Moulding tool and device for forming a thermoplastic semi-finished product

Abstract

The invention relates to a moulding tool (1) for forming a semi-finished product made from at least one thermoplastic material, comprising at least one mould sleeve (5) providing a mould cavity (2) for receiving the formed semi-finished product and a mould receptacle (4) receiving the at least one mould sleeve (5), wherein the mould sleeve (5) can be heated and at least in regions is spaced apart from the mould receptacle (4) by an insulation gap (38, 41), wherein at least one at least substantially circumferential positioning ring (20, 24) which bears against the mould receptacle (4) is provided on the outer side of the mould sleeve (5) in order to position the mould sleeve (5) in a positioning plane defined by the positioning ring (20, 24). According to the invention, to allow more precise and reliable trimming of the moulded parts received in the mould cavity, insulation gaps (38, 41) which space the mould sleeve (5) apart from the mould receptacle (4) are provided between bearing surfaces (21, 25) which bear against the mould receptacle along the at least one positioning ring (20, 24).

Description

[0001] Forming tool and forming device for forming a thermoplastic semi-finished product

[0002] The invention relates to a forming tool for forming a semi-finished product made of at least one thermoplastic material, comprising at least one forming sleeve providing a forming cavity for receiving the formed semi-finished product and a forming receptacle receiving the at least one forming sleeve, wherein the forming sleeve is heatable and at least partially separated from the forming receptacle by an insulating gap, wherein at least one positioning ring, at least substantially circumferential and abutting the forming receptacle, is provided on the outside of the forming sleeve for positioning the forming sleeve in a positioning plane defined by the positioning ring.Furthermore, the invention relates to a forming device for forming a semi-finished product made of at least one thermoplastic material, comprising a forming tool and a punching tool, wherein the forming tool and the punching tool are adjustable from a spaced-apart position relative to each other to an approximate punching position and back, and wherein the forming tool, in particular the forming sleeve and / or the punching sleeve, plunges into the punching tool in the punching position in such a way as to trim the edges of the formed semi-finished product by punching.

[0003] Forming devices for shaping thermoplastic materials, for example in thermoforming machines, are known in various designs. In many cases, these devices include forming tools that provide mold cavities into which semi-finished products made of thermoplastic material are placed and thermoformed. The preheated semi-finished products conform to the inner contour of the mold cavity, forming parts with an outer contour that corresponds to the inner contour of the mold cavity. The semi-finished products are typically preheated films or sheets that are placed on the forming tool. A top die is then pressed onto the forming tool to shape the semi-finished product within the mold cavity using a vacuum and / or pressure.The semi-finished product can first be partially pre-stretched into the mold cavity using a pre-stretching die before being pressed against the inner contour of the mold cavity by means of vacuum and / or pressure. A molded part produced in this way can then be punched out using a die to remove excess material, particularly at the edges of the part. Punching can be performed while the part is still in the mold. This eliminates the need for a separate punching step in an additional die-cutting unit.

[0004] The forming cavities for the semi-finished products are typically provided by so-called forming sleeves, which are held in a mold holder and have an adjustable base to eject the formed parts from the mold cavity, particularly after the mold holder has been pivoted to the side. To ensure that the forming sleeve can be positioned precisely in the mold holder, it has at least one positioning ring on its outer surface that is at least substantially circumferential and rests against the mold holder. By resting the forming sleeve against the mold holder, it is positioned relative to the mold holder in a predefined manner.

[0005] To trim the molded parts while they are still held in the mold cavity of the die sleeve, at least the upper edge of the die sleeve is surrounded by the mold housing, which provides a cutting edge at the appropriate location. This cutting edge interacts with a corresponding cutting edge of the die-cutting tool. When these cutting edges are moved past each other by a mutual cutting stroke, they form a very narrow cutting gap between them and trim the edge of the molded part. Contact between the die sleeve and the die-cutting tool is thus avoided. Suitable semi-finished products include, for example, those made of polypropylene (PP), polystyrene (PS), polyethylene (PE), polylactic acid (PLA), and polyethylene terephthalate (PET).When the semi-finished products are made of PET, a molded part with increased crystallinity can be produced by slowly cooling the part so that its temperature remains sufficiently higher than the glass transition temperature of the PET material for an extended period, allowing the PET to crystallize. This is also referred to as C-PET (crystalline polyethylene terephthalate). For PET crystallization, the molded part is typically heated to temperatures between 160 and 190 °C. Molded parts made of C-PET exhibit higher temperature resistance than those made of amorphous PET. Therefore, these molded parts are preferred for holding hot foods or foods that need to be heated, for example, in a microwave oven.

[0006] To produce molded parts from C-PET, the mold sleeve must be heated to ensure uniform crystallization of the PET material. Simultaneously, the temperatures of the mold holder, especially the die sleeve, and the die must be very precisely set and coordinated, as the temperature of the components determines their thermal expansion. Only if the specified component temperatures are maintained very accurately will a cutting gap of the required width be maintained between the mold and the die. If the cutting gap is too large, the molded part cannot be trimmed as desired. If no cutting gap is provided in certain sections, the mold and die will collide during the die stroke, which can lead to permanent damage to the forming device.

[0007] To avoid the aforementioned problems, it has already been proposed to thermally insulate the die sleeve from the die holder and to heat only the die sleeve. The temperature of the corresponding cutting edge should thus be decoupled from the temperature and temperature fluctuations of the die sleeve, so that a low and as uniform a temperature as possible can be achieved in the die holder in the area of ​​the cutting edge. This would then very reliably provide a very narrow cutting gap for trimming the formed part with the punching tool. However, practical experience with corresponding forming devices is not yet satisfactory.

[0008] Therefore, the present invention is based on the objective of designing and further developing the forming tool and the forming device of the type mentioned at the outset and explained in more detail above in such a way that the trimming of the molded parts received in the mold cavity can be carried out more precisely and reliably.

[0009] This problem is solved in a forming tool according to the preamble of claim 1 by providing insulating gaps between the forming sleeve and the forming holder between the contact surfaces along the at least one positioning ring on the forming holder.

[0010] The aforementioned problem is further solved in a forming device according to the preamble of claim 13 by the fact that the forming tool is designed according to one of claims 1 to 12.

[0011] The positioning ring has contact surfaces for contact with the mold holder only at certain points around its circumference. Insulation gaps are provided between at least some of these contact surfaces, separating the mold sleeve and the mold holder. Thus, the positioning ring performs the function of positioning the mold sleeve relative to the mold holder and also the function of thermally insulating both the mold sleeve and the mold holder. These two functions are provided by different sections of the positioning ring. This ensures, on the one hand, that the mold sleeve is positioned precisely relative to the mold holder by the at least one positioning ring, and on the other hand, that the temperature of the mold holder, particularly the area of ​​the associated cutting edge, is significantly decoupled from the temperature and any temperature fluctuations of the mold sleeve.The temperature of the die holder in the area of ​​the cutting edge is subject to only very minor temperature fluctuations and deviations from a predetermined temperature during operation of the die. As a result, a very precise and very narrow cutting gap forms between the corresponding cutting edges of the die and the associated die. The die parts can therefore be trimmed very precisely and reliably without damage to the cutting edges from mutual contact.

[0012] The at least one positioning ring is preferably made of the same material as the mold sleeve in the mold cavity area. Due to the high thermal conductivity and durability of the mold cavity, this is preferably a metallic material. This material also preferably forms the contact surfaces for contact with the mold holder. In contrast, a different material is provided in the insulating gaps between the positioning ring and the mold holder, the thermal conductivity of which is significantly lower than that of the positioning ring material and / or the mold sleeve material. In the area of ​​the insulating gap, the area-specific heat transfer from the mold sleeve to the mold holder is significantly lower than in the area of ​​the contact surfaces between the mold sleeve and the mold holder.

[0013] The forming tool can have a single forming sleeve or multiple forming sleeves. If several forming sleeves are provided, they can, for the sake of simplicity, be held in different recesses of a single mold holder. For further simplicity, the forming sleeves and their recesses are then designed identically. The number of forming sleeves also corresponds to the number of cutting edges of the die. Each forming sleeve is assigned one cutting edge of the forming tool and one cutting edge of the die. For this reason, this document primarily describes a forming sleeve and its associated mold holder, without specifically mentioning that the forming tool can also have several identical forming sleeves, which can be held in identical recesses of a common mold holder.

[0014] In a first particularly preferred embodiment of the mold, the at least one positioning ring is provided at least substantially at one free end of the mold sleeve. This serves, on the one hand, to ensure precise positioning of the mold sleeve in the mold receptacle and, on the other hand, to minimize heat transfer to the mold receptacle. The positioning ring can be located quite far from the at least one directly or indirectly heated area of ​​the mold sleeve at this point. Furthermore, the wall thickness in the region of the free end can be thin and / or tapered, thus further reducing heat transfer across the positioning ring in that area.

[0015] Alternatively or additionally, the die holder can include a receiving unit and at least one die sleeve. The die sleeve can then advantageously be positioned around the free end of the die sleeve, surrounding it. The cutting edge is thus provided by the die sleeve, which is thermally decoupled from the die sleeve. Should the die sleeve be accidentally damaged because it unintentionally comes into contact with the die-cutting tool, the die sleeve can be easily replaced without necessarily having to replace the die sleeve and / or the die holder as well.

[0016] To improve the positioning of the mold sleeve in the mold holder, it is advantageous to provide at least two positioning rings, at least substantially circumferential, on the outer surface of the mold sleeve. These positioning rings can each bear against the mold holder. Each positioning ring defines a positioning plane. Along each positioning ring, contact surfaces against the mold holder and insulating gaps separating the mold sleeve from the mold holder are provided. The more such positioning rings are provided, the more reliably the mold sleeve can be positioned relative to the mold holder. Simultaneously, the more positioning rings a mold sleeve has, the more heat will tend to be transferred from the mold sleeve to the mold holder.

[0017] Regardless of the number of positioning rings, for the sake of design simplicity, it can be advantageous to arrange the contact surfaces and the insulation gaps of each positioning ring alternately. This is even more true if the contact surfaces and the insulation gaps are arranged consecutively. In this case, only contact surfaces and insulation gaps are provided around the perimeter of at least one positioning ring. For insulation purposes and for manufacturing reasons, it is also advantageous if the insulation gaps are formed by air gaps. To provide these air gaps, recesses can be easily incorporated circumferentially in the positioning ring, which limit the air gaps on one side as well as the form-fitting on the opposite side of each air gap.

[0018] For simple and precise positioning of the mold sleeve relative to the mold holder, an orientation of at least one positioning ring that is at least substantially perpendicular to a longitudinal axis of the mold sleeve and / or the mold cavity can be advantageous. The same can be achieved alternatively or additionally if the at least two positioning rings are arranged at least substantially parallel to each other. Furthermore, it is advantageous if the positioning rings are spaced relatively far apart along the longitudinal extent of the mold sleeve. To achieve effective thermal decoupling of the heated mold sleeve from the mold holder, an insulating gap, in particular an air gap, can be provided between the mold sleeve and the mold holder, extending at least substantially around the entire circumference between the two positioning rings.For the same reason, it is also advisable if this isolation gap extends at least substantially over the entire distance between the corresponding positioning rings.

[0019] On the side of a positioning ring facing away from the free end of the mold sleeve, a mounting ring may be provided, which may have contact surfaces for mold retention. However, no insulating gap is required between the mounting ring and the mold retention. Regardless, an insulating gap, at least substantially circumferential, may be provided between the mounting ring and the adjacent positioning ring, between the mold sleeve and the mold retention. This further improves the thermal decoupling of the guide sleeve and the mold retention. This is especially true if the aforementioned insulating gap extends at least substantially across the entire distance between the positioning ring and the mounting ring. For the sake of simplicity and effectiveness, it is generally advisable for this insulating gap to be designed as an air gap.

[0020] At least one positioning ring can be assigned to a middle or lower area of ​​the mold cavity to improve positioning between the mold sleeve and the mold holder. Alternatively or additionally, at least one positioning ring and / or the mounting ring can be positioned against a mounting sleeve of the mold holder. This simplifies the manufacture, maintenance, and cleaning of the mold.

[0021] The aforementioned advantages are further enhanced if the insulation gap between the positioning ring and the mounting ring is at least substantially continuous and bounded by the mounting sleeve. This allows for easy assembly of the mold and / or, for example, facilitates the simple provision of an insulation gap between the mounting sleeve and the receiving unit. For increased effectiveness, this insulation gap can be one through which cooling water flows.

[0022] The forming tool can be manufactured simply and precisely if the holding unit has an upper and a lower part. A suitably shaped forming sleeve can then simply be inserted into the lower part. The upper part can then be attached. This also allows, for example, the use of forming sleeves with larger diameters or dimensions in the lower area than in the upper area. It is also preferred if the upper part holds the die-cutting sleeve and / or the lower part the mounting sleeve. Assembly can thus be carried out quickly and easily. If necessary, the forming sleeves can also be easily changed to provide different forming cavities.

[0023] To keep the mold holding area cool and at a very precise temperature, it can be advantageous if the insulation gaps of at least one positioning ring are designed to allow cooling air to flow through them. The same applies to the insulation gap between two positioning rings and / or the insulation gap between a positioning ring and the mounting ring.

[0024] Cooling can be achieved particularly easily and efficiently if the insulation gaps of the at least one positioning ring and / or the insulation gaps between two positioning rings and / or the insulation gap between a positioning ring and the mounting ring are interconnected for a common flow of cooling air. All insulation gaps can be interconnected for a common flow of cooling air. However, it is also possible to connect only certain insulation gaps for a common flow of cooling air. Which gaps are preferable can vary from application to application. In a first particularly preferred embodiment of the forming device, the forming sleeve and / or the punching sleeve of the forming tool, in the punching position, is inserted into the punching tool in such a way that the edges of the formed part can be trimmed by punching.It is advantageous if the punching tool and the punching sleeve have corresponding cutting edges for trimming the formed part when adjusting the forming tool and the punching tool from the spaced position to the punching position.

[0025] In order to reliably accomplish the forming of the semi-finished product, the stamping tool can have a pre-stretching punch in addition to the cutting edge. With the pre-stretching punch, a heated semi-finished product arranged above the mold cavity can then be pressed into the mold cavity and stretched in the process.

[0026] The invention will now be explained in more detail with reference to a drawing that illustrates only one embodiment. The drawing shows

[0027] Fig. 1 shows a forming tool according to the invention with a plurality of forming sleeves held in receptacles for forming molded parts in a perspective view,

[0028] Fig. 2 shows a detail of the forming tool in the area of ​​a forming sleeve together with the associated stamping tool in a sectional view parallel to the longitudinal extent of the forming sleeve.

[0029] Fig. 3 shows a detail of the mold sleeve in a perspective view,

[0030] Fig. 4 shows a detail of the forming tool in the area of ​​a forming sleeve in a

[0031] Sectional view perpendicular to the longitudinal extent of the mold cavity, Fig. 5 a detail of the mold tool in the area of ​​a mold sleeve in a

[0032] Top view and

[0033] Fig. 6 shows a detail of the forming tool in the area of ​​the upper positioning ring in a top view.

[0034] Figure 1 shows a forming tool 1 of a thermoforming machine. The forming tool 1 interacts with a die to form and subsequently trim parts from a thermoplastic semi-finished product. The semi-finished product, which is typically a film, is first heated and placed between the forming tool 1 and the die. The forming tool 1 and the die are then brought together, and the heated semi-finished product is pressed and stretched into the forming cavities 2 of the forming tool 1 by pre-stretching dies of the die. Subsequently, overpressure and / or underpressure is created in the forming cavities 2, which conforms the semi-finished product to the inner contours of the forming cavities 2. The semi-finished product is thus formed into parts whose outer contour corresponds at least partially to the inner contour of the forming cavities 2.

[0035] The illustrated forming tool 1 is mounted on a mounting plate 3 and comprises a forming holder 4 with six forming sleeves 5, which are received in the forming holder 4. The forming holder 4 also includes a receiving unit 6 with six recesses 7, each of which holds a forming sleeve 5. The receiving unit 5 is formed by a lower part 8 and an upper part 9. For clarity, the stamping tool is not shown in Fig. 1.

[0036] Figure 2 shows a section through the forming tool 1 in the area of ​​a forming sleeve 5 together with an associated part of the stamping tool 10. The mounting plate 3 has openings 11 corresponding to the forming sleeves 5. Plungers 12 are guided through the openings 11 and are connected to an adjustable base 13 of the forming sleeve 5. The bases 13 form the bottoms of the forming cavities 2 and can be adjusted into the forming cavities 2 via the plungers 12 to eject the formed parts from the forming cavities 2, for example, after the forming tool 1 with the mounting plate 3 has been pivoted to one side. In principle, however, the mounting plate 3 could also be omitted in this case.

[0037] The base 13 of the mold sleeve 5 is equipped with a rod-shaped, electrical heating element 14, similar to a heating resistor. In addition, further rod-shaped heating elements 15, similar to heating resistors, are distributed around the perimeter of the side wall of the mold sleeve 5, extending into the area of ​​the mold cavity 2 of the mold sleeve 5, but not to the free end of the mold sleeve 5. The heating elements 14, 15 allow the mold sleeve 5 to be heated to a temperature of, for example, between 160°C and 190°C and do not necessarily have to be rod-shaped and / or similar to heating resistors.

[0038] The lower part 8 of the receiving unit 6 sits on the mounting plate 3, while the upper part 9 of the receiving unit 6 sits on the lower part 8. In the illustrated and thus preferred embodiment, the forming sleeve 5, which is received in the receptacle 7 of the receiving unit 6, is not in direct contact with the receiving unit 6. A mounting sleeve 16 is received by the lower part 8 of the receiving unit 6, while a stamping sleeve 17 is received by the upper part 9 of the receiving unit 6. The receiving unit 6, together with the stamping sleeves 17 and the mounting sleeves 16, forms the forming receptacle 4, which in turn provides receptacles 7 for the forming sleeves 5.

[0039] In the area of ​​the mounting plate 3, the molded sleeve 5 has a mounting ring 18 through which, in the illustrated embodiment, the connecting cables 19 for the lateral heating elements 15 are guided. The mounting ring 18 can come into contact with the adjacent mounting sleeve 16. In the upper area of ​​the mounting sleeve 16, the molded sleeve 5 has a positioning ring 20, which comes into contact with the mounting sleeve 16 via contact surfaces 21. Between the positioning ring 20 and the mounting ring 18, a circumferential insulating gap 22 extending over the entire distance between the positioning ring 20 and the mounting ring 18 is provided between the mounting sleeve 16 and the molded sleeve 5. In this area, an insulating gap 23 is also provided between the mounting sleeve 16 and the receiving unit 6, which is also circumferential. A cooling fluid, in particular cooling water, can be pumped through this insulating gap 23 for additional cooling.

[0040] At the free end of the forming sleeve 5, a further positioning ring 24 is provided, which, with contact surfaces 25, comes into contact with the punching sleeve 17, which is otherwise spaced from the forming sleeve 5 by an insulating gap 26. Between the punching sleeve 17 and the receiving unit 6, a further insulating gap TI is also provided, through which a cooling fluid, in particular cooling water, can be pumped for additional cooling. In the region of the upper end of the lower part 8, the receiving unit 6 engages in an annular manner between the punching ring 17 and the mounting ring 16 in the direction of the forming sleeve 5. However, even in this region, the forming sleeve 5 is spaced from the receiving unit 6 by an insulating gap 28.

[0041] In the illustrated and thus preferred embodiment, the aforementioned insulation gaps 22, 26, 28 are each designed as air gaps, the air in the air gaps serving as thermal insulation for the heated mold sleeve 5 relative to the unheated components of the mold holder 4. To further improve the thermal insulation, the insulation gaps 22, 26, 28 are fluidly connected to one another, so that cooling air can be directed through the aforementioned insulation gaps 22, 26, 28 and the heat is carried away from the insulation gaps 22, 26, 28.

[0042] A detail of the punching tool 10 is shown, corresponding to the upper end of the forming sleeve 5 and the punching sleeve 17. The punching sleeve 17 and the upper end of the forming sleeve 5 enter the punching tool 10 when the punching tool 10 is moved from a position spaced apart from the forming tool 1 to the punching position shown. During this movement, a circumferential cutting edge 30 of the punching sleeve 17 and a circumferential cutting edge 31 of the punching tool 29 are guided past each other, so that the cutting edges 30, 31 trim the edge of the formed part (not shown in Fig. 2), which is received in the forming cavity 2 and extends laterally beyond the punching sleeve 17. Due to the thermal insulation of the forming sleeve 5 and the punching sleeve 17, a very small cutting gap 32 between the cutting edges 30,31 can be set and maintained without the cutting edges 30,31 colliding with each other and thereby being damaged.The punching tool 10 also includes a hold-down device 43, which presses the heated semi-finished product against the upper edge of the die sleeve 5 while the semi-finished product is inserted into the die cavity 2. Furthermore, a pre-stretching punch 44 is provided on the punching tool 10, which can be inserted into the die cavity to push the heated semi-finished product, held by the hold-down device 43, a short distance into the die cavity 2 and thereby pre-stretch it.

[0043] Figure 3 shows a detail of the mold sleeve 5 in a perspective view. In the lower part of the illustration, openings 33 distributed around the mold sleeve 5 are visible, through which small amounts of cooling air from the insulation gap 22 between the mold sleeve 5 and the mounting sleeve 16 can enter the mold cavity 2. Above these openings is the lower positioning ring 20, which is arranged around the mold sleeve 5 at least substantially perpendicular to its longitudinal extent. The positioning ring 20, by virtue of its circumferential arrangement, defines a lower positioning plane in which it is located. The openings 34 at the upper edge of the lower positioning ring 20 are connected to the channels for receiving the heating elements 15. When the heating elements 15 are inserted into the channels, air can escape from these openings 34.

[0044] Around the positioning ring 20, contact surfaces 21 for contact with the mounting ring 16 or the mold holder 4 alternate with recesses 36, between which insulating gaps in the form of air gaps are formed and the mounting ring 16 or the mold holder 4. Cooling air can pass through the insulating gap 22 in the lower positioning ring 20 from the insulating gap 22 between the mold sleeve 5 and the mounting sleeve 16, over the positioning ring 20, and into the insulating gap 26 between the mold sleeve 5 and the punch sleeve 17. A cooling airflow in the opposite direction would also be conceivable.

[0045] The upper positioning ring 24, associated with the free end of the forming sleeve 5, is analogous to the lower positioning ring 20 but narrower. The upper positioning ring 24 is also oriented at least substantially perpendicular to the longitudinal extent of the forming sleeve 5 and defines a correspondingly oriented upper positioning plane. Along the upper positioning ring 24, contact surfaces 25 for contact with the punching ring 17 or the mold holder 4 alternate with recesses 37, whereby insulating gaps in the form of air gaps are formed between the recesses 37 and the punching ring 17 or the mold holder 4. Cooling air from the underlying insulating gap 26 between the forming sleeve 5 and the punching sleeve 17 can escape upwards through the insulating gaps in the area of ​​the upper positioning ring 24.

[0046] Figure 4 shows a detail of the mold holder 4 in a section transverse to the longitudinal extent of a mold sleeve 5, with the section positioned at the level of the lower positioning ring 20. The mounting sleeve 16 of the mold holder 4 is seated in the receiving unit 6, bearing against contact surfaces 21 of the lower positioning ring 20. Between these surfaces are recesses 36 of the positioning ring 20, between which and the mounting ring 16 are insulating gaps 38 in the form of air gaps. A total of six openings 39 are provided around the perimeter of the mold sleeve 5, through which the connecting cables 19 for the six different lateral heating elements 15 are guided. The bottom of the mold cavity 2 is formed by the bottom 13 of the mold sleeve 5, which can be adjusted relative to the other areas of the mold cavity 2 in the longitudinal direction of the mold sleeve 5.In the illustrated and thus preferred embodiment, the lower positioning ring 20 has flat outer surfaces 40 between the contact surfaces 21, i.e., in the area of ​​the recesses 36, which are very easy to manufacture. The contact surfaces 21, on the other hand, are curved according to corresponding circular segments of the mounting sleeve 16.

[0047] Figure 5 shows a top view of the forming tool 1 in the area of ​​a forming sleeve 5. Adjacent to the receiving unit 6 is the punching ring 17 of the mold holder 4. The punching ring 17 provides the circumferential cutting edge 30 and is adjacent to the forming sleeve 5. The forming sleeve 5 has a corrugated inner contour, which is assumed as the outer contour of the molded parts formed in the forming sleeve. The positioning ring 24 has alternating contact surfaces 25 around its circumference for contact with the punching sleeve 17 and recesses 37, in the area of ​​which the punching sleeve 17 is spaced from the positioning ring 24 by insulating gaps 41 in the form of air gaps. In the area of ​​the recesses 37, the outer surfaces 42 are flat.

[0048] Figure 6 shows a detail of the connection between the forming sleeve 5 and the punching ring 17. The punching ring 17 rests against contact surfaces 25 of the positioning ring 24 on the forming sleeve 5. The contact surfaces 25 are curved corresponding to the punching ring 17. The outer surfaces 40 of the positioning ring 24 extend flat between the contact surfaces 25, so that recesses 37 are provided there, defining insulating gaps 26 in the form of air gaps between the forming sleeve 5 and the punching sleeve 17.

[0049] The insulation gaps 38, 41 are designed as air gaps and are fluidly connected to each other via the insulation gap 26 between the forming sleeve 5 and the punching sleeve 17. All previously mentioned insulation gaps 22, 26, 28, 38, 41 are fluidly connected to each other and are supplied with cooling air during operation of the forming device. Reference numeral list

[0050] 1 forming tool

[0051] 2 Mold cavity

[0052] 3 Mounting plate

[0053] 4. Form recording

[0054] 5 Form sleeve

[0055] 6 recording unit

[0056] 7th recording

[0057] 8 Lower part

[0058] 9 Top

[0059] 10 punching tools

[0060] 11 Opening

[0061] 12 pestles

[0062] 13 Floor

[0063] 14 Heating element

[0064] 15 heating element

[0065] 16 Mounting sleeve

[0066] 17 Punch sleeve

[0067] 18 Mounting ring

[0068] 19 connection cables

[0069] 20 positioning rings

[0070] 21 Plant area

[0071] 22 Insulation gap

[0072] 23 Insulation gap

[0073] 24 Positioning ring

[0074] 25 Plant area

[0075] 26 Insulation gap

[0076] ZI insulation gap

[0077] 28 Insulation gap

[0078] 30 cutting edge

[0079] 31 Cutting edge

[0080] 32 Cutting gap

[0081] 33 Opening

[0082] 34 Opening

[0083] 36 Exclusion

[0084] 37 Exclusion

[0085] 38 Insulation gap

[0086] 39 Opening

[0087] 40 outdoor area

[0088] 41 Insulation gap

[0089] 42 outdoor area

[0090] 43 hold-down devices

[0091] 44 Pre-stretch stamps

Claims

Patent claims 1. Forming tool (1) for forming a semi-finished product made of at least one thermoplastic material, comprising at least one forming sleeve (5) providing a forming cavity (2) for receiving the formed semi-finished product and a mold receptacle (4) receiving the at least one forming sleeve (5), wherein the forming sleeve (5) is heatable and at least partially separated from the mold receptacle (4) by an insulating gap (38, 41), wherein at least one positioning ring (20, 24) bearing against the mold receptacle (4) is provided on the outside of the forming sleeve (5) for positioning the forming sleeve (5) in a positioning plane defined by the positioning ring (20, 24), characterized in that insulating gaps (38, 41) separating the forming sleeve (5) from the mold receptacle (4) are provided between contact surfaces (21, 25) bearing against the mold receptacle along the at least one positioning ring (20, 24).41) are provided for., 2. Forming tool according to claim 1, characterized in that the at least one positioning ring (20, 24) is provided at least substantially at a free end of the forming sleeve (5) and / or that the forming receptacle (4) has a receiving unit (6) and at least one punching sleeve (17) provided circumferentially to the forming sleeve (5) in the area of ​​the free end of the at least one forming sleeve (5).

3. Forming tool according to claim 1 or 2, characterized in that at least two at least substantially circumferential positioning rings (20, 24) abutting the mold receptacle (4) are provided on the outside of the forming sleeve (5) for positioning the forming sleeve (5) in positioning planes defined by the positioning rings (20, 24) and that isolation gaps (38, 41) separating the forming sleeve (5) from the mold receptacle (4) are provided between contact surfaces (21, 25) abutting the forming sleeve (5) along the positioning rings (20, 24).

4. Forming tool according to one of claims 1 to 3, characterized in that the contact surfaces (21, 25) and the isolation gaps (38, 41) of the at least one positioning ring (20, 24) are arranged alternately to each other, in particular successively, and / or that the isolation gaps (38, 41) are formed by air gaps, in particular in recesses (36, 37) of the at least one positioning ring (20, 24).

5. Forming tool according to one of claims 1 to 4, characterized in that the at least one positioning ring (20, 24) is aligned at least substantially perpendicular to a longitudinal axis of the forming sleeve (5) and / or the forming cavity (2) and / or that the at least two positioning rings (20, 24) are arranged at least substantially parallel to each other.

6. Forming tool according to one of claims 3 to 5, characterized in that an insulation gap (26), in particular an air gap, is provided between two positioning rings (20, 24) at least substantially over the entire distance between the positioning rings (20, 24).

7. Forming tool according to one of claims 1 to 6, characterized in that an at least substantially circumferential insulation gap (22), in particular an air gap, is provided between the at least one positioning ring (20) and a mounting ring (18) provided on the side of the positioning ring (20) facing away from the free end of the forming sleeve (5), in particular abutting the forming receptacle (4), and preferably that the insulation gap (22) is provided at least substantially over the entire distance between the positioning ring (20) and the mounting ring (18).

8. Forming tool according to one of claims 1 to 7, characterized in that the at least one positioning ring (20) is assigned to a middle area or lower area of ​​the forming cavity (2) and / or that the forming receptacle (4) has a mounting sleeve (16) which in particular comes into contact with the positioning ring (20) and / or the mounting ring (18).

9. Forming tool according to claim 7 or 8, characterized in that the insulation gap (22) between the positioning ring (20) and the mounting ring (18) is at least substantially continuously limited by the mounting sleeve (16) and / or that an insulation gap (23) is provided between the mounting sleeve (16) and the receiving unit (4).

10. Forming tool according to one of claims 2 to 9, characterized in that the receiving unit (6) has an upper part (9) and a lower part (8) and, preferably, that the upper part (9) receives the punching sleeve (17) and / or the lower part (8) receives the mounting sleeve (16).

11. Forming tool according to one of claims 1 to 10, characterized in that the insulation gaps (38, 41) of the at least one positioning ring (20, 24) and / or the insulation gap (26) between two positioning rings (20, 24) and / or the insulation gap (22) between a positioning ring (20) and the mounting ring (18) are designed for the flow of cooling air.

12. Forming tool according to claim 11, characterized in that the insulation gaps (38, 41) of the at least one positioning ring (20, 24) and / or the insulation gaps (26) between two positioning rings (20, 24) and / or the insulation gap (20) between a positioning ring (20) and the mounting ring (18) are connected to each other for common flow with cooling air.

13. Forming device for forming a semi-finished product made of at least one thermoplastic material, comprising a forming tool (1) and a punching tool (10), wherein the forming tool (1) and the punching tool (10) are adjustable from a spaced-apart position relative to each other to an approximate punching position and back, and wherein the forming tool (1) in the punching position plunges into the punching tool (10) in such a way as to trim the edges of the formed part by punching, characterized in that the forming tool (1) is designed according to one of claims 1 to 12.

14. Forming device according to claim 13, characterized in that the forming sleeve (5) and / or the punching sleeve (17) of the forming tool (1) in the punching position immerses into the punching tool (10) in such a way as to trim the edges of the formed part by punching and / or that the punching tool (10) and the punching sleeve (17) has corresponding cutting edges (30, 31) that trim the formed semi-finished product when moved from the spaced position to the punching position.

15. Forming device according to claim 13 or 14, characterized in that the punching tool (10) comprises a hold-down (43) for pressing the heated semi-finished product against the upper edge of the forming sleeve (5) and a pre-stretching punch (44) for pre-stretching a heated semi-finished product into the forming cavity (2).

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