WO2022263921A1

WO2022263921A1 - Method for sealing a seam in a vehicle bodywork and associated sealant

Info

Publication number: WO2022263921A1
Application number: PCT/IB2021/061178
Authority: WO
Inventors: Merita MALOKU-KRASNIQI
Original assignee: KRASNIQI, Bashkim
Priority date: 2020-12-01
Filing date: 2021-12-01
Publication date: 2022-12-22
Also published as: BE1028848A1; NL2029969B1; BE1028848B1

Abstract

The invention provides a method for sealing a seam in a vehicle bodywork substrate, the method comprising: providing a, preferably metal, iron or steel, substrate (5, 6) with a seam (9); at least partially applying a liquid curable material (7) in the seam; applying over the liquid curable material in the seam an elastic ribbon part (2) made of a deformable (silane modified) polymer material thereby filling the seam; then curing the liquid curable material thereby sealing the seam with the elastic ribbon part. The invention also provides an elastic ribbon (2) made of a deformable (silane modified) polymer material appropriate for use in the method. The elastic ribbon is preferably used as a sealant for sealing a seam in a repair of a damaged vehicle body. The vehicle body is preferably a van, a jeep, a camper or a truck.

Description

METHOD FOR SEALING A SEAM IN A VEHICLE BODYWORK AND ASSOCIATED

SEALANT

TECHNICAL FIELD

The invention relates to a method for sealing a seam in a vehicle bodywork. The invention also relates to an associated sealant and use thereof. The invention is situated in the field of vehicle damage repair and parts for vehicle damage repair. The invention is of particular interest to bodywork shops, car body repair shops and the automotive industry.

BACKGROUND

In the automotive industry, joining two components - such as panels or the like - by methods such as riveting, welding, clinching or other processes is a common procedure. In the manufacture of car bodies, a regular feature of such locations where two panels meet, is discontinuities in the body surface. These discontinuities or seams form attack points for moisture, air, and contaminants. They are places with increased susceptibility to rust. In order to reduce these sensitivities, the seams in the body surface are sealed using a sealant.

A known sealant for this application is a liquid, viscous mass sprayed into a seam of a body surface by means of a spray gun. After application, the sealant is cured to a tough and elastic seal. Curing can be achieved by heating or by cross-linking after contact with air humidity. The cured sealant provides surface protection. The problem with this method is obtaining a seam with a smooth, regular appearance. In the assembly of a vehicle, tools are used, therefore. However, after the assembly, parts and seams of the bodywork are less accessible. The repair of incorrectly or badly applied sealant is always detrimental to obtaining a smooth, regular appearance.

Another known sealant is a self-adhesive foil or adhesive tape with a surface that can be painted or varnished after bonding. The use of this type of sealant is laborious to fill a seam in a body surface. Repositioning a poorly placed sealant is difficult. This sealant does not give the repaired vehicle the appearance provided by the original car manufacturer.

Consequently, there is a need for further alternatives and improvements. The present invention aims to solve one or more of the above-mentioned problems.

The invention seeks to provide a method that is easily implementable and provides filled seams in a body piece that are smooth and have a regular appearance. The method should be robust and easy to repeat. The invention also seeks to provide a means for use in the method.

SUMMARY OF THE INVENTION

Thereto, the invention provides a method of sealing a seam in a vehicle body, the method comprising:

- providing a, preferably metal, iron or steel, substrate with a seam,

- at least partially applying a liquid and curable material in the seam,

- over the liquid and curable material previously applied to the seam, applying an elastic ribbon part made from a deformable polymer material thereby filling the seam,

- subsequently curing the liquid and curable material thereby sealing the seam with the elastic ribbon part.

In a second aspect, the invention provides an associated sealant. More particularly, the invention provides an elastic ribbon fabricated from a deformable silane-modified polymer material.

In a third aspect, the invention provides in use of the aforementioned elastic ribbon made of a deformable polymer material as a sealing agent for sealing a seam in a damaged vehicle body, wherein the elastic ribbon does not have an adhesive. The vehicle body is preferably a van, a jeep, or a truck.

In a final aspect, the invention provides in a vehicle bodywork substrate having a seam comprising a seam sealing in the seam with an elastic ribbon part manufactured from a deformable polymer material wherein the elastic ribbon part has a partially oval or circular cross-section with at least one flattened side, wherein the seam sealing has a convex surface.

Further preferred embodiments have been described in the dependent claims. DESCRIPTION OF THE FIGURES

Figure 1 shows a schematic representation of a vehicle body substrate having a seam with elastic ribbon part made of a deformable polymer material. The cross-section of the elastic ribbon part is part is partly circular with two flattened sides providing a V- shape.

Figure 2 shows a schematic representation of an alternative embodiment of a vehicle body substrate having a seam with elastic ribbon part made of a deformable polymer material. The cross-section of the elastic ribbon part is partially oval-shaped with two flattened sides providing a V-shape.

Figure 3 shows a schematic representation of an alternative embodiment of a vehicle body substrate having a seam with elastic ribbon part made of a deformable polymer material. The cross-section of the elastic ribbon part is a polygon with a U-shape protruding from the seam and a V-shape in the seam.

Figure 4 shows a schematic representation of an alternative embodiment of a vehicle body substrate having a seam with elastic ribbon part made of a deformable polymer material. The cross-section of the elastic ribbon part is partially oval-shaped with two flattened sides providing a V-shape. The V-shape is rounded at the bottom.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise specified, all terms used in the description of the invention, including technical and scientific terms, shall have the meaning as they are generally understood by the worker in the technical field the present invention relates to. Furthermore, definitions of the terms have been included for a better understanding of the description of the present invention.

As used here, the following terms shall have the following meaning: "A", "an" and "the", as used here, refer to both the singular and the plural form unless clearly understood differently in the context. For example, "a compartment" refers to one or more than one compartment. "Approximately" as used here, that refers to a measurable value such as a parameter, a quantity, a period or moment, etc., is meant to include variations of +/-20% or less, preferably +/-10% or less, more preferably +/-5% or less, still more preferably +/-1% or less, and even still more preferably +/-0.1% or less of the cited value, as far as such variations are appropriate for realizing the invention that is described. It will however be clear that the value to which the term "approximately" relates, will also be described specifically. The terms "comprise", "comprising" and "included", as used here, are inclusive or open terms that indicate the presence of what follows e.g. a component, and that do not exclude the presence of additional, non-specified components, characteristics, elements, members, steps, that are well-known from or described in the state of the art.

The citation of numeric intervals by means of end points includes all integers and fractions included within that interval, including these end points.

The term "sealing" as used herein refers to the sealing against intrusion of something undesirable. Undesirable in this case, are moisture and air.

The term "vehicle body" or simply "body" as used herein, refers to the bodywork of a motor vehicle. This means the upper structure or construction of the motor vehicle, excluding parts such as the engine, wheels, drive train, and the interior.

The "body part" or "substrate" with seam which is treated in the method, is preferably a metal, iron, or steel substrate. Preferably, the substrate with a seam is a steel substrate.

The term "curable material", as used herein, means a material that can pass from liquid to solid form. The "curing" may be achieved by heating or by contact with atmospheric moisture and cross-linking of polymers.

The invention provides a solution to the problem of easily providing a seam filler with a smooth and regular appearance in a vehicle body.

More specifically, in a first aspect, the invention provides a method for sealing a seam in a vehicle body, the method comprising:

- providing a substrate with a seam, - at least partially applying a liquid and curable material in the seam,

- subsequently curing the liquid, curable material thereby sealing the seam with the elastic ribbon part.

This two-step method of first applying the seam in depth and then inserting a ribbon to fill the seam, has the advantage that the seam is filled, the ribbon is secured, and the seam is sealed. The result of the method is a seam in a vehicle bodywork protected against moisture, air, and corrosion. The final result is not sensitive to an irregularly applied first coating. After all, the appearance of the seam is determined by the elastic ribbon part.

Preferably, the liquid and curable material applied in the seam of the substrate is a silane-modified polymer. The term "silane-modified polymer", also known as silyl- terminated polymer or silyl-modified polymer, refers to a non-silane polymer main chain terminated by silane groups. The silane groups may be independent or supported by urethane groups. An example of silane-modified polymer is a silyl- modified polyether. Alternative materials that are suitable, are liquid and curable sealants with adhesive properties. Preferably, no liquid and curable sealants with adhesive properties are used in the method according to the invention.

Preferably, said material is cured by using heat, more preferably by heating situated between a temperature of 35°C and 80°C, still more preferably between 40°C and 75°C, most preferably between 50°C and 70°C. When using heating, the curing time can be reduced to 40 minutes. Without the use of heating, the curing is preferably achieved after max. 48 hours at a seam depth of max. 5 mm, 23°C and 50% relative humidity. Preferably, the curing is achieved after max. 24 hours at a seam depth of max. 5 mm, 23°C and 50% relative humidity. The above-mentioned temperature is below the melting temperature of the ribbon part.

In a method according to an embodiment of the invention, the curable material is preferably cured for at least 10 minutes. Preferably, the curing process takes at least 30 minutes and up to 48 hours, more preferably at least 40 minutes and up to 24 hours, most preferably 30 to 45 minutes. Preferably, the deformable polymer material in the ribbon part is a silane-modified polymer. A silane-modified polymer is an elastic deformable material. More preferably, the silane-modified polymer is a solvent-free and isocyanate-free silane- modified polymer. Most preferably, the silane-modified polymer is a solvent-free and isocyanate-free silane-modified polymer that cures as a result of polymer cross- linking due to absorption of moisture from the air.

For a good adhesion and placement of the ribbon part, it is important to work in a low-moisture environment. The skilled worker will understand that the method cannot be performed in the rain. The relative humidity should be less than or equal to 50%.

The term "elasticity" refers to the degree to which a material exerts a counterforce when not permanently being deformed. The elastic material has the ability to return to its original state after deformation.

The elastic ribbon part used in the method is preferably extendable to at least 2 and at most 10 times its original length. More preferably, the elastic ribbon part is extendable between 3 and 5 times its original length.

More preferably, both the liquid deformable polymer material and the elastic ribbon part for application in the seam are a silane-modified polymer. Most preferably, the same silane-modified polymer is used for the deformable polymer material and said curable material. This is advantageous for the compatibility of the materials.

In a method according to an embodiment of the invention, the elastic ribbon part is preferably obtained by clipping or cutting a part of desired size from an elastic ribbon. The desired size is determined by the size of the seam to be sealed. Using an elastic ribbon has the advantage that a part can be removed at a time. There is less waste than working with a spray gun which needs to be changed regularly because of the hardening of product in the opened package.

After placing the ribbon part in the liquid deformable polymer material, the placement is preferably finished by applying a small amount of liquid deformable polymer material to the place where the ribbon part was cut. This ensures a clean finishing. Preferably, the ribbon part is heated slightly before being placed. This makes the material less tough, more pliable, and easier to place. The heating temperature is preferably between 30°C and 50°C. A warm air blower can be used for heating.

Before any further work is done, the placement of the ribbon is preferably checked. Should the inspection reveal holes in the seal of the seam, one can proceed as follows. An adhesive tape is applied over the ribbon part and the substrate is glued. One waits up to 24 hours to obtain the adhesion of the adhesive tape to the substrate. In an alternative step, holes are filled with liquid deformable polymer material.

A method according to an embodiment of the invention preferably has the following additional steps: a layer of primer is applied over the substrate and the seam filled with the elastic ribbon part, the layer of primer is sanded, and the sanded layer of primer is then sprayed over with paint in the colour of the vehicle body.

The above-mentioned elastic ribbon part preferably has a partially oval or circular cross-section with at least one flattened side. More preferably, the elastic ribbon part has a partially oval or circular cross-section with two flattened sides providing a V- shape.

Preferably, the at least one flattened side of the ribbon part is applied into the seam thereby providing a seam seal with a convex surface. This step has the advantage that the bodywork substrate acquires the same appearance as in the original state at the time of production. The convex seam has the same quality and appearance as the original OEM seams.

Additionally, a method according to an embodiment of the invention may have a step in which the ribbon part is at least partially heated between 40°C and 80°C. This step is particularly advantageous when the substrate has a wavy portion or forms an angle. Heating of the ribbon part after insertion provides additional formability. The ribbon part gives way well to the shape of the substrate. The effect is a seam that nicely follows the contour of the substrate.

In a second aspect, the invention provides for a sealant for use in a method according to the invention. More particularly, the invention provides an elastic ribbon fabricated from a deformable silane-modified polymer material. For storage, the ribbon is preferably applied over an outer surface of a cylinder. This prevents unwanted and premature deformation.

Most preferably, the elastic ribbon includes a deformable polymer material. Still more preferably, the deformable elastic ribbon comprises a silane-modified polymer material. Most preferably, the deformable elastic ribbon includes a silane-modified polymer material and is silicone-free and isocyanate-free.

Preferably, the elastic ribbon has a partially oval or circular cross-section with at least one flattened side. More preferably, said elastic ribbon has a partially oval or circular cross-section with two flattened sides providing a V-shape. The tip of the V-shape may be rounded.

Said deformable silane-modified polymer material is preferably silicone-free. This material is paintable. This selection has the advantage that no fisheyes are formed when painting. Problems with peeling paint or varnish are reduced or even avoided.

The elastic ribbon can be provided in different colours. Preferably, the elastic ribbon is white, grey or black. The elastic ribbon can have different dimensions. Preferably, the elastic ribbon is at least 2 meters and no more than 100 meters. More preferably, the elastic ribbon is 2 meters 20 centimetres, 4 meters 40 centimetres or any other multiple of 2 meters 20 centimetres. In an alternative preferred embodiment, the elastic ribbon is at least 10 meters, at least 20 meters, at least 40 meters, at least 60 meters or at least 80 meters. Preferably, the ribbon is stored wound on a roll. A cardboard or wooden roll is suitable. Storage on a roll is advantageous for maintaining the shape of the ribbon. The ribbon stays tight.

The elastic ribbon can be provided in different dimensions. The elastic ribbon preferably has a width between 3 and 15 mm. Preferably, the elastic ribbon has a width of 3, 5, 6, 7, 8, 9 or 10 mm. Most preferably, the elastic ribbon has a width of 3, 5 or 10 mm.

Elastic ribbon for use in a method according to the invention can be obtained by applying liquid, elastic, curable polymer material in a mould having a recess. The recess has the desired shape according to the body seam to be sealed. After drying, the cured polymer material is removed from the mould in a solid state. In a third aspect the invention provides uses of said above-mentioned elastic ribbon.

An elastic ribbon made of a deformable polymer material, as described above, and in which the elastic ribbon is not provided with an adhesive, is preferably used as a sealant for sealing a seam in a repair of a damaged vehicle body. The vehicle body is preferably a van, a jeep, a camper or a truck.

A sealant without an adhesive is more convenient to manipulate and apply closely in a seam. The absence of an adhesive on the elastic ribbon allows for repositioning.

The term "van" as used herein means a small truck or delivery van. It is a car meant for transporting goods and stuff. Ambulances are also included.

In a final aspect, the invention provides in a vehicle bodywork substrate having a seam comprising a seam sealing in the seam with an elastic ribbon part manufactured from a deformable polymer material wherein the elastic ribbon part has a partially oval or circular cross-section with at least one flattened side, wherein the seam sealing has a convex surface. Preferably, the elastic ribbon has a partially oval or circular cross-section with two flattened sides providing a V-shape.

The invention is further illustrated by a number of examples. These are non-limiting. Preferred embodiments of the invention are illustrated in Figures 1 to 4.

EXAMPLES

Example 1

In example 1, with reference to Figure 1, a repair of a fine seam 9 in a van is schematically illustrated. The original seam filler became damaged when a panel of the bodywork was damaged. The seam 9 is situated between a steel plate of the roof 5 and a steel plate of the sidewall 6 of the vehicle.

The original seam was convex. In order to reproduce the original seam, an elastic ribbon with a curved surface having a length of 2 meters 20 centimetres is selected. Furthermore, the ribbon has two flattened sides that provide a V-shape. A ribbon part 2 having a length corresponding to the seam to be filled of 2 meters 5 centimetres is obtained by cutting or clipping a piece of the ribbon. The thickness of the ribbon is 5 mm, corresponding to the seam to be filled. The selected ribbon is a paintable silane- modified polymer.

The seam in the steel body substrate 1 is exposed. Subsequently, a liquid and curable silane-modified polymer paste 7 is injected into the seam 9 forming a thin layer on the sheet metal parts 4, 5 forming the seam 9. The ribbon part 2 made of paintable silane-modified polymer is pushed into the liquid silane-modified polymer paste and fills the seam 9. Subsequently, the filled bodywork substrate 1 is dried at a temperature of 23°C for at least 30 minutes.

After drying of the filled seam 9, a primer is applied over the steel plates 4, 5 and the seam 9 filled with elastic ribbon part 2. The primer layer is then sanded to promote adhesion of a paint or varnish layer. Subsequently, the sanded layer is sprayed with paint in the colour of the vehicle body.

The result is a body piece with seam seal 10 with a convex and even surface, just like at the original car manufacturer.

Example 2

In example 2, with reference to Figure 2, a repair of a seam 9' in an ambulance (vehicle body substrate 1') is schematically illustrated. The original seam filler became damaged when a panel of the bodywork was damaged. The seam 9’ is located between two steel plates 5', 6' of a wall of the vehicle. For this horizontal seam filler on the side of the vehicle, a ribbon of 4 meters 40 centimetres in length is selected.

The original seam was curved. In order to reproduce the original seam, an elastic ribbon with a curved surface is selected. Furthermore, the ribbon has two flattened sides that provide a V-shape. A ribbon part 2' having a length corresponding to the seam 9' to be filled is obtained by cutting a piece of the ribbon. The thickness of the ribbon part 2 is 10 mm, corresponding to the seam to be filled 9'. The selected ribbon part 2' is a paintable silane-modified polymer.

The seam 9’ in the steel body piece is exposed. Subsequently, a liquid and curable silane-modified polymer paste is injected into the seam forming a thin layer 7' on the sheet metal parts 5', 6' forming the seam 9. The elastic ribbon part 2' made of paintable silane-modified polymer is pushed into the liquid layer 7' of silane-modified polymer paste and fills the seam 9'. Subsequently, the filled bodywork substrate 1' is dried at a temperature of 30 °C for 45 minutes.

After drying of the filled seam 9', a primer is applied over the steel plates and the seam 9' filled with elastic ribbon part 2'. The primer layer is then sanded to promote adhesion of a paint or varnish layer. Subsequently, the sanded layer is sprayed with paint in the colour of the vehicle body.

The result is a body piece substrate 1' with filled seam 10' with a convex and even surface, just like at the original car manufacturer.

Example 3

With reference to Figure 3, an additional embodiment of the invention is shown schematically. The cross-section of the elastic ribbon part 2" is a polygon with a U- shape protruding from the seam and a V-shape in the seam. The V-shape is rounded at the bottom. The width of the selected ribbon part 2" is 15 mm. The result is a body piece substrate 1" with filled seam 10" with an even surface.

Example 4

With reference to Figure 4, an additional embodiment of the invention is shown schematically. The cross-section of the elastic ribbon part 2"' is a partially oval shape with a V-shape. The V-shape is rounded at the bottom. The width of the selected ribbon part 2"' is 10 mm. The result is a body piece substrate 1"' with filled seam 10"' with an even surface.

Claims

1. A method for sealing a seam (9) in a vehicle body, the method comprising:

- providing a, preferably metal, iron or steel, vehicle body substrate (1) with a seam (9),

- at least partially applying a liquid and curable material (7) in the seam (9),

- over the liquid and curable material (7) previously applied in the seam (9), applying an elastic ribbon part (2) made from a deformable polymer material thereby filling the seam (9),

- subsequently curing the liquid and curable material (7) thereby sealing the seam (9) with the elastic ribbon part (2).

2. The method according to claim 1, in which the elastic ribbon part (2) and/or the curable material (7) for insertion into the seam (2) is/are a silane-modified polymer.

3. The method according to claim 1 or 2, in which the elastic ribbon part (2) is obtained by clipping or cutting a ribbon part (2) of desired size from an elastic ribbon.

4. The method according to any of the previous claims 1 to 3, in which the liquid and curable material (7) is cured for at least 30 min.

5. The method according to any one of the previous claims 1 to 4, in which a layer of primer is applied over the substrate and the seam (9) filled with the elastic ribbon part (2), the layer of primer is sanded, and the sanded layer of primer is then sprayed over with paint in the colour of the vehicle body.

6. The method according to any one of the previous claims 1 to 5, in which the elastic ribbon (2) has an oval or circular cross-section with at least one flattened side.

7. The method according to claim 6, in which the elastic ribbon (2) has an oval or circular cross-section with two flattened sides (3, 4) providing a V-shape.

8. The method according to claim 6 or 7, in which the at least one flattened side (3, 4) is applied into the seam (9), thereby providing a seam seal (10) with a convex surface (8).

9. The method according to any one of the previous claims 1 to 8, in which the ribbon part (2) is heated to a temperature below the melting temperature of the ribbon part and situated between 40°C and 80°C.

10. An elastic ribbon for use in a method according to any one of the claims 1 to 9, made of a deformable silane-modified polymer material.

11. The elastic ribbon according to claim 10, in which the elastic ribbon has an oval or circular cross-section with at least one flattened side.

12. The elastic ribbon according to claim 11, in which the elastic ribbon has an oval or circular cross-section with two flattened sides providing a V-shape.

13. The elastic ribbon according to any one of the previous claims 10 to 12, in which the deformable silane-modified polymer material is a paintable deformable silane- modified polymer material.

14. The elastic ribbon according to any one of the previous claims 10 to 13, in which the elastic ribbon is not provided with an adhesive.

15. The elastic ribbon according to any one of the previous claims 10 to 14, in which the ribbon is white, grey or black.

16. The elastic ribbon according to any one of the previous claims 10 to 15, with a width situated between 3 and 15 mm, endpoints included.

17. A use of an elastic ribbon made of a deformable polymer material, preferably a silane modified polymer material, as a sealant for sealing a seam (9) in a repair of a damaged vehicle body, in which the elastic ribbon is not provided with an adhesive.

18. The use according to claim 17, in which the vehicle body is a van, a jeep, a camper or a truck.

19. A vehicle body substrate (1) with a seam (9) comprising a seam seal (10) in the seam (9) with an elastic ribbon part (2) made of a deformable polymer material wherein the elastic ribbon (2) has a partially oval or circular cross-section (8) with at least one flattened edge (3, 4), in which the seam seal (10) has a convex surface

(8).

20. The vehicle body substrate (1) according to claim 19, in which the elastic ribbon part (2) has a partially oval or circular cross-section (8) with two flattened sides (3, 4) providing a V-shape.