CN111319194A

CN111319194A - Medical injection part mold convenient for demolding and manufacturing process thereof

Info

Publication number: CN111319194A
Application number: CN202010151543.9A
Authority: CN
Inventors: 李华; 张晓辉
Original assignee: Yancheng Moyinbao New Material Co ltd
Current assignee: Yancheng Moyinbao New Material Co ltd
Priority date: 2020-03-06
Filing date: 2020-03-06
Publication date: 2020-06-23

Abstract

The invention discloses a medical injection molding die convenient for demoulding and a manufacturing process thereof, wherein the die comprises the following steps: the mould is provided with an injection molding hole, a core is arranged in the injection molding hole, a gap between the side wall of an inner cavity of the injection molding hole and the outer surface of the core is a cavity, one end of the cavity, which is close to the injection molding hole, is in a strip or rod shape, the side wall of the inner cavity of the injection molding hole and the outer surface of the core are both provided with ceramic layers, the surface of each ceramic layer is provided with a groove body, a metal piece is arranged in each groove body, namely, the surface of the inner cavity of the cavity is provided with a plating layer in; when molten injection molding materials are injected into the cavity, the volume of metal is increased to the extent that the surface of the metal surface is flush with the surface of the inner cavity of the cavity due to heating, and the metal is recessed into the surface of the cavity after the injection molding materials are cooled and shaped. The mold provided by the invention can effectively avoid the adhesion condition of the injection molding part with a rod-shaped or strip-shaped structure in the injection molding process, and reduce the force for demolding.

Description

Medical injection part mold convenient for demolding and manufacturing process thereof

Technical Field

The invention relates to an injection mold for medical devices, in particular to a medical injection part mold convenient for demolding and a manufacturing process thereof.

Background

Compared with metal, stone and wood, the plastic product has the advantages of low cost, strong plasticity and the like, is widely applied in national economy, has an extremely important position in the current world in the plastic industry, and is developed at a high speed all over the world for years. Products made of plastics are widely used: mobile phone, portable computer, various plastic shells, communication, micromotor, computer, electric appliance, electron, toy, clock, lamp decoration, locomotive and other industries. Injection molding, also known as injection molding, is a method of molding by injection and molding. The injection molding method has the advantages of high production speed, high efficiency, automation of operation, various colors, various shapes from simple to complex, small sizes, accurate product size, easy replacement of products, capability of forming products with complex shapes, and suitability for the molding processing fields of mass production, products with complex shapes and the like. Stirring the completely molten plastic material by a screw at a certain temperature, injecting the plastic material into a mold cavity by high pressure, and cooling and solidifying to obtain a molded product. The method is suitable for mass production of parts with complex shapes, and is one of important processing methods.

The medical injection molding part has extremely high requirements on the material, and the injection mold often limits the material of the injection molding part in order to solve the problem of demolding, so that some medical injection molding parts are difficult to demold, and even chemical means such as a demolding agent are added, the effect is difficult to achieve. But the in-process that corresponds shaft-like or rectangular form injection molding processing, when the injection molding drawing of patterns, the condition of adhesion easily takes place, because the structure at injection molding here is the body of rod or flat rectangular, incomplete to the finished product, when the quality is the detection of accuse, the required finished product of above-mentioned incomplete is repaired and the mould clearance is loaded down with trivial details relatively, so need the mould can be after the completion of moulding plastics, when the injection molding on the mould was opened at the mould, take place the adhesion degree with the mould and want little or even not take place the adhesion.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides the medical injection molding part mould convenient for demoulding and the manufacturing process thereof.

2. In order to achieve the purpose, the invention adopts the technical scheme that: a medical injection molding mould convenient to demold, comprising: the mould is provided with an injection molding hole, a core is arranged in the injection molding hole, a gap between the side wall of an inner cavity of the injection molding hole and the outer surface of the core is a cavity, one end of the cavity, which is close to an injection molding hole connector, is in a strip or rod shape, the side wall of the inner cavity of the injection molding hole and the outer surface of the core are both provided with ceramic layers, the surface of each ceramic layer is provided with a groove body, metal pieces are arranged in the groove bodies, namely, a plating layer with alternately arranged ceramic and metal is formed on the surface of the inner cavity of the cavity, the coefficient of expansion with heat and contraction with cold of the ceramic is smaller than that of the metal; when molten injection molding materials are injected into the cavity, the volume of metal is increased to the extent that the surface of the metal surface is flush with the surface of the inner cavity of the cavity due to heating, and the metal is recessed into the surface of the cavity after the injection molding materials are cooled and shaped.

In a preferred embodiment of the invention, the mold is provided with a plurality of through grooves capable of being blocked along the length direction of the mold, and the through grooves can enable air in the cavity to be exhausted nearby in the injection molding process.

In a preferred embodiment of the present invention, the arrangement of the ceramic and the metal is as follows: on the inner cavity surface of the cavity, the ceramic and the metal are alternately arranged in the form of parallel lines.

In a preferred embodiment of the present invention, the arrangement of the plating layer on the sidewall of the cavity is as follows: arranged in a spiral form in space.

In a preferred embodiment of the invention, the pitch of the helix is smaller in the region of the greater surface difference in the side wall of the cavity.

In a preferred embodiment of the invention, the side wall of the inner cavity at the end of the cavity is provided with patterns.

In a preferred embodiment of the invention, the other end of the cavity is a functional end of an injection molding part, and the metal coating is arranged on the side wall of the inner cavity at the junction of the two ends.

In a preferred embodiment of the invention, the middle part or the end part of the cavity is bent, and the thickness of the coating on the side wall of the cavity at the bent part is thinner than that of the coating in other areas.

In order to achieve the purpose, the invention adopts another technical scheme as follows: a manufacturing process for conveniently demoulding medical injection molding part molds comprises the following manufacturing steps:

s1, finishing primary manufacturing of a mold according to the shape of an injection molding piece, plating a ceramic layer on the side wall of an inner cavity of a mold cavity, and selecting an arrangement mode of a groove body according to the structure of the cavity;

s2, improving the temperature and pressure of the mold, simulating and maintaining the ambient temperature and pressure during injection molding, and filling the groove body with metal pieces;

s3, after the temperature of the die is reduced to be lower than the room temperature, impacting and extruding the surface of the inner cavity of the cavity to ensure that the metal piece can be smoothly recessed into the surface of the cavity;

and S4, recording the flattening or sinking of the surface of the coating in the temperature rising and falling process, and checking the finishing degree of the die.

In a preferred embodiment of the invention, in the cavity, the width of the ceramic layer or the metal part is about small in a region where the bending degree of the cavity is larger or the fluctuation difference of the side wall of the cavity is larger.

The invention solves the defects in the background technology, and has the following beneficial effects:

(1) according to the mold, the injection molding part with the strip or rod main body structure is processed, the metal-ceramic coating is arranged, when injection molding materials in a molten state are injected, the coating is heated to expand, the surface of an inner cavity of a cavity is smooth, the coating is cooled and shrunk in the molding and cooling stage of the injection molding part, according to the specific arrangement of metal or ceramic, the contact between the mold and the injection molding part can be reduced microscopically, the probability of adhesion is reduced, the required force is relatively reduced during demolding, and accordingly demolding can be performed easily.

(2) The cladding material is in the form of helix sets up in the die cavity, and the pitch on the helix is shortened like bending or thickness or the relatively less region of diameter to the special construction in the die cavity, and the die cavity region that corresponds the special construction promptly is the region that takes place the adhesion comparatively easily, and this region is at the in-process of moulding plastics, needs the drawing of patterns slow relatively, and it will be little to ensure the degree of adhesion simultaneously, the metal in the cladding material and the ceramic high density interval in turn, the adhesion of mould and the injection molding that can effectual reduction special construction department.

(3) The die cavity of mould is equipped with a plurality of along self length direction and leads to the groove, it does not belong to the structure of cast injection molding, but in order to reserve certain exhaust hole, because the surface structure of injection molding probably can have the condition of relative complicacy, need carry out gaseous discharge when pouring into the material of moulding plastics this moment, because material or air retention nature, can not be with gaseous discharge, the hole degree and the prosthetic degree of difficulty on the surface of injection molding can rise like this, the logical groove of reservation can be outside the air guide, can reduce the hole degree on the finished surface of injection molding, operating procedure when reducing the restoration.

(4) The plating layer is mainly displayed on the surface of the inner cavity of the cavity by ceramic and ceramic according to a certain proportion, the ceramic mainly aims at a smooth area, the force applied during demoulding can be reduced, the metal and ceramic alternately spaced areas and the alternately arranged density are mainly determined according to the specific structure of an injection molding piece or the thickness of a specific area, the degree of adhesion occurrence of key parts of the injection molding piece can be weakened, the probability of injection molding success of the injection molding piece is improved, meanwhile, the injection molding success rate of the mold is high, the cleaning of the mold can be reduced, and the integral injection molding efficiency is improved.

Drawings

The invention is further explained below with reference to the figures and examples;

FIG. 1 is a diagram of the sidewall of the cavity at both hot and cold temperatures for the mold of the preferred embodiment of the present invention;

FIG. 2 is a perspective view of a ceramic layer of the mold surface of the preferred embodiment of the present invention;

fig. 3 is a comparison of the structure of the metal layer of the preferred embodiment of the present invention at two temperatures.

Wherein, 1: injection molding hole, 2: through groove, 3: metal piece, 4: caulking groove, 5: a mold and 6: a ceramic layer.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings and examples, which are simplified schematic drawings and illustrate only the basic structure of the invention in a schematic manner, and thus show only the constituents relevant to the invention.

FIG. 1 shows a block diagram of the sidewall of an internal cavity of a medical injection mold of the present invention at two temperatures, cold and hot, to facilitate demolding the mold.

As shown in fig. 1, a medical injection molding mold facilitating demolding comprises: the mould is provided with an injection molding hole, a core is arranged in the injection molding hole, a gap between the side wall of an inner cavity of the injection molding hole and the outer surface of the core is a cavity, one end of the cavity, which is close to an injection molding hole connector, is in a strip or rod shape, the side wall of the inner cavity of the injection molding hole and the outer surface of the core are both provided with ceramic layers, the surface of each ceramic layer is provided with a groove body, metal pieces are arranged in the groove bodies, namely, a plating layer with alternately arranged ceramic and metal is formed on the surface of the inner cavity of the cavity, the coefficient of expansion with heat and contraction with cold of the ceramic is smaller than that of the metal; when molten injection molding materials are injected into the cavity, the volume of metal is increased to the extent that the surface of the metal surface is flush with the surface of the inner cavity of the cavity due to heating, and the metal is recessed into the surface of the cavity after the injection molding materials are cooled and shaped.

The cold and hot temperatures of the same mold in fig. 1 are respectively the two temperatures at the time of cooling (temperature near room temperature or below) and at the time of injection molding (depending on the material to be tested). In the figure, the grooves formed by the left die and the right die are areas where the metal pieces are located, the width of the metal pieces is increased in order to show the arrangement positions of the metal pieces in the figure 1, and in the actual production process, unless the size of a cavity exceeds 40cm, the width and the depth of the metal pieces exceed 5mm, and no obvious groove can be formed under the change of a certain temperature. The illustrated arrangement of the metallic elements and ceramic layers presents a plurality of concentric rings and the degree of alternation of metallic elements and ceramic layers per unit length increases near specific areas, such as bends or junctions, in the mold cavity.

It should be noted that the left and right molds shown in the figure are the same mold at two different temperatures, the left and right molds represent the structural changes of the inner cavity of the mold at different temperatures, and the mold shown in the figure is one side of the whole mold after being separated. The mold provided by the invention has the advantages that the produced injection molding part is in a strip or rod shape, a core is also arranged in an injection molding hole in a matching way, the core is mainly used for opening certain areas of the mold to occupy a space, a gap between the side wall of an inner cavity of the injection molding hole and the surface of the core is a cavity (the core is not particularly shown), one end of the cavity close to an interface of the injection molding hole is in a strip or rod shape, one end close to the interface of the injection molding hole comprises an interface of the injection molding hole (injection molding materials are injected into the whole cavity through the interface on the mold) and the cavity close to the interface area of the injection molding hole, the cavity is usually a hand-held area, the shape of the other end of the injection molding hole is not specifically mentioned (the injection molding hole refers to the inner cavity of the whole container, and the interface of the injection molding holes is the inlet of the injection molding materials of the. The side wall of the inner cavity of the injection hole and the outer surface of the mold core are both provided with a coating which is a layer expanding with heat and contracting with cold, and the coating can generate surface fluctuation along with the change of temperature. Ensures that the coating expands at the temperature, so that the coating is relatively smooth and has high goodness of fit with injection molding parts. The thermal expansion and cold contraction layer is a plating layer formed by alternately arranging ceramic and metal, specifically, the metal and the ceramic can be distributed in parallel lines and can be staggered in a square form, the ceramic surface on the surface of the inner cavity of the cavity is provided with a groove body, and the metal is positioned in the groove body. The circulating cooling device is arranged on the outer side of the mold, when molten injection molding material is injected into the cavity, metal is heated and increased to the extent that the metal surface is flush with the inner cavity surface of the cavity, specific control on temperature is realized, the metal is ensured to have integral fluctuation (namely expansion protrusion and cooling depression) smoothly at the current temperature (the temperature of the injection molding material in a molten state), after the injection molding material is cooled and shaped, the metal in the expansion and contraction layer is recessed into the inner cavity surface of the cavity, it is noted that ceramic is subjected to expansion and contraction in the whole temperature change process, but the integral change amplitude is very small, and as plastic products are mostly used for manufacturing shells and the like, even if products are precision instruments, errors caused by small amplitude change of the shells cannot influence the precision inside of the instruments, so in later discussions, the default ceramic has ignored amplitude of variation.

The mold is mainly used for producing rod-shaped or strip-shaped plastic products, specific structures such as grooves, bulges, patterns and bends exist in the length direction of an injection molding piece, air required in the injection molding process is removed, the mold is different from liquid, the air retention is large, air remained in a fluctuation area on the surface of a cavity cannot be smoothly removed, the air can be quickly floated out by rotating the integral mold, the air is discharged in a rotating mode, the position of an exhaust hole is overlapped with the position of an injection molding hole, an inner cavity exists at one end of a rod body on a finished product of the injection molding piece, namely the structural strength is reduced, the injection molding piece is judged to be failed in injection molding during acceptance, and if the air cannot be exhausted completely, the cavity can cause direct defect of the outer surface of the injection molding piece. Therefore, in order to reduce the surface defect degree of the injection molding part and the number of internal cavities and improve the air discharge rate, a through groove is arranged along the side wall in the length direction of the mold, particularly the area close to the area where the air stagnation area is easy to form, and in the process of rotating the integral mold, the injection quantity of the injected mold and the air discharge quantity are counted to calculate the air residual quantity of the current cavity. The air is drawn to the through groove as far as possible to be discharged (a plurality of cones on the side wall of the cavity in figure 1 are through grooves, the outlets of the through grooves are small, the cones are connected to the outer side of the mold through the tops of the cones, passages leading to the outer side of the mold can be blocked, the passages are not shown in the figure due to the fact that the through grooves are narrow, the through grooves can be blocked, injection molding parts at the through grooves can be incomplete, the space structures of the through grooves are not planned structures of the injection molding parts, the injection molding parts are finally formed by the injected areas in the through grooves, one parts of the injection molding parts need to be eliminated through hot melting or physical cutting, and the like. The through groove is arranged, only in the injection molding process, the near through groove is selected for air in the cavity to be pumped out (or air bubbles are guided to the outlet of the through groove through rotation), and after the bubbles are almost removed, the outlet of the through groove is blocked.

The ceramic and the metal are alternately arranged on the surface of the inner cavity of the cavity in a parallel line mode, the surface of the produced injection molding part is smooth because the produced injection molding part is mainly an object with a strip-shaped or rod-shaped structure, and the influence on the smoothness of the surface of the injection molding part is small by selecting the arrangement mode of the parallel lines. The parallel lines can be a plurality of circular rings arranged at intervals along the axial direction of the injection molding piece or a spiral line along the axial direction of the injection molding piece. Namely, the arrangement mode of the plating layer on the side wall of the inner cavity of the cavity is as follows: the injection molding machine is arranged in a spiral line mode in space, and the advancing direction of the spiral line is consistent with the axial direction of an injection molding piece.

In the region of the greater surface difference in the side wall of the interior of the mold cavity, the pitch of the helix is smaller, i.e. the frequency of the alternation of metal and ceramic and the surface width of the individual metal or ceramic are smaller. The larger the surface drop in the side wall of the inner cavity of the cavity is, the higher the probability of adhesion is, and the larger the easy stress point is during demolding, that is, the adhesion and the breakage may occur, so that the correspondingly arranged plating layer and the alternation degree on the plating layer need to be greatly improved.

Set up the decorative pattern at the inner chamber lateral wall mountain of the one end of being close to the injection molding hole, except that increase pleasing to the eye degree and trade competitiveness, the lateral wall surface on the corresponding mould, if can accomplish the accurate control of temperature to the fluctuation of cladding material, then can set up the cladding material on the mould and be used for the extrusion to form the region of injection molding decorative pattern, the sunken or level and smooth extrusion of cladding material, can play positive effect to the extrusion of decorative pattern or the smooth drawing of patterns, if can not be accurate select the material ratio, or to gas content when moulding plastics, the fluctuation of cladding material carries out accurate grasp, then in order to reduce cladding material adhesion or the form of walking of decorative pattern, the region of pressing the decorative pattern on the mould can not set up the cladding material.

Plastic articles with a strip-like or rod-like structure such as: the other end of the cavity is a functional end of an injection molding piece, the mold shown in figure 1 only represents the functional end and the bending, and the specific injection molding piece can be structurally replaced with the functional end according to actual requirements. The cladding material that corresponds the inner chamber lateral wall of the juncture at the both ends of die cavity is equipped with the metal coating, corresponds whole die cavity promptly, and the juncture area of metal and pottery mainly concentrates on specific structure area department, to the region that is smooth relatively but difficult for taking place the adhesion, can reduce the use of cladding material, perhaps reduces metal and the alternating frequency of pottery and density. When the middle part or the end part of the cavity is in a bent shape, although the alternating density of metal and ceramic in the plating layer of the region is improved, the whole thickness of the plating layer on the side wall of the cavity at the bent part is thinner than the plating layer of other regions, namely, the corresponding metal expansion degree and the thickness of the metal plating layer are in a direct relation, namely, although the metal and the ceramic are alternately arranged in the region corresponding to the bending part to reduce adhesion, if the amplitude of the protrusion and the recess of the metal is too large, and if the temperature control is not accurate, the influence caused by the thicker metal plating layer is larger, and the bent part of the mold can be directly over-thick or over-thin.

The invention relates to a manufacturing process of a medical injection molding part mould convenient for demoulding, which comprises the following manufacturing steps:

It should be noted that, in the early stage of making the mold, it is necessary to perform corresponding analysis on the overall structure of the injection molded part, determine the material selection and the heat conduction performance of the current mold, and determine whether the temperature transfer at a specific area, such as a bend or a core surface, will be greatly different from the rest areas of the cavity, and then establish the manufacturing scheme of the mold. The method is characterized in that the melting temperature and the cooling timing temperature of the injection molding part manufactured by the current mold are recorded, the preliminary manufacturing of the mold is completed, the cavity of the mold at the moment is composed of an injection molding hole and a mold core, the shape of the cavity is similar to that of the current target injection molding part, and the cavity is reserved with a space of a partial coating and a plurality of through grooves. The specific arrangement scheme of the plating layer needs to be determined according to the shape of an actual injection molding part, and the regions corresponding to the pattern region and the region with large thickness difference are regions needing the plating layer. After the proportion of the metal and the ceramic on the plating layer to be plated is determined, the plating layer, namely the expansion and contraction layer and the expansion and contraction layer, is formed integrally, namely the groove body on the surface of the ceramic for filling the metal is formed integrally.

When filling the metal in the expend with heat and contract with cold layer, need heat the mould to the temperature under the material molten state of moulding plastics, promote the ambient temperature and the pressure that the mould provided promptly to the mould when moulding plastics to keep, begin to carry out the packing of metal according to the structure of die cavity this moment, fill the cell body on ceramic surface with the metal in, fill and polish the cell body region of not filling the metal. After the filling, the circulating cooling device outside the mold starts to operate, and the change of the thermal expansion and contraction layer in the lower cavity is recorded. When the temperature is cooled to room temperature or below, the metal is reheated to the previous melting temperature, whether the metal in the corresponding area is convex or concave is recorded, meanwhile, certain impact force and extrusion are carried out on each area, the resistance in the primary deformation process of the metal is reduced, the resistance is mainly influenced by factors such as the metal inside, the junction of the metal and the ceramic, the respective specific structures of the metal and the ceramic, and the like, so that the metal does not change along with the rise and fall of the temperature, or the change degree is not to the required obvious degree or exceeds the change range, the recording is carried out corresponding to various conditions, the temperature rise and the temperature decrease are carried out at least twice, the extrusion and the impact are carried out after each temperature decrease, and the thermal expansion and cold contraction layer is ensured, particularly, the metal layer can be flush with the surface of the cavity at the melting temperature of the injection. The situation after heating or cooling of the metal layer is shown in fig. 3. The left side of fig. 3 shows the thermal expansion caused when the mold contacts the molten injection molding material, and the change of the flatness is actually a microscopic change, and the metal part region shown on the right side of fig. 3 is concave, and the volume is reduced due to the cooling of the metal, and the ambient temperature set when the metal part is filled into the groove body in the manufacturing process is the temperature of the molten injection molding material. When the injection-molded part is cooled and set or the injection-molded material is not yet put in or taken out, the coating at room temperature is concave, and the degree of the concave is related to the thermal expansion coefficient of the metal part (because the thermal expansion coefficient of the ceramic layer is relatively small, the volume change of the ceramic layer is not considered here).

When the volume of injection molding is great, the cermet cladding material of arranging according to comparatively intensive in turn is not required on the cladding material, the width of the ceramic layer of unit width and metalwork will be relatively broad this moment, the thickness of metalwork is corresponding also to have and is promoted, stability to the structure of cladding material is a challenge, so can set up the caulking groove along the length direction of the cell body on the ceramic layer at the interval, when pouring into metal or the bar metalwork of molten condition, the metal piece can coincide inlay and establish on the ceramic layer, reducible metal piece drops, the structure mode of arranging is specifically as shown in fig. 2.

The invention mainly utilizes the fact that the numerical difference of linear expansion coefficient and linear contraction coefficient of cold of metal and ceramic in the expansion layer is large, when the injection molding is carried out, the metal can be flush with the surface of a cavity when being heated and expanded, and the metal in a groove body on the surface of the ceramic can be sunken after being cooled, so that the surface of an injection molding piece and the metal are staggered microscopically, and a mold can be opened easily after the injection molding piece is cooled in the cavity of a rod-shaped or strip-shaped structure.

It will be appreciated that when the surface structure of the injection molded part is large, the number of cores in the injection hole is also increased, the opening and closing of the mold is not limited to the two shown in the figure, and a plurality of molds may be buckled together to form a finished injection hole. In the expansion and contraction layer, when the bending degree or the surface fall amplitude of the front cavity is larger, the proportion of metal in the expansion and contraction layer is larger. That is, when the shape of the cavity determines that the structure of the injection molding part is special, smooth injection molding of a specific structure of the injection molding part needs to be ensured, the possibility of adhesion in the current region needs to be reduced, if necessary, a through groove is additionally arranged on the injection molding part around the region, that is, the through groove is provided with a left gas outlet and a right gas outlet and can also be used as a sacrificial part, that is, generally, a dead angle exists on the periphery of the injection molding part, and when the injection molding material fluid can not smoothly enter, the injection molding material fluid can be processed and molded in the later period, the plastic product can be generally cut more and less for repair, that is, the injection molding part is relatively complicated in the repair process for the incomplete part, because the temperature and the pressure of the material in the corresponding incomplete region are different from those in the original period during the later repair, an obvious fault is generated, that the appearance and the structure are both defective products, generally, when the cross section of, the incomplete area correspondingly forms a cavity which is relatively obvious, but for the stress condition of the whole structure, a leak in the structural strength exists. When the defect can not be avoided, the introduced through groove space is used as a sacrificial structure, the through groove is positioned in the edge area of the mold on the turnover angle of any mold, so that air can be concentrated in the through groove, the through groove can be columnar, the cross section of the through groove is crescent, namely, when the surface of the mold is corrected, the shape structure cast by the through groove to be removed is easy to remove, and the area to be treated and repaired in the removing process is relatively small.

In light of the foregoing description of the preferred embodiment of the present invention, it is to be understood that various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A medical injection molding mould convenient to demold, comprising: the mould is provided with an injection hole and is characterized in that a core is arranged in the injection hole, a gap between the side wall of an inner cavity of the injection hole and the outer surface of the core is a cavity, one end of the cavity, which is close to an injection hole connector, is in a strip or rod shape, the side wall of the inner cavity of the injection hole and the outer surface of the core are both provided with ceramic layers, the surface of each ceramic layer is provided with a groove body, metal pieces are arranged in the groove bodies, namely, the surface of the inner cavity of the cavity is provided with a coating layer in which ceramics and metals are alternately arranged, the coefficient of expansion with heat and contraction with cold of the ceramics is smaller than the coefficient of expansion with heat and contraction;

when molten injection molding materials are injected into the cavity, the volume of metal is increased to the extent that the surface of the metal surface is flush with the surface of the inner cavity of the cavity due to heating, and the metal is recessed into the surface of the cavity after the injection molding materials are cooled and shaped.

2. The medical injection molding mold facilitating demolding as claimed in claim 1, wherein: the mold is provided with a plurality of through grooves capable of being blocked along the length direction of the mold, and the through grooves can enable air in the cavity to be exhausted nearby in the injection molding process.

3. The medical injection molding mold facilitating demolding as claimed in claim 1, wherein: the arrangement mode of the ceramic and the metal is as follows: on the inner cavity surface of the cavity, the ceramic and the metal are alternately arranged in the form of parallel lines.

4. The medical injection molding mold facilitating demolding as claimed in claim 3, wherein: the arrangement mode of the plating layers on the side wall of the inner cavity of the cavity is as follows: arranged in a spiral form in space.

5. The medical injection molding mold facilitating demolding as claimed in claim 4, wherein: the greater the surface drop in the side wall of the cavity, the smaller the pitch of the helix.

6. The medical injection molding mold facilitating demolding as claimed in claim 1, wherein: patterns are arranged on the side wall of the inner cavity at the end of the cavity.

7. The medical injection molding mold facilitating demolding as claimed in claim 1, wherein: the other end of the cavity is a functional end of the injection molding part, and the side wall of the inner cavity at the junction of the two ends is provided with the metal coating.

8. The medical injection molding mold facilitating demolding as claimed in claim 1, wherein: the middle part or the end part of the cavity is bent, and the thickness of the plating layer on the side wall of the cavity at the bent part is thinner than that of the plating layer in other areas.

9. The process for manufacturing a medical injection molding mold facilitating demolding according to any one of claims 1 to 8, wherein: the method comprises the following manufacturing steps:

10. The manufacturing process of the medical injection molding die convenient for demolding as claimed in claim 9, wherein: in the cavity, the width of the ceramic layer or the metal piece is smaller in an area where the bending degree of the cavity is larger or the fluctuation and fall of the side wall of the cavity is larger.