CN101462351A - Plastic special-shaped section bar same-mold different-exit extruding mold - Google Patents

Abstract

The invention discloses an extruding die for plastic profiled materials with the same die and different output, and belongs to the field of design and manufacture of plastic extruding dies. It is characterized in that the extruding mold includes a distribution base, a transition plate, a distribution cone, a transition backing plate, a distribution support plate, a pre-compression plate, a compression plate, a pre-forming plate, a die plate and a mold core. The plastic melt extruded from the extruder is diverted through the runners with different structural parameters on the diverter base, and then enters the left and right runners of the mold with different structural parameters, and is extruded from the die plate after diversion and compression , forming plastic parisons with different cross-sectional shapes, and finally forming plastic profiles with different cross-sectional shapes after cooling and shaping. The structural parameters of the mold flow channel are determined by finite element numerical analysis and optimization methods to ensure the flow balance of the melt in each flow channel and the same extrusion speed, and realize the simultaneous production of two plastic profile products with different cross-sectional shapes on one extrusion line . The invention has the advantages of simple structure and high production efficiency.

Description

A kind of plastic special-shaped section bar same-mold different-exit extruding mold

Technical field

The invention belongs to extrusion die design and manufacturing technology field, relate to a kind of design of plastic special-shaped section bar same-mold different-exit extruding mold.

Background technology

Plastic extruding forming becomes one of main forming method of plastic products owing to having advantages such as efficient height, small investment, easily manufactured, continuity production and clean environment.According to statistics, the output of extruded product has accounted for more than 40% of whole plastic products total output.Extrusion molding mould almost can molded all thermoplastics and some thermosetting plastics, particularly door and window with plastic irregular profile have energy-conservation, economize material, anticorrosion, fire-retardant, sound insulation, attractive and durable, a series of characteristics such as construction is convenient, make it promptly be used and promote.

Extrude in the production process at plastic irregular profile, extrusion die plays crucial effect, and it directly affects profile shapes Products Quality and production efficiency.In order to enhance productivity, extrusion die can carry out extruding synchronously with a kind of bifilar or multiply of profile shapes at present, and mold runner is identical two or more independent die cavity.Because characteristics such as plastic shaped material products demand has single product duration weak point, product consumption is big in the cycle, variety variations is many, and the particularity of continuity production, make profile shapes production big to the unit consumption of water, electricity, gas equal energy source, make profile shapes production become short, wide in variety centralized production of cycle, therefore use two-chamber and multi-cavity extrusion die can significantly improve production efficiency.

Yet, along with increasing gradually of plastic irregular profile new range new varieties, renewal speed is constantly accelerated, two-chamber and multi-cavity extrusion die can not practical requirement, this just needs enterprise to carry out large scale investment to buy extrusion die and extrude production equipment, and this has become the especially capital bottleneck that further develops of medium-sized and small enterprises of profile shapes manufacturing enterprise.Therefore, how better to solve problems such as plasticity height that production equipment less investment, mould produce and product matching are strong, become the problem that present profile shapes manufacturing enterprise mainly considers.If can not increase under the prerequisite of extruding production equipment, utilize existing working condition, produce the plastic irregular profile of many kinds by manufacturing and designing novel extrusion die, this will directly accelerate profile shapes manufacturing enterprise and develop growth rapidly, also will solve the low problem of present extruding production line production capacity simultaneously.

Summary of the invention

The object of the present invention is to provide a kind of plastic special-shaped section bar same-mold different-exit extruding mold, be used on same strip extrusion production line, extruding simultaneously the plastic shaped material products of two kinds of different cross section shapes, can solve enterprise is that increase profile shapes kind significantly increases the problem to the extrusion equipment capital input, significantly improve production efficiency, shorten the manufacturing cycle, reduce manufacturing cost.

Technical scheme of the present invention is a kind of plastic special-shaped section bar same-mold different-exit extruding mold, comprising: shunting base, rebound, branch flow cone, transition backing plate, shunting supporting plate, precompression plate, compressive plate, preformed board, mouth template and core.This mould is installed on the ring flange of extruder, the polymer melt of fusion is after the runner shunting of passing through different structure parameter on the shunting base under the effect of pressure, enter the mould left side and the right side runner of different structure parameter separately, after shunting and compression, extrude from mouth template at last, form the plastic parison of different cross section shape, at last through forming the plastic irregular profile of different cross section shape behind the cooling and shaping.Influencing the dynamically balanced flow passage structure parameter of melt-flow in this mould adopts finite element numerical analysis and optimization method to determine, promptly with flow equilibrium as the optimization aim function,, fall as state variable with pressure as design variable with structural parameters, moving numerical analysis side realizes in conjunction with limited flow filament.The mode of pin location, bolted is all adopted in connection between each plate of this mould.The shunting base is divided into upper and lower two parts in the horizontal direction, is beneficial to machining, adopts the mode of pin location, bolted to connect into an integral body.

For the less plastic shaped material products of sectional dimension, the left and right sides runner that links to each other with the shunting base in the mould also can be designed to two or more runners separately, realizes two kinds of profile shapes goods one extrusion moldings that mould four goes out or a mould has more.

Effect of the present invention and benefit are: by the novel plastic special-shaped section bar same-mold different-exit extruding mold that manufactures and designs, can be implemented in the plastic shaped material products of two kinds of different cross section shapes of extrusion molding on the same strip extrusion production line, this will directly solve section bar manufacturing enterprise carries out large scale investment to extrusion die and production equipment capital bottleneck, significantly improve production efficiency, shorten the manufacturing cycle, reduce manufacturing cost, promote the fast development that plastics are extruded industry.

Description of drawings

Fig. 1 is the plastic special-shaped section bar same-mold different-exit extruding mold schematic diagram.

Among the figure: 1 shunting base; 2 rebounds; 3 fens flow cones; 4 transition backing plates; 5 shunting supporting plates; 6 precompression plate; 7 compressive plates; 8 preformed board; 9 mouth templates; 10 cores; 11 part runner on the left side; 12 part runner on the right side.

Fig. 2 is a mold runner design of Structural Parameters flow chart of the present invention.

Fig. 3 is the sectional view of PVC plastic irregular profile BR80.

Fig. 4 is the sectional view of PVC plastic irregular profile HS80.

Fig. 5 is a same-mold different-exit extruding mold installation diagram front view.

Fig. 6 is a same-mold different-exit extruding mold installation diagram vertical view.

The specific embodiment

Be described in detail most preferred embodiment of the present invention below in conjunction with technical scheme and accompanying drawing.

Going out with PVC plastic door and windows profile HS80 and BR80 isotype different below is example, and the process that manufactures and designs of same-mold different-exit extruding mold is described, Fig. 3 and Fig. 4 are respectively the sectional view of profile shapes goods HS80 and BR80.The embodiment step is as follows:

Step 1. is set up the three-dimensional flow analysis simulation model

In CAD system, set up the mold runner threedimensional model, import to then in the flow simulations software systems, set up flow analysis emulation threedimensional model.

Step 2. dividing elements

Adopt substep dividing elements strategy, the flow simulations threedimensional model is carried out dividing elements, under the prerequisite that guarantees computational accuracy, improve computational efficiency.Present embodiment adopts 3D FLOTRAN Unit 142 that model is carried out dividing elements.

Step 3. applies initial and boundary condition

At first apply primary condition: plastic pvc density, specific heat and thermal conductivity factor, rheological equation adopts the Bird-Carreau model; Apply boundary condition then: the entrance velocity of melt, outlet pressure, wall slippage speed and forming temperature.

Step 4. flow simulations result and analysis

After finishing the finite element solving of melt flows process in the die head, by corresponding post processing is set, can obtain the VELOCITY DISTRIBUTION and the pressure distribution of plastic melt in the mold runner, whether whether balance is identical with exit, mould left and right sides extruded velocity to judge the interior melt flows of runner, if imbalance of flow and extruded velocity are inequality, then need to adjust mold structure parameter.If imbalance of flow then needs to adjust the structural parameters (angle of flare, diversion angle, compression ratio, compression angle, shaping segment lenght) of mold runner; If extruded velocity is inequality, then need to adjust the structural parameters (diameter, angle, length) of shunting base runner.

Step 5. mold runner structure optimization design

If melt flows is uneven and extruded velocity is inequality, the mold runner structural parameters need be carried out the optimal design of mold runner structural parameters as the optimal design variable, optimization aim is represented the mean square deviation of outlet average speed with die head exit place all subregion average speed.More even, the isotype different identical extruded velocity that goes out to have of each position melt flow of mould outlet place after the optimal design.Carry out the mould design according to the optimal design result, Fig. 5 and Fig. 6 are respectively the front view and the vertical view of profile shapes HS80 and BR80 same-mold different-exit extruding mold installation diagram.

The manufacturing of step 6. same-mold different-exit extruding mold with extrude production

Adopt Machining Technology to finish the manufacturing of extrusion die.The runner of extrusion die is mainly based on changes of section and elongated runner, so mold runner processing mainly is to adopt line cutting and NC Milling method.After finishing a whole set of mould manufacturing, on extruding production line, carry out extrusion molding debugging and production.

Step 7. is isotype differently to go out the shape product quality testing

Differently go out extrusion molding and obtain HS80 and two kinds of profile shapes goods of BR80 through isotype, cross sectional shape, size and the surface quality of goods are carried out coherent detection, the result shows that two kinds of profile shapes goods reach criterion of acceptability fully.

Claims (3)

1. An extrusion die for plastic profiled materials with the same mold and different exits, including a diversion base (1), a transition plate (2), a diversion cone (3), a transition backing plate (4), a diversion bracket plate (5), a pre-compression plate (6), compression plate (7), preformed plate (8), mouth template (9) and core (10), it is characterized in that: the left runner (11) on the diverter base (1) is connected with the left side of the mould. The runners are connected, and the right runner (12) is connected to the runner on the right side of the mold; the structure of the left runner (11) and the right runner (12) on the runner base (1) are different, and the structures of the left and right runners of the mold are different , determined by finite element numerical analysis and optimization methods, so that the melt flow balance and extrusion speed in the flow channel are the same. 2. A kind of extrusion die for plastic profiled material with same mold and different exit according to claim 1, characterized in that: the left and right flow channels connected with the diversion base (1) in the mold are respectively designed as two or more The flow channel realizes the extrusion molding of two special-shaped products in one mold with four outs or one mold with multiple outs. 3. A kind of extrusion die for plastic profiled material with same mold and different output according to claim 1, characterized in that: the diverter base (1) is divided into upper and lower parts in the horizontal direction, which are fixed by pins and fastened by bolts. connected into a whole.

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