CN112549439A

CN112549439A - Multicolor injection molding piece and injection molding process thereof

Info

Publication number: CN112549439A
Application number: CN202011239515.9A
Authority: CN
Inventors: 王宁捷
Original assignee: Ningbo Sengcze Macrospray Co Ltd
Current assignee: Ningbo Sengcze Macrospray Co Ltd
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2021-03-26
Anticipated expiration: 2040-11-09
Also published as: CN112549439B; WO2022095285A1

Abstract

The invention discloses a multicolor injection molding part, wherein the multicolor injection molding part comprises an injection molding part body, the injection molding part body is formed by injection molding of at least one injection molding material, and the injection molding part body at least comprises two colors. Also discloses an injection molding process of the multicolor injection molding piece. The multi-color injection molding piece can realize the mutual fusion molding of multiple injection materials with different colors and the same material, and can also realize the mutual fusion molding of multiple injection materials with different colors and different materials; the appearance of the multicolor injection molding piece can be a color block splicing type injection molding piece or a color channel mixing type injection molding piece, so that the injection molding piece can present regular patterns or irregular moire patterns and colors, and the appearance color is rich; the problem that in the prior art, the injection materials made of different materials cannot be fused with each other or the injection materials made of the same or different materials can only be fused with one color or two colors is effectively solved.

Description

Multicolor injection molding piece and injection molding process thereof

Technical Field

The invention relates to the technical field of injection molding parts, in particular to a multicolor injection molding part and an injection molding process thereof.

Background

The multicolor injection molding process is the leading injection molding process in the global technology at present, bright-colored packages enable consumers to feel infinite visual enjoyment, and the process is a revolutionary promotion to cosmetics, daily chemical packages, food and beverage packages, commodity packages and the like, and makes injection molded products have a great breakthrough in anti-counterfeiting technology.

Compared with a single-color injection molding part, the injection molding part uses two or more colors on the same injection molding part, different positions on the part are distinguished, and the injection molding part is not the first choice of people, so that higher requirements are provided for injection molding products, particularly, a multicolor injection molding part becomes a process technology which needs to be overcome urgently in the current injection molding industry, and the same product uses different colors, so that great challenges are provided for the injection molding process. In order to overcome the difficult problem of multi-color injection molding of a product, a disposable injection molding process and a secondary or multiple injection molding process are adopted at present, the disposable injection molding process has extremely high requirements on injection molding conditions, two to three colors can be used on the same injection molding part at most, and a multi-color injection molding part injected by the secondary injection molding process can adopt various colors, but injection molding equipment and an injection molding process have complex structures and high operation difficulty, and are not beneficial to general popularization and use.

For example, Chinese patent literature (publication date: 2019, 12, 6 and publication number: CN 209738194U) discloses a multicolor mold, and belongs to the technical field of molds. It has solved the lower problem of production efficiency of current polychrome mould. This polychrome mould, including the fixed die plate and can be relative fixed die plate pivoted movable mould board, link firmly at least three fixed type groove on the fixed die plate, be connected with corresponding rotatory type groove on the movable mould board, each rotatory type groove forms an injection moulding die cavity with the butt joint of the fixed type groove that corresponds, rotatory type groove connects gradually into cyclic annularly, and adjacent rotatory type groove pastes each other and lean on, fixed type groove connects gradually into cyclic annularly, and adjacent fixed type groove pastes each other and leans on. The invention improves the compactness and the production efficiency of the die. The technical scheme is that corresponding rotation and injection molding are carried out according to the number of the injection molding cavities, so that the preparation of the multicolor plastic part of the multicolor mold can be realized.

For another example, chinese patent document (publication No. CN102357983B, 8/7/2013) discloses a multicolor calculus magic color injection molding apparatus for polymer materials, which belongs to the field of polymer material molding machinery, and mainly comprises three injection devices, a mold closing device, a color matching device, and a molding mold, wherein the molding mold is installed between a movable mold plate and a fixed mold plate of the mold closing device, the color matching device mainly comprises a heating device, a servo motor, a coupler, a bearing, a melt distribution shaft, a sprue bush, a melt distributor and a converging nozzle, the melt distributor comprises a sprue bush i, a sprue bush ii, a sprue bush iii, a melt distribution shaft, a converging nozzle, a bearing end cover, and a melt distributor, and the melt distribution shaft is connected with the servo motor through the coupler. The melt feeding amount of each sprue bush is accurately controlled through a servo motor, the color of the plastic product can be adjusted at will in the production process, and the appearance requirements of products with different colors are met. The principle of the equipment is simple and easy to realize, the equipment is reasonable in design, and the technical problem does not exist in processing and manufacturing. According to the technical scheme, the melt feeding amount of each sprue bush is accurately controlled through the servo motor, the color of the plastic product can be adjusted at will in the production process, the appearance requirements of products with different colors are met, and the plastic product with different color stripes can be formed by injection molding at one time.

Chinese patent literature (publication date: 11/1/2019, publication number: CN 108145909B) discloses an instantaneous forming process of a multicolor product, breaks through the process form of traditional forming, and performs injection molding on a multicolor product blank in a cold mold state; the blank of the multicolor product is kept in the same die without leaving the die cavity, so that the blank of the multicolor product can be ensured not to generate human operation error, gaps and air entering between the blank of the multicolor product and the die, the molded product can not generate low-quality conditions such as paint tracing and surface scorching caused by color cross, the condition that the traditional process needs to be performed with vacuum pumping operation before molding and the vacuum pumping is incomplete is avoided, and then the die is rapidly heated to the molding temperature to mold the multicolor product; opening the mold and taking out a multicolor product finished product; the mould is rapidly cooled to a cold mould state, and the multicolor product blank is injection-molded again in the cold mould state, so that the circulating instantaneous cooling and heating are carried out, and the multicolor product is formed simply, efficiently and smoothly with high quality.

In summary, although the above-mentioned technical solutions provide a multi-color injection mold, a multi-color injection molding machine and an injection molding process, and also meet the requirement that the same injection molding piece adopts different colors to a certain extent, the problem that different colors of the same injection material are fused together is solved in the existing technical solutions, and for different injection materials, the different colors are not fused together, and at the same time, the problem that different colors are not faint to each other is also met, which cannot be achieved; more crucial is, different notes material, whether the boundary line of different color junctions accords with the design requirement, can guarantee not to appear the boundary line skew, distortion, ladder scheduling problem. Therefore, a multicolor injection molding part and an injection molding process thereof are urgently needed to be designed, wherein the requirement that different injection materials are fused with each other, different colors are not faint with each other, and a boundary line meets the design expectation requirement.

Disclosure of Invention

The invention aims to provide a multicolor injection molding part which can realize that the injected materials with different colors cannot be faint, has clear boundaries, short molding period and high efficiency and an injection molding process thereof. This polychrome injection molding can be applicable to PP (polypropylene), HDPE (low pressure polyethylene), LLDPE (high pressure polyethylene), TPE (thermoplastic elastomer), multiple materials such as TPU (polyurethane elastomer are moulded plastics, and also can fuse each other between the different materials, overcome among the prior art in the injection molding only can adopt the defect of single material, the notes of having overcome different colors simultaneously produce the faint between the material, the boundary line is not conform to the anticipated requirement of design, lead to adopting injection molding outward appearance subalternation scheduling problem more.

The technical scheme adopted by the invention for realizing the first invention purpose is as follows: the utility model provides a polychrome injection molding, includes the injection molding body, the injection molding body at least by a material of moulding plastics form, the injection molding body contain two kinds of colors at least. The multicolor injection molding piece is an innovation aiming at the single color of the existing injection molding piece, and particularly relates to a multicolor injection molding piece which is formed by injecting materials with different colors and has different colors. The multi-color injection molding piece can be a color lump splicing injection molding piece and also can be a color channel mixing type injection molding piece, so that the injection molding piece can present regular patterns or irregular moire-shaped patterns, and the appearance color is rich.

Preferably, the injection molding material is one or more of polypropylene, low-pressure polyethylene, high-pressure polyethylene, thermoplastic elastomer and polyurethane elastomer. When selecting injection molding materials, the mating materials of the multi-colored injection molding materials must satisfy two basic compatibility conditions, i.e., adhesion compatibility and processing compatibility, respectively. The materials have high bonding compatibility and processing compatibility, and can ensure that injection molding materials with different colors and different materials are integrally formed after injection molding.

Preferably, the injection molding body is a part formed by injection molding, and the injection molding body is a spray pump pressing pump head, a bottle cap, a cover cap, a bottle body, a spray gun, a foam pump, a small spray pump, a household appliance and the like. The multicolor injection molding part disclosed by the invention mainly comprises a pressing pump head, a bottle cap and other closed injection molding parts, and the product has the advantages of small volume and clear structures of different color areas, and can ensure the normal installation and use of the skeleton type sideline correcting part.

Preferably, the injection molding part body is a secondary injection molding part and comprises a basic color injection molding body and a colorful injection molding body; thin-wall fusion bodies are arranged between the basic color injection molding bodies and the colorful injection molding bodies and between the colorful injection molding bodies. The utility model provides an injection molding body can be secondary injection molding spare, through the inside insulator of taking the isolation groove that sets up in the die cavity, the different colors that the quantity in the groove of isolation groove set up as required set up, and the isolation groove sets up through the baffle, and is provided with the basic look between the baffle and annotates the material chamber way, and the basic look is annotated the material chamber way and is used for annotating the material through the basic look and form thin wall fusion body. For example, seven colors are set, seven different color injection grooves need to be arranged on the isolation groove, the isolation body is arranged inside the die cavity before injection molding, basic color injection materials are injected into the die cavity and the natural color injection material cavity, in the basic color injection molding process, thin-wall fusion bodies which are integrally formed with the basic color injection materials can be formed at different color injection grooves, after the basic color injection materials are formed, the isolation body is taken out, pigments with different colors and the same material are respectively injected into different color injection grooves formed by the thin-wall fusion bodies, or pigments with different colors and different materials are injected into different color injection grooves, so that the thin-wall fusion bodies and the basic color injection molding bodies are mutually matched into a whole, multi-color injection molding pieces can be quickly formed, the injection materials of the different colors can be mutually fused, meanwhile, the color shading can be guaranteed, the boundary is clear, and the appearance effect is good.

Preferably, the thin-walled fusion body is integrally formed with the base color injection-molded body and is fused to the multicolor injection-molded body.

Preferably, the injection molding body is a one-time injection molding part and comprises a plurality of color block injection molding bodies; and a fusion line is formed at the mutual fusion position of the color block injection molded bodies. The injection molding part body can also be formed by one-time injection molding through arranging the isolating body with the isolating grooves, when the injection molding is carried out through the isolating body, the height of the isolating grooves on the isolating body is smaller than the height of the injection molding part, namely, a free fusion area with a certain height is reserved at the top of the isolating plate, so that injection materials with different colors are fused into a whole at the position, the height is generally set by taking the thickness of the injection material as a standard, namely, if the wall thickness of a bottle cap is 2mm, the height of the free fusion area is 2mm, and as the height is smaller than the size of the whole injection molding part, cross-area phenomena cannot be generated among the injection materials with different colors in the fusion process, namely, color halo phenomena cannot be generated, even if the injection materials are slightly deviated, the injection materials with different colors are not easily reflected on the whole appearance effect, so that the mutual fusion among the injection materials with different materials or the same material and different colors is realized, finally, the separator is removed through demoulding, and one-time injection molding is realized.

Preferably, the injection molding part body is an injection molding part, the skeleton type sideline correcting part is arranged at the joint of different colors of the injection molding part body, a through hole is formed in the skeleton type sideline correcting part, and the joint of the different colors of the injection molding part body penetrates through the through hole and is fused into a whole. The utility model provides an injection moulding also can adopt the mode realization of built-in skeleton formula sideline correction piece, when needs injection moulding, then only need be at the inside different color junction built-in skeleton formula sideline correction piece of die cavity, skeleton formula sideline correction piece sets up in the die cavity along different color boundary lines, guarantees that the material of annotating of different colors can not appear taking place on the surperficial integration of injection molding, colour mixture, the faint before the work feeding of moulding plastics finishes, guarantees that the different color boundary lines on injection molding surface are smooth-going, forms clear boundary line according to predetermineeing the pattern, can not appear annotating the material and follow the circumstances of the skew about the boundary line. The through holes on the framework type sideline correcting piece are used for mutually fusing and connecting the injection materials on the two sides of the framework type sideline correcting piece before cooling, so that the joint strength between different color areas can meet the manufacturing requirement. The built-in skeleton type sideline correcting piece can realize multi-material multi-color one-time injection molding of the injection molding piece body, and can also enhance the use strength of the injection molding piece,

Preferably, the shrinkage rate of the skeleton type sideline correcting piece is larger than that of the two-side injection molding materials. The shrinkage rate of the plastic material refers to the percentage of the difference between the size of the plastic part at the molding temperature and the size of the plastic part after being taken out of the mold and cooled to room temperature, and the parameters of the shrinkage rate are influenced by the type and molding mode of the plastic. When the material of the framework type sideline correcting piece is selected, the framework type sideline correcting piece which accords with the shrinkage rate relation is obtained through tests according to the types of the materials on the two sides; if the skeleton type sideline correcting piece is limited by experimental conditions, the shrinkage rate of the skeleton type sideline correcting piece can be ensured to be larger than that of injection molding materials on two sides according to the selection of a list of shrinkage rates of common plastic materials, the design ensures that two ends of the skeleton type sideline correcting piece are jointed with the inner wall and the outer wall of a die cavity in the expansion process of the skeleton type sideline correcting piece after heat transfer of molten injection materials on two sides, and the two ends of the skeleton type sideline correcting piece are gradually far away from the die cavity in the cooling shrinkage process and enter the multicolor injection molding piece. Because the heat is gradually dissipated in the cooling process, the surface of the injection molding part body is firstly changed from a liquid state to a solid state, and therefore when the skeleton type sideline correcting part gradually shrinks into the injection molding part body, the surface of the injection molding part body is basically shaped, and the problems of color mixing, deviation, distortion and non-design pattern forming of color boundary lines can be avoided. When the skeleton type sideline correcting piece gradually contracts and is influenced by structural stress, the surface of the injection molding piece body is closed and molded to form a smooth outer surface with clear color boundaries.

The technical scheme adopted by the invention for realizing the second invention purpose is as follows: an injection molding process of a multicolor injection molded part comprises the following steps:

step 1) starting an injection molding machine, and injecting various molten injection materials of the same or different materials into a plurality of injection molding plasticizing charging barrels of the injection molding machine according to the required color of an injection molding part;

step 2) controlling the corresponding injection units connected with the injection plasticizing charging barrel through a control system, and controlling the injection molding material amount of each injection unit;

step 3), arranging an isolation groove or arranging a skeleton type sideline correcting piece at the joint of different color areas in a mold cavity according to a preset structure of the multicolor injection molding piece;

step 4) controlling the injection temperature of the injection unit through a control system and injecting injection materials with colors and the same or different materials into a mold cavity with an isolated body or a skeleton type sideline correcting piece;

step 5) controlling the feeding temperature and the feeding time of each material in the die cavity through a control system, and realizing secondary molding or one-time molding of various color injection materials of the same or different materials after cooling;

and step 6), opening the mold to obtain the multicolor injection molding piece.

In the injection molding process disclosed by the invention, various injection materials with different colors required by injection molding are stored by a plurality of injection molding plasticizing charging barrels arranged in different injection units, and an isolating body with an isolating groove is arranged in a mold cavity according to the design scheme of an injection molding part body or a skeleton type sideline correcting part is arranged and fixed on a color boundary line of the isolating body, so that step-by-step feeding and secondary molding can be selected according to requirements; and synchronous feeding and one-step forming are realized. However, no matter secondary molding or primary molding, mutual fusion of multiple colors of injection materials with the same or different materials can be realized, finally, injection molding parts required in the invention, such as sprayer pump heads, bottle caps and the like, can be formed through injection molding of small-sized closure parts, in the secondary injection molding process, the isolating bodies are used as auxiliary parts of a mold cavity, and the isolating bodies are demolded with injection molding part bodies after injection molding, so that the injection parts need to be manufactured into isolating bodies with different structures according to different injection structures, and the formed multiple color injection parts have obvious thin-wall fusion bodies, so that color blocks of the multiple color injection parts are distinguished more obviously. The skeleton type sideline correcting piece required by one-time injection molding is built-in, and the skeleton type sideline correcting piece and the injection molding piece are integrally molded and then built in the multicolor injection molding piece to be used as a part of the injection molding piece and are not taken out any more, so that the skeleton type sideline correcting piece can be directly arranged according to different color boundary lines, and the areas with different colors are ensured to be separated before injection molding and feeding. According to a preset program, the control system controls the corresponding injection unit connected with the injection plasticizing charging barrel to carry out quantitative injection molding, and monitors the feeding temperature and feeding time of each injection material in the injection molding process to ensure that the solidification process of the injection materials on the two sides of the skeleton type sideline correcting piece is controllable. The skeleton type sideline correcting piece is heated to expand in the feeding process, two ends of the skeleton type sideline correcting piece are connected with the die cavity in the expansion process, the clear outlines of different color boundary lines are ensured, the positions are accurate, and the materials injected at two sides of the skeleton type sideline correcting piece are mutually fused and connected in the injection molding piece body through the through holes; and starting a cooling process after feeding is finished, wherein the injection molding part body and the skeleton type sideline correcting part contract together, and because the shrinkage rate of the skeleton type sideline correcting part is large, two ends of the skeleton type sideline correcting part are gradually far away from the mold cavity and enter the multicolor injection molding part in the contraction process, the injection materials on two sides of the end part of the skeleton type sideline correcting part are jointed to form a finished surface, and the boundary is clear and accurate. And opening the mold after cooling to obtain the multicolor injection molding part with good appearance effect and color boundary meeting the design requirement.

Preferably, in the secondary molding process, the height of the isolation body with the isolation groove, the height of the isolation plate forming the isolation groove, and the height of the injection molding piece are equal, the injection materials with different colors are not dissociated, and the injection unit is controlled by the control system to firstly inject the basic color injection material into the mold cavity; and after the basic color injection materials are cooled to the molding temperature, injecting injection materials with different colors into the isolation groove respectively, controlling the molding temperature of each injection material, and fusing each injection material with the basic color injection material to form a multi-color injection plastic part formed secondarily. The two-shot injection molding process is realized by adopting an isolating body, so that the process needs to determine a basic color, namely the integral color of a component, for example, a bottle cap, in the two-shot injection molding process, the peripheral cap body with a thread ring of the bottle cap is determined as the basic color, the top of the cap is selected to be injection molded into a multicolor structure, thus a isolating body is manufactured in advance, six isolating grooves are arranged on the isolating body, injection molding is firstly carried out on the basic color injection material required by the cap body to a mold cavity, after the cap body is molded, six thin-wall fusion bodies are formed on the cap body, then injection molding is carried out on the injection molding materials with different colors and the same or different materials in the six isolating grooves respectively, and the injection molding can be fused with the cap body to form the final bottle cap.

Preferably, in the one-step molding process, the isolation body with the isolation groove is provided, the height of the isolation plate forming the isolation groove is smaller than that of the injection molding part, free fusion areas of injection materials in different color areas are formed at the top of the isolation plate, the injection materials in different colors are fused in the free fusion areas in the injection molding process, and the injection unit is controlled by the control system to inject the injection materials in different colors into the isolation groove in the mold cavity; the two adjacent color materials are fused together in the free fusion area to form a fusion line, the molding temperature of each color material is controlled, and the multi-color plastic part is molded in one step.

Preferably, in the one-step molding process, the feeding temperature and the feeding time of each material in the mold cavity are controlled by the control system in the one-step molding process, the injection molding temperature of each material is obtained by calculation, the framework type sideline correcting piece undergoes an expansion-contraction process under the heat transfer of the injection materials at two sides, and the one-step molding of the injection materials with the same or different materials is realized after cooling.

Preferably, different color molding areas are arranged on the movable mold and the fixed mold corresponding to the injection unit, and a color point isolation structure for preventing halation is arranged between the adjacent color molding areas. The color point isolation structure is formed by a skeleton type sideline correction piece, the skeleton type sideline correction piece is of a composite structure in the method, and comprises a fusion section close to the surface of an injection molding piece body and a joint section arranged on the inner side of the fusion section, a through hole used for ensuring that injection materials on two sides of the joint section are fused and connected with each other is arranged on the joint section, and the melting point of the fusion section is higher than that of the injection materials on the two sides. In the process of moulding plastics, the higher heat transfer in-process that fuses the section of melting point can not annotate the material in both sides melts to this ensures that the faint color phenomenon does not appear between the different color molding region, annotates the material and finishes and fuses the section both sides and annotates the material and fill the back in place, carries out local secondary heating to fusing the section, makes fuse section and both sides and annotate the material and melt and combine simultaneously under local high temperature, because the existence that fuses the section, makes the both sides color region can not appear faint color phenomenon. The fusion section in the present claim is preferably made of transparent material, and if the contour of the boundary line of the different color regions of the injection molded part body is more demanding, the lighter color of the two side materials can be used as the natural color of the fusion section.

Preferably, the injection unit comprises a vertical injection unit arranged on the top of the fixed die plate, at least one piggy-back injection unit arranged on the non-operation side, and a main injection unit arranged on the movable die side. The injection molding process disclosed by the invention adopts a horizontal/vertical/parallel free combined injection molding device for processing, vertical injection is carried out from the top of a fixed mold, a backpack injection unit on the non-operation side and a main injection unit are arranged on the same plane, and injection is carried out from two directions. The main injection unit adopts a parallel injection unit mode and at least comprises more than one injection unit. It is worth noting that each injection unit is internally controlled by a computer and is in signal connection with each other, the injection amount is accurately controlled by an electric servo motor driving system, and multi-color injection molding can be carried out according to design requirements.

Preferably, the movable die is driven by a rotating disc to realize station switching. Namely, the movable mold can rotate, and only the fixed mold part can be influenced by the geometric shape of the product, so that the single-side good design concept can be realized by utilizing the technology. This technique is often used to save processing cycles, since it allows simultaneous injection molding. The technology is mainly suitable for processing drinking cups, handles, covers, sealing parts and the like.

Therefore, the invention has the following beneficial effects: (1) the multi-color injection molding piece can realize the mutual fusion molding of multiple injection materials with different colors and the same material, and can also realize the mutual fusion molding of multiple injection materials with different colors and different materials; the appearance of the multicolor injection molding piece can be a color block splicing type injection molding piece or a color channel mixing type injection molding piece, so that the injection molding piece can present regular patterns or irregular moire patterns and colors, and the appearance color is rich; the problems that in the prior art, the injection materials of different materials cannot be fused with each other or the injection materials of the same or different materials can only be fused with one color or two colors are effectively solved;

(2) the injection molding can be realized once or twice through the isolated body with the isolation groove, and the molded appearance has no color mixing and color halo;

(3) the skeleton type sideline correcting piece can be formed in one-step injection molding mode, the skeleton type sideline correcting piece is arranged in the die cavity along boundary lines of different colors, the fact that injection materials of different colors are fused, mixed and faint on the surface of the injection molding piece before injection molding work feeding is finished is guaranteed, smooth and smooth boundary lines of different colors on the surface of the injection molding piece are guaranteed, clear boundary lines are formed according to preset patterns, and the situation that the injection materials are deviated left and right along the boundary lines is avoided; the through holes on the skeleton type sideline correcting piece are used for fusing and connecting the injection materials on the two sides of the skeleton type sideline correcting piece before the injection materials are not cooled, so that the joint strength between different color areas can meet the manufacturing requirement;

(4) in the cooling process of the injection molding process, the injection molding part body and the skeleton type sideline correcting part contract together, and because the shrinkage rate of the skeleton type sideline correcting part is large, two ends of the skeleton type sideline correcting part are gradually far away from a mold cavity and enter the multicolor injection molding part in the contraction process, the injection materials on two sides of the end part of the skeleton type sideline correcting part are jointed to form a finished surface, and the boundary is clear and accurate;

(5) the skeleton type sideline correcting piece shrinks into the injection molding piece body, a structure that materials are injected at two sides of the through hole of the skeleton type sideline correcting piece and are fused and connected with each other is formed at the through hole of the skeleton type sideline correcting piece, and the skeleton type sideline correcting piece is used as a skeleton structure of the injection molding piece body after the injection molding piece body is molded to effectively increase the overall structural rigidity of the injection molding piece body;

(6) the color point isolation structure formed by the composite skeleton type sideline correcting piece needs to be heated secondarily after the materials are injected, so that the fusion section of the color point isolation structure is fused with the materials injected on two sides, and the integral molding of the injection molding piece body can be ensured by selecting the color of the fusion section, and the appearance of the injection molding piece body is free from the phenomenon of color faint.

Drawings

FIG. 1 is a schematic view of a multi-colored injection molded part of the present invention;

FIG. 2 is a top view of the multi-colored injection molded part of FIG. 1;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a cross-sectional view taken at X in FIG. 3;

FIG. 5 is a front view of the skeletal sideline corrector of the present invention;

FIG. 6 is a cross-sectional view of a skeletal sideline corrector of the present invention;

FIG. 7 is a side view of the skeletal trim component of the present invention;

FIG. 8 is a schematic view of a second structure of the skeleton edge corrector according to the present invention;

FIG. 9 is a schematic view of a third structure of the skeleton edge corrector in the present invention;

FIG. 10 is a schematic diagram of the structure of the color dot isolation structure before melting in example 2 of the present invention;

FIG. 11 is a schematic diagram of a molten color dot isolation structure in example 2 of the present invention;

FIG. 12 is a front view of the cross-section-varying skeleton type edge corrector in embodiment 3 of the present invention;

FIG. 13 is a cross-sectional view of the transformer section at a skeletal trim B-B of FIG. 12;

FIG. 14 is a cross-sectional view of the transformer section at a skeletal trim C-C of FIG. 12;

FIG. 15 is a schematic view of an injection-molded article body according to embodiment 4 of the present invention;

FIG. 16 is a schematic view showing a structure of a septum in example 4 of the present invention;

FIG. 17 is a schematic view of a structure of an injection-molded article body in embodiment 5 of the invention;

FIG. 18 is a schematic view showing a structure of a septum in example 5 of the present invention;

FIG. 19 is a schematic view of a configuration of an injection molding machine according to the present invention;

in the figure: 100. the injection molding machine comprises an injection molding machine body 1, an injection molding part body 101, a basic color injection molding body 102, a colorful injection molding body 103, a thin-wall fusion body 11, a first color block 12, a second color block 13, a third color block 14, a fourth color block 15, a fifth color block 16, a sixth color block 2, a skeleton type side line correction part 21, a contour line 3, a via hole 4, a color point isolation structure 41, a fusion section 42, a joint section 5, a vertical injection unit 51, a backpack injection unit 52, a main injection unit 53, a rotating disc 6, a variable-section skeleton type side line correction part 61, a shuttle part 7, an isolation body 71, an isolation groove 72, a partition plate 73, a basic color injection material cavity channel 74, a free fusion area 8 and a fusion line.

Detailed Description

The technical documents of the present invention will be further described in detail by the following specific embodiments in conjunction with the drawings attached to the specification.

Example 1:

as shown in fig. 1, 2 and 3, the multicolor injection molding part comprises an injection molding part body 1, wherein the injection molding part body 1 is formed by injection molding of at least one injection molding material, and the injection molding part body 1 at least comprises two colors. The injection molding material is one or more of polypropylene, low-pressure polyethylene, high-pressure polyethylene, thermoplastic elastomer and polyurethane elastomer, the injection molding body 1 is a part formed by injection molding, and the injection molding body is a spray pump pressing pump head, a bottle cap, a cover cap, a bottle body, a spray gun, a foam pump, a small spray pump, household appliances and the like. In this embodiment, the injection molding body 1 is the pump head is pressed to the spray pump. The multi-color injection molding part disclosed by the embodiment is an innovation aiming at the single color of the existing injection molding part, and particularly, the multi-color injection molding part with different colors is formed by injection molding of injection materials with different colors. The multi-color injection molding piece can be a color lump splicing injection molding piece and also can be a color channel mixing type injection molding piece, so that the injection molding piece can present regular patterns or irregular moire-shaped patterns, and the appearance color is rich. When selecting injection molding materials, the mating materials of the multi-colored injection molding materials must satisfy two basic compatibility conditions, i.e., adhesion compatibility and processing compatibility, respectively. The materials have high bonding compatibility and processing compatibility, and can ensure that injection molding materials with different colors and different materials are integrally formed after injection molding. The multicolor injection molding part disclosed by the invention mainly comprises a pressing pump head, a bottle cap and other closed injection molding parts, and the product has the advantages of small volume and clear structures of different color areas, and can ensure the normal installation and use of the skeleton type sideline correcting part.

As shown in fig. 4, the injection molding body 1 is a one-step injection molding part, and the joints of the injection molding body 1 with different colors are provided with skeleton type sideline correction pieces 2. The skeleton type sideline correcting piece 2 is provided with a through hole 3, and different color connecting positions of the injection molding piece body 1 penetrate through the through hole and are fused into a whole. The shrinkage rate of the skeleton type sideline correction piece 2 is larger than that of injection molding materials on two sides. As shown in fig. 5, 6, and 7, the skeleton-type sideline correction piece 2 is arranged in the mold cavity along the boundary of different colors, so that the situation that the injected materials of different colors are fused, mixed and faint on the surface of the injection molding piece before the injection molding work is finished and the feeding of the injected materials is finished is ensured, the boundary of different colors on the surface of the injection molding piece is smooth, a clear boundary is formed according to a preset pattern, and the situation that the injected materials are deviated left and right along the boundary is avoided. The through holes 3 on the skeleton type sideline correcting piece 2 are used for mutually fusing and connecting the injection materials on the two sides of the skeleton type sideline correcting piece before being cooled, so that the joint strength between different color areas can meet the manufacturing requirement, and the through holes 3 are arranged at the positions, far away from the edges, of the skeleton type sideline correcting piece 2, so that the surface appearance effect of the injection molding piece body 1 cannot be influenced by the blending of the injection materials at the through holes 3, and clear boundary lines are generated on the surface of the injection molding piece body 1 under the separation of the skeleton type sideline correcting piece 2. The shrinkage rate of the plastic material refers to the percentage of the difference between the size of the plastic part at the molding temperature and the size of the plastic part after being taken out of the mold and cooled to room temperature, and the parameters of the shrinkage rate are influenced by the type and molding mode of the plastic. When the material of the framework type sideline correcting piece 2 is selected, the framework type sideline correcting piece 2 which accords with the shrinkage rate relation is obtained through tests according to the types of the materials on the two sides; if the design is limited by experimental conditions, the shrinkage rate of the framework sideline correcting piece 2 can be selected according to a list of shrinkage rates of common plastic materials, and the shrinkage rate of the framework sideline correcting piece 2 is ensured to be larger than that of injection molding materials on two sides, so that in the expansion process of the framework sideline correcting piece 2 after heat transfer of melting injection materials on two sides, two ends of the framework sideline correcting piece 2 are jointed with the inner wall and the outer wall of a mold cavity, the contour lines of two ends of the framework sideline correcting piece 2 are flush with the surface of the injection molding piece body 1 and no groove structure is generated, if the condition is met, the section of the framework sideline correcting piece 2 along the normal direction of the color block boundary of the injection molding piece body 1 is required to be of a narrow-wide-narrow structure, and the influence of the two ends on the surface integrity of the. As shown in fig. 6, the cross section of the skeleton type sideline correcting piece 2 is in a shuttle-shaped structure; as shown in fig. 8, the cross section of the skeleton type sideline correction piece 2 is a diamond structure; as shown in fig. 9, the cross section of the skeleton type borderline corrector 2 may be an irregular diamond structure. And in the cooling shrinkage process, the two ends of the skeleton sideline correcting part 2 are gradually far away from the mold cavity and enter the multicolor injection molding part. Because the heat is gradually dissipated in the cooling process, the surface of the injection molding part body 1 is firstly changed from a liquid state to a solid state, and therefore when the skeleton type sideline correcting part 2 gradually shrinks into the injection molding part body 1, the surface of the injection molding part body 1 is basically shaped, and the problems of color mixing, deviation, distortion and non-shaping of color boundary lines according to design patterns cannot occur. When the skeleton type sideline correcting piece 2 gradually contracts and is influenced by internal stress, the surface of the injection molding piece body 1 is formed in a closed mode, and a smooth outer surface with clear color boundaries is formed. The shrinkage rate of the injection molding material selected in the embodiment is as follows, the polypropylene processing temperature is 250-270 ℃, and the shrinkage rate is 1.0-2.5%; the low-pressure polyethylene processing temperature is 250-270 ℃, and the shrinkage rate is 1.0-2.5%; the processing temperature of the high-pressure polyethylene is 160-260 ℃, and the shrinkage rate is 1.5-5.0%; the processing temperature of the high-pressure polyethylene is 260-300 ℃, and the shrinkage rate is 1.5-5.0%; the processing temperature of the polyurethane elastomer is 195-230 ℃, and the shrinkage rate is 0.9%; in the embodiment, the skeleton sideline correction part 2 can be made of plastic materials with higher shrinkage rate in the same processing temperature range according to the shrinkage rate of the injected materials at two sides, such as polyvinylidene fluoride, and the shrinkage rate of the polyvinylidene fluoride is 3.0-6.0% at the processing temperature of 250-270 ℃.

As shown in fig. 19, the multi-colored injection molded part disclosed in the present embodiment is realized by an injection molding process, comprising the steps of:

step 1) starting an injection molding machine 100, and injecting various molten injection materials of the same or different materials into a plurality of injection molding plasticizing charging barrels of the injection molding machine according to the required color of an injection molded part;

step 3), arranging skeleton type sideline correcting pieces at joints of different color areas in a mold cavity according to a preset structure of a multi-color injection molding piece;

step 4) controlling the material injection temperature of the injection unit through a control system and injecting colored injection materials with the same or different materials into the mold cavity;

step 5) controlling the feeding temperature and the feeding time of each material in the die cavity through a control system, and realizing one-step molding of various color injection materials of the same or different materials after cooling; in the one-step molding process, the feeding temperature and the feeding time of each material in the die cavity are controlled by the control system, the injection molding temperature of each material is obtained by calculation, the framework type sideline correction piece undergoes an expansion-contraction process under the heat transfer of the injection materials at two sides, and the one-step molding of the injection materials with different colors of the same or different materials is realized after cooling;

and step 6), opening the mold to obtain the multicolor injection molding piece.

In the injection molding process disclosed in this embodiment, various injection materials with different colors required for injection molding are stored in a plurality of injection molding plasticizing material cylinders arranged in different injection units, and a skeleton type sideline correction piece 2 is arranged and fixed on a color boundary line of an injection molding piece body 1 in a mold cavity according to a design scheme of the injection molding piece body, so that synchronous feeding and one-step molding are realized. The injection molding piece is a small-sized closure piece such as a sprayer pump head, a bottle cap and the like, so the skeleton type sideline correcting piece 2 can be directly arranged according to different color boundary lines, and the areas with different colors are ensured to be separated before injection molding and feeding. According to a preset program, the control system controls the corresponding injection unit connected with the injection plasticizing charging barrel to carry out quantitative injection molding, and monitors the feeding temperature and feeding time of each injection material in the injection molding process, so as to ensure that the solidification process of the injection materials at two sides of the skeleton type sideline correcting piece 2 is controllable. The skeleton type sideline correcting piece 2 is heated to expand in the feeding process, two ends of the skeleton type sideline correcting piece 2 are connected with the mold cavity in the expansion process, contour lines 21 at two ends of the skeleton type sideline correcting piece are flush with the surface of the injection molding piece body 1, the clear contours and accurate positions of boundary lines with different colors are ensured, injection materials at two sides of the skeleton type sideline correcting piece are fused and connected with each other in the injection molding piece body 1 through the through hole 3, the distance between the contour lines at two ends of the through hole 3 is equal, the joint of the injection materials at two sides is always located at the center of the injection molding piece body 1 after the injection materials are filled, and the uniformity and the overall quality of the injection molding; and after the feeding is finished, the cooling process is started, the injection molding part body 1 and the skeleton type sideline correction part 2 contract together, and because the shrinkage rate of the skeleton type sideline correction part 2 is large, the two ends of the skeleton type sideline correction part 2 are gradually far away from the mold cavity and enter the multicolor injection molding part in the contraction process, the injection materials on the two sides of the end part of the skeleton type sideline correction part 2 are jointed to form a complete surface, and the boundary is clear and accurate. And opening the mold after cooling to obtain the multicolor injection molding part with good appearance effect and color boundary meeting the design requirement.

As shown in fig. 19, the injection unit includes a vertical injection unit 5 disposed on the top of the stationary mold plate, at least one piggy-back injection unit 51 disposed on the non-operation side, and a main injection unit 52 disposed on the movable mold side. The movable mould is driven by a rotating disc 53 to realize station switching. The injection molding process disclosed by the invention adopts a horizontal/vertical/parallel free combined injection molding device for processing, vertical injection is carried out from the top of a fixed mold, a backpack injection unit on the non-operation side and a main injection unit are arranged on the same plane, and injection is carried out from two directions. The main injection unit adopts a parallel injection unit mode and at least comprises more than one injection unit. It is worth noting that each injection unit is internally controlled by a computer and is in signal connection with each other, the injection amount is accurately controlled by an electric servo motor driving system, and multi-color injection molding can be carried out according to design requirements. The movable mold of the injection molding device in the embodiment can rotate, and only the fixed mold part can be influenced by the geometric shape of a product, so that a single-side good design concept can be realized by utilizing the technology. This technique is often used to save processing cycles, since it allows simultaneous injection molding. The technology is mainly suitable for processing drinking cups, handles, covers, sealing parts and the like. In this embodiment, as shown in fig. 1, 2 and 3, the injection molded part body 1 is an aerosol pump pressing pump head, and includes a first color block 11 (lower connector of the pump head), a second color block 12 (gland), a third color block 13 (right part of the pump head), and a fourth color block 14 (left part of the pump head). And skeleton type sideline correction pieces are arranged among the color blocks.

Example 2:

as shown in fig. 10, unlike embodiment 1, different color molding regions are provided on the movable mold and the fixed mold corresponding to the injection unit in this embodiment, and a color dot isolation structure 4 for preventing halation is provided between the adjacent color molding regions. The color point isolation structure is formed by a skeleton sideline correction piece, in the embodiment, the skeleton sideline correction piece is of a composite structure and comprises a fusion section 41 close to the surface of the injection molding piece body 1 and a joint section 42 arranged on the inner side of the fusion section, the joint section is provided with a through hole 3 used for ensuring that injection materials on two sides of the joint section are fused and connected with each other, and the melting point of the fusion section is higher than that of the injection materials on two sides. In the injection molding process, the fusion section with higher melting point can not be melted in the heat transfer process of the injection materials at the two sides, so that the phenomenon of color faint between the molding areas with different colors can be ensured. As shown in fig. 11, after the material injection is completed and the materials are injected and filled in place at the two sides of the fusion section, the fusion section is locally heated for the second time, so that the materials injected at the two sides of the fusion section are simultaneously melted and combined at a local high temperature, and the color halo phenomenon does not occur in the color areas at the two sides due to the existence of the fusion section. If the position of the fusion section is not completely contracted into the injection molding part body, the redundant part of the fusion section protruding out of the surface of the injection molding part body can be removed through local polishing. In the embodiment, the fusion section is preferably made of a transparent part, and if the outline of the boundary of the different color regions of the injection molding part body has higher requirements, the light color of the materials on the two sides can be used as the natural color of the fusion section. In this embodiment, the fusion section and the joint section are made of different materials, and the material selection of the fusion section and the joint section needs to be selected according to two separated injection materials, the shrinkage rate of the joint section is greater than that of the two injection materials, and the melting point of the fusion section is greater than that of the two injection materials.

Example 3:

as shown in fig. 12, 13, and 14, unlike embodiment 1, in this embodiment, the skeleton-type edge line corrector has a variable cross-section structure along the length direction and the cross-section thereof along the normal direction of the color boundary, that is, the variable cross-section skeleton-type edge line corrector is a strip-shaped member with a wavy streamline profile, the skeleton-type edge line corrector includes a plurality of shuttle portions 61 connected end to end, a via hole 3 is disposed at the joint of the shuttle portions, and the via hole 3 is used for fusing and connecting the injection materials at the two sides of the skeleton-type edge line corrector 2. The variable cross-section framework sideline correcting piece is matched with the middle through hole, so that the existence of bubbles in the through hole of the framework sideline correcting piece with a certain cross section in embodiment 1 can be effectively avoided, in the embodiment, the variable cross-section framework sideline correcting piece is arranged behind a die cavity, in the material injection process, injection materials on two sides of the variable cross-section framework sideline correcting piece enter from an injection port, and after the injection materials contact the surface of the variable cross-section framework sideline correcting piece, the injection materials can smoothly and closely flow along the streamline structure on the outer surface of the variable cross-section framework sideline correcting piece, so that the injection materials flow along the length direction of the variable cross-section framework sideline correcting piece, and gas is smoothly discharged under the action of the streamline. And the via hole that sets up in shuttle type portion junction does not possess the space of gaseous retention because its place cross-section is the narrowest cross-section of variable cross section skeleton style sideline correcting part, and this makes annotate the inside bubble that can not remain of material back injection molding body, has stopped the inside bubble of injection molding body and has moved to the injection molding surface and cause appearance defect's problem. Effectively promote the injection molding body degree of consistency and surface bubble quantity, and then promote the whole quality of injection molding body.

Example 4:

in the present embodiment shown in fig. 15 and 16, the injection molded part body 1 is an over-molded part, and the injection molded part body 1 includes a basic color injection molded body 101 and a multicolor injection molded body 102; thin-wall fusion bodies 103 are arranged between the basic color injection molding body 101 and the multicolor injection molding body 102 and between the multicolor injection molding bodies 102. The thin-walled fusion 103 is integrally formed with the basic color injection molded body 101 and is fused with the multicolor injection molded body 102. The multicolor injection molding body 102 comprises six color blocks with different colors, namely a first color block 11, a second color block 12, a third color block 13, a fourth color block 14, a fifth color block 15 and a sixth color block 16, wherein each color block is respectively fused with the basic color injection molding body.

The multi-color injection molding part disclosed by the embodiment is realized by an injection molding process, and comprises the following steps:

step 3) arranging an isolating body with an isolating groove in the die cavity according to the preset structure of the multicolor injection molding part;

step 5) controlling the feeding temperature and the feeding time of each material in the die cavity through a control system, and realizing secondary molding of various color injection materials of the same or different materials after cooling; in the secondary molding process, the height of the isolation body 7 with the isolation groove 71 and the height of the partition plate 72 forming the isolation groove are equal to the height of an injection molding part, the injection materials with different colors are not dissociated, and the injection unit is controlled by the control system to firstly inject basic color injection materials into the mold cavity; after the basic color injection materials are cooled to the molding temperature, injecting injection materials with different colors into the isolation groove respectively, controlling the molding temperature of each injection material, and fusing each injection material with the basic color injection material to form a multi-color injection plastic part formed secondarily;

and step 6), opening the mold to obtain the multicolor injection molding piece.

An isolation body 7 with isolation grooves 71 is arranged in a mold cavity (see figure 16), the number of the grooves of the isolation grooves 71 is set according to different colors required to be set, for example, seven colors are set, seven different color injection grooves are required to be arranged on the isolation grooves, the color block isolation grooves are separated by partition plates 72, the partition plates are of a double-layer structure, basic color injection cavity channels 73 communicated with the mold cavity are formed between the partition plates, the isolation body is arranged in the mold cavity before injection molding, basic color injection materials are injected into the mold cavity, the basic color injection materials enter the mold cavity and the basic color injection cavity channels 73 to form a basic color injection molding body 101, thin-wall fusion bodies integrally molded with the basic color injection materials are formed at the different color injection grooves in the basic color injection molding process, and pigments of different colors of the same material or pigments of different colors of different materials are injected into the seven different color injection grooves respectively after the basic color injection molding, make it and basic colour injection moulding body mutually support as an organic whole, then can the rapid prototyping polychrome injection molding, the material of each colour notes can enough fuse each other, can also guarantee simultaneously not halation, and the boundary is clear, and the appearance is effectual. Since the two-shot molding process is realized by using an isolated body, the process needs to determine a basic color, i.e. the whole color of a component, as shown in fig. 16, in the embodiment, taking a two-shot molded bottle cap as an example, in the two-shot molding process, the cap body with a threaded ring of the bottle cap is determined as the basic color, and the top of the cap is selected as a multi-color structure by injection molding, so that an isolated body 7 is manufactured in advance, six isolation grooves 71 are arranged on the isolated body 7, partition plates 72 are arranged between the isolation grooves 71, the height of the partition plates 72 is equal to the height of an injection molding part, basic color injection material cavities 73 are formed between the partition plates 72, the basic color injection material required by the cap body is formed by injection molding to a mold cavity, six thin-wall blends formed by the basic color injection material are formed on the cap body after the cap body is molded, then the isolated body is taken out, and six injection materials with the same color or different materials are respectively injected into the six isolation grooves, the cover body can be provided with six color blocks, namely a first color block 11, a second color block 12, a third color block 13, a fourth color block 14, a fifth color block 15 and a sixth color block 16, which are fused with the cover body, and finally the multi-color bottle cap is formed (see fig. 15).

Example 5:

in the embodiment shown in fig. 17 and 18, the injection molded part body 1 is a one-time injection molded part, and the injection molded part body 1 comprises a plurality of color block injection molded bodies; and a fusion line 8 is formed at the mutual fusion position of the color block injection molded bodies. In this embodiment, the injection molding body is an integrated spray gun housing, and the housing is formed by one-step injection molding and comprises a first color block 11, a second color block 12, a third color block 13 and a fourth color block 14; the first color block 11, the second color block 12, the third color block 13, and the fourth color block 14 are formed with a blending line 8 therebetween.

step 5) controlling the feeding temperature and the feeding time of each material in the die cavity through a control system, and realizing one-step molding of various color materials of the same or different materials after cooling; in the one-step molding process, the isolation body with the isolation groove is provided, the height of the isolation plate forming the isolation groove is smaller than that of the injection molding part, free fusion areas of injection materials in different color areas are formed at the top of the isolation plate, the injection materials in different colors are fused in the free fusion areas in the injection molding process, and the injection unit is controlled by the control system to inject the injection materials in different colors into the isolation groove in the mold cavity; the two adjacent color materials are fused together in the free fusion area to form a fusion line, the molding temperature of each color material is controlled, and a multi-color plastic part is molded in one step;

and step 6), opening the mold to obtain the multicolor injection molding piece.

In this embodiment, the injection molded body 1 is formed by one-time injection molding by arranging the isolation body 7 with the isolation grooves 71 (see fig. 18), when the injection molded body 7 is formed by one-time injection molding, the height of the partition plates 72 between the isolation grooves 71 on the isolation body 7 is smaller than the height of the injection molded body, that is, a free fusion area 74 with a certain height is left on the top of the partition plates 72 for fusing injection materials with different colors, and the height is generally set according to the thickness of the injection materials, in this embodiment, a cover is taken as an example, the wall thickness of the cover is 2mm, the height of the free fusion area is 2mm, because the height is smaller than the whole injection molded body, the cross-over phenomenon between the injection materials with different colors in the fusion process can not be generated, that is, the color halo phenomenon can not be generated, even if the injection materials slightly deviate, the overall appearance effect is not easily realized, therefore, the mutual fusion between the injection materials of different materials or different colors of the same material is realized, and finally, the injection molding is realized once through demoulding and separating the body.

The person skilled in the art will be able to implement the invention on the basis of the above-described embodiments. In addition, the above-described embodiments are merely examples of the present invention, and are generally not all examples of the present invention. Therefore, all other technical documents and embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

Claims

1. The utility model provides a polychrome injection molding, includes injection molding body (1), its characterized in that: the injection molding body (1) is at least formed by injection molding of one injection molding material, and the injection molding body (1) at least comprises two colors.

2. The multi-colored injection molded part of claim 1, wherein: the injection molding material is one or more of polypropylene, low-pressure polyethylene, high-pressure polyethylene, thermoplastic elastomer and polyurethane elastomer.

3. A multicolor injection-molded part according to claim 1 or 2, characterized in that: the injection molding part body (1) is a secondary injection molding part, and the injection molding part body (1) comprises a basic color injection molding body (101) and a colorful injection molding body (102); thin-wall fusion bodies (103) are arranged between the basic color injection molding bodies and the multicolor injection molding bodies and between the multicolor injection molding bodies.

4. A multicolor injection molded part according to claim 3, characterized in that: the thin-wall fusion body (103) and the basic color injection molding body (101) are integrally molded and are fused with the colorful injection molding body (102).

5. The multi-colored injection molded part of claim 1, wherein: the injection molding part body (1) is an injection molding part, and the injection molding part body (1) comprises a plurality of color block injection molding bodies; and a fusion line (8) is formed at the mutual fusion position of the color block injection molded bodies.

6. A multicolor injection-molded part according to claim 1 or 2, characterized in that: the injection molding body (1) be once injection molding spare, injection molding body (1) in be provided with skeleton sideline correction piece (2) along different color boundary lines, be provided with via hole (3) on skeleton sideline correction piece (2), injection molding body (1) different color junction link through hole (3) and fuse each other and be an organic whole.

7. The multi-colored injection molded part of claim 6, wherein: the shrinkage rate of the framework type sideline correcting piece (1) is larger than that of injection molding materials on two sides; the skeleton type sideline correcting piece (2) is arranged along the boundary line of the connection position of different colors of the injection molding piece body (1), and the cross section of the skeleton type sideline correcting piece (2) along the normal direction of the color boundary line is of a structure with a wide middle part and narrow two ends.

8. An injection molding process of a multicolor injection molding part is characterized by comprising the following steps:

step 3), arranging an isolating body with an isolating groove or arranging a skeleton type sideline correcting piece at the joint of different color areas in a mold cavity according to a preset structure of the multicolor injection molding piece;

step 4) controlling the injection temperature of the injection unit through a control system and injecting injection materials with same or different colors and materials into a mold cavity provided with an isolated body or a framework type sideline correcting piece;

and step 6), opening the mold to obtain the multicolor injection molding piece.

9. The injection molding process of a multicolor injection molded part according to claim 8, wherein: in the secondary molding process, the height of the partition plate with the isolation groove is equal to the height of the injection molding part, the injection materials with different colors are not dissociated, and the injection unit is controlled by the control system to inject basic color injection materials into the mold cavity; and after the basic color injection materials are cooled to the molding temperature, injecting injection materials with different colors into the isolation groove respectively, controlling the molding temperature of each injection material, and fusing each injection material with the basic color injection material to form a multi-color injection plastic part formed secondarily.

10. The injection molding process of a multicolor injection molded part according to claim 8, wherein: in the one-step molding process, the isolation body with the isolation groove is provided, the height of the isolation plate forming the isolation groove is smaller than that of the injection molding part, free fusion areas of injection materials in different color areas are formed at the top of the isolation plate, the injection materials in different colors are fused in the free fusion areas in the injection molding process, and the injection unit is controlled by the control system to inject the injection materials in different colors into the isolation groove in the mold cavity; the two adjacent color materials are fused together in the free fusion area to form a fusion line, the molding temperature of each color material is controlled, and the multi-color plastic part is molded in one step.

11. The injection molding process of a multicolor injection molded part according to claim 8, wherein: in the one-step molding process, the feeding temperature and the feeding time of each material in the die cavity are controlled by the control system, the material injection molding temperature of each material is obtained through calculation, the framework type sideline correcting piece undergoes an expansion-contraction process under the heat transfer of the material injection at two sides, and the one-step molding of the material injection of each color of the same or different materials is realized after cooling.

12. The injection molding process of a multicolor injection molded part according to claim 8, wherein: different color molding areas are arranged on the movable mold and the fixed mold corresponding to the injection unit, and a color point isolation structure for preventing halation is arranged between the adjacent color molding areas; the injection unit comprises a vertical injection unit arranged at the top of the fixed die plate, at least one piggy-back injection unit arranged on the non-operation side and a main injection unit arranged on the movable die side; the movable mould realizes the switching of station through a rotary disk drive.