KR102499830B1 - Method for forming expanded grain - Google Patents

Abstract

The present invention relates to a method for molding foam granules. Such a foam lip molding method includes: (a) advancing the movable mold part 5 in the direction of the fixed mold part 3 by the ball screw 12 of the foam lip molding device 1 to combine the movable and fixed molds; (S100) and; (b) a braking step (S110) of fixing the movable mold unit 5 to a predetermined position by the braking unit 8; (c) the step of increasing the pressure of the movable and fixed mold parts 3 and 5 (S120); and (d) moving the movable mold part 5 backward by the ball screw 12 to separate and move backward from the fixed mold part 3 (S130).

Description

Method for forming expanded grain {Method for forming expanded grain}

The present invention relates to a method for forming a foam lip, and more particularly, includes a step of moving a mold body equipped with a moving mold forward and backward by a screw method, and also a step of preventing the mold from being pushed when pressure is increased by applying a braking unit. It relates to a method for molding expanded granules, which can more effectively foam-mould the expanded granules by additionally applying the present invention.

In general, Styrofoam is an expandable polystyrene (EPS) that is heated and cured by adding a foaming agent such as pentane or butane to generate bubbles at the same time.

Styrofoam moldings are not only lightweight, but also have excellent water resistance, heat insulation, sound insulation, and cushioning properties, so they are widely used as packaging cushioning materials, building materials, decorations, and insulation materials.

When manufacturing a styrofoam molding, polystyrene particles impregnated with a foaming agent are preliminarily foamed through heating and aged for a predetermined time. Thereafter, a filling process in which pre-expanded and aged polystyrene particles (hereinafter referred to as "raw resin") are put into the mold, a process of heating the mold with steam to mold a molded product, and a process of cooling the molded product and mold to separate the molded product from the mold. It goes through the process of discharging the cooled molded product through separation of the process and mold.

Molding of such a foamed resin can be performed by a molding device proposed in Patent Registration No. 10-1401390 (name: foamed resin molding device) previously registered by the present applicant.

That is, the foamed lip molding device includes a fixed mold unit; a housing disposed at a predetermined distance from the fixed mold unit; a movable mold part movably disposed between the fixed mold part and the housing and coupled to the fixed mold part to proceed with molding of the foamed resin; a link unit that connects the housing and the movable mold unit to push the movable mold unit toward the stationary mold unit when deployed or pull the movable mold unit toward the housing when contracted; And it consists of a crank part that pushes or pulls the link part.

In addition, the movable mold unit has a structure in which four tie bars are disposed through each corner, and the movable mold unit moves forward and backward along the tie bars.

However, in the process of bringing the movable mold frame close to the fixed mold mold, in order to fill the cavity formed in the mold with raw material beads (expandable resin raw material), a predetermined cracking clearance is secured between them to temporarily stop, After filling the raw material, close the mold to close it. At this time, the cracking gap is important as an air retraction path when the raw material is introduced into the mold by the flow of air.

However, in the case of using a hydraulic cylinder, the pressing force fluctuates according to variables such as the transport speed and weight of the moving mold, so the control of the position is unstable, causing an error in the cracking gap to the set value, resulting in uneven molding conditions. there is

Patent Registration No. 10-1401390 (Name: foamed resin molding device)

Therefore, the present invention has been devised to solve this problem, and an object of the present invention is to apply a step of moving a mold body equipped with a moving mold forward and backward by a screw method, and also to apply a braking unit so that the mold is It is an object of the present invention to provide a method for forming foamed granules capable of more effectively foam-molding foamed granules by additionally applying a step of preventing pushing.

In order to achieve the above object, one embodiment of the present invention,

(a) advancing the movable mold part 5 in the direction of the fixed mold part 3 by the ball screw 12 of the foam lip molding apparatus 1 to combine the movable and fixed molds (S100);

(b) a braking step (S110) of fixing the movable mold unit 5 to a predetermined position by the braking unit 8;

(c) the step of increasing the pressure of the movable and fixed mold parts 3 and 5 (S120); and

(d) moving the movable mold part 5 backward by the ball screw 12 to separate and move backward from the fixed mold part 3 (S130).

As described above, the foamed lip molding method according to an embodiment of the present invention has the following effects.

First, by applying a two-platen structure by replacing the conventional four tie bars and applying a ball screw method to move the forward and backward structure of a mold body equipped with a moving mold, it can be more simplified and workability can be improved.

Second, by additionally applying a step of applying a damping unit to the ball screw, it is possible to improve the foam molding quality of the foamed granules by preventing the shape from being pushed when the pressure is increased.

Third, by applying an LM-type guide member to the moving die, stable forward movement of the moving die is possible.

1 is a flow chart showing a foamed lip molding method of the present invention.
2 is a perspective view of a foamed lip molding apparatus for performing the foamed lip molding method of FIG. 1;
3 is a side view of the foamed lip molding apparatus shown in FIG. 2;
4 is a plan view of the foamed lip molding apparatus shown in FIG. 2;
5 is a front view of the foamed lip molding apparatus shown in FIG. 2;
FIG. 6 is a partially enlarged plan view showing an enlarged portion "A" of FIG. 5 .
FIG. 7 is a partially enlarged plan view showing an enlarged portion “B” of FIG. 6 .

Hereinafter, the foamed lip molding method according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 7, the foamed lip molding method proposed by the present invention proceeds in the following order.

That is, the foam lip molding method includes the step of (a) advancing the movable mold part 5 in the direction of the fixed mold part 3 by the ball screw 12 of the foam lip molding device to combine the movable and fixed molds (S100). )and;

(b) a braking step (S110) of fixing the movable mold unit 5 to a predetermined position by the braking unit 8;

(c) the step of increasing the pressure of the movable and fixed mold parts 3 and 5 (S120); and

(d) moving the movable mold part 5 backward by the ball screw 12 to separate and move backward from the fixed mold part 3 (S130).

In this foamed lip molding method,

In the step of combining the movable and fixed molds (S100), the movable mold unit 5 is moved forward using the ball screw type foam lip molding apparatus 1 according to an embodiment of the present invention.

That is, this foamed lip molding apparatus has a structure as shown in FIGS. 2 to 7, a frame 2, a fixed mold part 3 fixed to the front end of the frame 2; A movable mold part 5 movably disposed at the rear end of the frame 2 and separated by a predetermined distance from the fixed mold part 3; a pair of guide members 4 disposed on the frame 2 and guiding the movable mold unit 5 in forward and backward directions; a connecting member 9 connecting the movable mold part 5 and the fixed mold part 3; a drive unit 7 provided in the movable mold unit 5 and moving the movable mold unit 5 forward and backward by rotating the connecting member 9; It includes a braking unit 8 integrally provided with the drive unit 7 to prevent the loosening of the connecting member 9 so that the fixed and movable mold units 3 and 5 are combined to maintain the mold closed state.

In the foamed lip molding device having such a structure,

The movable mold part 5 may move forward in the direction of the fixed mold part 3 by the driving part 7 and the connecting member 9 .

That is, when the servomotor 23 of the driving unit 7 is driven, the driving pulley 26 provided on the rotating shaft 24 rotates, and the two belts 25 connected to the driving pulley 26 apply rotational force. The pair of ball screws 12 are respectively rotated by transmitting to the driven pulleys 27 disposed on both sides, respectively.

Further, the connecting member 9 includes a ball screw 12, and as the ball screw 12 rotates, the moving die 13 moves forward in the direction of the fixed die 11, and the moving mold 17 is fixed. It is integrally incorporated into the mold 15.

Conventionally, the moving die 13 has a structure in which the moving die 13 moves forward and backward by four tie bars, but in the present application, it can move forward and backward more efficiently by applying a ball screw method.

And, the moving die 13 can be stably moved forward by the pair of guide members 4 .

The pair of guide members 4 include brackets 19 provided on both sides of the moving die 13; a slider 20 mounted on the bottom of the bracket 19; It is disposed on the upper surface of the frame 2 in the longitudinal direction, and includes a pair of rails R on which the slider 20 is movably seated.

When the step of advancing and combining the movable mold part (S100) is completed in this way, a braking step (S110) of fixing the movable mold part to a predetermined position proceeds.

In this braking step (S110), the movable mold 17 is fixed in place to prevent slipping.

This braking step (S110) is performed by the braking unit 8,

The braking unit 8 includes a disk 30 mounted at the rear end of the ball screw 12; A pad 32 is disposed on the support bracket 28 mounted on the rear surface of the moving die 13 to press and fix the disk 30 thereto.

When the braking step (S110) is performed by the braking unit 8, the hydraulic pack 34 provided in the pad 32 of the braking unit 8 is driven first, so that the pad 32 is moved by the cylinder 37. is pressed toward the inside of the braking hole 36.

Rotation of the ball screw 12 can be prevented by frictional contact between the pressurized pad 32 and the surface of the disk 30 provided on the ball screw 12 .

In this way, the pair of ball screws 12 can be fixed in place when the disk 30 is braked by the pad 32 when the pressure is increased.

After the braking step (S110) is completed, the step of increasing the pressure of the movable and fixed mold (S120) proceeds.

The foaming process proceeds in a state where the moving mold 17 and the fixed mold 15 are combined. In the pressure increasing process, foam particles are supplied to the cavity of the mold through the injection hole, and foaming proceeds under high temperature and high pressure, thereby moving The internal pressure of the mold 17 and the fixed mold 15 increases.

After the step of increasing the pressure (S120) is completed, a step (S130) of moving the die backward and returning it to the original position is performed.

In this step (S130), the pad 32 is separated from the disk 30 by first releasing the hydraulic pressure transmitted to the pad 32.

And, by driving the servomotor 23 in the reverse rotation direction, the ball screw 12 is also rotated in the reverse direction.

Accordingly, the movable die 13 moves backward by the reverse rotation of the ball screw 12 and returns to the original position.

In this way, after the movable die 13 is separated from the fixed die 11, the molded product can be taken out of the mold.

Claims (5)

(a) advancing the movable mold part 5 in the direction of the fixed mold part 3 by the ball screw 12 of the foam lip molding apparatus 1 to combine the movable and fixed molds (S100);
(b) a braking step (S110) of fixing the movable mold unit 5 to a predetermined position by the braking unit 8;
(c) the step of increasing the pressure of the movable and fixed mold parts 3 and 5 (S120); and
(d) moving the movable mold part 5 backward by the ball screw 12 to separate and move backward from the fixed mold part 3 (S130);
The foamed lip molding apparatus 1 of step (a),
A fixed mold part 3 fixed to the front end of the frame 2;
A movable mold part 5 movably disposed at the rear end of the frame 2 and separated by a predetermined distance from the fixed mold part 3;
a pair of guide members 4 disposed on the frame 2 and guiding the movable mold unit 5 in forward and backward directions;
As a ball screw 12, one end is rotatably fastened to the moving die 13, and the other end is rotatably fastened to the fixed die 11, so that the moving die 13 moves forward and backward during rotation (9) and;
a drive unit 7 provided in the movable mold unit 5 and moving the movable mold unit 5 forward and backward by rotating the connecting member 9; and
It includes a braking unit 8 integrally provided with the drive unit 7 to prevent the loosening of the connecting member 9 so that the fixed and movable mold units 3 and 5 can be coupled to keep the mold closed,
The driving unit 7 includes a servomotor 23 disposed on the moving die 13; driven pulleys 27 each mounted on a pair of ball screws 12; One end is connected to the driving pulley 26 provided on the rotation shaft 24 of the servomotor 23, and the other end is connected to the driven pulley 27 mounted on a pair of connecting members 9, respectively, to transmit rotational force Foamed lip molding method comprising a belt (25). delete delete According to claim 1,
The pair of guide members 4 include brackets 19 provided on both sides of the moving die 13; a slider 20 mounted on the bottom of the bracket 19; A foam lip molding method comprising a pair of rails (R) disposed on the upper surface of the frame (2) in the longitudinal direction and on the upper side of which the slider (20) is movably seated. According to claim 1
The braking unit 8 of step (b) includes a disk 30 mounted on the rear end of the ball screw 12; It includes a pad 32 disposed on the support bracket 28 mounted on the rear surface of the moving die 13 to press and fix the disk 30,
The pad 32 is connected to the hydraulic pack 34, so that when the hydraulic pressure is applied, the pad 32 is pressed inwardly into the braking hole 36 and comes into frictional contact with the surface of the disk 30, thereby stopping the rotation of the disk 30. .

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