JPH0780204B2 - Injection molding method of synthetic resin artificial grass - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an injection molding method for synthetic resin artificial grass, and more particularly to an injection molding method for antistatic synthetic resin artificial grass.

(Prior Art) Synthetic resin artificial turf with a structure in which leaf-shaped parts like natural grass are erected on the surface of a sheet-like base is used for tennis, baseball, softball and other stadiums and practice fields, or a veranda of a general household. It is commonly used for rugs and sunrooms. However,
Since the synthetic resin has an electric insulation property, the molded product is usually easily charged, and the artificial turf made from this material is no exception. In particular, if it is laid outdoors in a stadium with a high degree of friction or in a practice area, it will accumulate on the human body when the weather is sunny or the air is extremely dry, and the stadium will be used during the competition. If you touch the metal poles or nets that are installed, you may not be able to play happily because you will be severely shocked by the electric discharge.

Therefore, various studies have heretofore been carried out, such as applying a coating material containing an antistatic agent onto the surface of the artificial grass, or using a molding material containing a conductive material in advance.

(Problems to be solved by the present invention) However, in the method of applying a paint mixed with an antistatic agent onto the surface of an artificial grass made of synthetic resin, there is a problem that the quality is difficult to stabilize because the painting work is manual work. However, the finished product also has a problem in that the coating film may fall off due to friction with the shoes of the athlete or aging due to ultraviolet rays, and the effect cannot be maintained for a long time.

On the other hand, when the conductive material is kneaded, the desired effect cannot be obtained unless the compounding ratio is usually 50% or more, which causes a problem of increasing the material cost.

The present invention provides an injection molding method for synthetic resin artificial grass that solves the above-mentioned problems of the prior art and is excellent in moldability and quality, and that does not deteriorate in function over time. It was made for the purpose.

(Means for Solving the Problems) The first aspect of the present invention is to provide an injection molding apparatus including an injection molding die having a mold cavity for molding an artificial turf main body and a mold cavity for molding a conductive portion, and two injection devices. Using, first, from one injection device into the artificial turf body molding mold cavity or the conductive part molding mold cavity, inject the artificial turf body molding resin or the conductive part molding resin,
Next, the resin for molding the conductive part or the resin for molding the artificial grass body is injected into the mold for molding the conductive part or the mold for molding the artificial grass from another injection device to integrate the artificial grass body and the conductive part. The present invention is directed to an injection molding method of synthetic resin artificial turf, which is characterized in that
2. When injecting a kind of molten resin into one of the mold cavities, inserts a nesting pin in the other mold cavity to prevent the inflow of the one kind of molten resin. The gist is the injection molding method of the synthetic resin artificial turf.

In the present invention, the artificial turf body molding resin to be injected into the artificial turf body molding die is a synthetic resin which is usually used in an injection molding method, and does not contain a conductive material at all or contains it. Also refers to the content of the extent that does not have the effect of the conductive portion formed of a conductive synthetic resin described later,
Specifically, thermoplastic resins such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, and polyester are preferably used. Especially when these soft thermoplastic resins are selected and used, the human body is barefoot. Feels good when stepped on.

In the present invention, as the conductive portion molding resin to be injected into the conductive portion molding mold cavity, a generally known conductive synthetic resin can be adopted, and in the artificial turf body molding resin,
It is made by kneading and filling powder of metal such as stainless steel, copper, brass, aluminum and the like having excellent corrosion resistance, carbon or the like, or short fibers (fibrous chops). However, it is preferable to select and use the synthetic resin having a high compatibility with the synthetic turf body molding resin, and it is better to use the same type of resin if possible.

In the present invention, an injection mold capable of splitting and closing having a mold cavity for molding an artificial turf main body and a mold cavity for molding a conductive part, and a synthetic resin of a different type, that is, an artificial turf main body molding, independently of each of these mold cavities A two-color injection molding machine is suitable as a commercially available device corresponding to this, since it uses a resin for molding and two injection devices capable of injecting a resin for molding a conductive portion.

In the present invention, since it is necessary to integrally mold the artificial turf body and the conductive portion, it is inevitable that the mold cavities communicate with each other in the mold closed state. Since the time of injection is different, when first injecting one kind of molten resin into one of the mold cavities, it is necessary to take some measures so as not to inject the other kind of molten resin into the other mold cavity. .

A second aspect of the present invention is a method which solves this point by a simple means. First, when injecting the artificial turf body molding resin or the conductive portion molding resin into one of the mold cavities from one injection device. In order to prevent the artificial turf main body molding resin from flowing into the mold cavity by inserting a nesting pin into the other mold cavity, and to remove the nesting pin from the mold cavity before injecting another kind of molten resin, Alternatively, it is preferable to use an air cylinder as a means for inserting / removing the nesting pins by moving to form the other mold cavity. When injecting a kind of molten resin, the insert pin is inserted into the other mold cavity, and when the injection of the one kind of molten resin is finished, the insert pin is pulled out to form the other mold cavity. , From one other injection device to the other mold The other type of molten resin is injected into the mold, and when the mold is continuously opened and the artificial turf is released from the mold and the mold is closed, the nesting pin is inserted into the other mold cavity again. An air cylinder may be installed so that the operation of inserting and removing can be performed in conjunction with the opening and closing operation of the mold.

In the method of the present invention, when the molten resin is first injected from one injection device, either the artificial turf main body molding resin or the conductive part molding resin may be used, but the artificial turf main body molding resin is the conductive part molding resin. Because the amount of resin is much larger than the resin for use,
The resin does not easily cool, and it is easy to obtain a good result in terms of heat fusion property with the resin for molding the conductive portion, which is injected in the next step. Therefore, it is better to inject the resin for molding the artificial turf body first.

The artificial turf body in the present invention, the sheet-shaped base and the leaf-shaped portion are integrally molded, but depending on the case, one of them is pre-molded and then inserted into the artificial turf molding mold cavity, Then, the injection operation of the resin for molding the artificial grass main body from one injection device may be started.

The shape of the conductive portion in the present invention is preferably such that the head portion thereof is sharpened so that it is easy to discharge in the air and the leg portions are widely in contact with the ground so that the earth effect is easily exhibited.

(Operation) An injection molding method of an artificial grass made of synthetic resin according to the present invention comprises an injection molding device having an injection molding die having a mold cavity for molding an artificial grass body and a cavity for molding a conductive portion, and an injection molding device having two injection devices. First, one injection device is used to inject the artificial turf body molding resin or the conductive part molding resin into the artificial turf body molding mold cavity or the conductive part molding cavity, and then the other turret molding device In the mold cavity for molding the part or the mold cavity for molding the artificial grass body,
Since the resin for molding the conductive part or the resin for molding the artificial grass body is injected to integrally mold the artificial grass body and the conductive part,
The resulting artificial grass can be partially made conductive.

Further, the proportion of the conductive synthetic resin in the whole can be remarkably small.

Further, since different kinds of synthetic resins are continuously injected into desired mold cavities from different injection devices, it is possible to obtain a resin excellent in adhesion.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

1 and 2 are main parts of an injection molding apparatus suitable for carrying out the injection molding method for synthetic resin artificial grass of the present invention,
That is, FIG. 1 is a view showing a molding die used in a two-color injection molding machine, and FIG. 1 shows a state in which an artificial turf body molding resin is injected from a single injection cylinder (not shown) into an artificial turf body molding die A. FIG. 2 is a partially cutaway sectional view showing a state immediately after a conductive portion molding resin is injected from another injection cylinder (not shown) into the conductive portion molding die B as well. In the figure, a is a moving side mold and b is a fixed side mold, which is opened and closed in the lateral direction.

However, 1 is an artificial turf body, which is formed by injecting the resin for molding an artificial body from one injection cylinder (not shown) into the mold cavity A via the runner 2 and the gate as described above.

Reference numeral 3 is a sheet-like base of the artificial body 1, and a large number of upper water-permeable holes 4 are formed in the sheet-like base at substantially equal intervals from one surface side to the other surface side. Reference numeral 5 is a leaf-shaped portion which is provided upright around the upper water-permeable hole 4 at substantially equal intervals (two in the drawing). On the other side of the sheet-like base 3, the leaf-like portion 5
Correspondingly, the legs 6, 7, and 8 are provided. The leg 6 is relatively short, the leg 7 is slightly long, and the leg 8 has the same length as the leg 7 and is slightly thicker. or,
A lower water-permeable hole 9 is formed at a position corresponding to the upper water-permeable hole 4 of each leg portion 6, 8, and the leaf-shaped portion 5, the sheet-shaped base 3 and each leg portion 6, 7, 8 are integrally formed. Is molded into.

Then, the mold plate 10 of the moving-side mold a and the mold plate mounting plate 11 located on the outer side of the mold plate 10 have their tips in the cavity of the leg portion 7,
A bush 12 which is tapered so that it can be tightly and freely inserted / removed can be fitted, and a head-forming mold cavity 13 of a conductive portion, which will be described later, is provided axially inside from a tip end surface thereof. .

Further, 14 is a mold plate of the fixed side mold b, 15 is a mold plate mounting plate thereof, and a bush 16 is fitted at a position corresponding to these bushes 12, and a center thereof is shown in the drawing. A molten resin passage through which the resin for molding the conductive portion can be injected into the mold cavity B from the other injection cylinder via the runner 17 and the gate is formed.

As shown in FIG. 2, the bush 16 has a mold cavity 18 for forming the leg portion of the conductive portion at the front and in front of the bush 16. However, at the stage shown in FIG. The tapered portion of the bush 12 is tightly fitted in the mold cavity 18, and the outer peripheral surface of the bush 12 and the recess 19 filled with the leg portion 7 form the mold cavity of the leg portion 7 of the artificial turf body, and the tip surface of the bush 12 is formed. The tip surface of the bush 16 and the tip surface of the bush 16 abut in the fixed-side template 14.

By doing so, the resin for molding the artificial turf main body is made into the leg 7
It is possible to prevent the conductive portion formed in the fixed-side mold plate 14 from entering the leg-forming mold cavity 18 when injected into the mold cavity.

Further, the mold surface of the fixed side mold b is provided with a recess 20 for filling the leg portion 6.
Also, a concave portion 21 for filling the leg portion 8 is formed. Incidentally, 22 is a protruding pin.

The injection molding method of the present invention will be described below using the above molding apparatus.

As shown in FIG. 1, first, an artificial grass body molding resin is injected into the mold cavity A to mold the artificial grass body 1. At this time,
Since the conductive part molding cavity B is closed by the nesting pins 12, the artificial turf body molding resin is not injected into the conductive part molding cavity B.

Next, an air cylinder (not shown) is operated to slightly retract the nesting pin 12 to form the leg-forming mold cavity 18 of the conductive portion where the nesting pin 12 is fitted.

Next, by injecting the conductive part molding resin into the mold cavity B, the artificial turf body 1 and the conductive part 23 are integrally molded, and then the mold is opened to release the molded product to complete one cycle. To do.

In the case of the above embodiment, as an order of injecting two kinds of resins one after another, an example in which the artificial turf main body molding resin is first and then the conductive portion molding resin is shown is shown, but the order is reversed. The case will be described with reference to FIGS. 3 and 4.

In FIG. 3, reference numeral 12 'is a nesting pin, which is provided with a mold cavity B'for molding a conductive portion from its tip end surface toward the inside in the axial direction, and a mold cavity A'for molding an artificial grass main body and a conductive portion molding. Recesses 19 'filled with legs so as not to communicate with the mold cavity B'
It fits inside. In such a state, first, the conductive part molding resin is injected into the mold cavity B'to mold the conductive part 23 '. At this time, since the recess 19 'in which the leg of the artificial turf main body molding die A'is filled and the die cavity B'are separated from each other by the nesting pin 12', electrical conduction is made from the die cavity B'to the die cavity A '. The molding resin does not flow in.

Next, an air cylinder (not shown) is operated to retract the nesting pin 12 'and stop at a position where its tip end surface is flush with the upper surface of the sheet-like base 3'of the artificial grass body. As shown, an annular cavity for forming the leg portion is formed between the leg portion of the conductive portion 23 'and the recess 19' in which the leg portion is filled.

Next, the artificial turf body molding resin is injected into the artificial turf body molding die A'to mold the artificial turf body 1 '.

At this time, the resin for molding the electrically conductive portion, which was previously injected, is completely fused with the resin for molding the artificial turf body at the legs.

The artificial turf obtained as above is installed on the ground 24 as shown in FIG. 5, and the legs of the conductive part 23 (23 ') are grounded.
It comes into contact with 24 and is grounded, and its head also discharges into the air.

(Effect) The injection molding method for synthetic grass made of synthetic resin according to the present invention includes an injection molding apparatus having an injection molding die having a mold cavity for molding an artificial grass body and a cavity for molding a conductive portion, and two injection devices. First, use one injection device to inject the artificial turf main body molding resin or the conductive part molding resin into the artificial turf main body molding mold or the conductive part molding mold, and then from the other one injection device. Since the resin for molding the conductive part or the resin for molding the artificial grass body is injected into the mold for molding the conductive part or the mold for molding the artificial grass body, the artificial grass body and the conductive part are integrally molded, so that the artificial The turf may be partially conductive. Therefore, the molding operation is substantially automated throughout the entire process, and a product of stable quality can be easily obtained.

Further, the proportion of the conductive synthetic resin in the whole can be remarkably small. Therefore, the material cost is reduced and the molding is easy.

Moreover, since the conductive material is also kneaded, the effect is excellent in sustainability.

Further, different kinds of synthetic resins are continuously injected into desired mold cavities from different injection devices, so that the previously injected resin is not completely solidified yet, and therefore the resin injected after that is strong. A resin having excellent adhesion to each resin can be obtained. Therefore, the quality is further improved.

In addition, if you prepare a mold according to the type of artificial grass and conductive material and the use of artificial grass, you can change the size, number, installation interval, etc. of the conductive parts as appropriate, and ensure proper antistatic properties. Can be granted.

[Brief description of drawings]

FIG. 1 and FIG. 2 are views showing an embodiment of the molding method of the present invention which is carried out by using a molding apparatus suitable for carrying out the injection molding method of the synthetic resin artificial turf of the present invention. FIG. 1 is a partially cutaway sectional view showing a state in which a resin for molding an artificial turf main body is injected into a mold cavity for molding an artificial turf body, and FIG. 3 is a partially cutaway cross-sectional view showing a state immediately after injecting a synthetic resin, and FIG. 3 is a view showing another embodiment of the method of the present invention which is carried out by using another molding apparatus. FIG. 4 is a partially cutaway sectional view showing a state immediately after injecting a conductive synthetic resin into the mold, and FIG. 4 shows a mold cavity for molding an artificial turf main body, and immediately after injecting the resin for molding an artificial turf main body into the mold cavity. Is a partially cutaway sectional view showing the state of FIG. 5, and FIG. It is a missing side view. A and A '... Mold cavity for molding artificial turf body, B and B' ...
Molds for molding conductive parts, a and a '... moving side molds, b and b' ... fixed side molds, 1 and 1 '... artificial turf body, 3 and 3' ... sheet-like base, 4 ...... Upper permeable hole, 5 ...... Leaf-shaped part, 6, 7, 8 ...... Legs, 9 ...... Lower permeable hole, 10 ......
Mold plate of moving die a, 12 and 12 '... Bushing, 13 ...
Mold cavity for forming the head of the conductive part, 14 ... Mold plate of fixed side mold b,
16 ... Bushing, 18 and 18 '... Mold for forming leg of conductive part, 19, 19', 20, 20 ', 21 ... Recess for filling each leg, 22 ... Ejection pin, 23, 23 '... Conductive part, 24 ...
Ground.

Claims (2)

[Claims] 1. An artificial turf is first prepared from one injection device by using an injection molding device having an injection molding die having a mold cavity for molding an artificial turf main body and a mold cavity for molding a conductive portion, and two injection devices. Inject the artificial turf body molding resin or conductive part molding resin into the main body molding mold or conductive part molding mold, and then use another injection device to mold the conductive part molding mold or artificial grass An injection molding method for synthetic resin artificial turf, characterized by injecting a resin for molding a conductive part or a resin for molding an artificial turf main body into a mold cavity to integrally mold the artificial turf main body and the conductive part. 2. When injecting one kind of molten resin into one of the mold cavities, a nesting pin is inserted into the other mold cavity to prevent the inflow of the one kind of molten resin. Item 1
A method for injection-molding the synthetic resin artificial turf described.