NL1033052C2 - Form element provided with a polar coating. - Google Patents

Description

The present invention relates to a method for manufacturing a form element, to a form element obtainable by means of this method, to a form element, to the use of the form element in the manufacture of vehicles and to a vehicle provided with such a form element.

When manufacturing vehicles, the aim is generally to lower the weight of the vehicle, such as, for example, a car or an airplane. A lower weight has a favorable effect on the fuel consumption of the vehicle. In order to achieve this lower weight of vehicles, much use is now made of plastics.

Plastics that are widely used in the automobile industry for forming molded parts include polypropylene and polyethylene. All kinds of different products can be manufactured from these plastics, such as, for example, base plates, doors, chairs, etc. In the automotive industry in particular, composite materials are also used. These are plastics that have been reinforced with another component, for example glass fibers (such as GMT 25 or LFT).

Nowadays many of these plastic parts are glued together or are glued to natural materials, such as leather, glass or glued to metal parts (such as parts of aluminum, iron, steel, etc.) of a vehicle such as for example the body of a car . In order to achieve good bonding, the plastic parts must have a relatively polar surface, that is, a surface with a surface tension that is 1033052 2 greater than 32 dynes / cm, preferably greater than 35 dynes / cm. Namely, if this is not the case, there is no good spreading of the adhesive over the surface of the plastic part. This is because the adhesives such as, for example, epoxy resins and polyurethane resins are relatively polar (both with a surface tension of approximately 45 dynes / cm). In order to make the plastic surfaces relatively polar, they are generally pre-treated. Such a pretreatment can then consist, for example, of a so-called corona treatment and / or inflammation of the surface of the plastic part and / or the application of different primer layers (such as, for example, diphenylmethane diisocyanate) on the surface of the plastic part. Such treatments are relatively expensive because they introduce an additional processing step into the production process and because they are relatively laborious. Such treatments also use relatively expensive raw materials.

The present invention has for its object to provide a solution to the above-mentioned problems.

A first aspect of the present invention relates to a method for manufacturing a form element comprising: i) applying a coating layer of polar plastic material in a mold; ii) contacting at least a portion of the coating layer with elevated temperature thermoplastic plastic material at elevated pressure; iii) allowing the thermoplastic plastic material and the polar coating layer to cool, wherein the thermoplastic plastic material forms a solid plastic element adhered to at least a portion of the polar coating layer.

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An advantage of such a method is that a molding element of plastic is obtained in an efficient and cost-effective manner which has a relatively polar surface and which can be glued well and efficiently with parts of (partial) glass, metal (for example iron, aluminum, etc.). steel), natural products (for example leather) or with other, relatively polar, plastic parts. The forming element therefore does not first have to be subjected to, for example, a corona treatment and / or inflammation after shaping. It is also not necessary for the form element and / or the surface of the part with which it is glued to be primed with primers.

Due to the relatively high pressure and high temperature (approximately 200 ° C at 200-250 bar), the polar coating layer 15 is attached (by melting and / or mechanical connection) to the thermoplastic plastic material. After cooling, a solid connection forms between the coating layer and the cooled thermoplastic plastic material, i.e. the plastic element formed. The connection is hereby such that the covering layer can no longer be easily separated from the plastic element. A form element is thus obtained which has a polar surface and which can be directly connected to, for example, a metal part of for instance a part of the bodywork of a car. The adhesive used, such as, for example, 3M Fastbond® (a polyurethane adhesive), will indeed flow well over the two, relatively polar, surfaces and therefore guarantee a good connection.

It is preferred if the thermoplastic plastic material comprises a fiber-reinforced plastic material for forming the plastic element. An advantage of the use of fiber-reinforced plastic material is that a forming element is obtained with very good mechanical properties. As a result, it can be used, for example, as an element that forms an essential part of the bodywork of a car, i.e. a so-called structural element. Furthermore, the use of fibers facilitates the manageability of the plastic material, in particular in the case where the forming element is formed in a so-called press mold.

Furthermore, it is preferable if the plastic element of the mold element is a covering element. Here, the plastic element, which has been formed from the thermoplastic plastic material, does not play a constructive role in the vehicle. The plastic element can then be relatively thin or not provided with a fiber structure.

Furthermore, it is preferable if the plastic element 15 is formed into a plate. As a result, the form element, that is to say the plastic element with the polar coating layer attached thereto, also acquires a plate shape. The obtained form element can then be substantially flat, such as a bottom plate of a car, but it can also be a plate with a certain relief, such as a cover plate for an engine or an engine space indicator.

The so-called surface voltage is often measured for determining the polar properties of a surface. This surface tension is measured with a standard test, the DIN 53 364 test, which is a standard test for measuring the surface tension of a surface. The higher the surface tension of a surface, the more polar it is.

It is preferable if the coating layer of polar plastic material used in the present method has a surface tension higher than 35 dynes / cm, preferably 40-50 dynes / cm, more preferably about 40-43 dynes / cm. When such a coating layer 5 is used, the surface tension of the molded element obtained becomes above 32, preferably above 35 dynes / cm, which is desirable for good adhesion with the adhesive and the surface with which the molded element is glued, such as, for example, a metal surface.

It is particularly preferred if the polar plastic material of the coating layer comprises polyester, polyamide and / or polyvinyl chloride. These materials give the surface of the mold element very good polar properties. Furthermore, they can be well connected to the thermoplastic plastic material of the plastic element. The polyesters polyethylene terephthalate and polybutylene terephthalate are particularly preferred as polar plastic material of the coating layer.

The covering layer is preferably a woven or a non-woven. One of the advantages of using such materials is that they are easy to handle and therefore easy to process.

Furthermore, it is preferred if the covering layer is a foil or a fleece.

Preferably, in step i) of the method described above, two coating layers are applied in the mold and in step ii) the thermoplastic plastic material is applied between the coating layers. A form element is thus obtained in which the plastic element is coated over its entire outer surface with a polar coating layer. This means that the form element can be glued over its entire outer surface.

The thermoplastic plastic material for forming the plastic element preferably has a surface tension that is lower than 30 dynes / cm. It is particularly preferred if the thermoplastic plastic material is a polyolefin, preferably polypropylene, polyethylene or polyamide. These plastic materials are very versatile, relatively inexpensive and can be brought in all kinds of desired forms.

These plastic materials are preferably fiber-reinforced.

The fiber percentage is then preferably in the range of 5 to 80% by weight, preferably 10 to 40% by weight, more preferably approximately 25% by weight. Furthermore, the fibers preferably comprise glass fibers and / or basalt fibers and / or natural fibers. The natural fibers can herein comprise hemp fibers, banana fibers, chef's fibers and / or flax fibers.

It is particularly preferred if the mold comprises a so-called press mold. With such a mold, for example, first the coating layer is introduced into the mold 15 and thereafter a plastic element of increased temperature is applied thereto. The mold then closes and presses the plastic element against the covering layer and the wall of the mold. Due to the relatively high temperature of the plastic element, the covering layer melts to the plastic element. Furthermore, the desired shape of the molding element is obtained due to the high (pressure) pressure and the shape of the wall of the mold.

Instead of a press mold, use can also be made of a so-called injection mold. The thermoplastic plastic material is then introduced into the mold under high pressure, preferably between 200 and 400 bar and at a temperature in the range of 150 ° C to 300 ° C, preferably 190 ° C to 250 ° C. The plastic material then flows against the coating layer, which coating layer is then pressed together with the plastic material against the wall of the mold and fuses together. A form element is thus obtained with a certain desired shape and with a surface with polar properties.

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A second aspect of the present invention relates to a molding element obtainable according to the method described above.

A third aspect of the present invention relates to a forming element comprising a plastic element of thermoplastic plastic material, wherein at least a part of the surface of the plastic element is coated with a coating layer of polar plastic material.

A fifth aspect of the present invention relates to the use of the above-described forming element in the manufacture of vehicles, such as cars, lorries, aircraft and ships.

A final aspect of the present invention relates to a vehicle which is provided with a form element 15 as described above.

Mentioned and other features of the forming element and the method for manufacturing this element according to the invention will be further elucidated hereinafter on the basis of a number of exemplary embodiments which are only given by way of example without the invention being thereby considered to be limited . Reference is hereby made to the accompanying drawings, in which:

Example 1 describes experimental results of five tests that have been carried out, which show that a molding element according to the present invention has very good gluable properties compared to untreated fiber-reinforced polypropylene (GMT).

Figure 1 is a plan view of an embodiment of a method for manufacturing an embodiment of a molding according to the invention;

Figure 2 shows a view of the press mold of Figure 1 for manufacturing an embodiment of a molding element according to the invention, as well as an embodiment of a molding element according to the invention;

Figure 3 is a plan view of an embodiment of a form element according to the invention and a metal surface of a vehicle to which the form element is attached;

Figure 4 shows an exploded view of an embodiment of a form element according to the present invention.

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Example

Twenty test bars of fiber-reinforced polypropylene (GMT) approximately 10 cm long, 1.6 cm wide and 0.5 cm thick were used in the present tests. Fifteen of these bars were provided with a polar coating layer of polyethylene terephthalate. The treated surface of these bars had a surface tension of approximately 34 dynes / cm. The other five bars were untreated and had a surface tension of approximately 28 dynes / cm.

Five of the fifteen bars provided with a polar coating were provided with a layer of adhesive (3M Fastbond Contact Adhesive 30) of approximately 0.5 cm thick. This layer of adhesive extended over a length of approximately 5 cm and over the entire width of the bars, i.e. approximately 1.6 cm. After drying for some time (as prescribed by the manufacturer), the five adhesive bars were contacted with five untreated bars. Thus a connection was formed between the bars. After the adhesive has hardened, the bars were subjected to a tensile test (5 mm / min), the shear stress to fracture being measured. The results are shown in Table 1.

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Subsequently, five of the fifteen bars that were provided with a polar coating (surface tension approximately 45 dynes / cm) were coated with adhesive in the same way as the bars above. Subsequently, these rods 5 were connected to the five other rods provided with a polar coating. A connection was thus formed between the rods which were provided with a polar coating. After the adhesive hardened, these rods were also subjected to a tensile test (5 mm / min) in which the shear stress to fracture was measured. The results of this are shown in Table 2. It is clear from Tables 1 and 2 that the shear stress of the connection between bars that are both provided with a polar coating is considerably higher than in the connection between an untreated bar and a bar that is provided with a polar coating.

Table 1: Shear stress GMT rod with polar coating and untreated GMT rod 20 Sample Width Length Shear joint connection stress (mm) (mm) [Mpa] 1 16.2 50 0.2 2 16.1 55 0.3 3 15.5 52 0.3 4 16, 5 52 0.2 25 5 17 53 0.2 10

Table 2: Shear stress GMT rod with polar coating layer and GMT rod with polar coating layer

Sample Width Length Shear connection voltage (mm) (mm) [Mpa] 5 1 16.5 47.5 0.9 2 16.0 52 0.8 3 16.2 48 0.9 4 16.8 52, 8 0.7 5 16.6 47 0.8 10

Figures

Figure 1A shows a first part 2 of a pressing mold 1 for manufacturing a molded part 3. In this first part 2 a covering layer 4 of polyester (surface tension of approximately 42-46 dynes / cm) is applied, as shown in Figure 1B. The part 2 of the mold 1 has a specific shape 5 with which a certain shape can be obtained from the surface of the mold part 3. After the coating layer 20 has been applied to the part 2 of the mold 1, a plastic element 6 of fiber-reinforced polypropylene (GMT) is applied to the coating layer 4. This plastic element 6 is heated to approximately 220 ° C in an infrared oven before it is placed in the mold. As a result of heating, the thermoplastic material becomes softened and flows out under pressure, so that it can be pressed into a desired shape relatively easily. It is noted here that it is not necessary for the plastic element 6 to extend entirely over the covering layer 4 prior to pressing. This is because during the pressing of the soft plastic element 6, the thermoplastic material 11 will completely flow out. Figure 1D shows the mold 1 in the closed state, wherein the plastic element and the covering layer are pressed into the desired shape. During this pressing, the thermoplastic plastic material of the plastic element 6 flows out over the coating layer and they melt together. The whole is then allowed to cool in such a way that the thermoplastic plastic material and the coating layer solidify and thus form a form element.

Figure 2 shows a cross-section of the die 1 of Figure 1, wherein a forming element 3 is formed. The molding element 3 comprises the plastic element 6 in the solid state to which the covering layer 4 is adhered by means of fusing and / or mechanical connection. Depending on the structure of the covering layer 4 (for example a honeycomb structure) and the pressure that is used, a part of the plastic element 6 can be located on the surface of the forming element 3.

Figure 3 shows a view of a forming element 8 of fiber-reinforced polypropylene which is provided on the underside with a covering layer 9 of polar plastic material (polyester fleece). The downwardly extending tray 10 which forms part of the forming element 8 is not provided with the covering layer 9. This tray 10 can serve for storing, for example, a spare wheel of a car.

Furthermore, figure 3 shows a part 11 of the metal chassis of a car. This part 11 of the car is provided with a layer of adhesive 12 (for example Betaseal 1759® or 3M Fastbond Contact Adhesive 30). By bringing the part of the forming element 8 which is provided with the covering layer 9 into contact with the part 11 of the chassis provided with the adhesive, a good connection between these two parts is obtained.

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Figure 4 shows, in removed parts, a view of a molding element 13. The molding element 13 comprises a coating layer 14 of polyester (surface tension 42-46 dynes / cm) which is bonded to a plastic part 15 by means of a melt and / or mechanical connection. The plastic part comprises fiber-reinforced polypropylene, which has a surface tension of approximately 29 dynes / cm. The surface of the molding with the covering layer attached thereto has a surface tension of approximately 34 dynes / cm.

The present invention is not limited to the embodiments described above, the rights sought are rather determined by the following claims within the scope of which many possible modifications are conceivable, such as, inter alia, a combination of the embodiments described above.

1033052

Claims (46)

Method for manufacturing a forming element 5 comprising: i) applying a coating layer of polar plastic material in a mold; ii) contacting at least a portion of the coating layer with elevated temperature thermoplastic plastic material at elevated pressure; iii) allowing the thermoplastic plastic material and the polar coating layer to cool, wherein the thermoplastic plastic material forms a solid plastic element adhered to at least a portion of the polar coating layer. Method according to claim 1, wherein the plastic material for forming the plastic element comprises a fiber-reinforced plastic material. 3. Method as claimed in claim 1 or 2, wherein the plastic element comprises a structural element or a covering element. Method according to any of claims 1-5, wherein the plastic element comprises a plate. 5. Method as claimed in any of the claims 1-4, wherein the coating layer has a surface tension of 35-50 dvnes / cm, preferably approximately 40-43 dynes / cm. The method according to any of claims 1-5, wherein the polar plastic material of the coating layer comprises polyester, polyamide and / or polyvinyl chloride. The method of claim 6, wherein the polyester comprises polyethylene terephthalate and / or polybutylene terephthalate. 1033052 A method according to any of claims 1-7, wherein the coating layer is a woven or a non-woven. The method of any one of claims 1-8, wherein the coating layer is a foil or a fleece. A method according to any of claims 1-9, wherein step in step i) two coating layers are applied in the mold and wherein in step ii) the thermoplastic plastic material is applied between the coating layers. A method according to any of claims 1-10, wherein the plastic material for the plastic element is a plastic material with a surface tension of less than 30 dynes / cm. 12. Method according to any of claims 1-11 / wherein the plastic material for the plastic element is a polyolefin, preferably polypropylene, polyethylene or polyamide. 13. Method as claimed in any of the claims 1-12, wherein the plastic material for the plastic element 20 is fiber-reinforced. A method according to claim 13, wherein the plastic material for the plastic element has a fiber percentage in the range of 5 to 80% by weight, preferably 10 to 40% by weight, more preferably approximately 25% by weight. Method according to claim 13 or 14, wherein the fibers comprise glass fibers and / or basalt fibers and / or natural fibers. 16. Method as claimed in claim 15, wherein the natural fibers comprise hemp fibers, banana fibers, chefs fibers and / or flax fibers. The method of any one of claims 1-16, wherein the mold comprises an injection mold. The method of claim 17, wherein in step ii) the thermoplastic plastic material is introduced into the mold at a pressure in the range of 200 to 400 bar. A method according to any of claims 17 or 18, wherein in step ii) the thermoplastic plastic material has a temperature in the range of 150 ° C to 300 ° C, preferably 190 ° C to 250 ° C. The method of any one of claims 1-16, wherein the mold comprises a press mold. The method of claim 20, wherein the thermoplastic plastic material in step ii) comprises a plastic element of elevated temperature. 22. Form element obtainable according to the method of any one of claims 1-21. 23. Form element comprising a plastic element of thermoplastic plastic material, wherein at least a part of the surface of the plastic element is coated with a coating layer of polar plastic material. 24. Form element as claimed in claim 23, wherein the covering layer is fused to the plastic element and / or is mechanically connected. 25. Form element as claimed in claim 23 or 24, wherein the plastic element and the covering layer of polar plastic material are integrated with each other. 26. Form element as claimed in any of the claims 23-25, wherein the thermoplastic plastic material of the plastic element comprises a fiber-reinforced plastic material. 27. Form element as claimed in any of the claims 23-26, wherein the plastic element comprises a structural element or a covering element. 28. Form element as claimed in any of the claims 23-27, wherein the plastic element comprises a plate. 29. Form element as claimed in any of the claims 23-28, wherein the surface has a surface tension of 32-50 dynes / cm, preferably approximately 40-43 dynes / cm. A molding element according to any of claims 23-29, wherein the polar plastic material of the coating layer comprises polyester, polyamide and / or polyvinyl chloride. The molding element of claim 30, wherein the polyester comprises polyethylene terephthalate and / or polybutylene terephthalate. 32. Form element as claimed in any of the claims 23-31, wherein the covering layer is a woven or a non-woven. 33. Form element as claimed in any of the claims 23-32, wherein the covering layer is a foil or a fleece. 34. Form element as claimed in any of the claims 23-33, wherein the plastic material of the plastic element is a plastic material with a surface tension of less than 30 dynes / cm. 35. Form element as claimed in any of the claims 22-34, wherein both the top surface and the bottom surface of the plastic element are coated with the coating layer. 36. Form element as claimed in any of the claims 23-35, wherein the plastic material for the plastic element is a polyolefin, preferably polypropylene, polyethylene or polyamide. 37. Form element as claimed in any of the claims 25-36, wherein the plastic material for the plastic element is fiber-reinforced. 38. Form element as claimed in claim 37, wherein the plastic material for the plastic element has a fiber percentage in the range of 5 to 80% by weight, preferably 10 to 40% by weight, more preferably approximately 25% by weight. 39. Form element as claimed in claim 37 or 38, wherein the fibers comprise glass fibers and / or basalt fibers and / or natural fibers. 40. Form element as claimed in claim 39, wherein the natural fibers comprise hemp fibers, banana fibers, chefs fibers and / or flax fibers. A method for connecting a form element according to any of claims 22 or 23-40 to an element with a polar surface comprising applying an adhesive to the polar surface of the element and / or the form element and then contacting it bringing the form element with the polar surface of the element. The method of claim 41 wherein the surface of the polar element has a surface tension greater than 40 dynes / cm, preferably between 250 and 1200 dynes / cm, more preferably between 700 and 1000 dynes / cm. A method according to any of claims 41 or 42, wherein the element comprises an element of glass, iron, steel, aluminum or leather. The method of any one of claims 41 to 43, wherein the adhesive has a surface tension greater than 40 dynes / cm. 45. Use of a form element according to claim 22 or 23-40, in the manufacture of vehicles, such as cars, trucks, aircraft and ships. 46. Vehicle provided with a form element according to claim 22 or 23-40. 30 1033052