CN107246927B

CN107246927B - plastic demolding force testing method

Info

Publication number: CN107246927B
Application number: CN201610267930.2A
Authority: CN
Inventors: 邱琪浩; 徐小武; 周志峰; 周浩; 施懿军; 傅建永
Original assignee: NINGBP ZHETIE DAFENG CHEMICAL Co Ltd
Current assignee: NINGBP ZHETIE DAFENG CHEMICAL Co Ltd
Priority date: 2016-04-26
Filing date: 2016-04-26
Publication date: 2020-01-31
Anticipated expiration: 2036-04-26
Also published as: CN107246927A

Abstract

The invention discloses a plastic demolding force testing mold and a method thereof, which solve the problems that molds can completely and comprehensively test plastic particles and the evaluation on the demolding performance of the plastic particles causes the difficulty of fixation, and the technical scheme is characterized in that an ejection device comprises an ejection plate and ejector pins, a bottom plate of a fixed mold is provided with ejector pin grooves for the ejector pins to penetrate through, two opposite side plates of the fixed mold are pivoted with the bottom plate to be capable of outwards turning by 0.2-5 degrees to form corresponding demolding angles, the fixed mold is fixed through corresponding fixing devices, the bottom plate and the side walls on the inner side of the fixed mold are respectively provided with a pressure sensor and a pressure terminal, and detection signals of the pressure sensors are processed through a processing unit, so that the two opposite side plates of the fixed mold can outwards pivot to realize different demolding slopes, the change angles are rapid and convenient, the cycle of comprehensive detection of adjusting the demolding angles is greatly saved, and comprehensive and data can be obtained.

Description

plastic demolding force testing method

Technical Field

The invention relates to the field of molds, in particular to a method for testing the demolding force of types of plastics.

Background

With the rapid development of the mold industry, various molds are widely applied to the mass production process of industrial products, the injection molded products are molded by corresponding molds, the injection molded products are molded and cured, and then are taken out from a mold cavity or a mold core, so called demolding is commonly known, the poor demolding is which is an important reason of the quality defect of the injection molded products and influences the production efficiency, if the demolding performance is poor, the problems of deformation of the products, white marks on the thimble, size deviation and the like can be caused, if the demolding performance is poor, the materials can be easily adhered and remained on the metal cylinder wall, further coking and decomposition are carried out to form impurities, surface particles are lightly pitted, surface scratches and ripples are seriously caused, the surface condition of the products is seriously damaged, whether the design of a demolding mechanism in the mold is reasonable or not, the surface quality and the physical performance of the products are directly influenced, the internal pressure of the mold needs to be monitored in real time in the injection molding, pressure maintaining and cooling and demolding stages, but plastic particles in the prior art can not be completely tested, and the comprehensive demolding performance of the plastic particles is difficult to be evaluated.

Disclosure of Invention

The th invention of the present invention is to provide kinds of test molds which can test the demolding force of the side wall and the bottom wall at different demolding angles conveniently, rapidly and comprehensively.

The technical purpose of the invention is realized by the following technical scheme:

kinds of plastics mold release force test mould, including injection apparatus, movable mould, cover half and ejecting device, characterized in that, ejecting device includes ejector plate and thimble, be provided with the thimble groove that supplies the thimble to wear to establish on the bottom plate of cover half, two relative curb plates of cover half and bottom plate pivot mutually and make and can outwards overturn 0.2 ~5 to form its corresponding drawing of patterns angle to fix through corresponding fixing device, the bottom plate and the lateral wall of cover half inboard all are provided with pressure sensor, still include pressure terminal, the pressure terminal with pressure sensor is coupled to with pressure sensor to handle pressure sensor's detected signal through processing unit, final output initial drawing of patterns force.

By adopting the technical scheme, the simulation of a real simple injection mold is realized, at least pressure sensors are arranged in the movable mold, and the pressure sensors are connected with an external pressure terminal, so that the pressure in the mold in the injection molding, pressure maintaining cooling and demolding ejection stages in the fixed mold can be detected, and the pressure is fed back to the pressure terminal after being processed by the processing unit, therefore, the simulation device has the advantages of low cost and reliable detection data, and because the demolding inclination is required to be adjusted frequently in the demolding process, the adjustment angle of the mold is approximately between 0.2 and 5 degrees, two opposite side plates of the fixed mold can be pivoted outwards to realize different demolding inclinations, the change angle is quick and convenient, the cycle of adjusting the comprehensive detection of the demolding angle is greatly saved, and comprehensive and accurate data can be obtained.

A further step of the invention is that the exterior of the fixed die is provided with a outer die, a cavity into which a positioning block can be inserted is formed between the outer die and the side wall of the fixed die, and the positioning block is provided with a slope which is matched with the side plate after the side plate is turned over at an angle of .

Through adopting above-mentioned technical scheme, can realize through inserting the fixed plate that has face inclination and the inclination degree of curb plate is the same in the cavity behind the drawing of patterns angle that curb plate upset was decided, can play and fix the curb plate after rotatory corresponding angle, avoid the off tracking of inclination.

A further step is provided in that the movable mold and the fixed mold form an even number of rectangular parallelepiped shaped cavities.

By adopting the technical scheme, multiple cavities are formed in dies, so that multiple groups of data can be acquired times.

A step of the present invention is that the top of the thimble is provided with a pressure sensor.

By adopting the technical scheme, the sensor is also arranged at the top of the ejector pin, so that the bottom demolding force at the position of the ejector pin rod can be detected most visually.

A further step of the present invention is where each sidewall in the stationary mold is provided with a pressure sensor.

Through adopting above-mentioned technical scheme, all be provided with pressure sensor at every lateral walls departments, can play many places and measure, it is that measured data is more comprehensive.

The invention further provides , wherein the raw materials in the injection device are at least of polyethylene, polypropylene, polycarbonate, ABS, PS and PA.

Through adopting above-mentioned technical scheme, can make the multiple raw materials that plastics were moulded plastics obtain test data, and test data can also transversely contrast, and data are comprehensive effective.

The second invention aims to provide methods for testing the demolding force of plastics, which comprise the following steps of (a) pivoting two side plates of a fixed die outwards at the same angle of to form a demolding angle of α, (b) inserting corresponding positioning blocks into a cavity to position the side plates, (c) selecting corresponding raw materials to be added into an injection device, homogenizing and melting the raw materials by the injection device, (d) injecting the raw materials into a cavity between the fixed die and a movable die for injection molding, cooling and shaping, and opening the die, (e) ejecting out by an ejecting device, wherein a pressure sensor on an ejector pin obtains a pressure value Ft1 and a pressure sensor on a side wall obtains a pressure value Fb, and (f) processing the obtained pressure values Ft1 and Fb by a processing unit to obtain the final initial demolding force.

The invention further provides , wherein the step f comprises (1) converting Ft2 ═ Fb (mu cos α -sin α) by substituting the collected Fb value of the side wall into the formula to obtain Ft₂(ii) a (2) Collecting Ft1 values and Ft2 values in each cavity to obtain Ft_1a、Ft_1b、Ft_1c、Ft_1d、Ft_1e...Ft_1nAnd Ft_2a、Ft_2b、Ft_2c、Ft_2d、Ft_2e....Ft_2nAveraging the above data to obtain Ftavg₁＝(Ft_1a+Ft_1b+Ft_1c+Ft_1d+Ft_1e+...Ft_1n)/n；Ftavg₂＝(Ft_2a+Ft_2b+Ft_2c+Ft_2d+Ft_2e+...Ft_2n)/n。

A further step of the method includes collecting Ft in step 2 before averaging_1a、Ft_1b、Ft_1c、Ft_1d、Ft_1e...Ft_1nAnd Ft_2a、Ft_2b、Ft_2c、Ft_2d、Ft_2e....Ft_2nThe maximum and minimum values were removed from both sets of data.

Drawings

FIG. 1 is an external overall schematic view of a plastic release force testing mold;

FIG. 2 is a schematic view of a movable mold, a fixed mold and an ejection device of the plastic demolding force testing mold;

FIG. 3 is a schematic view of a stationary mold of example 1;

FIG. 4 is a schematic view of a stationary mold of example 2;

FIG. 5 is a cross-sectional view of the stationary mold (wherein the locating block is not placed in the chamber);

FIG. 6 is a cross-sectional view of the stationary mold (with the locating block placed in the chamber);

fig. 7 is a flow chart of a method of testing a mold for plastic ejection force.

In the figure, 1, a moving die; 11. a main flow to the aperture; 2. fixing a mold; 21. a cavity; 211. a side plate; 22. an outer membrane; 221. a cover plate; 222. a chamber; 23. positioning blocks; 3. an ejection device; 31. ejecting the plate; 32. a thimble; 4. a pressure sensor; 5. and (5) an injection molding machine.

Detailed Description

The present invention is further described in detail below with reference to the attached figures.

Example 1:

referring to fig. 1, a schematic diagram of a mold for testing a plastic mold release force sequentially includes an injection molding machine 5, a fixed mold 2, a movable mold 1 and an ejection device 3, wherein the fixed mold 2 is rectangular and includes 2 rectangular cavities 21, main channel holes are formed in the movable mold 1, the main channel holes respectively flow into the two cavities 21 through two sub-channels, the injection molding machine 5 is communicated with the main channel holes, and a heated and melted raw material is injected into the cavity 21 formed between the fixed mold 2 and the movable mold 1, wherein the raw material may be at least of polyethylene, polypropylene, polycarbonate, ABS, PS and PA, and certainly, in order to test different mold release force performances after different raw materials are added, the raw materials may be a plurality of combinations.

Referring to fig. 2 and 3, the pressure sensors 4 are disposed at the centers of four side walls and the bottom of the cavity 21 of the fixed mold 2, the top ends of the positions of the pressure sensors 4 are on the same horizontal line with the side walls and the bottom wall of the fixed mold 2 to prevent the data detection deviation of the protruded pressure sensors 4 during the inspection, the pressure sensors 4 are coupled to pressure terminals, and the pressure sensors 4 are processed by a processing unit to finally output the initial mold release force.

Referring to fig. 5 and 6, outer films 22 are respectively arranged on the outer parts of the fixed mold 2, the length of the outer films 22 is greater than that of the fixed mold 2, that is, a cavity 222 is formed between two opposite side walls of each cavities 21 and the outer films 22, a openable cover plate 221 is arranged on the bottom wall of the cavity 222 opposite to the fixed mold 2, the two opposite side walls of the fixed mold 2 can pivot on the bottom wall by 0.2-5 degrees, after the two side plates 211 pivot by the same angle, the cover plate 221 can be opened, and a positioning block 23 is inserted, wherein the positioning block 23 has an inclined surface matched with the side plate 211 after being turned over by degrees, so as to fix the side plate 211.

FIG. 7 is a flow chart of a method for testing a mold for testing a plastic demolding force, please and refer to the attached drawings, first two side plates 211 of a fixed mold 2 are pivoted outwards at the same angle to form a demolding angle α, then a cover plate 221 at the bottom is opened, a positioning block 23 with a corresponding α inclined surface is selected, the positioning block 23 is inserted into a cavity 222 to position and fix the side plates 211, corresponding raw materials are selected, an injection device is started to homogenize and melt the raw materials, the raw materials are injected into a cavity 21 between the fixed mold 2 and a movable mold 1 for injection molding, the mold is cooled and shaped, the mold is opened, a jacking device is ejected, the jacking device is ejected, pressure sensors 4 on a thimble 32 and a bottom wall obtain pressure values Ft1 and a pressure value Fb on a side wall obtain a pressure value Fb, the obtained by a pressure sensor 4 on the side wall, the obtained data are collected by a processing unit, the obtained by substituting Ft 2-Fb (mu cos α -sin α) value in a formula to obtain an Ft2, an average Ft2, an F

Ftavg1＝(Ft1a+Ft1b+Ft1c+Ft1d+Ft1e+...Ft1n)/n；

Ftavg2 ═ (Ft2a + Ft2b + Ft2c + Ft2d + Ft2e +. Ft2n)/n, the final initial release force was obtained and displayed by press termination.

So come, the simulation of real simple and easy injection mold, can implement the detection to the inside pressure of mould at the inside injection moulding of cover half 2, pressurize cooling, the ejecting stage of drawing of patterns, and after handling through the processing unit, feed back to pressure terminal department, it is with low costs, detect the reliable effect of data, and wherein two relative curb plates 211 of its cover half 2 can realize outwards pivoting in order to realize different drawing of patterns inclinations, it is convenient fast to change the angle, the cycle that the adjustment drawing of patterns angle detected comprehensively has been saved greatly, and can also analyze according to the combination of different materials, can obtain comprehensive and accurate data.

Example 2:

referring to fig. 4, on the basis of embodiment 1, the difference from embodiment 1 is that a square cavity 21 is provided in the fixed mold 2, that is, after times of injection molding, four groups of data can be collected for comparison analysis, the larger the number of the collected groups is, the smaller the error rate is, the ejector device 3 includes ejector pins 32 and an ejector plate 31, and four ejector pins 32 are provided in each cavities 21, and a pressure sensor 4 is also provided on the top of each ejector pin 32, so that the data of the initial mold release force on the ejector pins 32 can be obtained, and the error can be reduced by steps.

Example 3:

on the basis of embodiment 1, in the processing process of the processing unit, before averaging, the maximum value and the minimum value of the two sets of data of Ft1a, Ft1b, Ft1c, Ft1d, Ft1e.. Ft1n, Ft2a, Ft2b, Ft2c, Ft2d, and Ft2e.. Ft2n are removed, so as to reduce the error value.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

The method for testing the demolding force of the plastics is characterized by comprising plastic demolding force testing molds, wherein each plastic demolding force testing mold comprises an injection device, a movable mold, a fixed mold and an ejection device, each ejection device comprises an ejection plate and an ejector pin, an ejector pin groove for the ejector pin to penetrate through is formed in a bottom plate of the fixed mold, two opposite side plates (211) of the fixed mold pivot with the bottom plate to enable the fixed mold to turn outwards by 0.2-5 degrees to form a corresponding demolding angle of the fixed mold and are fixed through corresponding fixing devices, pressure sensors are arranged on the bottom plate and the side wall of the inner side of the fixed mold, pressure terminals are further included, the pressure terminals are coupled with the pressure sensors, detection signals of the pressure sensors are processed through a processing unit, and initial demolding force is finally output, and the method further comprises the following steps:

a, pivoting two side plates (211) of the fixed die outwards at the same angle of to form a demoulding angle of α;

b, inserting a corresponding positioning block (23) into the cavity (222) to position the side plate (211);

c, selecting corresponding raw materials to be added into an injection device, and homogenizing and melting the raw materials by the injection device;

d, injecting the raw material into a cavity between the fixed die and the movable die for injection molding, cooling and shaping, and opening the die;

e, ejecting the ejector device, obtaining pressure values Ft1 on the ejector pins and the pressure sensors on the bottom wall, and obtaining pressure values Fb on the pressure sensors on the side wall;

f, processing the obtained pressure values Ft1 and Fb by a processing unit to obtain the final initial demoulding force.
2. The method for testing plastic mold release force according to claim 1, wherein step f includes:

(1) substituting the Fb value collected from the side wall into a formula, converting Ft2 ═ Fb (mu cos α -sin α) to obtain Ft 2;

(2) acquiring Ft1 values and Ft2 values in each cavity to obtain Ft1a, Ft1b, Ft1c, Ft1d, Ft1e.. Ft1n, Ft2a, Ft2b, Ft2c, Ft2d and Ft2e.. Ft2n, and averaging the data

Ftavg1＝(Ft1a+Ft1b+Ft1c+Ft1d+Ft1e+...Ft1n)/n；

Ftavg2＝(Ft2a+Ft2b+Ft2c+Ft2d+Ft2e+...Ft2n)/n。
3. The plastic demolding force testing method as claimed in claim 2, wherein in step 2, before averaging, the maximum value and the minimum value are removed from the two sets of data of Ft1a, Ft1b, Ft1c, Ft1d, Ft1e.. Ft1n, Ft2a, Ft2b, Ft2c, Ft2d, Ft2e.. Ft2 n.
4. The plastic demolding force testing method according to claim 1, wherein the exterior of the fixed die is provided with a outer die, a cavity (222) into which a positioning block (23) can be inserted is formed between the outer die and the side wall of the fixed die, and the positioning block (23) is provided with a slope which is matched with the side plate (211) after being turned over at an angle of degrees.
5. The plastic demolding force testing method as claimed in claim 4, wherein the movable mold and the fixed mold form an even number of rectangular parallelepiped-shaped cavities.
6. The plastic demolding force testing method of claim 5, wherein the top of the ejector pin is provided with a pressure sensor.
7. The plastic demolding force testing method as claimed in claim 6, wherein each side wall in the stationary mold is provided with a pressure sensor.
8. The plastic demolding force test method of claim 7, wherein the raw materials in the injection device are at least of polyethylene, polypropylene, polycarbonate, ABS, PS, and PA.