Methods for producing design models in automotive development

Abstract

Main claim: Method for the production of design models in automotive development, wherein the design model consists of at least a porous base body, consists of at least one binder and at least one layer of industrial plasticine wherein the porous base body is designed as a porous foam body, wherein the binder is formed as an intermediate layer between the porous foam body and the industrial plasticine, wherein the binder consists of at least a wax and possibly other additives, wherein at least one wax of the binder is formed from a base wax component and a synthetic wax component where the melting point of the synthetic wax component is greater / higher than the melting point of the base wax component, wherein the base wax component of the binder is formed as micro wax and / or paraffin wax, the base wax component has a melting point between 60 and 80°C, the synthetic wax component is an ethylene propylene polymer, Polyethylene wax and / or poly-alpha olefin is present where the synthetic wax has a melting point greater than 80 °C, wherein the industrial plasticine contains microwax and paraffin wax, and wherein the binder consists of 20 - 70 wt. % base wax and / or base wax content (BW) 30 - 80 wt. % synthetic wax (SW) and 0 - 20 wt. % other additives is composed the procedure is divided into the following steps. Step 1: Providing a base body in the form of a porous foam body with a porous structure. Step 2: Applying a coating to the substrate using a manual or machine application process, wherein the binder has a temperature of 60 to 120 °C, preferably 70 to 100 °C, at the time of application; Step 3: Solidification of the coating on the substrate, through passive cooling at room temperature and / or active cooling by cooling systems; Step 4: Application of one or more layers of industrial plasticine, wherein the plasticine has a temperature of approximately 60 - 80 °C at the time of application, wherein the application of the plasticine is carried out semi- and / or fully automatically.

Description

[0001] The invention relates to a method for producing design models in automobile development.

[0002] Agents / primers for improving the adhesion between a base layer / base body and an overlying top layer are known in principle.

[0003] It's also well known that in the automotive design process, realistic and true-to-scale models are created, among other things, from modeling clay applied to a base body. The combination of modeling clay and the base body is necessary to achieve a weight reduction of the molded clay models.

[0004] To achieve sufficient adhesion between the base body and the modeling clay, the modelers typically apply a thin layer of modeling clay in a first step, usually using considerable force. Only in a subsequent step can they begin applying the required layer thicknesses—the modeling or design process—of approximately 5 cm.

[0005] In the production of models according to the known state of the art, the base body is pre-treated with a barrier layer, such as shellac, in order to bind the dust on the surface of the base body, since the dust on the one hand contributes to the soiling of the modeling clay and on the other hand reduces the adhesion force between the clay and the base body.

[0006] This problem occurs both when clay is applied manually to a base body and when clay is applied semi- and / or fully automated to the surfaces of a base body.

[0007] One example is the semi-automatic application of clay, as described in more detail in DE 29720892 U1 and DE 102016109816 A1. The modeling clay is heated and conveyed in the machines shown, before being conveyed through a conveyor hose to an application nozzle. While the actual application of the industrial plasticine is noticeably easier for the modeler using such a system, it has also proven disadvantageous in that there is a significant reduction in adhesion between the modeling clay and the surface of the base body. With the help of the semi-automatic application system, the pressure required to apply a first thin layer of clay cannot be applied. The direct consequence is that the clay is simply deposited on the surface of the base body, and thus the necessary adhesion is not or will not develop.

[0008] Furthermore, it has been shown that conventionally used agents / primers cannot compensate for the lack of force required to achieve good adhesion.

[0009] Furthermore, US 2014 / 0134368 A1 discloses a method for coating metallic surfaces with an aqueous composition containing polymers. How such a method can be used to coat a porous substrate remains unclear.

[0010] In addition, US 2016 / 0215176 A1 and US 2016 / 0304756 A1 are known from the prior art, which disclose sealants and hot-melt adhesives that are intended to have good adhesion to certain surfaces.

[0011] The object of the invention is therefore to provide a method which does not have the disadvantages mentioned above and in particular ensures sufficient adhesion at the contact surfaces / interfaces between a porous base body and industrial plasticine.

[0012] Furthermore, it is an object of the invention to use the coating agent for use in the design process in automobile development.

[0013] The problem is solved with the features included in claims 1 and 2.

[0014] The method according to the invention for producing design models in automobile development comprises the design model at least one porous base body, which consists of at least one binder and at least one layer of industrial plasticine.

[0015] The porous base body is a porous foam body.

[0016] The binder is formed as an intermediate layer between the porous foam body and the industrial plasticine.

[0017] The binder consists of at least one wax and possibly other additives, whereby the at least one wax of the binder consists of a base wax component and a synthetic wax component.

[0018] The melting point of the synthetic wax component is greater / higher than the melting point of the base wax component.

[0019] The base wax component of the binder is formed as micro wax and / or paraffin wax.

[0020] The base wax component has a melting point between 60 and 80°C.

[0021] The synthetic wax component is present as an ethylene propylene polymer, polyethylene wax and / or poly-alpha-olefin, wherein the synthetic wax has a melting point greater than 80 °C and wherein the industrial plasticine contains micro wax and paraffin wax.

[0022] The binding agent consists of 20 - 70 wt.% Base wax and / or base wax content (BW) 30 - 80 wt.% synthetic wax (SW) and 0 - 20 wt.% other additives together.

[0023] The method according to the invention is divided into the following steps.

[0024] Step 1: Providing a base body in the form of a porous foam body with a porous structure.

[0025] Step 2: Application of a coating to the base body using a manual or mechanical application method, wherein the binder has a temperature of 60 to 120°C, preferably 70 to 100°C, at the time of application; Step 3: Solidification of the coating on the base body by passive cooling at room temperature and / or active cooling by means of cooling systems; Step 4: Application of one or more layers of industrial plasticine, wherein the plasticine has a temperature of approximately 60 - 80°C at the time of application, wherein the application of the plasticine is carried out semi-automatically and / or fully automatically.

[0026] The coating agent consists of at least one wax component and, if necessary, other additives. The at least one wax component is present as a base wax component and a synthetic wax component.

[0027] The coating agent could also be called a primer.

[0028] The base wax component is present as a wax and / or wax mixture with a melting range between 60 and 80°C. The melting point of the base wax component is thus slightly below the application / processing temperature of industrial plasticine, which is up to approximately 80°C. It has proven advantageous for the wax and / or wax mixture to be present as microwax and / or paraffin wax. The base wax component is 20 to 70 wt.%, preferably 25 to 65 wt.% of the coating agent.

[0029] It has also been surprisingly shown that a special effect is achieved by combining the wax and / or wax mixture described above, the so-called base wax component, with a synthetic wax or synthetic wax mixture. The synthetic wax component has a melting point higher than the melting point of the base wax component.

[0030] Synthetic waxes are ethylene-propylene polymer, polyethylene wax (oxidized polyethylene), and / or poly-alpha-olefins. The synthetic wax content is 30 to 80 wt.%, preferably 35 to 65 wt.% of the coating composition.

[0031] The combination of the base wax component with a synthetic wax component offers the advantage that after the coating agent is applied to the porous base body, the heat introduced into the subsequent application by the industrial plasticine at processing temperature only partially melts the base wax component in the coating agent. This ensures that a sufficient bond between the industrial plasticine and the base body is always established by the synthetic wax, which is not melted or partially melted, and thus no or only a weak lubricating film is created by the melted base wax component.

[0032] By melting the base wax component in the coating agent, a direct connection to the industrial plasticine is created, which, after cooling, results in increased adhesion between the base body and the industrial plasticine.

[0033] Before the industrial plasticine is actually applied to the base body, the coating agent is heated and melted and then applied to the base body either manually using a brush and / or silicone roller or mechanically using a hot wax spray gun. The adhesion improvement effect can be achieved with manual and / or mechanical application of the coating agent.

[0034] However, it has surprisingly been shown that when applied by spraying, for example with a hot wax gun, “cobweb-like” threads and / or thread structures are created, since wax components of the coating agent already solidify during the spraying process.

[0035] An advantage of the formed thread structure is that no unwanted aerosol is formed in the ambient air and the user does not have to wear a respiratory mask.

[0036] It is important for the process steps described above in the design model production that the coating agent is cooled and thus solidified on the base body before the actual application of the industrial plasticine in order to ensure good adhesion of the industrial plasticine to the base body.

[0037] The significant increase in adhesion is due to the fact that the heat input of the hot-applied industrial plasticine causes part of the wax and / or wax components, in particular the base wax components, to melt or at least melt, thereby forming a direct increased adhesion between components of the industrial plasticine and the base body.

[0038] An example is a semi-automatic application process for industrial plasticine using an application machine, which conveys heated industrial plasticine from a storage container via a heated hose system to the application site on the base body. To ensure that the coating agent at least partially remelts during the application process, base waxes and / or base wax mixtures must be used that have a melting range within the application temperature of the industrial plasticine. The application or processing temperature of industrial plasticine is 60 to 80°C. Microwaxes and / or paraffin waxes meet this requirement and can be used.

[0039] By combining the coating with a synthetic wax, only a partial melting of the coating agent is achieved, as the melting point of the synthetic wax component is above the processing temperature of industrial plasticine. This ensures that a sufficient bond to the substrate or the surface of the base body is formed at all times during the application of coating agents and / or the process for producing design models, as only a very weak lubricating film is created by the melted base wax and / or base wax component.

[0040] Furthermore, the synthetic wax content creates the cobweb-like texture when applied with a hot wax gun. Using only paraffin and / or microwax as the coating agent would result in reduced adhesion and, in addition, an aerosol would form in the air during spraying, requiring additional protective measures.

[0041] Other additives in the coating agent include, for example, rheology additives, tackifiers and / or colorants.

[0042] Rheological additives can be used to specifically modify the flow behavior, especially at elevated temperatures. This is particularly important at the vertical points of the base body.

[0043] Colorants can be in the form of dyes or pigments. One advantage of using colorants is that, after applying the coating agent to the base body, it is easy to determine whether and where the coating agent is already present on the surface of the base body.

[0044] The use of tackifiers increases the adhesiveness of the coating when hot. Furthermore, coatings with tackifiers solidify more quickly.

[0045] The invention will be illustrated in more detail using two framework examples and some recipe examples. Frame example 1 20 - 70 wt.% Base wax and / or base wax content (BW) 30 - 80 wt.% synthetic wax (SW) 0 - 20 wt.% other additives Framework example 2 35 - 65 wt.% Base wax content (BW) 65 - 35 wt.% synthetic wax (SW) 0 - 10 wt.% other additives Recipe example 1 - Coating compound 40 wt.% Paraffin wax (BW) 60% by weight synthetic wax (SW) Recipe example 2 - Coating compound 28% by weight Paraffin wax 30 wt.% Microwax 42% by weight synthetic wax Recipe example 3 - Coating compound 58% by weight Microwax 37% by weight synthetic wax 5 wt.% Colorant, rheology additive and tackifier Recipe example - light industrial plasticine (state of the art) 33 wt.% Paraffin wax + micro wax 5 wt.% white oil 45% by weight Calcium stearate (filler) 16% by weight Lightweight filler 2 wt.% Iron oxide as a colorant

[0046] To determine and evaluate any improvement in adhesion, tensile tests were conducted using a Zwick universal testing machine. The specimen is clamped at both ends. After the specimen is clamped, the clamping system moves apart at a defined speed, and the maximum force Fmax required at the moment of separation of the specimen is measured.

[0047] In the case of the present application, the test specimen consists of a layered model consisting of a base body, coating agent, and industrial plasticine, with the clamping points forming one part of the base body and the other part of the industrial plasticine. The tensile tests were conducted at room temperature.

[0048] Fmax was determined, whereby an increase in Fmax is associated with an increase in the adhesion force.

[0049] The porous base body in the test was a porous foam body. The sample dimensions were 55 mm long, 10 mm wide, and 120 mm high.

[0050] The following tables will illustrate the present invention with an increase in adhesion between plasticine and base body in more detail. Table: Increase in adhesion force Fmax Solution according to the invention with coating agent according to formulation example 1, wherein the layer is applied with a brush and wherein the plasticine is applied mechanically; 209 N State-of-the-art solution, sample coated with shellac and manual clay application process 189 N State-of-the-art solution, sample coated with shellac and machine-applied clay 21 N

[0051] The method according to the invention for producing models or design models in automotive development is described in more detail below.

[0052] The procedure is divided into the following steps: Step 1: Providing a base body with a preferably porous structure. Step 2: Applying a molten coating agent to the base body using a manual or mechanical application method, wherein the coating agent described above has a temperature at the time of application at which the base wax portion and the synthetic wax portion are molten. Step 3: Solidification of the coating agent on the surface of the base body, by passive cooling at room temperature and / or active cooling by cooling systems, such as fans. Step 4: Applying at least one layer of industrial plasticine, wherein the plasticine has a temperature of approximately 60 to 120°C, preferably 70 to 100°C, at the time of application, wherein the application of the plasticine is carried out manually, semi-automatically and / or fully automatically. Optional Step 5: Fine-tuning / finishing the surface to perfect and / or customize the design.

[0053] The coating agent is used in the production of design models in automotive development, wherein the coating agent is formed as an intermediate layer between the porous base body and the industrial plasticine.

Claims

[1] Methods for producing design models in automotive development, wherein the design model consists of at least a porous base body, at least one binder and at least one layer of industrial plasticine, wherein the porous base body is formed as a porous foam body, wherein the binder is formed as an intermediate layer between the porous foam body and the industrial plasticine, wherein the binder consists of at least one wax and possibly other additives, wherein the at least one wax of the binder is formed from a base wax portion and a synthetic wax portion where the melting point of the synthetic wax component is greater / higher than the melting point of the base wax component, wherein the base wax portion of the binder is formed as microwax and / or paraffin wax, wherein the base wax portion has a melting point between 60 and 80°C, wherein the synthetic wax portion is present as an ethylene propylene polymer, polyethylene wax and / or poly-alpha-olefin, wherein the synthetic wax has a melting point greater than 80 °C, wherein the industrial plasticine contains microwax and paraffin wax, and wherein the binder consists of 20 - 70 wt.% Base wax and / or base wax content (BW) 30 - 80 wt.% synthetic wax (SW) and 0 - 20 wt.% other additives is composed, The procedure is divided into the following steps Step 1: Providing a base body in the form of a porous foam body with a porous structure. Step 2: Applying a coating to the base body using a manual or mechanical application method, wherein the binder has a temperature of 60 to 120°C, preferably 70 to 100°C, at the time of application; Step 3: Solidification of the coating on the base body, by passive cooling at room temperature and / or active cooling by cooling systems; Step 4: Application of one or more layers of industrial plasticine, whereby the plasticine has a temperature of approximately 60 - 80 °C at the time of application, whereby the application of the plasticine is carried out semi- and / or fully automated. [2] Method according to claim 1, characterized by that in step 5 a fine machining / finishing of the surface takes place in order to perfect and / or adapt the design.