WO2013099932A1

WO2013099932A1 - Device for deburring pellets of liquid crystal polymer molding material and pellets of liquid crystal polymer molding material

Info

Publication number: WO2013099932A1
Application number: PCT/JP2012/083631
Authority: WO
Inventors: 山口　裕
Original assignee: パナソニック株式会社
Priority date: 2011-12-27
Filing date: 2012-12-26
Publication date: 2013-07-04
Also published as: JP5297518B2; JP2013132891A

Abstract

Provided are a device for deburring pellets of a liquid crystal polymer molding material and pellets of a liquid crystal polymer molding material, making it possible to stabilize weighing during molding of a molded article, reduce trapping of air in pellets, and minimize the occurrence of blistering of the molded article. The present invention is characterized by being composed of: a cylindrical fixed drum (2) which is provided with a pellet intake port (21) for taking in pellets of a liquid crystal polymer molding material at an upper part in the vicinity of one end and a pellet discharge port (22) for discharging pellets at a lower part in the vicinity of the other end, and which has a side wall (23) where a plurality of opening holes (24) for removing burrs are formed at a side surface between the two ends; a rotatable elongated cylindrical member (3) provided within the fixed drum (2), and having a pellet feeding means in which a helical continuous projection section (32) is formed, and a screw section (33) for pressing the pellets inside the fixed drum (2) toward the side surface of the fixed drum (2); and a rotating means for rotating the elongated cylindrical member (3).

Description

Liquid crystal polymer molding material pellet deburring device and liquid crystal polymer molding material pellet

The present invention relates to a liquid crystal polymer molding material pellet deburring device and a liquid crystal polymer molding material pellet.

When producing LCP molded products using liquid crystal polymer (hereinafter abbreviated as LCP) molding material, LCP molding is performed by injection molding using pellets of LCP molding material (hereinafter abbreviated as pellets). A method of manufacturing a product is generally performed.

For the production of this LCP molded product, an injection molding machine having an inline screw type plasticizing device is generally used (for example, see Patent Document 1).

In this type of plasticizer for an injection molding machine, raw material pellets are charged into a hopper and supplied from the hopper into a heating cylinder. A screw is accommodated in the heating cylinder, and the raw material is sent by rotation of the screw.

The heating cylinder is configured from the hopper side in the order of a hopper zone (input part), a feed zone (supply part), a compression zone (compression part), and a metering zone (metering part).

Pellets thrown from the hopper zone (feeding section) are sent to the feed zone (feeding section) and compression zone (compression section) in a molten state, and one shot is weighed in the metering zone (weighing section). The LCP molded product is molded by being injected into the mold.

JP 2005-186593 A

On the other hand, since the LCP of the raw material shows great anisotropy in physical properties, when a pellet is formed by mixing a fibrous filler or the like as a raw material of an LCP molded product, there is a burr at the end of the pellet when the pellet is formed. Many occur. It should be noted that burrs do not occur in nylon resin molding materials and polypropylene resin molding materials.

When such a burr-generated pellet is put into an injection molding machine having the above-mentioned inline screw type plasticizing device, the feed zone (feeding unit) in the heating cylinder can be successfully applied to the screw due to pellet burr. There is a problem that slippage occurs without being bitten and supply is delayed, resulting in poor meterability in the metering zone (metering section) and reduced productivity.

In the metering zone (metering section), the pellets are in a melted state at about 350 ° C. On the other hand, the temperature of the mold for injecting the pellets has a temperature difference of about 60 ° C. As soon as it is injected, it solidifies and the LCP molded product is molded instantly. For this reason, the meterability in the metering zone (metering unit) directly affects the productivity.

Also, when pellets in which air is entrained in burrs are used as raw materials, there are problems that blisters are generated in the LCP molded product and the aesthetic appearance is impaired, and the strength of the LCP molded product is weakened.

The present invention has been made in view of the circumstances as described above, and improves the biting property to the screw of an injection molding machine having an in-line screw type plasticizing device, thereby forming an LCP molded product. Liquid crystal polymer (LCP) molding material pellet deburring device and liquid crystal polymer molding material capable of stabilizing meterability and further reducing the occurrence of blisters in LCP molded products by reducing air entrainment in the pellets It is an object of the present invention to provide pellets.

The present invention has the following features in order to solve the above problems.

That is, the liquid crystal polymer molding material pellet deburring device of the present invention has a pellet inlet for feeding a liquid crystal polymer molding material pellet in the upper part near one end and a pellet in the lower part near the other end. A cylindrical fixed drum having a side wall portion having a plurality of opening holes for removing burrs on a side surface between both end portions, and a spiral shape provided in the fixed drum, having a pellet discharge port for discharging A rotatable long cylindrical member having a pellet delivery means formed with a continuous projection portion, a screw portion for pressing pellets in the fixed drum against the side surface of the fixed drum, and for rotating the long cylindrical member It is characterized by comprising the rotating means.

In this liquid crystal polymer molding material pellet deburring device, the screw portion formed on the long cylindrical member has a slanting angle with the straight portion parallel to the longitudinal direction of the long cylindrical member. It is preferable that a bent portion is formed.

In the deburring apparatus for pellets of the liquid crystal polymer molding material, the long cylindrical member preferably has an air outlet provided in the vicinity of the screw portion for sending air introduced from the air introduction pipe. .

Further, in the liquid crystal polymer molding material pellet deburring device, it is preferable that an outlet valve for adjusting the amount of air sent from an air outlet provided in the vicinity of the screw portion is provided.

Further, the liquid crystal polymer molding material pellet of the present invention is characterized in that burrs are removed.

In the pellet of the liquid crystal polymer molding material, it is preferable that the weight change rate before and after deburring is in the range of 0.5 to 3%.

According to the deburring device for pellets of the liquid crystal polymer molding material of the present invention, a rotatable long cylindrical member is disposed in the fixed drum, and the pellet is placed on the side of the fixed drum by a screw portion provided on the long cylindrical member. Since deburring is performed by pressing, when using the liquid crystal polymer molding material pellets deburred using the liquid crystal polymer molding material pellet deburring device of the present invention, in-line screw type plasticization By improving the biting ability of the injection molding machine having the device into the screw, it is possible to stabilize the metering property at the time of molding the LCP molded product, and further reduce the entrainment of air in the pellet to reduce the LCP molded product. It becomes possible to suppress generation | occurrence | production of a blister.

It is the perspective view which cut and showed the principal part of one Embodiment of the deburring apparatus of the pellet of the liquid crystal polymer molding material of this invention. It is a schematic front sectional drawing which shows the structure of the deburring apparatus of the pellet of the liquid crystal polymer molding material in one Embodiment same as the above. It is a perspective view which shows a long cylindrical member. It is front sectional drawing which shows the structure of an outlet valve. It is the external appearance photograph of the pellet before removing a burr | flash. It is the external appearance photograph of the pellet after removing a burr | flash.

The present invention has the characteristics as described above, and an embodiment thereof will be described below.

FIG. 1 is a perspective view showing a part of an embodiment of a deburring apparatus for pellets of a liquid crystal polymer molding material according to the present invention. FIG. 3 is a schematic front sectional view showing the configuration of the deburring device, FIG. 3 is a perspective view showing a long cylindrical member, and FIG. 4 is a front sectional view showing the configuration of the outlet valve.

The liquid crystal polymer molding material pellet deburring apparatus 1 according to the present invention discharges a pellet inlet 21 for feeding a pellet to the upper part near one end and discharges the pellet to the lower part near the other end. A cylindrical fixed drum 2 having a pellet discharge port 22 is provided.

The main body portion of the fixed drum 2 has a hexagonal cross section, and includes a side wall portion 23 in which a plurality of opening holes 24 for peeling and removing burrs are formed on the side surfaces between both end portions.

The shape of the opening hole 24 in the side wall portion 23 is appropriately set according to the size, shape, and type of the pellet to be deburred. In the case of the slit-like opening hole 24, the width of the opening hole 24 is set. Is preferably 1.0 to 1.5 mm.

Further, the material of the side wall portion 23 is preferably iron or stainless steel having high rigidity and high wear resistance so that it can withstand repeated use and is not damaged even if the pellet is pressed, and iron is particularly preferable. .

By using iron, when debris or wear powder of the side wall portion 23 is generated, recovery by a magnet or detection by a metal detector becomes possible.

The thickness of the side wall portion 23 can be appropriately set depending on the material to be used, but usually a thickness in the range of 0.8 to 1.5 mm is preferable.

The entire fixed drum 2 is accommodated in the hood 7.

In this embodiment, the fixed drum 2 has a hexagonal cross section, but is not limited to this, and is not limited to a polygonal shape such as a triangular shape, a quadrangular shape, an octagonal shape, or a cylindrical shape. Can also be used.

A long cylindrical member 3 is provided in the fixed drum 2. One end of the long cylindrical member 3 is connected to an air introduction pipe 4 that is rotatably attached to the hood 7 via a bearing 41, and is integrally rotatable with the air introduction pipe 4.

Further, it is preferable that the arrangement position of the long cylindrical member 3 is provided so that the central axis of the fixed drum 2 and the rotation axis of the long cylindrical member 3 coincide.

The long cylindrical member 3 is provided with delivery means 31 for delivering the introduced pellets in the direction of the pellet discharge port 22 from the position below the pellet input port 21 toward the pellet discharge port 22. .

The delivery means 31 is provided with a spiral continuous protrusion 32, and the pellet is urged by the spiral continuous protrusion 32 by the rotation of the long cylindrical member 3 and is sent in the direction of the pellet discharge port 22. .

Further, as shown in FIG. 3, a rib-shaped screw portion 33 is formed on the long cylindrical member 3 from the intermediate portion in the longitudinal direction of the long cylindrical member 3 toward the pellet discharge port 22. ing.

The screw part 33 is formed in order to stir the pellet by the rotation of the long cylindrical member 3 and forcibly press the pellet against the side wall part 23.

Although the shape of the screw portion 33 is not particularly limited, a straight portion 33a parallel to the longitudinal direction of the long cylindrical member 3 is formed, and a bent portion having a gently inclined angle. 33b is preferably formed.

The angle of the bent portion 33b is an angle downward with respect to the rotation direction of the long cylindrical member 3. By setting the angle downward, a force for returning the pellet in the direction of the pellet inlet 21 by the rotation of the long cylindrical member 3 acts, and the residence time of the pellet in the fixed drum 2 can be lengthened.

Also, the residence time of the pellet can be adjusted by appropriately changing the angle of the bent portion 33b. Specifically, the residence time can be lengthened by increasing the angle. For example, a range of about 2 to 4 ° is preferable.

Furthermore, in addition to changing the angle of the bent portion 33b, the residence time can also be adjusted by changing the length of the straight portion 33a and the bent portion 33b.

In the vicinity of the screw portion 33 of the long cylindrical member 3, an air outlet 34 for sending air introduced from the air introduction pipe 4 is formed, and an opening 35 is provided at one end of the long cylindrical member 3. Is formed.

In addition, the number of the screw parts 33 provided in the elongate cylindrical member 3 is not limited, A plurality may be provided.

A pulley 42 is fixed to the opposite side of the air introduction pipe 4 to which the long tubular member 3 is attached with the hood 7 therebetween, and a pulley 62 provided on the drive shaft 61 of the drive motor 6 and the pulley 42. The rotation operation of the drive motor 6 is transmitted to the air introduction pipe 4 by the timing belt 63 spanned between the two, and the long cylindrical member 3 connected to the air introduction pipe 4 is rotated.

The air introduced from the air introduction pipe 4 is sent out from an air outlet 34 provided in the vicinity of the screw portion 33 of the long cylindrical member 3 and an opening 35 provided at one end. That is, air is introduced into the fixed drum 2 through the long cylindrical member 3.

Thereby, an air flow is formed from the inside of the fixed drum 2 to the outside, and burrs, fine particles, and the like removed by the air flow can be forcibly discharged through the opening holes 24 of the side wall portion 23.

Further, since the long tubular member 3 can be cooled by the air passing through the inside of the long tubular member 3, a more stable deburring effect can be obtained.

Furthermore, the amount of air sent from the air outlet 34 provided in the vicinity of the screw portion 33 can be adjusted by the outlet valve 5. The outlet valve 5 is installed so as to close the opening 35 provided at the end of the long cylindrical member 3, and controls the amount of air delivered from the opening 35 by adjusting the strength of the spring 51. As a result, the amount of air delivered from the air delivery port 34 provided in the vicinity of the screw portion 33 is adjusted.

Next, the deburring operation of the deburring apparatus 1 for pellets of the liquid crystal polymer molding material of the present invention will be described in detail.

First, a pellet before removing the burrs shown in FIG. Then, air is introduced from the air introduction pipe 4 to release air from the air delivery port 34 provided in the vicinity of the screw part 33 formed in the long cylindrical member 3, and the drive motor 6 is operated, The long tubular member 3 is rotated together with the air introduction tube 4.

The pellets in contact with the spiral continuous protrusion 32 of the delivery means 31 provided on the long cylindrical member 3 are moved in the direction of the pellet discharge port 22 by the rotation of the long cylindrical member 3.

The pellets moved to the screw part 33 by the delivery means 31 are stirred by the rotation of the screw part 33 and pressed against the side wall part 23 of the fixed drum 2 to remove burrs. At this time, the bending portion 33 b of the screw portion 33 acts to return the pellet toward the pellet inlet 21, and the pellet stays in the fixed drum 2.

Then, the processed pellets from which burrs have been removed are sequentially discharged from the pellet discharge port 22 provided at the lower end of the fixed drum 2.

The removed burr is discharged out of the fixed drum 2 from the opening hole 24 of the side wall portion 23 by the air discharged from the air delivery port 34 provided in the vicinity of the screw portion 33, and further provided in the lower portion of the hood 7. It is discharged out of the hood 7 through the discharge port 71.

In this way, the pellets shown in FIG. 6 from which burrs have been removed by the pellet deburring device 1 of the present invention can stabilize the meterability during molding of LCP molded products.

Specifically, the metering time in the metering zone (metering unit) of an injection molding machine having an in-line screw type plasticizing device can be in the range of 0.3 to 1.3 seconds.

In addition, it is possible to reduce the occurrence of blisters in the LCP molded product by reducing the air entrainment of the pellets. Specifically, the blister generation rate can be set in the range of 0 to 0.1%.

Further, the rate of removal of burrs in the pellets of the liquid crystal polymer molding material from which burrs have been removed according to the present invention is not particularly limited, but from the relationship between the rate of removal of burrs and weight loss, The weight change rate after deburring is preferably in the range of 0.5 to 3%.

If the rate of weight change is within this range, deburring can be sufficiently performed, and the material use efficiency can be improved.

Of course, the present invention is not limited to the above embodiments, and various aspects are possible for details.

In the above embodiment, the pellets of the liquid crystal polymer molding material used for the LCP molded product have been described. Needless to say, the present invention can also be applied to deburring pellets of other thermoplastic resins and thermosetting resins.

Further, the pellet may be formed by molding a general-purpose LCP resin alone, but is preferably mixed with an inorganic filler and glass fiber. Moreover, you may add antioxidant, a flame retardant adjuvant, etc. as needed.

Examples of the present invention are shown below, but the present invention is not limited to these.

<Example 1>
LCP resin compositions were obtained from the blending components and blending amounts (blending ratios) shown in Table 1.

The LCP resin composition was molded into 3φ × 3 cylindrical pellets using a pelletizer (biaxial extruder) at 50 kg / h.

The pellets were deburred under the following conditions using the pellet deburring apparatus of the present invention, and the deburred pellets were used as samples.
Long cylindrical member: Screw part straight part length 42mm, bent part length 87mm (angle 4 °)
Rotation speed: 80rpm
Air pressure: 2 atm

<Example 2>
Deburring was performed in the same manner as in Example 1 except that a long cylindrical member having a straight part length of 84 mm and a bent part length of 87 mm (angle 4 °) was used, and the deburred pellet was sampled. It was.

<Example 3>
Deburring was performed in the same manner as in Example 1 except that a long cylindrical member having a screw portion straight portion length of 42 mm and a bent portion length of 87 mm (angle 2 °) was used. It was.

<Comparative example>
Pellets that were not deburred were used as samples.

The following items were evaluated for the pellet samples of Examples 1 to 3 and Comparative Example.

<Weight change rate>
The weight difference between the LCP resin pellets before and after deburring was measured to determine the weight change rate (%) of the burr before deburring. The results are shown in Table 2.

<Molding machine weighing time>
For each of the pellet samples of Examples 1 to 3 and Comparative Example above, the measurement time when molding a test piece (LCP molded product) using an injection molding machine having an in-line screw type plasticizer was measured. . The weighing time was the average time during 200 shot molding. Table 2 shows the results and the production rate of the test pieces (ratio of the production amount of the example with respect to the comparative example).

<Blister incidence>
50 test pieces (LCP molded products) molded during measurement of the molding machine measurement time were treated in a thermostatic bath at 270 ° C. for 10 minutes, the surface of the test piece was visually observed, and the sample pieces with blisters were observed. The number of blisters was determined by counting the number. Table 2 shows the results and the production rate of non-defective test specimens free from blisters (ratio of the non-defective product production amount of the example to the comparative example).

From the above results, pellets that were deburred using the deburring device of the present invention of Examples 1 to 3 were significantly reduced in the molding machine weighing time compared to pellets that were not deburred in the comparative example. The production rate for the comparative example was about 150% (when 100 comparative examples were manufactured, 150 examples could be manufactured).

This is because when the pellets deburred using the deburring apparatus of Examples 1 to 3 are put into an injection molding machine having an in-line screw type plasticizing apparatus, to the screw in the feed zone in the heating cylinder It is thought that the reason is that the biting property is improved.

In addition, the pellets that were deburred using the deburring device of the present invention of Examples 1 to 3 gave better results for the blister generation rate than the pellets that were not deburred in the comparative example ( When 50 products were manufactured, 23 of the comparative examples were good and 27 were bad, but in the example, all 50 were good, that is, the yield of non-defective products was about 217%. ).

Further, the production rate of non-defective products with respect to the total comparative example including the molding machine measurement time was about 326% (when the comparative example produced 100 good products, the example could produce 326 good products).

DESCRIPTION OF SYMBOLS 1 Deburring apparatus 2 Fixed drum 21 Pellet insertion port 22 Pellet discharge port 23 Side wall part 24 Opening hole 3 Long cylindrical member 31 Delivery means 32 Spiral continuous protrusion 33 Screw part 33a Straight part 33b Bending part 34 Air delivery port 4 Air introduction pipe 5 Outlet valve

Claims

There is a pellet inlet for feeding liquid crystal polymer molding material pellets near the top of one end, and a pellet outlet for discharging pellets near the bottom of the other end. A cylindrical fixed drum having a side wall portion formed with a plurality of opening holes for removing
A rotatable long cylindrical member having a pellet delivery means provided in the fixed drum and formed with a spiral continuous projection and a screw part for pressing the pellet in the fixed drum against the side surface of the fixed drum;
A deburring device for pellets of a liquid crystal polymer molding material, characterized in that it comprises rotating means for rotating a long cylindrical member.
The screw part formed on the long cylindrical member is formed with a straight part parallel to the longitudinal direction of the long cylindrical member and a bent part having a gently inclined angle. Item 2. A deburring device for pellets of a liquid crystal polymer molding material according to Item 1.
3. The liquid crystal polymer molding material according to claim 1, further comprising an air delivery port provided in the vicinity of the screw portion for delivering air introduced from the air introduction pipe to the long cylindrical member. Pellet deburring device.
The liquid crystal polymer molding material according to any one of claims 1 to 3, further comprising an outlet valve for adjusting an amount of air sent from an air outlet provided in the vicinity of the screw portion. Pellet deburring device.
¡Pellets of liquid crystal polymer molding material, characterized by removing burrs.
6. The pellet of liquid crystal polymer molding material according to claim 5, wherein the weight change rate before and after deburring is in the range of 0.5 to 3%.