JP2854802B2 - How to set the time to remove the thermosetting resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for setting a take-out time from a mold when molding with a thermosetting resin.

[0002]

2. Description of the Related Art In molding a thermosetting resin molded article,
By properly setting the time for removing the molded product from the mold (the time for curing the resin in the mold), it is possible to shorten the molding cycle and to suppress the occurrence of defective products due to insufficient molding time. Therefore, efficient molding can be performed.

For this purpose, the time-curing degree characteristics of the resin filled in the cavity are estimated by calculation based on the shape of the molded article, the characteristics of the molding resin, and the molding conditions at the time of injection molding of the thermosetting resin. The molding removal time is set based on the simulation result.

[0004]

However, the thermosetting resin has a complicated behavior, and there are portions that cannot be captured by the above-mentioned analysis simulation. Further, as disclosed in Japanese Patent Publication No. 3-60646, when the thermal expansion phenomenon during gelation and the contraction phenomenon during curing are utilized, and these expansions and contractions are captured by minute displacement of a mold, the minute Although it is possible to set the take-out time based on the displacement, since the above-mentioned minute displacement differs depending on the mold, if the mold is different, correlation data between the minute displacement of the mold and the degree of curing of the resin is obtained. Since it is collected by actually performing molding and the extraction time is set based on this data, unlike the case only by analysis, until the extraction time can be set appropriately, It takes a lot of labor and time for each mold.

[0005] The present invention has been made in view of such a point, and an object of the present invention is to provide a thermosetting resin that can easily and accurately set a take-out time even when a mold is different. It is an object of the present invention to provide a method for setting a molding removal time of a resin.

[0006]

According to the present invention, a time-curing degree characteristic of a resin filled in a cavity is estimated by calculation based on the shape of a molded product, characteristics of a molding resin, and molding conditions. In setting the molding removal time based on the estimation result, the time-curing degree characteristics of the resin obtained by actual measurement with a curing degree sensor arranged in advance in a specific mold cavity, and the case of using this specific mold From the time-curing degree characteristic obtained by the above analysis, a correction amount for the time-curing degree characteristic obtained by the analysis is calculated, and the time-curing degree characteristic obtained by the arithmetic analysis for the mold for setting the take-out time is calculated. The mold removal time is set based on the corrected time-curing degree characteristic and the settable removable curing degree by correcting the correction amount based on the correction based on the difference between the two molds. It has a feature to Rukoto.

[0007]

According to the present invention, the time-curing degree characteristic of a resin obtained by analysis of a certain mold and the time-curing degree characteristic of a resin obtained by actual molding with the mold are obtained. Using the correction amount, the time-curing degree characteristic obtained by the operation analysis is corrected for the mold for setting the removal time, and the removal time is set based on the corrected time-curing degree characteristic. For this reason, it is possible to set the removal time in a state that includes conditions that could not be obtained by analysis alone, and if the time-curing characteristics at the time of actual molding with a certain mold are first examined, the gold Even if the mold is changed, it is possible to set an appropriate take-out time for the changed mold only by the analysis operation.

At this time, if the retrievable curing degree is individually set in the molded part of the mold and the resin flow path part reaching the molded part, and the molding removal time is set,
Since the curing of the resin flow path portion is usually slower than the curing of the molded product portion, more accurate setting of the molding take-out time can be performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In the present invention, the time-curing degree characteristic of a resin as a molding material is determined by flow analysis and curing analysis of the resin. From the curing degree characteristic and the settable removable curing degree, the removal time is set,
At this time, instead of using the time-curing degree characteristic of the resin for the mold for setting the removal time as it is, it is characterized by using the time-curing degree characteristic of the resin corrected by a previously determined correction amount. Here, the correction amount is obtained as follows.

That is, a specific mold (this mold does not need to be the same as the mold for setting the take-out time, but may be completely separate) is injected by using a certain thermosetting resin. The time-curing degree characteristics of the resin in molding are determined by flow analysis and curing analysis. In other words, molded product shape data (data of the cavity shape of the mold used, obtained by dividing into minute finite elements), resin data (viscosity, specific heat, density, curing reaction characteristics, solidification temperature, etc.) Flow analysis and hardening analysis are performed based on physical property data), molding condition data, and mold characteristics (thermal conductivity, specific heat, density) and the like. For example, the equation of motion

[0011]

(Equation 1)

(X, y: flow direction, z: thickness direction, τ
_x , τ _y : shear stress in x, y directions, P = pressure),

[0013]

(Equation 2)

(U, v: a continuous equation given by the flow velocity in the x and y directions (distribution in the thickness direction)

[0015]

(Equation 3)

(T: temperature (distributed in the thickness direction), η: viscosity, λ: thermal conductivity, ρ: density, C _P : specific heat, γ: shear rate (distributed in the thickness direction), J: constant, t: time), an energy equation given by (∂α / ∂t) T = f (α, T) (α: degree of cure), and η = f (γ, τ *, T, Tb, α, α _g ) (τ *: shear stress parameter, Tb: time parameter,
The flow field of the molding resin is obtained as a function of the position and the time, and the resin pressure, the resin viscosity, the degree of resin curing, and the like are obtained together with the position information and the time information by the equation of the viscosity characteristic given by α _g : gel point.

The resin temperature distribution, filling time distribution, resin pressure distribution, resin viscosity distribution,
By adding the molded product shape data, molding condition data, and mold characteristics to the resin shear rate distribution, curing degree distribution, etc., and conducting a curing analysis using the above formula, the time variation of the resin curing degree, resin temperature, etc. Ask for. As a result of such analysis,
Time when molding using a certain resin in the above mold-
Curing degree characteristics F (T) can be obtained.

Then, the mold is actually manufactured, and the transition of the degree of cure of the molded product when the mold is molded using the mold and the resin is measured by actual measurement. FIG. 2 shows a curing degree measuring device for this purpose. In the drawing, reference numeral 1 denotes a mold, 2 denotes a molding machine, 3 denotes an amplifier, and 4 denotes a measuring device constituted by a computer. Is curing degree sensor 5
The time-curing degree characteristics of the resin when the mold 1 is filled with the resin and molded can be measured.

If the measured time-curing degree characteristic G (T) of the resin in the mold 1 as shown in FIG. 3 is obtained in this way, as shown in FIG. The correction amount D1 is obtained from the time-curing degree characteristic F (T) obtained by analyzing the resin and the time-curing degree characteristic G (T) obtained by actual measurement.
(T) = F (T) -G (T) is calculated. Further, by performing molding while sequentially changing the curing time, a curing degree (removable curing degree) at which the molded article made of the resin can be taken out is obtained. This is, as shown in FIG.
The quality of the molded product molded in the cavity 10b provided with the curing degree sensor 5 and the cavity 10b equivalent to the resin curing is evaluated at the same position as the position where the curing degree sensor 5 is provided, and FIG. As shown in
The retrievable curing degree E is determined from the intersection of the measured resin time-curing degree characteristic G (T) curve and the time t at which a molded article of good quality was retrieved.

Now, in order to set the molding removal time when molding is performed using a mold different from the above-described mold and the above-described resin, first, a mold for which the molding removal time is to be set must be set. The degree-of-curing characteristics F (N, T) of the resin in each part N divided into minute regions of the mold when the resin is used are obtained by the flow analysis and the curing analysis. A correction amount D2 (T) obtained by correcting the correction amount D1 (T) based on the ratio between the time-curing degree characteristic F (T) and the time-curing degree characteristic F (N, T) for the difference between the two dies. by the time - degree of curing characteristics F (N, T) by correcting the, as shown in FIG. 5, the time - obtain a cured size characteristics Q (N, T).

Q (N, T) = F (N, T) −D2 (T) (D2 (T) = D1 (T) * F (N, T) / F (T)) Time-curing degree characteristic Q of each part of mold
As shown in FIG. 7, of (N, T), as shown in FIG. 7, the time-curing degree characteristic at the position where the point of time at which the retrievable curing degree E is reached is the latest (in FIG. The time T (En) at which the degree of cure E is reached is defined as the time during which a molded article can be taken out of the mold and the resin.

As shown in FIG. 8, the above-mentioned retrievable curing degree E is determined by the molded product part A in the mold and the resin flow path part B such as the sprue 11, the main runner 12, the sub-runner 13 and the gate 14. 9 are set individually, and FIG.
A time TA at which the molded article part A shown in FIG. 9A reaches the removable hardening degree EA is compared with a time TB at which the resin flow path part B shown in FIG. 9B reaches the removable hardening degree EB. Big
It is preferable that the square of time and the molding taken out time.

[0023]

As described above, in the present invention, the time-curing degree characteristics of a resin obtained by analysis of a certain mold, and the time-curing degree characteristics of a resin obtained by actual molding with the mold are used. Using the correction amount obtained by the comparison, the time-curing degree characteristic obtained by arithmetic analysis for the mold for setting the removal time is corrected, and the removal time based on the corrected time-curing degree characteristic is corrected. Because of the setting, it is possible to set the take-out time based on the prediction of curing under conditions including conditions that could not be obtained by analysis alone, thereby shortening the molding cycle and reducing the defect rate In addition to being able to perform molding, if the time-curing degree characteristics at the time of actual molding in a certain mold are first examined, as long as molding is performed with the same resin even if the mold is changed, For mold changed only by analysis calculation Be one can set the switching of extraction time, it has high versatility.

Further, if the molding removal time is set by individually setting the degree of cure that can be taken out of the molded article portion of the mold and the resin flow path section leading to the molded article section, the curing of the resin flow path section is performed. Is usually slower than the curing of the molded product part, so that the molding take-out time can be set more accurately.

[Brief description of the drawings]

FIG. 1 is a flowchart in one embodiment.

2 (a) is an explanatory view of an apparatus used for measuring the degree of cure, (b) is a perspective view of the mold, and (c) is an explanatory view of the mold.

FIG. 3 is an actual measurement time-curing degree characteristic diagram.

FIG. 4 is an explanatory diagram of correction amount calculation.

FIG. 5 is an explanatory diagram of correction.

FIGS. 6 (a) and (b) are explanatory diagrams of setting of a removable curing degree.

FIG. 7 is an explanatory diagram of a take-out time setting.

8 (a) is a side view, FIG. 8 (b) is a front view, and FIG. 8 (c) is a bottom view.

FIGS. 9A and 9B are explanatory diagrams of setting of a take-out time.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-196561 (JP, A) JP-A-5-507659 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/00-45/84 B29C 33/44-33/54 B29K 101: 10

Claims (2)

(57) [Claims] A time-curing degree characteristic of a resin filled in a cavity is estimated by calculation based on a shape of a molded article, characteristics of a molding resin, and molding conditions, and a molding removal time is set based on the estimation result. In doing so, the time-curing degree characteristic of the resin obtained by actual measurement with a curing degree sensor previously arranged in a specific mold cavity, and the time-curing degree characteristic obtained by the above analysis using this specific mold From the above, a correction amount for the time-curing degree characteristic obtained by the analysis is calculated, and the time-curing degree characteristic obtained by the operation analysis for the mold for setting the removal time is corrected based on the difference between the two molds. A thermosetting resin, wherein a molding removal time is set based on the corrected time-curing degree characteristic and a settable removable degree of cure. Setting method of molding removal time. 2. A molding removal time is set by individually setting a retrievable curing degree in a molded article part of a mold and a resin flow path part leading to the molded article part. Of setting and removing time of the thermosetting resin.