DE2437805A1 - PROCESS AND EQUIPMENT FOR THE MANUFACTURE OF GLASS FIBER REINFORCED PLASTIC HOLLOW BODIES - Google Patents

Description

Patent attorney

üf. Ing.C. HandzIK

SOl 1 Neiik-fsrloh b. Mchn. 2437805

Schwab, Nerweg 4

Hasler .itückfärberei AG · Basel

Process and device for the production of glass fiber reinforced plastic hollow bodies

The present invention relates to a method and a device for the production of glass fiber reinforced, rotationally symmetrical Plastic hollow bodies with a connecting sleeve arranged at one end.

It is known, the cylindrical jacket of a rotationally symmetrical Hollow bodies, e.g. a pipe or part of a container, can be manufactured using the centrifugal casting process and subsequently with a separately manufactured one as well fiberglass-reinforced plastic existing connection sleeve to provide. Apart from the fact that this manufacturing process requires three completely separate work operations, namely the production of the cylindrical pipe or container shell, the production of the sleeve and the connection of these two elements, and thus quite expensive, is no homogeneous connection between the pipe or container jacket and the socket is achieved even if it is carried out correctly. The present invention avoids these disadvantages? for this purpose, the method according to the invention is thereby

23. 7. 1974 / Vo. A 2344

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indicates that a β jacket and sleeve are produced as a unit by introducing the plastic necessary for their formation into a rotating centrifugal mold in the same operation. The procedure can be that during a first phase the plastic used to form the sleeve is introduced into the mold and immediately afterwards, namely before the start of the hardening of the sleeve plastic, the plastic used to form the shell is introduced into the continuously rotating mold will. However, it is also possible to distribute the plastic continuously over both sections and thus build up both sections in layers up to the full wall thickness at the same time * the curing of both sections takes place simultaneously in both cases. The glass necessary to reinforce both sections can be introduced in whole or in part before or during the introduction of the plastic into the relevant mold section (s); in the first case this is done conveniently in the form of a glass mat, in the second case by continuously feeding in individual pieces of fiber,

This new process not only brings the benefit of everyone Manufacturing steps can be carried out in one operation and thus also at the same place of work, but results, thanks to the simultaneous hardening of the entire plastic, an absolutely homogeneous plastic body.

The device also forming the subject of the invention for Implementation of this method is characterized in that a horizontally arranged, rotating drivable hollow mold, the one that can be introduced into the mold from an open side and in it axially parallel reciprocating material distribution head assigned iat, has an inner extension on said open side, in which with radial Distance a coaxial insert ring that is detachably fixed to the mold protrudes, which with the enlarged mold end part has an outwardly closed annular socket cavity limited. The insert that serves as the inner mold for the socket

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ring makes it possible to create the inner step profile required for sleeves, whereby the liquid plastic that has penetrated into it easily penetrates into the socket mold cavity when the mold is rotating, thanks to the expansion provided. The insert ring before the plastic or the pieces of glass fiber are introduced mounted on the stationary mold and only produced as a unit in a single operation after it has hardened Hollow body removed again, after which the molding is easily possible. It is useful for material delivery (Plastic, pieces of glass fiber and possibly other fillers such as sand etc.) and the movement of the material feed head is controlled by a program intended.

With reference to the accompanying drawing, which schematically shows an embodiment the device according to the invention shows, the method according to the invention is for example below explained.

In the drawing shows *

Fig. 1 schematically shows an embodiment of a device for the production of plastic hollow bodies, and

Fig. 2 shows the end of the mold on a larger scale and in axial section the device with insert ring for producing the socket.

In Fig. 1 is a device for the production of reinforced plastic pipes with horizontal, rotatably drivable Centrifugal mold 1 is shown as it is explained in more detail in Swiss patent 438 702, for example. Mean:

2 the front mold bearing,

3 the rear mold bearing arranged on a rocker,

5 shows a loading device which is attached to a carrier 6 in FIG Arrow direction a back and forth and thus through the

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front open side of the mold 1 is suspended in this insertable.

9 is a stationary storage container for the liquid plastic, which arrives through a flexible line 8 to the feeding device 5 provided with distribution head 7, the feed other aggregates, e.g. sand, can be done in a similar way; the glass used for reinforcement can, for example be stored at 4 in the form of coils, from where it is e.g. by means of compressed air to a cutting device provided distributor head 7 is promoted. The main part χ of the mold cavity is used to produce the actual cylindrical Tubular body or jacket, while the radially somewhat widened cavity y in the front, open end part la serves to manufacture sleeves. On an outer end flange Ib of the end part la is an end flange 11a of a coaxial one Insert ring 11 removably screwed. The outer surface of the insert ring 11 protruding into the mold cavity y with radial play is offset twice, that is to say on one first conical annular surface 12a directly on the end flange 11a is followed by a cylindrical surface 12b, to which a second Conical annular surface 12c adjoins, which in turn is followed by a cylindrical surface 12d. The inner end of the insert ring 11 is provided with an inner end flange 11b with a conical inner surface lic. As can be seen from Fig. 2, lies the inner end of the insert ring 11 in the area of the inner end of the enlarged mold cavity y, which is here by a Trumpet-like narrowing merges into the main cavity χ.

With the device described, in the same operation, in which the glass fiber reinforced main body of the plastic pipe is produced, including the one end at this create the sleeve to be provided; basically two ways of working are possible »

In one case, in a first phase (with the mold rotating) in the position shown in FIG.

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The current loading device 5 is supplied with plastic until it completely fills the annular cavity y; thanks to the radial expansion of this mold cavity y compared to the main space χ, this filling takes place under the effect the centrifugal force automatically, whereby it should be noted that the inner wall of the main room χ approximately the same radius as the Outer surface 12d of the insert ring 11 has, so that actually the annulus y is first filled with plastic before the plastic moves further into the main cavity χ can spread; in a phase that immediately follows, while the mold continues to rotate, the feed device device is moved back and forth in the main cavity χ, whereby the main body of the pipe is built up to the desired wall thickness is reached, which is the case with an inner diameter which is slightly smaller than the outer diameter of the ring surface 12d. The glass addition required for reinforcement can be used in the first phase, which is used to manufacture the socket as well as in the second phase, which is used to manufacture the main tubular body. The addition of glass can be used in both Phases can be controlled differently, e.g. so that the sleeve is formed from a relatively homogeneous glass / plastic mixture while the main pipe body is made of, for example, distance containing a mineral filler such as sand or the like or stiffening layers, separate glass fiber-containing layers can be built up. But it is also possible that the Glass fiber reinforcement for the socket (and possibly also for the main pipe body) before the plastic is introduced into the mold a mat or fabric into the mold. Since the two manufacturing phases follow each other immediately, i.e. before a noticeable hardening of the plastic occurs, the main body and sleeve form one with respect to one another after completion the completely homogeneous body of the plastic, which no longer requires any processing such as turning, etc. For molding of the pipe formed in one piece with the socket, the insert ring 11 is removed and the pipe is e.g. Area of the rear bearing 3 arranged ejector shaped forward.

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In the second pail, the procedure is carried out in one phase, that is, the loading device 5 is from the beginning with the supply of plastic (and the respective section in question desired aggregates) moved back and forth, in the area of the transition of the main cavity χ in the enlarged ring cavity y a short stop is switched on between each back and forth so that at this point the amount of plastic required to build the socket is released will. Since the inlet cross-section of the annular cavity y is relatively large, this cross-section will only close when when the entire ring cavity is filled with plastic. This is also the case with this procedure, in which the glass reinforcement is carried out beforehand (as a mat or fabric) or at the same time as the plastic (in Porm short pieces of fiber) can be introduced a homogeneous plastic pipe with a socket that no longer needs reworking.

It goes without saying that with a relatively large wall thickness Sleeve this can also serve as a reinforcement ring, which is particularly advantageous when two or more of these with one-piece sleeve provided pipes are assembled to form a container provided with appropriate bottoms. With one and the same device can be easily profiled by replacing the insert ring sleeves with different Shape the inside of the main body of the pipe. Instead of the conical steps of the socket, undercuts, e.g. for the insertion of seals, can also be created; in this pail is a multi-part, composed of segments Insert ring required.

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Claims (8)

PATENT CLAIMS 1. Process for the production of fiberglass-reinforced, rotationally symmetrical Plastic hollow bodies with a connecting sleeve arranged at one end, characterized in that the jacket and sleeve by introducing the plastic necessary for their formation into a rotating centrifugal mold in the same operation can be manufactured as a unit. 2. The method according to claim 1, characterized in that in a first working phase, the plastic for forming the sleeve at which the transition between the shell and sleeve cavity of the mold is fed to the corresponding point, during the plastic required to form the jacket before hardening of the first plastic introduced in a second, directly subsequent phase is introduced into the tubular shape in several strokes along the shell cavity. 3. The method according to claim 1, characterized in that the Plastic in several strokes along the shell cavity with the interposition of a brief standstill of the loading device in the area of the transition from the shell cavity and Sleeve cavity is introduced into the centrifugal mold. 4-. Method according to claim 2 or 3, characterized in that the glazing for the jacket and socket in the form of individual pieces of fiber during the introduction of the plastic or in the form of an insert prior to the introduction of the plastic is introduced into the mold. 5. Device for carrying out the method according to claim 1, characterized in that a horizontally arranged, rotatably drivable hollow mold (1), one of a The open side of the form can be introduced into this and is axially 5 09810/0702 Associated parallel reciprocating Materialverteillfopr (7) is, on the mentioned open side has an inner widening into which, at a radial distance, a coaxial, on the mold (l) removably fixed insert ring (11) protrudes, which with the enlarged mold end part (la) one after externally closed annular socket mold cavity (4) limited. 6. Device according to claim 5, characterized in that the outside of the insert ring (11) is axially inward twice is offset, the inner end face of the ring in the area of the transition between the main mold cavity (x) and the radially expanded socket cavity (y). 7. Device according to claim 6, characterized in that the axially outer end of the insert ring (11) on an outer one The end flange (Ib) of the centrifugal mold (l) is screwed on and can be removed is, while the axially inner ring end has an inner edge flange (lib) with a conical inner surface (lic). 8. Device according to claim 5t, characterized in that the Insert ring (11) is composed of individually removable segments. For Basler Stückfärberei AG: ffelentanwalt 509810/0702