A method for forming a banded sandwich structure DCPD product

Abstract

A method for forming a sandwich structure DCPD product, comprising: making an intermediate sandwich layer, setting a groove on the intermediate sandwich layer; making a mold, setting a top rod on the mold which is adapted to the groove; setting the intermediate sandwich layer in the mold to perform mold injection; separating the mold to obtain the product. In combination with the prior art, the beneficial effects of the present application are that the existing forming method is to directly cast the material into a solid product, which makes the wall thickness of the product too thick and easy to cause serious shrinkage to cause the product to deform. In the process of injection, the intermediate sandwich layer is used to lay the material on the intermediate sandwich layer to form the intermediate sandwich layer as the inner core embedded in the product, so that the wall thickness of the product is reduced, the material shrinkage is not too large during forming, the product will not be deformed, and the product quality will not be affected.

Description

Technical Field

[0001] This invention relates to the field of DCPD product structure and molding, and specifically to a method for molding DCPD products with a sandwich structure. Background Technology

[0002] DCPD is dicyclopentadiene, an organic compound with the chemical formula C. 10 H 12 Polydicyclopentadiene (PDCPD) is a dimer formed by the Diels-Alder reaction of cyclopentadiene. It has two isomers, an endogenous and an exogenous form, and is a colorless crystal, insoluble in water but soluble in alcohols, ethers, and carbon tetrachloride. PDCPD is a homopolymer or copolymer of polydicyclopentadiene (DCPD), a cross-linked three-dimensional network engineering plastic. In recent years, environmental factors have led some developed countries to strictly control the use of fiberglass products, and PDCPD, as an "environmentally friendly material," has seized this opportunity to experience rapid development. There have traditionally been two molding methods for thick-walled PDCPD products: one is to manufacture the inner and outer layers separately and then bond them together with structural adhesive. This method increases mold costs because separate molds are needed for the inner and outer layers, and it also reduces production efficiency due to the bonding of the inner and outer layers, while the adhesive used also increases product costs. The other method is to directly mix the A and B components of the DCPD material at the injection port and then inject it into an empty mold cavity to form a solid product. This product structure and molding method result in the consumption of a large amount of resin material when dealing with thick-walled products. Furthermore, the large shrinkage of PDCPD material during molding leads to more severe deformation in thick-walled products, ultimately affecting product delivery. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention provides a method for molding DCPD products with sandwich structure, so as to improve the technical problem that products with large shrinkage and thick walls will be severely deformed during material molding.

[0004] To achieve the above and other related objectives, the present invention provides a method for molding DCPD products with a sandwich structure, comprising:

[0005] The process involves: creating an intermediate core layer with grooves; fabricating a mold with ejector pins that fit the grooves; placing the intermediate core layer in the center of the mold for mold closing and material injection; and separating the mold to obtain the product.

[0006] In one example of the present invention, the fabrication of a mold, and the provision of an ejector pin adapted to a groove on the mold, includes:

[0007] The mold is made according to the shape of the intermediate sandwich layer and the product. The mold can be opened and closed. The mold has a hollow cavity in the middle and includes a sprue. The mold is equipped with ejector pins that are adapted to the grooves. The ejector pins can be inserted into the grooves. The ejector pins and the grooves cooperate to fix the mold and the intermediate sandwich layer.

[0008] In one example of the present invention, placing the intermediate sandwich layer in the middle of the mold for mold closing and injection includes:

[0009] Place the intermediate core layer into the hollow cavity of the mold, fix the ejector pin to the groove, and close the mold; mix the raw materials, and inject the mixed raw materials into the mold to fill the hollow cavity and the intermediate core layer; wait for the raw materials to solidify.

[0010] In one example of the present invention, obtaining the product by separating the mold includes:

[0011] After the product has solidified and formed, open the mold and take out the product, remove the excess material from the product sheet; fill the groove of the middle core layer with filler material; grind the outer wall of the product smooth; and spray paint according to the product requirements.

[0012] In one example of the present invention, after the intermediate core layer and the mold are closed, the intermediate core layer does not contact the mold. According to the method of claim 1, the intermediate core layer includes a through hole, the axial direction of which forms an angle of 0° to 60° with the normal to the surface of the intermediate core layer.

[0013] In one example of the present invention, the structure, shape and size of the intermediate sandwich layer are adapted to the product.

[0014] In combination with existing technologies, the beneficial effects of the present invention are as follows: the existing molding method directly casts solid products from materials, which makes the wall thickness of the product too thick and easily causes severe shrinkage, resulting in product deformation. The present invention uses an intermediate core layer during the injection process, lays the material in the intermediate core layer for molding, and uses the intermediate core layer as the inner core embedded inside the product, which reduces the wall thickness of the product, prevents excessive material shrinkage during molding, prevents product deformation, and does not affect product quality. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the intermediate core layer in one embodiment of the present invention;

[0017] Figure 2This is a schematic diagram of material injection according to an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of a molded product according to an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of a product molding method according to an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram illustrating the specific steps of an embodiment S300 of the present invention;

[0021] Figure 6 This is a schematic diagram illustrating the specific steps of an embodiment S400 of the present invention;

[0022] Figure 7 This is a schematic diagram illustrating the specific steps of an embodiment S500 of the present invention.

[0023] Component designation explanation

[0024] 100, intermediate sandwich layer; 110, groove; 120, through hole; 200, mold; 210, ejector pin. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of the present invention is for describing specific implementation schemes and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0026] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0027] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as part of the scope of the invention.

[0028] Please see Figures 1 to 7 A method for molding DCPD products with sandwich structures, comprising:

[0029] S100: Fabricate an intermediate core layer 100, and provide a groove 110 on the intermediate core layer. The groove 110 is used to fix the intermediate core layer; S200: Fabricate a mold 200, and provide ejector pins 210 on the mold 200 that are compatible with the groove 110; S300: Place the intermediate core layer 100 in the middle of the mold 200 for mold closing and material injection; S400: Separate the mold 200 to obtain the product. The structure, shape, and size of the intermediate core layer 100 are compatible with the product. The shape and appearance of the intermediate core layer 100 are the same as the product to be manufactured, and the size of the intermediate core layer 100 is smaller than the size of the product to ensure that the intermediate core layer 100 is inside the product. Placing the intermediate core layer 100 inside the product makes the wall thickness of the product thinner, avoiding severe deformation during molding that would affect the product. The number of grooves 110 and ejector pins 210 is several and the same. The size, depth, shape, and position of the groove 110 on the intermediate core layer 100 are not limited and are determined according to the specific product used.

[0030] In one embodiment of the present invention, fabricating an intermediate sandwich layer 100, including drilling through holes 120 and excavating grooves 110 in the sandwich layer, comprises: fabricating the intermediate sandwich layer 100 according to the product shape; drilling through holes 120 and excavating grooves 110 in the intermediate sandwich layer 100, wherein the axial direction of the through holes 120 forms an angle of 0° to 60° with the normal direction of the surface of the intermediate sandwich layer 100. Figure 1 As shown in angle α, the through-hole 120 is used to expel gas from the mold 200 and the intermediate core layer 100 during injection. The angle between the through-hole 120 and the intermediate core layer 100 allows for better gas expulsion, resulting in a tighter fit between the material and the intermediate core layer 100. Small protrusions and recesses can also be provided on the intermediate core layer 100 to further enhance the fit and increase tightness. Furthermore, after the mold 200 is formed, the material within the through-hole 120 allows the intermediate core layer 100 to adhere tightly and reliably to the product.

[0031] like Figure 5As shown, in one embodiment of the present invention, S200: fabricating a mold 200, and setting an ejector pin 210 adapted to the groove 110 on the mold 200 specifically includes: S210: fabricating the mold 200 according to the shape of the intermediate sandwich layer 100 and the product, the mold 200 being able to open and close, the mold 200 having a hollow cavity in the middle, and the mold 200 including an injection port; S220: setting an ejector pin 210 adapted to the groove 110 on the mold 200, the ejector pin 210 being able to engage with the groove 110, the ejector pin 210 cooperating with the groove 110 to fix the mold 200 and the intermediate sandwich layer 100. The cooperation between the ejector pin 210 and the groove 110 ensures that the intermediate sandwich layer 100 and the mold 200 are locked together during material injection, preventing displacement due to material flow and thus preventing product deformation. Furthermore, it is necessary to ensure that when the middle core layer is in the middle of the mold 200, the middle core layer 100 and the mold 200 do not contact each other except for the groove 110, leaving a gap.

[0032] like Figure 6 As shown, in one embodiment of the present invention, S300: placing the intermediate core layer 100 in the middle of the mold 200 for mold closing and material injection includes: S310: placing the intermediate core layer 100 into the hollow cavity of the mold 200, fixing the ejector rod 210 to the groove 110, and closing the mold 200; S320: mixing the raw materials, and injecting the mixed raw materials into the mold 200 in one go, filling the hollow cavity of the mold 200, as well as the area around and inside the intermediate core layer 100; S330: waiting for the raw materials to solidify. During the injection process, the material flow rate is set according to the injection speed to ensure that the material can fill the mold 200 and tightly bond with the intermediate core layer 100. After the intermediate core layer 100 and the mold 200 are closed, the intermediate core layer 100 does not contact the mold 200, and there is a gap between the intermediate core layer 100 and the mold 200. The intermediate core layer 100 and the mold 200 are only contacted and fixed by the groove 110 and the push rod 210, so that the material can be fully and tightly bonded to the intermediate core layer 100.

[0033] like Figure 7 As shown, in one embodiment of the present invention, S400: Separating the mold 200 to obtain the product includes: S410: After curing, opening the mold 200 to remove the product and removing excess material from the product sheet; S420: Filling the groove 110 of the intermediate core layer 100 with filler material; S430: Grinding the product smooth; S440: Applying appropriate paint according to product requirements. The paint can be selected according to color, pattern, etc., or according to function such as waterproof paint, anti-corrosion paint, fireproof paint, etc.

[0034] In one embodiment of the present invention, the number of intermediate sandwich layers 100 is several. After a product is completed, the following three steps can be repeated: S200: making a mold 200 and setting a push rod 210 adapted to the groove 110 on the mold 200; S300: setting the intermediate sandwich layer 100 in the middle of the mold 200 for mold closing and material injection; S400: separating the mold 200 to obtain the product. Products are continuously produced.

[0035] In one embodiment of the present invention, a matching intermediate core layer 100 and mold 200 are first manufactured according to the product requirements. The intermediate core layer 100 has a groove 110 and a through hole 120 drilled into it. The axial direction of the through hole 120 forms an angle of 0° to 60° with the normal direction of the surface of the intermediate core layer 100. The shape and size of the through hole 120 are not particularly limited. The angle between the through hole 120 and the intermediate core layer 100 helps to expel air bubbles during injection, resulting in a tighter fit between the material and the intermediate core layer 100. The core material can be a lightweight foamed material such as PVC or polyurethane, or a high-strength steel or engineering plastic. A push rod 210 is provided inside the mold 200. The push rod 210 matches the groove 110 of the intermediate core layer 100. When the intermediate core layer 100 is placed into the hollow cavity of the mold 200 and the mold is closed, the push rod 210 and the groove 110 are locked together, ensuring a tight fixation between the intermediate core layer 100 and the mold 200. After fixing the intermediate core layer 100 and the mold 200, materials A and B are mixed and injected through the injection port on the mold 200, filling the mold cavity and the area around and inside the intermediate core layer 100, ensuring a tight fit and treating the intermediate core layer as a single component. After curing, the mold 200 is opened, the semi-finished product is removed, and the groove 110 is filled with filler material or structural adhesive and sanded smooth. Finally, the product is painted to complete the process. After one finished product is completed, the mold 200 can be used to create the next product with a new intermediate core layer 100.

[0036] This invention discloses a method for molding DCPD products with a sandwich structure. By setting an intermediate core layer in the middle of the product, the wall thickness is reduced, preventing severe deformation of the product. Therefore, this invention effectively overcomes some practical problems in the prior art, thus having high utilization value and significance. The above embodiments are merely illustrative of the principles and effects of this invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of this invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A method for molding DCPD products with a sandwich structure, characterized in that, include: An intermediate sandwich layer is fabricated, and a groove is provided on the intermediate sandwich layer; A mold is made, and a push rod adapted to the groove is provided on the mold; The middle core layer is placed in the middle of the mold for mold closing and material injection; Separate the mold to obtain the product; Wherein, after the intermediate sandwich layer and the mold are closed, the intermediate sandwich layer does not contact the mold; The intermediate core layer includes through holes, and the axial direction of the through holes forms an angle of 0° to 60° with the normal direction of the surface of the intermediate core layer.

2. The method according to claim 1, characterized in that, Manufacturing the mold, wherein the ejector pin adapted to the groove is provided on the mold includes: A mold is made according to the intermediate sandwich layer and the product shape. The mold can be opened and closed. The mold has a hollow cavity in the middle and is provided with a material injection port. A push rod adapted to the groove is provided on the mold. The push rod can be inserted into the groove. The push rod cooperates with the groove to fix the mold to the intermediate core layer.

3. The method according to claim 1, characterized in that, Setting the intermediate core layer in the middle of the mold for mold closing and material injection includes: The intermediate sandwich layer is placed into the hollow cavity of the mold, the push rod is fixed to the groove, and the mold is closed. Mix the raw materials and inject the mixed raw materials into the mold to fill the hollow cavity and the middle core layer of the mold; Wait for the raw materials to solidify.

4. The method according to claim 1, characterized in that, Products obtained from the separation mold include: After the product has solidified and formed, the mold is opened to remove the product and excess material is removed from the product sheet. The grooves of the intermediate sandwich layer are filled with a filling material; The outer wall of the product is polished smooth. Perform the corresponding painting according to the product requirements.

5. The method according to claim 1, characterized in that, The structure, shape, and size of the intermediate core layer are adapted to the product.

Images