to be produced Container edge is formed, and that one in or under the serving as a base Plate (9) arranged, interacting with the mandrel (16, 22) and the outer shape of the Container edge adapted die (14, 24) is provided. 7. Apparatus according to claim 6, characterized in that the mandrel is formed from two coaxially arranged parts (20, 22), the inner part (22) is provided with a head serving as a stop and opposite the outer part (20) by a spring ( 27) is supported. Considered publications:
U.S. Patent No. 2,947,035. 1 sheet of drawings