DE102008054136B4 - Method for producing a component with a tool for thermal foam spraying - Google Patents

Abstract

Method for producing a component (4) with a tool for thermal foam spraying with a first mold plate (8) and a second mold plate (6), wherein in the first mold plate (8) a first mold segment (1) and second mold segment (2) and a third mold segment (3) are provided, and between the mold plate (8) and the mold plate (6) has a cavity (7) is formed, each mold segment (1, 2, 3) independently of the other mold segments (1, 2, 3 ) for venting the cavity (7), and a first group of nozzles (A), a second group of nozzles (B) and a third group of nozzles (C) is provided for injecting foam into the cavity (7), characterized by the time sequence of ventilation, wherein first the first mold segment (1) is opened during the injection process, where the cavity (7) is filled with melt, wherein then the second mold segment (2) and the third mold segment (3) geöff net, wherein the second mold segment (2) and the third mold segment (3) can only be opened when the region of the first mold segment (1) is filled with melt.

Description

The present invention relates to a method for thermal foam spraying according to the preamble of claim 1.

It is known that thermal foam syringes or tools for thermal foam spraying for the production of vehicle components, such as plastic components in the cockpit, instrument panels, plastic components in the front end, plastic components in the rear bumper, Kunststoffmontageträgem, wheel housing shells, div. Floor, Engine, Vehicle Interior, Plastic u. Metal components in the engine compartment, plastic components in the body area (such as fenders, ...) are used.

In this context, it is also known that with large components there is the problem that the filling times are too high to be able to foam. The melt cools.

EP 1 396 324 A2 discloses an injection molding process for propellant thermoplastic materials. For this purpose, a tool is described in which a cavity can be gradually increased by displaceable mold segments during an injection process.

EP 1 974 889 A1 discloses a tool for the manufacture of instrument panels for motor vehicles, by means of which a core can be overmolded with a thermoplastic melt.

Accordingly, the invention is based on the object to propose a method for thermal foam spraying, with the large plastic components, in particular plastic components with a length of more than 60 cm, can be foamed optimally.

According to the invention this object is achieved by a method having the features mentioned in claim 1. Inventively, the time sequence of the airing, wherein first the first mold segment is opened during the injection process, wherein subsequently the second mold segment and the third mold segment are opened, further by the time sequence of the injection, wherein in a first step, the nozzle of the group A is opened are opened, wherein in a second step, the nozzles of the group B are opened, wherein in a third step, the nozzles of the group C are opened.

Further advantageous embodiments of the proposed method will become apparent from the features of the dependent claims.

• 1 eine schematische Darstellung eines erfindungsgemäßen Werkzeugs;
• 2 eine schematische Schnittdarstellung eines erfindungsgemäßen Werkzeugs zu einem Zeitpunkt 1;
• 3 eine schematische Schnittdarstellung eines erfindungsgemäßen Werkzeugs zu einem Zeitpunkt 2;
• 4 eine schematische Schnittdarstellung eines erfindungsgemäßen Werkzeugs zu einem Zeitpunkt 3;
• 5 eine schematische Schnittdarstellung eines erfindungsgemäßen Werkzeugs zu einem Zeitpunkt 4;
• 6 eine schematische Schnittdarstellung eines erfindungsgemäßen Werkzeugs;
• 7 eine schematische Schnittdarstellung eines erfindungsgemäßen Werkzeugs in einem geöffneten Zustand;
• 8 eine Draufsicht auf eine erste Formplatte mit einem ersten Formsegment, einem zweiten Formsegment und einem dritten Formsegment.

Further features and advantages of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. Show in it

• 1 a schematic representation of a tool according to the invention;
• 2 a schematic sectional view of a tool according to the invention at a time 1;
• 3 a schematic sectional view of a tool according to the invention at a time 2;
• 4 a schematic sectional view of a tool according to the invention at a time 3;
• 5 a schematic sectional view of a tool according to the invention at a time 4;
• 6 a schematic sectional view of a tool according to the invention;
• 7 a schematic sectional view of a tool according to the invention in an open state;
• 8th a plan view of a first mold plate having a first mold segment, a second mold segment and a third mold segment.

First, it will open 6 Referenced.

A preferred embodiment of a tool according to the invention for thermal foam spraying essentially comprises a first mold plate 8th and a second mold plate 6 , The first mold plate 8th is preferably as a mold plate of the ejector side and the second mold plate 6 is preferably designed as a mold plate of the nozzle side. In addition, a tool according to the invention particularly comprises an ejector housing 20 and a hot runner manifold + plates 21 , In the first mold plate 8th is a first shape segment 1 , a second mold segment 2 and a third mold segment 3 intended. Between the first mold plate 8th , in particular the first mold segment 1 , the second mold segment 2 and the third mold segment 3, and the second mold plate 22 is a cavity 7 educated. The spatial arrangement of ejector housing 20 , second mold plate 6 , Cavity 7 , first mold plate 8 and hot runner manifold + plates 21 is the 6 to be taken schematically.

7 shows the tool according to the invention in an open state. It is a component 4 between the first mold plate 8th and the second mold plate 6 recognizable, which in the cavity 7 has been formed.

8th shows schematically the arrangement of the first mold segment 1 , the second form segment 2 and the third shape segment 3 within the first mold plate 8th ,

The following will be on 1 Referenced.

The shape segments 1 . 2 . 3 are shown only in outline, so that a component to be manufactured 4 can be seen in the tool for thermal foam spraying. Basically, the shape segments 1 . 2 . 3 arranged in the longitudinal direction one behind the other, wherein the first mold segment 1 between the second mold segment 2 and the third mold segment 3 is arranged.

It is further evident that each mold segment 1 . 2 . 3 equipped with at least one nozzle. The nozzles are basically designed to foam in the cavity 7 to squirt. The nozzles are in three groups A . B and C divided, which are opened during the component manufacturing process at different times.

Also is a Entformungsrichtung 5 indicated. The demoulding direction 5 indicates in which direction the form elements 1 . 2 . 3 can be moved to open. This process can also be called airing.

Below is on the 2 to 5 Referenced.

Between the mold segments 1 . 2 . 3 and the second mold plate 6 is the cavity 7 educated. The cavity 7 can be filled up with foam passing through the nozzles A . B , C is initiated. By curing the foam in the cavity 7 becomes the desired component 4 produced.

It is further contemplated that the mold segments 1 . 2 . 3 independently opened, ie from the second mold plate 6 can be spaced. It is inventively provided that no simultaneous ventilation of the complete component 4 but a sequential venting takes place during the injection process. For this purpose, it is provided in a preferred embodiment of the invention that, in a temporal order of airing, first the first mold segment 1 opens, then the second mold segment 2 and the third shape segment 3 is opened.

Also, a temporal order of injection is provided in a preferred embodiment of the invention. In a first step, the nozzles of the group A open. In a second step, the nozzles of the group B open. In a third step, the nozzles of the group C open.

This results in the following advantage. Because shortly after injecting the nozzles of the group A the first shape segment 1 the cavity 7 enlarged, foaming over a larger area is possible. Before that, however, the cavity must be in the area of the shape segment 1 be filled with melt, and then to enlarge the cavity over the segment. Thus, even larger components can be foamed easily. The reason lies in particular in the higher temperature of the melt.

In the 2 to 5 are now outlined four points in time of a method according to the invention for thermal foam spraying in conjunction with a tool according to the invention for thermal foam spraying.

The cavity 7 For reasons of more detailed description, it should be divided into individual sections, in particular a first section of cavity 11 , a second cavity section 12 and a third cavity section 13 to be divided. The aforementioned sections correspond to the mold segments 1 . 2 . 3 ie, the sections face the respective segments. Furthermore, the cavity sections 11 . 12 . 13 certain thicknesses. The cavity sections shall be designated K ₁ , K _2,1 and K _3,1 according to their thickness and section number, where K _{number of the section} shall designate _thickness .

In the 2 , in which a first time is shown schematically, it can be seen that the cavity 7 has a uniform thickness over its entire length, ie K _1,1 = K _2,1 = K _3,1 . This state can also be referred to as the initial state.

In the 2 is also hinted that the nozzles of the group A Foam in the cavity 7 contribute.

In the 3 is hinted that melt and gas from the nozzles of the group B into the cavity 7 is initiated. The relationship K _1,1 , K _2,1 and K _3,1 still applies.

In the 4 is now indicated that melt and gas from the nozzles of the group C into the cavity 7 is initiated. Likewise, the distance between the first mold segment 1 and the second mold plate 6 increases, so that the thickness of the cavity 7 in her cavity section 11 increased, so that now has a thickness K _1.2 of Kavitätsabschnitts 11 for which K _1,2 > K _1,1 applies. The demoulding direction 5 is indicated here by the arrow.

In the 5 is now indicated that the distance between the second mold segment 2 and the second mold plate 6 , as well as between the third shape segment 3 and the second mold plate 6 is enlarged. The thickness of the cavity sections 12 and 13 also increases, so that a thickness K _{2,2 of} the second Kavitätsabschnitts 12 and the thickness K _{3.2 of} the third cavity section 13 is set, where K is _2.2 > K _2.1 and K _3.2 > K _3.1 . Furthermore, the thickness of the cavity is also 7 total again the same, so that K _1,2 = K _2,2 = K _3,2 .

1. 1. Das Bauteil hat eine Fläche von min. 0,2 m²
2. 2. Die Anfangsdicke der Kavität beträgt min. 0.2 mm
3. 3. Die Einspritzzeit beträgt bis zum ersten Lüften 0.2s - 4s
4. 4. Bauteilmaterialien: Thermoplaste, Metalle
5. 5. Die Formsegmente haben eine Fläche (Af) min. 0.006 m²
6. 6. Es sind mind. zwei Formsegmente zum Lüften erforderlich
7. 7. Die Gesamteinspritzzeit beträgt mind. 1,5 s

The method according to the invention and the tool according to the invention can be used particularly advantageously under the following conditions:

1. 1. The component has an area of min. 0.2 m ²
2. 2. The initial thickness of the cavity is min. 0.2 mm
3. 3. The injection time is 0.2s - 4s until the first airing
4. 4. Component materials: thermoplastics, metals
5. 5. The shape segments have an area (Af) min. 0.006 m ²
6. 6. At least two mold segments are required for ventilation
7. 7. The total injection time is at least 1.5 s

It should be noted that the mold segment is not equipped with nozzles. The nozzles are opposite the mold segments.

LIST OF REFERENCE NUMBERS

1

first mold segment

2

second mold segment

3

third shape segment

4

component

5

unmolding

6

second mold plate (mold plate ejector side)

7

cavity

8th

first mold plate (mold plate nozzle side)

11

first cavity section

12

second cavity section

13

third cavity section

A

Nozzles (group A )

B

Nozzles (group B )

C

Nozzles (group C )

20

extractor housing

21

Hot runner manifolds and plates

Claims (5)

Method for producing a component (4) with a tool for thermal foam spraying with a first mold plate (8) and a second mold plate (6), wherein in the first mold plate (8) a first mold segment (1) and second mold segment (2) and a third mold segment (3) are provided, and between the mold plate (8) and the mold plate (6) has a cavity (7) is formed, each mold segment (1, 2, 3) independently of the other mold segments (1, 2, 3 ) for venting the cavity (7), and a first group of nozzles (A), a second group of nozzles (B) and a third group of nozzles (C) is provided for injecting foam into the cavity (7) are characterized , characterized by - the temporal sequence of the ventilation, wherein first the first mold segment (1) is opened during the injection process, where the cavity (7) is filled with melt, wherein then the second mold segment (2) and the third mold segment (3) open fnet, wherein - the second mold segment (2) and the third mold segment (3) can only be opened when the region of the first mold segment (1) is filled with melt. Method according to Claim 1 , characterized in that the initial thickness of the cavity (7) is at least 0.2 mm. Method according to one of the preceding claims, characterized in that the injection time to the first airing is 0.2 - 4 seconds. Method according to one of the preceding claims, characterized in that the total injection time is at least 1.5 seconds. Method according to one of the preceding claims, characterized in that the method is preferably used for the production of components (4) having a length of more than 60 cm.

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