NO802566L - METHOD AND APPARATUS FOR THE MANUFACTURE OF FORMED BODIES OF THERMOPLASTIC PLASTIC - Google Patents

Description

The present invention relates to a method and a device for the production of shaped bodies of thermoplastic resin which, if desired, can be set in their partially crystalline, crystalline state through physical influence, especially temperature influences, by: - formation of a semi-finished product, in particular continuous extrusion of a tape or a tube of the plasticized resin, - stabilization of the semi-finished product by cooling in<;> the smallest on a surface, - thermoconditioning of the stabilized semi-finished product to thermal - formability and

- thermal forming to. formation of shape-stable final shape-

ede bodies from the semi-finished product.

From DOS 28 30 740 and DOS 28 30 788 there is known progress

ways of producing thin-walled articles of crystal

inc thermoplastic material. The thermoplastic material

to be treated in this method, especially polyol-

fine, is in each case only of a crystalline type and therefore only gives the possibility to set the partially crystalline state in the wall of the body more or less strongly crystalline and through temperature control and the application of physical influences to influence the crystals that are present

in the resin in the wall of the body. Consequently, these known methods also aim to control the crystalline properties of the resin and the physical influence on the crystals in the plastic by the manufacturing method of the shaped bodies so that an optimal approach to the desired

the properties of the body's wall and, at the same time, usable conditions for the thermal forming.

From British patent 1 514 277 it is also known .manufacturing

of shaped bodies, especially bottles, of pplyester material V.ed combined injection molding and blow molding. Below shall

first a pre-formed body is produced by injection molding and the external surface is stabilized by cooling. There must then first be an initial expansion during stretching of the cooled wall areas and then a complete design by

blow molding... This known method is relatively complicated, takes considerable time and cannot be carried out as a continuous process during the formation of a semi-finished product.

Consequently, a task for the invention is to provide a method and a device which makes it possible for the user, when processing plastics, which by means of physical influences, especially temperature influences, can be set amorphous or semi-crystalline as desired, set the resin in the walls of the shaped bodies amorphous or in a desired crystalline state and degree of crystallization and thereby achieve desired • physical properties,

e.g. the desired elasticity, firmness and, respectively, or temperature resistance of the shaped body.

According to the present invention, this task is solved by the application of the following method characteristics: - for the production of various objects of such resin whose state of crystallinity can be set by choosing between amorphous and semi-crystalline, the setting of the desired state of crystallinity in the wall of the shaped body is carried out by a first' thermoconditioning which is carried out on the semi-finished product and a second thermo-conditioning which is carried out on the shaped object: - the physical influences that must - be exerted on the semi-finished product at the first thermoconditioning that must be carried out between stabilization and thermal forming is matched and modified es in a predetermined manner to achieve a desired preparatory state of crystallinity as well as thermoformability of the resin for semi-finished products, a preparatory temperature profile being set through the semi-finished product cross-section which is matched to the subsequent thermoforming process and the desired final state of crystallinity • in the resin in the wall of the shaped body; and - the second thermo-conditioning. is carried out during the thermal forming process and, if desired, also subsequently with temperature control in order to achieve or maintain the desired final state of crystallinity in the resin in the form

ede the body's wall in connection with the creation of the shape, the constancy of the shaped body.

The method according to the invention offers, on the one hand,

many modifiable and adjustable process parameters which reproducibly and precisely predeterminably affect the final state of crystallinity of the resin in the wall of the shaped body and the essential physical properties for the use of the shaped body. The effective application and mutual combination of the used process parameters, especially the heat treatment during the process, becomes particularly beneficial by using two thermo-conditioning operations.

Furthermore, the method according to the invention also allows

to include additional physical treatment steps such as stretching, rolling, calendering, densification, irradiation, electrostatic treatment, electromagnetic treatment and the like without affecting the stability of the manufacturing operation and the desired stable setting of the crystallinity state of the resin in the walls of the shaped the body.

Also for these additional physical processing steps provide

the two thermo-conditioning operations advantageous application and combination possibilities.

A favorable principled possibility of progress within the scope of the invention implies that

- the semi-finished product during the stabilization and the first thermo-conditioning throughout the entire cross-section is cooled while setting the desired final crystallinity

capable of reaching a temperature at which no particular change in the state of crystallinity takes place in the resin, and that such temperatures are also observed during pressing. the temperature profile for the requirements of thermoforming in all semi-finished product areas in which no significant change in the state of crystallinity occurs, and - during thermoforming a deep drawing and other thermoconditioning takes place to fix the state of crystallinity in the resin and the thus shaped and solid wall of the shaped body.

In this way, within the scope of the invention, possible principles

In the process, the desired final state of crystallinity is set in the resin in the wall of the shaped body to a large extent already early on, namely by stabilizing

ing and first thermoconditioning of the semi-finished product and- bi-retained at most until the end of the shaped body.

One can use this principled method to set a largely amorphous state in the resin in the semi-finished product during stabilization and then first thermoconditioning, and achieve this largely amorphous state during second thermoconditioning including thermoforming as much as possible. The shaped objects produced in this way have a practically amorphous state in the resin in the walls and are characterized by relatively high elasticity and compliance. In return, they only have relatively little temperature forming stability. Another principally possible method variant within the scope of the invention consists in that

the semi-fabric during stabilization and first thermo-conditioning is cooled quickly through the entire cross-section and is set to a temperature profile that allows thermoforming, but maintains temperatures in all areas of the semi-fabric. in which no significant change of the state of crystallinity occurs in the resin;

- the thermoforming takes place on at least one surface of the body which .

is heated to a temperature at which crystal growth occurs in the resin and

- .the second thermoconditioning that occurs or begins in the contact of the wall of the shaped body with the heated mold surface in temperature and time is matched to

setting a desired partial crystallinity of the molded body's wall resin..

In this method, a state of crystallinity is preliminarily set in the resin of the semi-finished product and based on this state of crystallinity, the desired final state of crystallinity in the wall of the shaped body is produced by thermoforming. You can thereby keep the resin of the semi-finished product in a mainly amorphous state during the first thermoconditioning. However, it is also possible to subject the semi-finished resin to a first small crystal growth during the first thermoconditioning. The choice of one or the other option depends, among other things, on of the desired final state of crystallinity in the resin in the wall of the molded body and of the desired degree of crystal growth during the thermal forming.

In order to achieve the desired degree of crystal growth during the thermal forming, the mold surface can be kept at a temperature in the range from below to above the optimum temperature for crystal growth in the present resin. If you want to achieve the highest possible degree of crystal growth during the thermal forming ■ with an appropriately short thermoforming time, you will want to keep the mold surface at a temperature for optimal crystal growth for the present resin, possibly in the upper part of this temperature range in order to set the appropriate temperature as quickly as possible for optimal crystal growth in the resin.

If, in the method according to the invention, when stabilizing and first thermo-conditioning the semi-finished product, temperature conditions are set at which practically no or only very small changes in the crystalline state occur, the semi-finished product can be exposed during the first thermo-conditioning and, respectively, or between the first thermo-conditioning and termof. the drming while practically maintaining the plastic's crystalline state for a stretch, e.g. biaxial stretching as additional physical treatment. This stretching can take place in a practically amorphous state of the resin or also in a more or less partially crystalline state of the resin. This

stretching has, within the scope of the method according to the invention, the surprising effect that the shaped bodies

which is produced under this further physical 'influence'

■ning has high strength, high elasticity and high temperature shape stability at the same time. A further embodiment of the method according to the present invention consists in that - the semi-finished product during stabilization and first thermo-conditioning on the surface areas is set at temperatures to make the semi-finished product firm for handling and inside • at a temperature for optimal crystal growth in the present resin, and - the thermoforming takes place in at least a mold surface which is heated to a temperature at which crystal growth occurs in the present resin.

The embodiment variant of the present invention is particularly

suitable for such cases in which the strongest possible crystallization of the resin is desired in the wall of the shaped object. Shaped bodies produced according to this variant of the method are distinguished by

eld high temperature shape resistance. In this embodiment variant of the method according to the invention, however,

time appropriate that the resin inside the semi-finished product through the influence of the set temperature and time

reasonable duration of the first thermoconditioning is set to form such a crystalline state at which the present resin is still thermally moldable. However, it is also possible, when this is desired, to transfer the resin inside the semi-finished product by the influence of the set temperature and the time course of the first thermoconditioning in a crystalline state that lies outside the limit of the actual thermal formability of the present resin. In this case, the surface areas of the semi-finished

one, which is kept more or less in an amorphous or only finely crystalline state during the thermal forming sufficiently

durable shells, between which the crystallized resin inside the semi-finished product can still be safely molded beyond the actual thermal moldability. In this last embodiment of the method according to the invention, it is particularly advantageous to heat the mold surfaces to a temperature for optimal crystal growth for the present resin. This results in a final heating of all the resin to the wall of the formed body and thereby a uniform crystallization.

A further possibility for carrying out the method according to the invention involves that

- the semi-finished product upon stabilization and first thermoconditioning on the surface areas of the cross-section of temperature-

is too suitable speed to handle the semi-finished product and inside essentially at the plasticizing temperature used for extruding the material strip;

- the thermoforming takes place on at least one mold surface that is heated to a temperature at which crystal growth in-

enters the present resin, and

- the wall of the shaped body for other thermoconditions-

ing is maintained at a temperature over a time which is adapted to the 'desired final crystalline state in the wall of the body, at which crystal growth takes place in the resin in the wall of the body.

In this possible process operation within the framework of the invention, the resin is kept in the semi-finished product at a temperature that lies above the temperature range in which crystal growth occurs in the present resin. The surface areas of the semi-finished product, on the other hand, are cooled so much that the present crystalline state is frozen in, e.g. amorphous state or slightly partially crystalline state. In contrast to the usual Inline thermal forming method, in the actual thermal forming operation a complete heating of the entire formed wall now takes place

the body and with this through-heating during the thermal form-

ing and other thermal conditioning setting of the desired more or less strongly partially crystalline add-

condition. Since the resin inside the semi-finished product in this type of process operation causes negligible amounts of heat in the first thermoconditioning and onwards in the thermal form-

•ing and other thermal conditioning, one would benefit from in-

set the temperature of the mold surfaces slightly below the

one for optimal crystal growth, thereby producing a rapid cooling of the resin inside the formed wall of the medical material in the temperature range in which optimal crystal growth occurs.

In all method variants according to the invention by

which crystal growth is allowed during the actual thermal forming, the wall of the body can be kept in contact with the mold surface for so long that the resin has reached the desired degree

of crystallinity. However, one can also simply initiate the crystal growth on the mold surface and take the shaped body away from the mold surface when sufficient shape stability has been reached and perform the second thermal conditioning in a heat treatment device that follows the output of the thermal forming device. This second thermoconditioning - which begins at the mold surface - can be carried out at a constant temperature. However, one can also change the temperature during the second thermoconditioning, e.g. with tempering at a temperature that decreases with time. With the latter type of temperature operation, one can start from a temperature on the mold surface that is suitable for optimal crystal growth in the present resin and cool the wall of the body in sufficient time. In the method according to the invention, the thermal forming can be carried out

es while exerting form pressure on the resin in the body wall. This mold pressure can optionally be chosen suitable for a certain compression of the resin.

The method according to the invention also allows the semi-finished product between the extrusion and the thermal forming to be subjected to a calendering and, respectively, or rolling operation suppression reduction for further physical

influence of the crystalline state. This calender-

ing or rolling can also be used in the stabilization of - the semi-finished product.

The method according to the invention can preferably be used for the production of shaped bodies of polyethylene terephthalate. However, it also comes equally into consideration for the production of shaped bodies of modified polyethylene terephthalate, e.g. 1,4 cyclohexyldimethyl-terephta-

lat / isophthalate copolymer. The production of shaped bodies of polybutylene terephthalate is also conceivable by the method according to the invention. In the latter case, however, it must be noted that the temperature range within which crystal growth occurs in polybutylene terephthalate goes far below, i.e. to approx. 30°C.

For carrying out the method according to the invention, spe-

particularly a device suitable with an extrusion device for continuous production of the semi-finished product, a stabilization device for the semi-finished product and a thermal forming device and a thermo-conditioning device for the semi-finished product, as well as possibly a device for separating the shaped objects from the surrounding parts of the semi-finished product.

a. According to the invention, such a device is characterized by

the following features:

- Between the stabilization device and the thermal forming device, a first thermo-conditioning station is arranged; - the thermal forming device is located in the second thermo-conditioning station;

- The stabilization device and the thermal forming device-

ning is equipped with a regulation device for predetermined, possibly programmable regulation of the in the stabilization device and the thermal forming device physical, especially thermal impact on the resin in the semi-finished product and

devices for physical, especially thermal impact on the resin in the semi-finished product, respectively the shaped body and control devices for pre-determined possibly programmable regulation of the impact device are assigned to the thermal conditioning stations.

Such a device offers the advantage that it can practically carry out all desired variants of the method according to the invention without significant changes. It also provides the advantage that devices for desired special physical effects such as stretching, rolling, irradiation, etc. without difficulty can be introduced in the desired place in the device.

The device according to the invention can in its thermo-conditioning station preferably in the first thermo-conditioning station for. semi-finished products be equipped with heating and cooling inputs for the semi-finished product or the shaped objects with the possibility of regulation of temperature and heating or cooling time. With this equipment, thermoconditioning can be carried out in the device according to the invention in all imaginable process variants with absolute safety and optimal operation.

The first thermo-conditioning station, namely the one for semi-finished products, can also have a stretching device for semi-finished products

with adjustable stretching temperature, degree of stretching and possibly stretching speed. The assignment of the stretching device to the first thermo-conditioning station has the particular advantage that the stretching operation is carried out at a stage of the semi-finished product at which optimal conditions for the stretching itself and also optimal conditions for the influence of the stretching on the crystallinity state of the resin can be set and also maintained until the 'thermal shaping.

Will one place additional devices for calendering and respectively or rolling of a strip-shaped semi-finished product

during thickness reduction in the device according to the invention, these can be assigned to the stabilization device.

In the device according to the invention, the cooling devices placed in the stabilization device can be equipped with - . devices to provide a timed effective, adjustable temperature control of the resin in the semi-finished product. This be-

tyre that by placing several cooling devices after each

others, these can be operated at different temperatures.

In the device, according to the invention, the thermal 'forming' device should preferably be equipped with at least one forming tool,

which has one adjustable heating and cooling mold surface. The thermal forming device may preferably have at least one forming tool,

which-is equipped with a regulating device to provide. a for-

ut determinable or programmable timed temperature change: respectively temperature control during the thermal forming operation on at least one mold surface. The thermal forming device can also contain at least one forming tool which is equipped with devices to provide a predetermined, adjustable forming pressure. - These devices for providing the forming pressure can be equipped with regulating devices for adjustable or programmable timed variation of the forming pressure during the thermal forming operation.

In the device according to the invention, the second thermal conditioning station can advantageously accommodate the thermal forming device in its entrance area and extend out through the output of the thermal forming device. Underneath, the second thermal conditioning station may contain a heat treatment device for the shaped bodies following the output of the thermal forming device.

Embodiments of the invention are illustrated in more detail in the following by the drawing.

It shows:

Fig. 1 a diagram for the principle course of the method according to the invention, respectively the principle

le construction of a device according to the invention;

Fig. 2 dependence of the crystal growth rate V on the temperature T for polyethylene terephthalate;

Fig. 3 a group of temperature profiles for a first embodiment of the method according to the invention with polyethylene terephthalate; Fig. 4 a group of temperature profiles for a second embodiment of the method according to the invention with polyethylene terephthalate; Fig. 5 shows a group of temperature profiles for a third embodiment of the method according to the invention with polyethylene terephthalate; Fig. 6 shows a group of temperature profiles for a fourth embodiment of the method according to the invention with polyethylene terephthalate; Fig. 7 shows a group of temperature profiles for a fifth embodiment of the method according to the invention with polyethylene terephthalate; Fig. 8 a group of temperature profiles for a sixth embodiment of the method according to the invention with polyethylene terephthalate and Fig. 9 a group of temperature profiles for a seventh embodiment of the method according to the invention with polyethylene terephthalate. Fig. 1 illustrates the sequence of work operations in a preferred embodiment of the invention for the production of thin-walled articles of thermoplastic resin, which can optionally be set to be amorphous or more or less semi-crystalline. In the example shown, an extrusion press 11 is arranged which is suitable for receiving the granulated thermoplastic resin, e.g. :polyethylene terephthalate and compress continuously and to heat until it is melted and feed it at a temperature T„ (Fig. 3 to 8) to the extruding

the equipment, e.g. a wide-slit nozzle 12, above the crystalline melting point. This wide-slit nozzle 12 gives i

.the present example is a ribbon-shaped semi-finished product 10, which is introduced from the wide-slit nozzle 12 into the stabilization device 13. In the stabilization device 13, the semi-finished product 10 is primarily made manageable by cooling on at least one surface for further processing. From the stabilization device 13, the strip-shaped semi-finished product 10 enters

a first conditioning station 14. This semi-finished product conditioning station 14 primarily serves the purpose of setting preparatory temperature profiles in the semi-finished product 10. However, the purpose of the semi-finished product conditioning station 14 is also to physically affect the semi-finished product 10 further as desired and to fix added additional physical influences in the semi-finished product. 10.

For this purpose, the semi-finished product conditioning station

14 equipped with heating devices and cooling devices which

have control devices which can be regulated and possibly programmed if desired. In addition, the semi-finished product conditioning station 14 may have devices for physically influencing the semi-finished product 10. This includes stretching devices, irradiation devices, possibly rolling and compression devices. However, the latter devices can also already be taken into the stabilization device 13.

In the example shown, the semi-finished product conditioning station 14 is designed in two stages, namely with a first stage 14a designed for treatment, i.e. for thermoconditioning of the continuously completed semi-finished product 10, and with a second stage 1.4b, which is designed for treatment and thermoconditioning of the stepwise completed semi-finished product 10. Between the two stages 14a and 14b in the semi-finished product conditioning station 14 - included in the semi-finished product conditioning station 14 - a device 15 is placed to control and convert the movement of the semi-finished product 10 from continuous progress to stepwise progress. With this device 15, the advance movement of the semi-finished product 10 is coordinated with the work rate of the finished part conditioning station 17 with thermal forming device 16 which takes up the semi-finished product 10 step by step.

'This pre-fab conditioning station . 1.7 respectively

second thermal conditioning station 17 contains in its first part the thermoforming device 16, which in the example shown is equipped with deep-drawing apparatus, whose mold surface can be optionally heated or cooled and also be designed to change the temperature during each work operation.

As shown in fig. 1 follows. after the thermal forming device-

ning 16 also a section, of f finished part conditioning station

a 17, which in the example shown is run through step by step

the strip-shaped semi-finished product with shaped bodies 18 which. comes from the thermal forming device 16. In this second section of the finished part conditioning station 17, heating and cooling devices are placed. Devices can also be added to this. for physical treatment of the shaped objects 18, e.g. for irradiation or sound effects or the like, be arranged there.

From the second thermal conditioning station 17 comes

the strip-shaped semi-finished product with shaped shaped bodies

18 in a punching device 19, with which the shaped bodies 18 is cut off and the semi-finished product remains 20 are taken away for material recycling, possibly direct return of the crushed the material of the extrusion press .11.

The resin band mentioned above as an example of the semi-finished product 10 can, when processing polyethylene terephthalate, have. a thick-else of approx. 2 mm.

Instead of ribbon-shaped semi-finished products, any will also come

other imaginable and continuously manufacturable semi-finished products

in consideration, e.g. pipes, profile strings, etc.

The semi-finished product can also be layer material of different types

resins of which, however, a significant part should be such • resins that through physical influences, especially wood

■temperature control, by choice can be set amorphous or partial

crystalline to the desired extent.

.A pressure treatment. of the resin can be made on the semi-finished product, e.g. by rolling or calendering in the stabilization station 13 or also in the first part 14a of the semi-finished product conditioning station 14. However, it is also conceivable to carry out a pressure treatment of the resin by 'stepwise' flat pressing by stepwise guidance through the second part 14b of the semi-finished product conditioning station 14 The invention further enables pressure treatment on the shaped body, respectively finished part, i.e. within the second thermal conditioning station 17. Preferably, this pressure treatment will be carried out on the finished part by applying a predetermined forming pressure in the thermal forming device 16.

Instead of the pressure treatment, either on the semi-finished product

or on the finished part, or in addition to this, an ultrasound treatment can also be carried out. In addition to the influence of the crystalline state, the pressure treatment or ultrasonic treatment also leads to significantly increased stiffness and thus improved cold form stability of the manufactured shaped bodies.

The curve in fig. 2 shows the dependence of the crystal growth rate V in polyethylene terephthalate depending on the temperature T

which is listed in °C. As fig. 2 shows, polyethylene terephthalate between 100°C and the crystalline melting point (250 - 260°C) has a crystal growth temperature range within which optimal crystal growth occurs at approx. 170°C to 175°C. Above the crystalline melting point, the polyethylene terephthalate turns into a plasticized state. Below 60°C, polyethylene terephthalate exists in a solid state without crystal growth taking place to any significant extent in the material. This means that the present crystalline state in the material can be frozen by cooling the polyethylene terephthalate below 60°C.

In order to simplify the explanations, within the scope of this application, the amorphous state shall also be considered as a crystallinity state, namely a state with "zero crystallinity". With the method according to the invention, economically advantageous manufacturing possibilities for shaped bodies of plastic with the above-described properties shall be provided, in that the method shall give the possibility of selection for the final crystalline state of the resin in the wall of the shaped body. In principle, this is achieved with the invention by utilizing the operating method explained in connection with Figure 2 to produce a semi-finished product by continuous extrusion at a temperature T (compare Fig. 3 to 8) of the resins mentioned here, which lie above the crystalline melting point in a temperature range in which the material is plasticized. From this plasticized state, the material must, depending on the relevant wishes and requirements for the shaped object, be cooled so re-.

nom the crystal growth temperature range reproduced in

■fig. 2 and is thermally conditioned so that when it arrives

to the temperature range in which it exists as a solid (in the case of polyethylene terephthalate below 60°C) has a desired state of crystallinity together with desired physical properties.

Some examples with possibilities that can be achieved by the thermoconditioning according to the invention can be seen from the following explanation of Figures 3 to 8.

In the example of fig. 3, the semi-finished product 10 during the production of shaped bodies of polyethylene terephthalate is cooled strongly by stabilization and by thermoconditioning to a temperature profile through the thickness of the semi-finished product. which lies in the range 55 to 100°C, in which practically no crystal growth or no crystal formation occurs. The outer areas or the surface areas of the semi-finished product can then be cooled to below this temperature range, while the resin inside the semi-finished product can be up to 100°C hot,

but should not exceed this temperature■significantly. When stabilizing, - as indicated in the upper part of fig. 3 - based on a temperature profile prevailing during the extrusion which lies at the extrusion temperature T£the amorphous state-

a in the resin essentially maintained respectively

is frozen through rapid cooling to the temperature shown on the left in the upper part of fig. 3. During subsequent thermoconditioning (middle part of Fig. 3) and the second thermoconditioning which includes the thermal forming

(Fig. 3 lower part) such temperature conditions can be maintained

on and inside the semi-finished product 10 and the shaped object 18

that then neither significant crystal growth nor substantial

lig crystal formation occurs. The shaped body produced in this way is - when it consists of pigment-free resin - clear■transparent, which means that the resin in the wall of ■

the shaped body is practically in an amorphous state. Temp-,

- yrres- j-^ i f^Hæ-Rrefyn d^ggrTP^-yt-^ r^ f^- T^^^^ i^^ tj^^^ m Æ^j^CT^ j=^>. Ad—r a. -

Will mah"by""this f remgarrg^iTrårteir allow or- form a certain degree of partially crystalline state in the resin in the wall of the shaped body, this can happen by stabilizing

sealing and first thermoconditioning by cooling down the semi-finished product 10 more slowly and thereby allowing the partially crystalline state to occur to a desired degree. This partially crystalline state can be maintained.

by the thermal forming and other thermoconditioning by corresponding temperature control (compare lower part of Fig. 3) in the resin of the shaped bodies or finished parts. are essentially.

Fig. 4 illustrates a possibility for operation of progress

the method according to the invention, by which it is true that cooling

is the semi-finished product 10 fast to make it firm and handle-

equal to the outer areas or surface areas. However, the resin inside the semi-finished product remains at a temperature significantly above 10TP"c"^ This transition _from the temperature profile located at the extrusion temperature—

■ the journey 1" le to the temperature profile that is set during stabilization can be seen in the upper part of Fig. 4. During the thermal conditioning that follows the stabilization of the semi-finished product, a temperature profile can then be set, in which the external areas of the semi-finished product are at temperatures of up to just over 50 °C and the core of the semi-finished product at temperature

trips above 100 C. With this temperature control during the stabilization and the first thermoconditioning, a

noticeable crystal formation in the polyethylene terephthalate inside the semi-finished product 10 and noticeable crystal growth, which

.to be seen if the material is unclear. Then the time between the semi-finished product conditioning (middle part of Fig. 4) and the thermal forming with finished part conditioning (lower part of

fig. 4) is determined in the method according to the invention,

can one determine in advance how great the degree of crystallization in the semi-finished product is at the beginning of the finished part conditioning through the temperature profile shown in the middle part of fig. 4 and the extent to which the temperature inside the semi-finished product 10 is above 100°C.

The thermal forming takes place in this example by drawing the material to a hot mold surface. whose temperature should be at 120 to 180°C. In the example shown, a temperature on the mold surface of 180°C is assumed. In the finished part conditioning that begins during the thermal forming and even

tuelt takes place beyond the thermal forming, thus an extensive crystallization of the polyethylene terephthalate occurs. The shaped object gets an opaque wall when walking

based on pigment-free material. The temperature stability of the shaped body is above 200°C.

A similar process sequence could be achieved according to fig. 5 if

during stabilization and, respectively, or the semi-finished product conditioning Under pressure, a temperature profile is set, as shown in the upper and middle parts of figures 3 and 5. In this case, will one achieve extensive crystallization in the resin at finished part conditioning the ionization,. based on the almost amorphous state of the polyethylene terephthalate, one would either need a longer time for crystallization, or one would not get as high a degree of crystallinity as with the initial conditions

the others according to fig. 4. As indicated in the lower temperature profile in fig. 5, one can in such cases also optionally

work with a somewhat higher temperature on the mold surface, e.g. up to 200°C. However, one can also, above all, measure time

ig extend the finished part conditioning accordingly after it

.thermal forming as indicated in fig. 1 with the second thermo-conditioning station 17. The shaped bodies produced in this way have (when starting from pigment-free material)

ale) transparent wall. The temperature stability of the shaped bodies produced in this way is at approx. 150°C to 200°C.

Figure 6 represents a possibility for operation of the method according to the invention which differs from that according to Figure 3 - respectively that according to Figure 5 in that during the semi-finished product conditioning (compare middle part of Figure 6), i.e.

.between the stabilization and the thermal forming, a stretch is made of the semi-finished product 10. During this stretch, as the middle temperature profile in figure 6 suggests - a further cooling of the semi-finished product 10 also occurs. The stretched, preferably biaxially stretched semi-finished product 10 is then deep drawn by thermal forming on the hot mold surface, which can have a temperature from, e.g. 150 to 200°C.

In the example in figure 6, a temperature of approx.

200°C on the mold surface of the thermal forming tool.

The shaped objects produced in the method operation according to Figure 6 again have a transparent wall (when pigment-free material is used), but also a substantial

re temperature shape stability, namely up to temperatures from 200°C to 250°C. In addition, the shaped bodies produced in this way are characterized by increased stability and elasticity.

In the example according to figure 7. is set in the semi-finished product 10

by stabilization and then by thermoconditioning a temperature profile in which relatively thick surface areas 10a are cooled to a temperature below 100°C and kept in practice

technically speaking amorphous state of the polyethylene terephthalate. Inside the semi-finished product 10, a temperature of a maximum of 150°C is set. Based on this temperature profile which is shown in the middle part of the figure. 7, the thermal forming' and finished part conditioning takes place on' mold surfaces that are heated to approx. 150

to 180°C. In the example shown, the temperature of both mold surfaces is that the wall 18 of the molded article is formed

'•between 180°C. The resin in the wall 18 of the shaped re-

state crystallizes to a large extent between the two mold surfaces

is which is kept at 180°C. The thus produced shaped body has a temperature shape stability of approx. 200°C.

In the example in Figure 8, a rapid cooling of both surfaces of the semi-finished product 10 is carried out during the stabilization. During the conditioning of semi-finished products, a temperature between

loam approx. 50 and 100°C. on the surfaces of the semi-finished product 10,

: while the polyethylene terephthalate in the core or inside the semi-finished product still largely retains the extrusion temperature, i.e. is at a temperature of approx. 270°C. The semi-finished product with this temperature profile (shown in the middle

part of figure 8) is formed thermally between two hot mold surfaces. The mold surfaces below can have a temperature of 150

to 160°C Between the mold surfaces occurs, as lower part 1 of Figure 8 shows - a significant equalization in the temperature profile -

one. Thereby, the polyethylene terephthalate is crystallized at approx. 160°C in the surface areas of the wall 18 of the shaped body and in the internal area of the wall 18 of the shaped body

they body at approx. 190°C to a large extent, i.e. in the outer areas

is somewhat below and in the inner region somewhat above the optimum crystallization temperature of approx. 170°C. The shaped bodies produced in this way have opaque walls (when pigment-free material is used). The temperature shape stability is at approx. 200°C.

Figure 9 indicates a modified mode of operation in which both surfaces of the semi-finished product are made manageable by stabilizing

ing through rapid cooling. During the semi-finished product conditioning •a temperature profile is set which - as the middle part of the figure shows - lies between the extrusion temperature (260°C to 290°C) and approx. 170°C. During thermal forming and finished part conditioning, a temperature profile between 120°C and 170°C is set on the wall of the shaped body.

The shaped bodies that are. produced on this modified

method also has opaque walls (when applying pigment

free material) and a temperature shape stability of approx. 200

in to 220°C.

In addition to the above, in addition to the stretch mentioned therein, other mechanical and physical treatments can also be carried out during semi-finished product conditioning and, appropriately, also: during finished part conditioning, e.g. compression and thickness reduction by rolling or form pressing, irradiation with beams of different types, ultrasound treatment and the like. The above described embodiments of the method according to the invention can be carried out with semi-finished products of different types such as e.g. hoses, profile strips, etc.

Claims (30)

1. Process for the production of shaped bodies of thermoplastic resin, which can be optionally set in their partially crystalline state by means of physical influences, in particular "temperature influences", by: Formation of a semi-finished product, in particular continuous extrusion. wearing a band or hose of the plasticized hair-' pik, - stabilization of the semi-finished product by cooling, at least on one surface, - thermoconditioning of the stabilized semi-finished product to thermal formability and - thermal forming for the formation of form-stable final forms ed bodies from the semi-finished product, characterized by that - that in order to produce shaped bodies of such resin whose crystalline state can be set between amorphous and semi-crystalline, the setting of the desired crystalline state in the wall of the shaped body is carried out by a first thermo-conditioning which must be carried out on the semi-finished product and a second thermo-conditioning which must be performed on the shaped body; - one adapts and modifies the physical influences that must be exerted on the semi-finished product in a predetermined manner during the first thermoconditioning that must be carried out between stabilization and thermal forming in order to achieve a desired prepared crystalline state as well as thermal formability of the resin -to the semi-finished product and thereby through the cross-section of the semi-finished product sets a shape-forming temperature profile which is matched to the subsequent thermal forming operation and the desired final crystalline state in the peak in the wall of the shaped body; and - carries out the second thermoconditioning during the thermal forming operation and, if desired, also afterwards with temperature control in order to achieve, if necessary, maintain the desired final crystalline state in the resin in the shaped body object in connection with producing shape stability. 2. Method according to claim 1, characterized in that - the semi-finished product during stabilization and first thermoconditioning is cooled throughout the cross-section while setting the desired final crystalline state to a temperature at which no significant change of the: crystalline state anymore takes place in the resin, and also when setting the temperature profile according to the requirements for thermal forming, such temperatures are observed in all the semi-finished product areas at which no significant change in the crystalline state occurs, and - during thermal forming, a deep drawing and other thermo-conditioning takes place to fix the crystalline state in the resin to the thereby formed and solid wall in the body. 3. Method according to claim 2, characterized in that the semi-finished product is rapidly cooled to a temperature at which no significant change of the crystalline state takes place during stabilization and first thermoconditioning while largely maintaining the amorphous state in the resin. 4. Method according to claim 2 or 3, characterized in that the shaped bodies are produced from polyethylene terephthalate and the temperature in the material band during stabilization and first thermoconditioning is set in a range of 50° to 100°C. 5. Method according to claim 1, kar achter i-sertvedat - the semi-finished product during stabilization and first thermoconditioning is cooled quickly throughout the entire cross-section and is set to a temperature profile that allows the thermal forming but complies with temperatures in all semi-finished areas, at which no significant change of the crystalline state of the present resin occurs; - the thermal forming takes place on at least one mold surface, which is heated to a temperature at which cry- .stall growth occurs in the present resin and - the second thermoconditioning that takes place or begins is in contact with the wall, of the shaped object with the heated mold surface is matched in temperature and duration of the setting of a desired partially crystalline state in the resin. 6. Method according to claim 5, characterized in that the mold surface is kept at a temperature in the ranges below to above the temperature for optimal crystal growth in the present resin. 7. Method according to one of claims 1 to 6, characterized in that the semi-finished product during the first thermoconditioning and respectively or between the "first thermoconditioning and the thermal forming while essentially maintaining the crystalline state of the resin is subjected to a stretch, preferably biaxial stretch as additional physical impact. 8. Method according to one of claims 5 to 7, characterized in that in the production of shaped bodies of polyethylene terephthalate - set during stabilization and initial thermoconditioning ing of the semi-finished product a temperature of 50 to 100°C and on the mold surface a temperature of 120 to 180°C. 9. Method according to claim 1, c a r a c t e r i - cert vedat the semi-finished product during stabilization and first thermoconditioning ering is set on its surface areas at temperatures suitable for the semi-finished product to become firm for handling and internally at temperatures for optimal crystal growth in the present resin and' - the thermal forming takes place on at least one mold surface which is heated to a temperature at which crystal growth occurs in the present resin. 10. Method according to claim 9, characterized in that the mold surfaces are heated to a temperature for optimal crystal growth in the present resin. 11. Method according to one of claims 9 or 10, characterized in that when producing. shaped bodies of polyethylene terephthalate is set during stabilization and first thermoconditioning of the material bands, the surface area temperature of approx. 50 to 100°C and the internal temperature of approx. 14 0 to 160°C and the mold surface is heated by thermal forming and others thermo conditioning to approx. 120 to 180°C. 12. Method according to claim 1, characterized - the semi-finished product during stabilization and first thermo-conditioning on the surface areas of the cross-section is set to temperatures that provide the necessary firmness for handling the semi-finished product and the inside is essentially allowed to retain the plasticizing temperature used during the extrusion of the material band; -■the thermal forming takes place on at least one mold surface, which is heated to a temperature at which crystal growth occurs in the present resin and - the wall of the shaped body for the second thermoconditioning is held for a period of time which is matched to the desired final crystalline state in the wall of the shaped object at a temperature at which crystal growth takes place in the resin in the wall of the shaped body. 13. Method according to claim 12, characterized in that the resin in the surface areas of the semi-finished product is largely kept in an amorphous state during stabilization and first thermoconditioning. 14. Method according to claim 12, characterized in that the resin in the surface areas of the semi-finished product is transferred in a predetermined weak semi-crystalline state during stabilization and first thermoconditioning. 15. Method according to one of claims 12 to 14, . characterized in that in the production of shaped bodies of polyethylene terephthalate - the surface area temperature is set to approx. 80° to 100°C during stabilization and initial thermoconditioning of the material bands and the temperature inside the band must remain at approx. 250° to 300°C and -'the mold surface during thermal forming and other thermoconditioning- OE OE ering hold.es pa approx. 140 to 160 C. 16. Procedure - according to one of claims 5 to 15, characterized in that the wall of the shaped body is kept at an essentially constant temperature during second thermoconditioning. 17. Method according to one of claims 5 to 15, characterized in that the wall of the shaped body is tempered by second thermoconditioning to a time-determined decreasing temperature. 18. Method according to claim 17, characterized in that the temperature control during second thermoconditioning in,, essentially takes place cooling from the temperature for optimal crystal growth in the present resin. 19. Method according to one of the claims 1 to 18, characterized in that the thermal shaping takes place during the exercise of shaping on the synthetic material in the wall of the shaped body. 20. Method according to one of claims 1 to 19, characterized in that the semi-finished product between the extrusion and the thermal forming is subjected to a calendering and respectively or rolling operation during the thickness reduction in order to further physically influence the crystalline state.. 21. Method according to claim 20, characterized in that the calendering or rolling operation is included in the stabilization of the semi-finished product. 22. Method according to one of claims 1 to 21, characterized in that glycol-modified polyethylene terephthalate is used as thermoplastic manufacturing material. 23. Method according to one of the claims.1 to. 21, characterized in that polybutylene terephthalate is used as thermoplastic manufacturing material. 24. Device for carrying out the method according to et of claims 1 to 23 with an extrusion device for continuous production of the semi-finished product, a stabilization device for the semi-finished product and a thermal forming device as well as possibly a device for separating the shaped bodies from the surrounding parts of the semi-finished product, characterized in that that between the stabilization device (13) and the thermal forming device (16) is provided with a first thermo-conditioning station (14); - the thermal forming device (16) is located in a second thermo-conditioning station (17); - the stabilization device (13) and the thermal forming device (16) is equipped with a regulation device for predetermined, possibly programmable regulation of the i the stabilization device (13) and the thermal shaping device (16) occurring physical, especially thermal effects on the resin of the semi-finished product (10); and - the thermal conditioning stations (14, 17) are assigned devices for physical, especially thermal impact on the resin of the semi-finished product (10) respectively shaped bodies (18) and control device for predetermined, possibly programmable regulation of impact devices. 25. Device according to claim 24, characterized in that the first thermo-conditioning station (14)' has assigned a stretching device for the semi-finished product (10) with the ability to regulate the stretching temperature, degree of stretching and possibly stretching speed. 26. Device according to claim 25, characterized in that the stretching device is designed for biaxial stretching of strip-shaped or snake-shaped semi-finished products (10). 27. Device according to one of claims 24 to 26, characterized in that the stabilization device (13) has been assigned devices for calendering and possibly or rolling a strip-shaped semi-finished product during the thickness reduction. 28. Device according to one of claims 24 to 27, characterized in that the cooling devices arranged in the stabilization device (13) are equipped with devices for producing a time-determined effective adjustable temperature control of the resin in the semi-finished product (10). 29.. Device according to one of claims 24 to 28, characterized in that the second thermo-conditioning .the station (17) in the entrance area contains the thermoforming device (16) and extends out through the output of the thermal forming device (16). 30. Device according to claim 29, characterized in that a second thermal conditioning station (17) contains a heat treatment device for the shaped bodies that follow the output of the thermal forming device (16).