JPS581658B2 - Ishiyokunojiyushiriyushinokatajyutenhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for filling molds with two or more different colored resin particles.

The present invention also relates to a method for filling a mold with resin particles of a different color used for producing a molded foam having a different color pattern, particularly a granite-like pattern.

Conventionally, a method is widely known in which pre-expanded polystyrene particles are introduced into a mold having vapor permeation holes through a number of nozzles, and then steam is applied within the mold to form a foam.

In such a method, the pre-expanded particles are generally filled from the back of the mold using a large number of filling guns, but the filling guns are arranged at regular intervals over the entire area of the back of the mold. or placed at regular intervals on the top of the mold.

The reason why they are installed over the entire area is to increase the filling speed of the supplied resin particles, and the reason why they are filled from the top is because the filling rate increases due to their own weight.

In addition, in order to obtain foam products with unique patterns, conventionally pre-expanded styrene resin particles of different colors were mixed in advance outside the mold using a mixer such as a V-blender, and then filled into the mold using a filling gun. It was foam molded.

Therefore, in order to obtain foam products with different color patterns, it was necessary to use a mixing device.

The present invention has been made by focusing on the above-mentioned points, and has developed a unique mold filling method for resin particles that eliminates the conventional blending process outside the mold and allows blending to be performed at the same time as filling. It is on offer.

That is, the gist of the present invention is to simultaneously supply two or more resin particles of different colors into a mold using pressurized air from each particle storage tank through a filling hole opened at the bottom of the mold. This invention relates to a method for filling a mold with resin particles of different colors in which the resin particles of different colors can be mixed in the mold by the action of the pressurized air.

At this time, as soon as the pressurized air that carries each resin particle into the mold enters the mold through the filling hole, it interacts with each other to create turbulence, such as a vortex, and this turbulence causes resin particles of different colors to Mixed in the mold.

If resin particles of a different color are filled only from the top of the mold, they may not be blended uniformly due to falling due to their own weight, or the filled raw materials may hit the mold surface at right angles and fall as they are, so they are filled from each filling gun. Raw materials are never mixed uniformly.

Therefore, such a filling method has the disadvantage that the expected pattern cannot be obtained.

In the present invention, the height position of the filling hole varies depending on the weight of the pneumatic resin particles used, etc., but is preferably 1/3 below the lower part of the height of the mold.

In addition, in the present invention, for example, the cross-sectional shape of the mold is 5 cm in length.
, when the width is 45 cm, it is possible to completely fill the mold up to a height of about 1 m, but if the filling is insufficient, the present invention can be implemented to fill the mold with resin particles. After that, by filling in the missing resin particles that have been blended in advance through the auxiliary filling hole drilled at the top of the mold, the resin particles of different colors are completely filled with the resin particles, regardless of the size of the mold. It can be filled into the mold.

Further, the filling holes may be located in a line in the horizontal direction as shown in FIG. 1, or may be located at the vertices of a triangle as shown in FIG.

The spacing between the filling holes depends on the pressure of the pressurized air, the desired pattern of the product, etc., but the spacing between the filling holes should be between 50 mm and 200 mm so that the pressurized air interacts with each other to create turbulent flow. A filling hole is provided.

The resin particles used in the present invention are thermoplastic resin particles having a density of 20 g/l to 900 g/l and a length of 0.5 mm to 20 mm.

For example, pre-expanded styrene resin particles having a density of 20 g/l to 80 g/l, low density or high density polyethylene foam resin particles having a density of 200 g/l to 850 g/l are used.

The pressure of pressurized air used is 2 kg/cm2 to 7 kg/cm2.

The pressure of the pressurized air that supplies each resin particle into the mold may be the same or may be different.

To obtain a product with a granite pattern, the pressure should be the same, and to obtain a psychedelic pattern such as stripes, the pressure difference should be increased.

Embodiments of the present invention will be described below while explaining the structure of the mold shown in the drawings.

Reference numeral 1 denotes a mold for forming a desired cavity 2, which is composed of split molds 1a and 1b that can be freely approached and separated.

3 is a chamber for introducing heating fluid and cooling fluid, 4 is a mold 1
Numerous steam holes, 5, 5', 5''...
- indicates multiple filling holes 6, 6', 6 drilled at the bottom of mold 1
″... is the filling hole 5, 5', 5″...
A plurality of filling guns inserted into the air pipe 7 function to fill the resin particles with pressurized air fed from the air pipe 7.

8, 8', 8''... are hoppers that store resin particles of different colors for each resin particle, and are connected to the filling guns 6, 6', 6'', etc. by the supply pipe 9. It is connected.

10 is a piston that can open and close the filling holes 5, 5', 5'', . When they are in contact, the filling holes 5, 5', 5'' of the mold 1 are closed, and on the other hand, when they are separated, the filling holes 5.5', 5'' of the mold 1 are closed.・
...is open.

Incidentally, an auxiliary filling hole 11 may be bored near the upper end of the mold 1.

Next, use the mold to create a mold with a length of 50 mm, width of 300 mm, and height of 90 mm.
A method of manufacturing high density polyethylene foam panels with 0 mm granite pattern is shown.

Three different types of high-density polyethylene foam resin particles [black resin particles B (bulk density 0.33 g/cc), gray resin particles G
(bulk density 0.45 g/cc) and white resin particles W (bulk density 0.48 g/cc)] were placed in three hoppers 8, 8.
',8''.

Then, pressurized air with a pressure of 2 kg/cm2 is passed through the air pipes 7, 7.
, 7, and through three filling guns 6, 6', and 6'' placed at a height of 250 mm from the lowest position of the mold 1 with a spacing of 70 mm in the horizontal direction, 70 l/70 l/m in the mold. Each hopper 8, 8', 8
'' resin particles are simultaneously introduced into the mold and the bulk volume of the mold is 1
It was filled to 40%.

At this time, the resin particles are mixed by the vortex generated by the mutual mixing of the pressurized air blown into the mold through the filling holes 5, 5', 5''.

Next, the filling holes 5, 5', 5'' of the female mold 1a are filled with the filling gun 6.
, 6', 6" pistons 10, 10', 10", the male mold 1b was advanced by 8 mm to compress the resin particles in the mold and bring the parting surfaces 12 of the male and female molds into contact. After that, 1.4 kg/cm2 steam was introduced into chambers 3 and 3 and heated for 5 minutes, and then the steam supply was interrupted and cooling water was flowed into chambers 3 and 3 for 25 seconds. Heat by introducing pressurized air for 10 seconds,
Cooling has finished.

The mold was opened and a foam panel with a density of 0.52 g/cc was removed.

As shown in FIG. 3, this foam panel was a foam product with a natural granite pattern in which gray resin G was interspersed with black resin B and white resin W was scattered on a white background.

In addition, fill holes 5, 5', and 5'' of the mold 1 are made at the locations corresponding to the joints of the block, and after molding, the joints of the molded product are painted with black 13, etc. By coloring, it is possible to eliminate unsightly appearance caused by insufficient mixing.

According to the present invention, as described above, each resin particle is forcibly filled into a mold from the bottom of the mold using pressurized air without blending resin particles of different colors in advance, and the resin particles are filled into the mold cavity. Combined with the action of air, the blending process can be completely omitted as the blending process can be completely omitted, and the supply amount of each unique resin particle can be adjusted by adjusting the size of the filling gun, the flow rate of the pressurized air, or By changing the size of the particles of the material resin, a desired variety of blended states can be obtained, and this has many characteristics, such as being able to add interest to molded products.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory perspective view for explaining an embodiment of the mold filling method for resin particles of a different color according to the present invention, FIG. FIG. 4 is a plan view of a product molded according to this embodiment, and FIG. 4 is a perspective view of a mold showing another embodiment. 1...: Mold, 1a...Female mold, 1b...
...Male type, 5,5',5''...Multiple filling holes, 6,6',6''...Multiple filling guns, 8,
8', 8''... Hopper for a plurality of single color resins of different color resins, 9... Supply pipe.

Claims (1)

[Claims] 1. Two or more resin particles of different colors are supplied into the mold from each resin particle storage tank by pressurized air through a filling hole opened at the bottom of the mold, and in the mold, the resin particles of different colors are A method of filling molds with unique resin particles that can be mixed using the action of compressed air.