MXPA05004042A

MXPA05004042A - Weather strip and method of manufacturing same.

Info

Publication number: MXPA05004042A
Application number: MXPA05004042A
Authority: MX
Inventors: M Fetcenko Raymond
Original assignee: Nordson Corp
Priority date: 2002-10-31
Filing date: 2003-10-24
Publication date: 2005-06-08
Also published as: WO2004041497A3; EP1560690A4; AU2003284155A1; WO2004041497A2; CA2499444A1; EP1560690A2; AU2003284155A8

Abstract

A method of manufacturing a weather strip (10) which includes forming a compressible bulb member (12) having a hollow interior (14). A liquid thermoplastic material (34), such as a hot melt material, is injected into the hollow interior (14). The thermoplastic material (34) cures into a resilient plug (40) to provide reinforcement to one or more locations along the length of the weather strip (10).

Description

SEALING STRIP AND METHOD TO MANUFACTURE THE SAME FIELD OF THE INVENTION The present invention relates generally to sealing strips and very particularly to methods for reinforcing portions of the sealing strip in areas of high stress concentration such as curves in the sealing strip.

BACKGROUND OF THE INVENTION Many varieties of climatic bands are used, for example in assemblies of doors, windows and hatches to seal the interior of a structure against the elements. For example, in automotive applications, weather strips have been used to seal around windows, doors, trunks and chests of a vehicle to prevent water and air from entering the interior of the car at these locations. Climatic bands of this type are typically made of a natural or synthetic plastic, such as plastic e t i 1 in -pr opi 1 in -diene (EPDM). The extracted sealing strip can be cured by heat and then cooled in a water bath before it is cut to a desired length. Frequently, the climatic bands are configured in a closed loop or in another curved shape so that they fit properly in the desired location, such as between the trunk frame and the flange thereof, or in other places such as in the chest area, in the door frame, in the window frame, etc. The sealer can be permanently thermoformed during the manufacturing process in the desired curved shape to facilitate the assembly procedure when said sealing strip is subsequently secured to its support structure. In many cases, it is necessary to reinforce the portions of the sealing strip, for example, to ensure that the shape and integrity of the bulb element is maintained, and not to break or fold or kink during application to the support structure, such as the structure of the window, door, chest or trunk. This is especially important in places where there is a sharp bend or a curved radius, since the bulb element is more likely to kink and therefore have a leak in these sites. Such reinforcement may also develop adequate sealing performance over extended periods of use. As shown in Figure 1, several types of tubular foam connections 18 are currently inserted in the interior cavity 14 of a bulb element 12 associated with the outlet strip 10. These tubular connections 18 are generally 10-20. centimeters, and they develop with a relatively rigid but resilient foam material. The tubular connections 18 are forced into the inner cavity 14 of the bulb element 12, either by a rod 20 or by using pressurized air. These connections typically increase the force to compress the bulb element 12 by means of ION to 30N depending on the application. Fasteners, such as rims (not shown) can be punched through the sealing strip and into the tubular connection to prevent it from coming out of the connection after insertion. The connections can also be secured by other means, such as by means of a structure in the connection itself or through the use of an adhesive. The sealed strip 10 is secured to the support structure, such as by means of the window frame, using a channel portion 1 or a conveyor configured in a U-shape. The connections can be inserted exactly so that they can be placed in the site or sites along the length of the sealing strip that will be subjected to high stress concentrations, such as at the corners of the window frame. To achieve this, these articles of manufacture can be placed with a clamp at the desired location along the sealing strip so that they work as a detent as the connection is pushed into the inner cavity of the bulb element. The insertion of solid foam connections within the formation of climatic bands generally as previously written, is a procedure in which much time is wasted, which in turn increases production costs. Other problems may also arise such as imprecise fitting of the connector within the sealing strip or axial change of the connection after insertion due to improper attachment of the same within the selvedge strip. To address the above problems, as well as other problems in this technique, there is a need for a reinforced sealing strip and a manufacturing method that reduces manufacturing times and costs, as well as to ensure optimum sealing performance over the necessary length of the product SUMMARY OF THE INVENTION In one aspect, the invention generally relates to a method for manufacturing a sealing strip that generally involves the injection of a thermoplastic liquid into the interior cavity of a compressible bulb element. The liquid thermoplastic material is at least partially cured within a resilient connection within the interior cavity. Preferably, the liquid thermoplastic material is a material melted by heat and very specifically, an immersion as a hot melt material which may be solid (not containing foam) or containing foam. It has been found that this material provides the necessary combination of compression strength and resilience during use. The liquid thermoplastic material can be first injected by forming a hole in the bulb element and then inserting a thermoplastic material by injecting the element through the hole and into the interior cavity. The hole can be formed by injecting the element itself or preforming it with another implement. The compressible bulb element is preferably formed by extracting EPDM. The liquid thermoplastic material is preferably injected along a portion of the length of the bulb element and most preferably, in a portion or portions of the length that will experience the greatest concentration of tension or pressure during assembly / use, such as at curved locations or sites along the length of the sealing strip. The invention further contemplates a sealing strip comprising a compressible bulb element having an interior cavity and a resilient thermoplastic material located in the interior cavity. The sealing strip may include one or more of the various functions and aspects as generally described in the preceding paragraph. These and other features and objects of the present invention will be more apparent to those skilled in the art from the following detailed description, which is considered in conjunction with the following figures.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is an elevation view, partially transverse, illustrating a prior art method for reinforcing a sealing strip. Figure 2A is an elevation view, partially transverse, illustrating a method for manufacturing a sealing strip according to a preferred embodiment of the invention. Figure 2B is a transverse view taken along line 2B-2B of Figure 2A. Figure 3A is an elevational view, partially transverse, illustrating a portion of the reinforced sealing strip according to the preferred embodiment of the invention. Figure 3B is a transverse view taken along line 3B-3B of Figure 3A. following description of allada, which was considered in conjunction with the following figures.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is an elevation view, partially transverse, illustrating a prior art method for reinforcing a sealed strip ra. Fig. 2A is an elevational view, partially transverse, illustrating a method for manufacturing a sealed strip in accordance with a preferred embodiment of the invention. Figure 2 B is a transverse salt is taken along the line ?? - 2? of figure 2A. Figure 3A is an elevational view, partially transverse, illustrating a portion of the reinforced sealing strip in accordance with the preferred embodiment of the invention. Figure 3B is a cross-sectional view taken along the line 3B-3B of Figure 3A.

DETAILED DESCRIPTION OF THE INVENTION Returning to FIGS. 2 A and 2 B, a heat-melt adhesive dispensing gun 30 receives a heat-melt material and removes it from a heated hose 32 and dispenses the material 34 through a valve 36. which has a discharge portion or injection element 38. The discharge portion 38 can be constructed so that it can pierce the bulb element 12 under a force that is applied in a sufficient manner. The waste portion 38 can be formed in several ways to allow easy pe r f o r a c i. or n, such as through the use of a needle-like discharge portion 38 or a lancet or a blade-like component, which engages the discharge portion 38. It could also be easier to inject the molten material by heat. at the base of the bulb element 12 adjacent to the transporting carrier or conveyor belt or channel 16. The channel 16 is a relatively rigid component and therefore, there will typically be more support in this area to allow a puncture to be made. Alternatively, a hole can be pre-formed through the bulb element 12 so that the discharge portion 38 simply needs to be inserted through the pre-ornulated hole prior to injecting the molten material by heat 34. The material melt heat 34 is preferably injected along a portion that only the length of the sealing strip 10 such as along the portion that is or will later be curved as shown in Figures 3A and 3B. Other areas, which represent the points or areas of greatest concentration of stress or pressure, can also be used in the principles of this operation. During the injection procedure, the desired area to be filled with the material]. heat-molten liquid 3, can be sealed at both ends thereof, for example, applying clamps (not shown) other methods. Alternatively, and as illustrated in FIG. 2A, the heat-melt material 34 may diffuse in both directions at the time of injection in order to fill the desired length of the interior cavity 1 after dispensing for a predetermined time at the speed of proper flow. The heat fusion material 34 can be introduced at one or more sites along the sealing strip 10 using one or more dispensers such as guns 30. 10 Multiple introduction sites would be necessary to be able to form multiple connections to separate parts of material, or it could be necessary or desirable to form a single elastically long connection of this material. Multiple introduction sites can be achieved using the same gun or multiple guns. To provide greater structural support to the bulb element 12, some suitable accessories can be provided to support and support at least a portion of the outer surface thereof. This would prevent the bulb element 12 from expanding di ately, and as a result, either separating or loosening the movement of the length of the heat fusion material 34 along the bulb element 12. Once cured as shown in Figures 3A and 3B, the heat-melted liquid material 34 is provided with a resilient connection 40 which can receive a significantly greater compressive force "F" and offer greater resistance to the compression than the non-reinforced areas of the sealing strip 10. Preferably, for automotive applications, the connection 40 will increase the force to compress the bulb element 12. approximately in ION or approximately 30N. However, this may change depending on the application. The reinforced area remains resilient enough to allow the sealing strip 10 to perform properly in terms of its sealing function for the necessary duration of the product. It has been found that the inventive method of injecting a molten material by heat takes a few seconds compared to about 90 seconds for the solid foam connection insert. The savings in labor costs due to the reduction of operators are also very significant, and this has been anticipated as a result of the invention. In such applications, a connection length of approximately 100 millimeters to approximately 400 millimeters is preferred, however, this can easily be changed based on the needs of the application. The preferred heat-melting material is the product no. H561-B from Heartland Adhesive Co. , Germantown, W I. However, other thermoplastic materials can be used instead, either foam or without foam. For example, the use of foamed materials, may allow a smaller bulb 12 durometer 12. Although the present invention has been illustrated by means of the description of the preferred embodiments, and although some of these modalities have been described in some detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims have detail or detail. Those skilled in the art will appreciate that some modifications can easily be made and additional advantages obtained. The various features and functions of the invention can be used either alone or in numerous combinations depending on the needs and preferences of the user. The foregoing has been a description of the present invention, together with the preferred methods of practicing the same as are currently known. However, the invention itself should be defined only by the spirit of the appended claims.

Claims

NOVELTY OF THE INVENTION Having described the is considered as a novelty and therefore it is claimed as a priority what is contained in the following CLAIMS to remove a strip that p a compressible bulb that has a cavity to inject a liquid optic material within its cavity and allowed the thermoplastic to cure partially in the resilient cavity connection. In accordance with claim 1, the thermoplastic is disposed of by the liquid thermoplastic material, in addition to forming a hole in the thermoplastic element. A thermoplastic injection is applied to and within the method. In accordance with claim p, the compressible bulb element further comprises extruding the bulb element in accordance with I 3 ca using the injection element to drill the hole in the method element. with characterized claim the bulb element has a length and liquid thermoplastic material is injected at the same time The method according to the claim is characterized in that it also forms the bulb element in a curved shape at the connection site. The method according to claim 1, the sealing strip comprises a transport element. which is coupled to a bulb element base and the method further injecting the liquid material or into the base of the strip bulb is acted because a compressible bulb element having a cavity and a resilient material resilient located in said inventive feature is characterized in that said resilient thermoplastic material comprises a molten material. The sealing strip in accordance with the capping said said compressible bulb element further comprises an extra noise. The sealing strip according to claim characterized in that said material Extruded plastic comprises and said resilient thermoplastic material comprises a solid molten material by sealing strip in accordance with the rei indicated characteristic because the item has and said material you only the length of one of 16 1 The sealing strip according to the claim because said bulb element includes at least one curve that extends along said length and said resilient thermoplastic material is located in said curve. SUMMARY OF THE INVENTION A method for manufacturing a sealing strip 10 including a compressible bulb element having an inner cavity a thermoplastic material such a molten material which is injected inside the interior of the moplastic material 34 is cured in a resilient connection 40 to provide reinforcement to or more sites along the length of the sealed strip insufficient OCRQuality