MXPA97008965A - Product of formula formed by sequential extrusion of cellular plastic resins and not cellular - Google Patents

Abstract

The present invention relates to a method for forming an extruded strip profile for a garage door having a rigid cellular base portion and a flexible non-cellular strip portion, characterized in that it comprises the steps of; extruding a cellular material through of a first die, hardening said cellular material in a rigid bead base portion after leaving said first die, said base portion having at least one outer upper surface and at least one outer lateral surface; cell through a second given at least a portion of said non-cellular material making contact with at least one of said outer surfaces of said base portion; hardening said non-cellular material in a flexible strip portion after leaving said second die, said portion of strip having first and second ends, a length extending from said first end to said second end and a thickness, firmly joining a portion of said length of said portion of strip to said first end of said portion of strip and extending parallel only along one of said outer surfaces of said base portion, said portion of strip having a second end that extends freely out of said portion of the ba

Description

STRETCH PRODUCT FORMED BY SEQUENTIAL EXTRUSION OF CELLULAR AND NON-CELLULAR PLASTIC RESINS Reference is made to the US patent. No. 5,508,103, which is also directed to an extrusion product and is incorporated herein by reference. This request demands priority over the provisional application of the United States. No. 60 / 031,342, filed on November 21, 1996, and the provisional application of the US. No. 60 / 052,360, filed July 11, 1997, entitled "Weatherstrip Product Formed?) And Sequential Extrusion of Cellular and Non-Celllular Plastic Resms," both incorporated as a reference.

BACKGROUND OF THE INVENTION Gaskets made by means of dual extrusion or coextrusion of cellular and non-cellular plastic reams are well known in the art. Examples of these products are shown in U.S. Pat. No. 3,535,852 and U.S. Pat. No. 3,685,206 for Kessler. The Kessler patents describe a dual extruded weatherseal product having a rigid base with a flexible strip that is mechanically interlocked and thermally fused to the base. The Kessler patents teach that the products are made by means of "well-known dual extrusion processes", which could include the normal treatment techniques shown for example in Boutiier, U.S. Pat. No. 3,879,505 or in Hoffman, P tente of the £ .11.A. No. k, 690, 862. These normal treatment techniques are described in the references of both Boutillier and Hoffinan, as well as in numerous other references, and have been used to produce products that are commercially available from at least early 1980s (eg, the Victopan Moldmg product made by Gossen Corporation). These procedures include the extrusion of cellular and non-cellular resins through separate extruders in a cornun die. The reams are located either inside the die or immediately upon exiting it, and then are sheared through a conformal casing and cooling tank, which are typically found under vacuum pressure conditions to maintain the dimension of the cellular plastic portion as the profile is cooled. Both Kessler and Hoffrnan taught the use of a bulbous tongue to form a mechanical interlocking between the two plastics, in addition to the thermal or chemical fusion that occurs between the plastics during the extrusion process. Hoffman, in particular, teaches that the bulbous tongue is important in maintaining the tongue portion within the corresponding slot portion of the complementary profile during the extrusion process and during the use of the product. The assignee of the Hoffman patent, Gossen Corporation, has commercially sold the weatherstrip product with and without the bulbous tongue shown in the Hof Financial patent. The present invention provides a weatherseal product for use in garage doors and similar applications in which the flexible portion is subjected to back and forward movements by the opening and closing of the garage door, and therefore needs to be supported. safely by the complementary portion. The present invention provides this weatherstrip product, but avoids the use of the bulbous tab configuration that was so important in the Hoffman patent. Other garage door weatherseat products have been provided in the prior art that eliminate the bulbous tongue, and thus any encapsulation of the tongue within the complementary slot. These prior art products (e.g., the Therrno * Stop, made by Marley riouldings, the assignee of the present invention), utilize thermal fusion (but not mechanical interlock) to hold a non-cellular flexible part within a V-shaped groove in a cell portion. Although these prior art products provide a satisfactory strip for the garage door without the need for the bulbous tongue (and thus the encapsulation) taught by Hoffman, the present invention in its preferred embodiment, avoids the formation of any groove in the cellular base to complement the non-cellular strip. Although other prior art weatherseal products have used a non-cellular part-which rests fixedly against a cell part, or a non-cellular cover extruded therefrom along the surface of a cell part, one embodiment of the present invention provides an area of extended contact surface that allows the use of the weather strip as a garage door burst product in which the flexible portion contacts or moves repeatedly through the garage door or other external forces. An example of an anti-weather seal of the prior art - for a garage door with a solid base and a pivot seal member is shown in US Pat. No. 5,092,079. An example of a prior art weatherseal with a cellular portion (foamed) and a solid, or a non-cellular portion, is shown in the United Kingdom U.S. patent application 2,183,707. An example of a sequential extrusion process of the prior art is shown in Guy, U.S. Patent No. 4,600,461. In that patent, a non-cellular part is extruded on top of a cellular base before both portions are drawn through a forming or cooling chamber. Another example of a sequential extrusion process of the prior art for extrusion formation of a double-walled uro-foam foam core duct, is shown in U.S. Pat. No. 4,322,260.

BRIEF DESCRIPTION OF THE INVENTION An extrusion product or profile is formed by extruding a cellular compound to form a base, and then subsequently extruding a non-cellular compound to form a bonded flexible strip. The final product or profile is used as a garage door weather strip in which the cellular base is mounted against the door leaf and the flexible non-cellular material strip extends out of the cellular base to prevent flow of a re through the openings between the doors and the adjacent frames or frames. The present invention also includes the process for forming this product. The process includes sequential extrusion of the two portions of the product. First, a cell base is extruded to birds from a die and conformer under vacuum and allowed to cool. Then, a chair die is used to apply the flexible non-cellular strip to a portion of the cellular base. Preferably, the chair die heats a portion of the cellular base to improve the bond between the cellular and non-cellular portions.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, which are not to scale, Figure 1 is a cross-sectional view of one embodiment of the weatherseal product of the present invention.

Figure 2 is a schematic drawing of one embodiment of the method of the present invention. Figure 3 is a schematic view of one embodiment of the product of the present invention, illustrating the non-cellular extruded product - in open cells of the cellular base. Figure 4 is a schematic view of a prior art weatherstrip having non-cellular and cellular portions. Figure 5 is a cross-sectional view of a second embodiment of the weatherstrip product of the present invention. Figure 6 is a cross-sectional view of a third embodiment of the weatherseal product of the present invention. Figure 7 is a cross-sectional view of a fourth embodiment of the weatherseal product of the present invention. Figure 8 is an illustration of the cross-sectional configuration of the die for one embodiment of the present invention, illustrating the contact area of the cellular and non-cellular resins. Figure 9 is a schematic drawing of another embodiment of the method of the present invention.

DESCRIPTION OF THE PREFERRED MODALITIES As shown in Figures 5, 6 and 7, in each of the different preferred embodiments, the product has a base that is formed by a conventional cell extrusion process. The procedure is shown schematically in Figures 2 and 9, which are not to scale. A cellular resin is heated to a molten state and is pushed by means of an extrusion horn through a conventional extruder 6 and then exits to a die 8. The die is configured to form a profile of the desired transverse configuration ( before expansion) of the cellular plastic portion or base 10. Typically, the cellular extrudate has a rectangular configuration with projections 12 along one side of the product, although the projections are not required. After the compound exits the die 8, the product ex-cellular noise reaches the open air and begins to expand or foam during its travel through the distance 14 of approximately 15 to 20 centimeters between the die and a conformation channel. The extruded product then enters the forming cavity 16, which is under vacuum entrainment to maintain the shape of the cellular material as it passes through the forming box. The configuration of the inlet to the shaping box has the same shape, but is slightly larger, than the outlet of the die 8 to accommodate the expansion of the cellular extruded product in the space 14 between the die 8 and the shaping box 16. The shaping box is immersed in a cold water tank 17. As the extruded product leaves the shaping box, which typically is 35 centimeters in length, continues through the remainder of the water tank 17, which is typically approximately 610 centimeters in length. The water tank is cooled to cool the cellular oxidized product. In this way, when the cellular extruded product emerges from the water tank, the extrusion profile has substantially hardened substantially and has reached its full size, but may still have some heat retained within the profile. The expansion of the cellular product is accompanied by the formation of bubbles or gas cells within the extrusion product. The extrusion product is typically made from the point of its exit from the die through the forming box 16 and tank 17. A handle 18, which is conventionally used in the final part of the die and the tank, acts to maintain a tension along the extrusion product from the die to the final cutting and finishing operation. An embossing wheel (not shown) can be used after the cellular product leaves the water tank to provide a simulated wood grain finish on the outside of the profile. In the method of one embodiment of this invention, after the cellular product leaves the water tank, a carbide blade (not shown) is used to cut a slot 20 along the cell part. In this way, as the cellular extruded product moves through the area 19 after its exit from the tank, a circular saw with a carbide blade continuously cuts a groove or channel along the product. The slot is located at a point along the width of the cell part to allow proper placement of the non-cellular flexible extruded product-22, as explained below. Other types of saws or cutting mechanisms can also be used. For example, a cutting tool can be held and dragged along the profile to form the slot as the profile is pulled forward. In the method of this embodiment, adhesion of the non-cellular product is promoted by cutting the groove deep enough to cut through any crust or hardened surface layer that could form on the outside of the cellular product as it cools, thus as through the cellular structure that is formed by the expansion of the cellular compound. The contact is shown schematically and substantially enlarged in Figure 3, with the non-cellular resin 26 above and within the open cells of the cellular resin 24. The opening of the cells 24 by means of the cor-te or formation of the groove pepiute that the flexible non-cellular clogged product 26 flows into the cells and forms a stronger bond. In the preterm embodiments of the present invention, no ranur-a is cut or otherwise formed in the plastic cell portion. In its Place, adhesion between the non-cellular and cellular portions is achieved by providing sufficient contact surface area between the two portions. Alternatively, a groove can be formed integrally in the cellular base as it passes through the die and vacuum former. After the cellular profile emerges from the cooling tank and passes under the spinning wheel, the profile passes below a second die 28 or saddle die, from which the non-cellular extruded product is placed on the profile cell phone. The chair die may also be below or along the cell profile, as appropriate. At this point, the cellular profile is generally cooled, but more likely has some retained or residual heat. The non-cellular flexible compound or resin is fed from a second extruder through the chair die 28 and along the cellular profile. The flexible resin is applied so that one end 30 of the width of the flexible strip is placed along the cell part. The other end 32 of the width of the flexible piece extends up and away from the cellular portion 10 to form the strip portion 22 of the weatherstrip. In the modality illustrated in Figure 8, the chair die is formed into two connected parts. The first portion is approximately 2.5 centimeters thick and the second portion approximately 0.62 centimeters thick. These dimensions of Jado vanan based on the formulations and sizes of the formed profiles In this embodiment, the chair die is placed in one side 50 and a corner 52 of the cell part 54 passes in contact with the first one. chair die portion Flexible non-cellular ream - also passes through this first portion of the chair die, but is kept separate from the cellular ream - in this die portion, both cellular and non-cellular resins are heated In the first die portion, the non-cellular resin is heated to maintain its Mujo capacity as it is added to the cell portion, the cell portion is also heated along the side on which it will be attached to the non-cellular portion. Cellular heating, both cellular and non-cellular, is considered important for the appropriate adhesion of the non-cellular flexible part to the cellular base in some modalities and applications. to the second portion of the chair die. In this portion, the opening on the side of the cellular ream is shaped so that the non-cellular resin flows in the proper configuration against the side of the cellular resin. In this die portion, the two resins make contact and join. After leaving the chair die, both resins pass through a cooling fitting. In one embodiment of the accessory tria water flows along both non-cellular and cellular-portions, to cool the profile. In another embodiment of the accessory, both cold water and cold air make contact with the profile to cool the product. In one embodiment, the cooling attachment is approximately 37.5 inches long. A conformation channel is not necessary in this portion of the process. After leaving the cooling attachment, the product is cut The appropriate length. The enhancement of the cellular portion is previously completed, therefore, it is not necessary, nor is it carried out, additional enhancement. It is important to note that the flexible compound is in a hot molten state (approximately 165 ° C) as it leaves the chair die 28 and makes contact with the cell portion. The heat of the flexible compound must cause at least some portion of the cells in the cell profile to be heated and partially liquefied. However, it is also believed that it is important for this process to have the cell-heated portion immediately before contact with the non-cellular resin. This heating preferably provides the cellular ream with a somewhat soft and sticky surface, but not a pure liquid or molten ream. This surface improves the union between the flexible and the cellular without affecting the intey of the cellular profile. It is noted that saddle dies have previously been used to place a flexible non-cellular composite along a portion of the cell profile. These extrusions were typically used in window frames in which the flexible extrusion extends outward from the cellular base to hold a window board in position. However, in these prior applications, the flexible portion moves only during insertion of the window into the frame. Unlike the door stop application of the present invention, the flexible portion does not repeatedly move in a hinge-like manner. Since the flexible portion 36 in these applications does not move repeatedly, it may be attached or attached to the uncut outer surface 38 of the cellular profile, as shown in Figure 4. The flexible portion is also not placed along a portion substantial from the top of the base or along the side of the base. Any extrudable material can be used with the present process. Preferred materials include polyvinyl chloride and polystyrene. Other extrudable materials such as acrylonitrile-butadiene-styrene (ABS) may also be used. The cellular compound can be made from the same material as the non-cellular compound or from a different one. Nevertheless, the cellular material - includes a conventional blowing agent to cause foaming or expansion of the cellular material. Blowing agents are well known in the extrusion technique. The extrusion materials may contain other plastics, fillers and pigments, as known and used by those skilled in the extrusion art. A preterm embodiment of the profile of the present invention is shown in Figure 5. The flexible non-cellular portion 60 has a length extending from an end pruner along the entire side 50 of the cell portion 54. The length extend upwardly from the upper corner 62 of the cellular portion to a second end of the flexible portion. Only a portion of the entire length of the flexible thread is firmly attached to the rigid base. In another embodiment, shown in Figure 6, a portion of the length of the flexible portion 70 extends along only a portion of the side 72 of the cellular portion 74. In another embodiment, shown in Figure 7, the portion flexible 80 extends upwardly from the upper portion 82 of the cellular portion. In each of these embodiments, the flexible portion preferably extends along the surface of the cellular portion for a length that is greater than the thickness of the flexible portion. Satisfactory per-files have been made for commercial use as a garage door stop of the embodiment shown in Figure 7, with the flexible portion 80 attached to the cellular portion 84 in a width of approximately twice the width 90 of the portion flexible. Satisfactory profiles have been made for commercial use as a garage top of the embodiment in Figure 6, in which the flexible portion 70 extends along the side 72 of the cellular portion by a distance 92 that is approximately 4 times the thickness 94 of the cell portion. In Figure 9 a dual filament or double filament production line is shown schematically. In that line, two parallel extrusions 100, 102 are produced by means of a sequential extrusion process. A main extruder 104 extrudes the cell ream through a hot die 106 into two parallel streams. Both streams enter the vacuum tank 108 in which they are cooled. After leaving the tank 108, the cellular resin is at least partially cooled and therefore proceeds through the booster 110 and puller 112. The second stage of the extrusion process is through the chair die 114. Two extruders separated 116, 118, feed the non-cellular ream-to chair die 114. Currents leave the chair die with the flexible non-cellular strip attached to the cell base. The resins are cooled in the cooling fitting 120 and then cut to size on a cutting table. Those skilled in the art related to the invention can make modifications and other modalities employing the principles of this invention without departing from their spirit or essential characteristics, particularly from the foregoing teachings. The described modalities are considered in all aspects only as illustrative and not as restrictive, and the scope of the invention, therefore, is indicated by means of the appended claims and not by the foregoing description. Accordingly, although the invention has been described with reference to particular embodiments, modifications to the structure, sequence, materials, and the like, which are within the scope of the invention, will be apparent to the person skilled in the art.

Claims (6)

NOVELTY OF THE INVENTION CLAIMS

1. An extruded strip profile for a garage door, comprising: a rigid base portion formed of cellular ream, said rigid base portion having at least one top surface and at least one side surface; a flexible portion formed from non-cellular ream, said portion of strip having first and second ends, a length extending from said first end towards said second end, and a thickness, said portion of strip being firmly attached to said end. base portion at said first end, said strip portion having the second end extending freely afar from said base, a portion of said length of the strip portion being firmly joined along one of the surfaces of said strip. said base portion; said attached length of the strip portion is at least twice as long as the thickness of said portion of t ra.

2. The weather strip according to claim 1, characterized in that said joined length of said strip portion is at least four times longer than the thickness of said strip portion.

3. The weatherstrip according to claim 1, further characterized in that said joined length of the strip extends through the entire length of the lateral surface of said base portion.

4. A method of forming the profile of the weatherstrip noise in accordance with claim 1, comprising the steps of. extruding said cellular material 'through a first die; hardening said cellular material in said rigid bead base portion after leaving the first die; Extrude said non-cellular material through a second die, at least a portion of said non-cellular material makes contact with at least one of the surfaces of said base portion; hardening said non-cellular material * in a flexible strip portion after leaving the second die, whereby said strip portion is firmly attached to said base portion at the first end, said strip portion having a second end extending freely outwardly from said base portion, and a portion of the length of said strip portion is firmly joined along a the surfaces of said base portion.

5. The method according to claim 4, further characterized in that it comprises the step of: cutting a groove in said cellular base portion after hardening the cellular material and before extruding the non-cellular material; said contact of non-cellular material with the cellular material is along said groove in said base portion.

6. The method according to claim 4, further characterized in that it comprises the step of heating at least a portion of the cellular material of the base portion within said second die. ? . - The method according to claim 6, further characterized in that it comprises the step of heating said non-cellular material dent or said second die. 8. The method according to claim 4, further characterized in that said step of hardening the cellular material includes passing said cellular material through a ba ba or vacuum pressure. 9. The method according to claim 4, further characterized in that it comprises the steps of: forming an integral groove in said cellular base portion during the extrusion and hardening steps; said contact of the non-cellular material with the cellular material is along said groove in said base portion.