High flowability raw material and its use

Abstract

The application discloses a kind of high flowability raw materials and its application, the high flowability raw material is by following component composition by weight fraction: 800-1200 parts of raw material powder, 60-100 parts of binder and 6-20 parts of oil composition, and by closed mixing into high flowability raw material;The binder includes POM, PP, rubber, particle wax, PE wax, SA one or more mixed into;The high flowability raw material is used for preparing thin-walled part.The application is by adjusting the formula and model of binder, additionally add a kind of lubricating effect oil, after closed mixing, flowability has obvious improvement, raw material melt index significantly improves;When preparing thin-walled part, it is easier to inject full, and do not affect the shape retention of raw material, can prepare smaller size product, injection pressure and injection speed parameter are all reduced in injection process, reduce product internal stress, can use low temperature sintering, product sintering degree of deformation is small;Product yield and aesthetic degree are improved.

Description

Technical Field

[0001] This invention relates to a high-flowability raw material, specifically to a high-flowability raw material and its applications. Background Technology

[0002] As smart products become increasingly complex and their structures increasingly miniaturized, smart hardware is becoming smaller and thinner. Internal structural components are as thin as 0.15mm and 10-15mm in length. This presents a significant challenge to injection molding raw materials in the MIM (Melt Injection Molding) industry, demanding higher flowability. Melt mass flow rate (MFR), also known as melt index, is an indicator used to evaluate the flowability of raw materials. A higher melt index indicates better flowability, making it easier to fill thinner structures during injection molding.

[0003] The melt flow index of typical MIM raw materials is 800-1600 g / 10 min. This type of feedstock is generally only suitable for injection molding of products with a thickness of 0.3 mm or more. The disadvantages of using it for injection molding of thin-walled parts with a thickness of less than 0.3 mm are as follows:

[0004] 1. It is prone to problems such as incomplete injection and material shortage;

[0005] 2. Due to the low fluidity of the material, a higher injection pressure, injection speed, mold temperature, and material temperature are required to achieve full filling of the product. Even if the product is fully filled, the internal stress will be greater, leading to increased warpage and deformation, and reducing the overall dimensional yield.

[0006] 3. The black streaks and flow lines at the gate and thin-walled areas of the product are quite severe, affecting the product's appearance.

[0007] 4. The product is prone to problems such as burrs and rough edges;

[0008] 5. Due to the extreme nature of the injection parameters, the molding process has a significant impact on the mold life, and the mold inserts are easily damaged.

[0009] 6. When the application parameters of the injection molding machine are set close to their limits, the consistency of injection molding deteriorates, and the lifespan of the injection molding machine is also affected.

[0010] In response to this, existing technologies include increasing the proportion of binder in the mixture to increase fluidity, but this will worsen the shape retention of the injection preform, making the injected product prone to deformation. Increasing the proportion of wax in the binder can also increase fluidity, but increasing the wax proportion will increase the difficulty of degreasing in the degreasing section and the sintering hot degreasing section, reduce degreasing efficiency, and easily lead to blockage of the dewaxing pipe in the sintering furnace, resulting in carbonization of the product and affecting the product size.

[0011] Therefore, developing a high-flowability raw material and its application, improving the melt index, enhancing injection fullness, reducing injection pressure and speed, reducing product sintering deformation, further reducing product deformation, preparing smaller products, and improving product qualification rate are obviously of practical significance. Summary of the Invention

[0012] The purpose of this invention is to provide a high-flowability raw material, adjust the formula and type of binder and add grease to improve flowability and melt index, thereby improving product yield.

[0013] To achieve the above objectives, the technical solution adopted by the present invention is: a high-flowability raw material, which, by weight, is composed of the following components: 800-1200 parts of raw material powder, 60-100 parts of binder and 6-20 parts of oil, and is prepared into a high-flowability raw material by internal mixing;

[0014] The adhesive comprises one or more of POM, PP, rubber, granulated wax, PE wax, and SA.

[0015] Preferably, the raw material powder includes metal powder.

[0016] Preferably, the metal powder includes stainless steel powder, iron-based alloy powder, nickel-based alloy, tungsten alloy, cemented carbide, and titanium alloy.

[0017] Preferably, the high-flowability raw material is composed of the following components by weight: 1000 parts raw material powder, 88 parts binder and 8-10 parts oil.

[0018] Preferably, the adhesive is composed of the following components by weight: 50-85 parts POM, 3-6 parts PP, 3-6 parts rubber, 2-5 parts granulated wax, 2-6 parts PE wax, and 1-3 parts SA.

[0019] Preferably, the adhesive is composed of the following components by weight: 80 parts POM, 5 parts PP, 5 parts rubber, 4 parts granulated wax, 4 parts PE wax, and 2 parts SA.

[0020] Preferably, in the adhesive, POM accounts for 80%, PP accounts for 5%, rubber accounts for 5%, granulated wax accounts for 4%, PE wax accounts for 4%, and SA accounts for 2%.

[0021] Preferably, the oil comprises edible vegetable oil.

[0022] Preferably, it includes soybean oil, rapeseed oil, peanut oil, sesame oil, and blended edible vegetable oil.

[0023] Preferably, the melt flow index of the high-flowability raw material prepared by internal mixing is 4000-4500 g / 10 min.

[0024] Preferably, the intensive mixing method specifically includes the following steps:

[0025] 1) Select the raw material ratio according to the capacity and filling coefficient of the internal mixer; weigh the corresponding raw material powder, binder and grease according to the ratio, and place them separately;

[0026] 2) Turn on the internal mixer, set the equipment parameters, and preheat it;

[0027] 3) Add the raw material powder, binder and grease to the internal mixer in sequence and mix for at least 1 minute;

[0028] 4) After cooling and discharge, a highly fluid raw material is prepared.

[0029] Preferably, the equipment coefficients include preheating temperature, mixing temperature, power, rotor speed, mixing time, and equipment pressure.

[0030] This application also claims the use of a highly fluid material for preparing thin-walled parts.

[0031] Preferably, a metal injection molding method is used to inject highly fluid raw materials into a mold using an injection device, followed by sintering, with injection parameters controlled during the injection process.

[0032] Preferably, the injection parameters include application parameters and limiting parameters, and the application parameters of the injection device account for less than 80% of its limiting parameters during the injection process.

[0033] Preferably, the application parameters are parameters used in the preparation process, including injection pressure, injection time, injection speed, model temperature, and raw material temperature; the limit parameters are the limit values ​​of the injection equipment. When the application parameters are set close to the limit values, the consistency of injection molding will deteriorate, and the life of the injection molding machine will also be affected.

[0034] Preferably, during the injection process, the high-flowability raw material described in this application is used, which fills the mold more fully. Due to its high flowability, the injection pressure and injection speed are significantly reduced. Compared with the same metal raw material powder without the addition of binder and grease in the prior art, the injection pressure and speed of this application are reduced by 25%-30%. The internal stress of the product is reduced, and the sintering deformation is reduced.

[0035] As described above, in the prior art, thin-walled parts, due to their weak structural strength, are difficult to offset the deformation caused by gravity and internal stress release during sintering. This typically results in significant deformation after sintering, affecting product dimensions and yield. However, using the high-flowability raw material described in this application to prepare thin-walled parts can lower the sintering temperature, thus reducing the degree of sintering deformation.

[0036] Preferably, the thickness of the thin-walled part is 0.12 mm to 0.3 mm.

[0037] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0038] 1. This invention improves the fluidity and melt flow index of raw materials by adjusting the formula and type of binder and adding a lubricating grease after intensive mixing.

[0039] 2. The high-flowability raw material designed by this invention makes it easier to inject fully when preparing thin-walled parts without affecting the shape retention of the raw material, enabling the preparation of smaller products. During the injection process, the injection pressure and injection speed parameters are reduced, reducing the internal stress of the product and minimizing the degree of sintering deformation. Low-temperature sintering can be used during the sintering process to further reduce the deformation of thin-walled parts.

[0040] 3. The high-flowability raw material designed in this invention can reduce the application parameters of the injection molding machine during the injection process, avoid damage to the model and injection molding machine, extend the life of the model and injection molding machine, and reduce equipment costs;

[0041] 4. The formula of this invention is simple, the preparation method is simple, the work efficiency is high, and the product yield and appearance are improved. Detailed Implementation

[0042] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1

[0044] A high-flowability raw material, by weight, is composed of the following components: 800-1200 parts of raw material powder, 60-100 parts of binder and 6-20 parts of oil, and is prepared into a high-flowability raw material by internal mixing;

[0045] The adhesive comprises one or more of POM, PP, rubber, granulated wax, PE wax, and SA.

[0046] Furthermore, the raw material powder includes metal powder.

[0047] Furthermore, the metal powder includes stainless steel powder, iron-based alloy powder, nickel-based alloy, tungsten alloy, cemented carbide, and titanium alloy.

[0048] Furthermore, the adhesive, by weight, comprises the following components: 50-85 parts POM, 3-6 parts PP, 3-6 parts rubber, 2-5 parts granulated wax, 2-6 parts PE wax, and 1-3 parts SA.

[0049] Furthermore, the adhesive, by weight, consists of the following components: 80 parts POM, 5 parts PP, 5 parts rubber, 4 parts granulated wax, 4 parts PE wax, and 2 parts SA.

[0050] Furthermore, the oils include edible vegetable oils.

[0051] Furthermore, this includes soybean oil, rapeseed oil, peanut oil, sesame oil, and blended edible vegetable oils.

[0052] Furthermore, the melt flow index of the high-flowability raw material produced by internal mixing is 4000-4500 g / 10 min.

[0053] Furthermore, the refining method specifically includes the following steps:

[0054] 1) Select the raw material ratio according to the capacity and filling coefficient of the internal mixer; weigh the corresponding raw material powder, binder and grease according to the ratio, and place them separately;

[0055] 2) Turn on the internal mixer, set the equipment parameters, and preheat it;

[0056] 3) Add the raw material powder, binder and grease to the internal mixer in sequence and mix for at least 1 minute;

[0057] 4) After cooling and discharge, a highly fluid raw material is prepared.

[0058] Furthermore, the equipment parameters include preheating temperature, mixing temperature, power, rotor speed, mixing time, and equipment pressure.

[0059] Example 2

[0060] This embodiment relates to the application of a high-flowability raw material, which is used to prepare thin-walled parts.

[0061] Furthermore, metal injection molding is used to inject highly fluid raw materials into a mold using an injection device, followed by sintering, with injection parameters controlled during the injection process.

[0062] Furthermore, the injection parameters include application parameters and limiting parameters, and the application parameters of the injection device account for less than 80% of its limiting parameters during the injection process.

[0063] Furthermore, the application parameters are the parameters used in the preparation process, including injection pressure, injection time, injection speed, model temperature, and raw material temperature; the limit parameters are the limit values ​​of the injection equipment. When the application parameters are set close to the limit values, the consistency of injection molding will deteriorate, and the life of the injection molding machine will also be affected.

[0064] Furthermore, during the injection process, the high-flowability raw material described in this application is used, resulting in a fuller filling in the mold. Due to its high flowability, the injection pressure and injection speed are significantly reduced. Compared with the same metal raw material powder without the addition of binders and greases in the prior art, the injection pressure and speed of this application are reduced by 25%-30%. The internal stress of the product is reduced, and the sintering deformation is decreased.

[0065] As described above, in the prior art, thin-walled parts, due to their weak structural strength, are difficult to offset the deformation caused by gravity and internal stress release during sintering. This typically results in significant deformation after sintering, affecting product dimensions and yield. However, using the high-flowability raw material described in this application to prepare thin-walled parts can lower the sintering temperature, thus reducing the degree of sintering deformation.

[0066] Furthermore, the thickness of the thin-walled part is 0.12 mm to 0.3 mm.

[0067] Example 3

[0068] This embodiment is based on the above embodiments one and two, and the similarities with the above embodiments will not be repeated.

[0069] In this embodiment, the high-flowability raw material is composed of the following components by weight: 1000 parts of raw material powder, 88 parts of binder and 8-10 parts of oil.

[0070] Furthermore, in the adhesive, POM accounts for 80%, PP accounts for 5%, rubber accounts for 5%, granulated wax accounts for 4%, PE wax accounts for 4%, and SA accounts for 2%.

[0071] The high-flowability raw material produced by internal refining in this embodiment has a melt index of 4500 g / 10 min; while the melt index of the same metal raw material in the prior art is 800-1600 g / 10 min.

[0072] When using this highly fluid material for injection molding thin-walled parts, it facilitates full injection while significantly reducing both injection pressure and speed; the injection pressure and speed for the same product are reduced by 25%-30%. This results in lower internal stress and less sintering deformation. With this material, thin-walled parts can be made as thin as 0.12mm, meeting the requirements of the vast majority of customers.

[0073] In existing technologies, thin-walled parts prepared from raw materials often exhibit significant deformation during sintering due to their weak structural strength. This makes it difficult to counteract the deformation caused by gravity and internal stress release, resulting in poor product dimensions and yield. The high-flowability raw material described in this embodiment lowers the sintering temperature, thus reducing the degree of deformation during sintering.

[0074] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A highly fluid raw material, characterized in that, By weight, it consists of the following components: 800-1200 parts of raw material powder, 60-100 parts of binder and 6-20 parts of oil, and is made into a high-flowability raw material through intensive mixing; The adhesive, by weight, consists of the following components: 50-85 parts POM, 3-6 parts PP, 3-6 parts rubber, 2-5 parts granular wax, 2-6 parts PE wax, and 1-3 parts SA. The melt flow index of the high-flowability raw material prepared by internal mixing is 4000-4500 g / 10 min; The method of intensive refining specifically includes the following steps: 1) Select the raw material ratio according to the capacity and filling coefficient of the internal mixer; weigh the corresponding raw material powder, binder and grease according to the ratio, and place them separately; 2) Turn on the internal mixer, set the equipment parameters, and preheat it; 3) Add the raw material powder, binder and grease to the internal mixer in sequence and mix for at least 1 minute; 4) After cooling and discharging, a highly fluid raw material is prepared; The raw material powder includes metal powder.

2. The high-flowability raw material according to claim 1, characterized in that, The oils and fats include edible vegetable oils.

3. An application of a highly fluid raw material, characterized in that, Thin-walled parts are prepared using the high-flowability raw material described in any one of claims 1-2.

4. The application of a high-flowability raw material according to claim 3, characterized in that, Metal injection molding is used to inject highly fluid raw materials into a mold using an injection device, followed by sintering. Injection parameters are controlled during the injection process.

5. The application of a high-flowability raw material according to claim 4, characterized in that, The injection parameters include application parameters and limit parameters, and the application parameters of the injection device account for less than 80% of its limit parameters during the injection process.

6. The application of a high-flowability raw material according to claim 3, characterized in that, The thickness of the thin-walled part is 0.12mm to 0.3mm.