PRODUCT OVERVIEW ④ PINS WITH GAS RELEASE FILTER
■ Overview
● Filter strength
● Features • A pin with a gas release filter press–fitted into the tip of the pin. There are ejector pins ( d P.455 / 456 ) and core pins ( d P.457 ). • Gas inside the mold is released from the ventilation groove of the filter part. Since the ventilation groove has a triangular shape, it reduces burrs that resin gets into due to surface tension and also exhibits a high gas release effect. • Since the ventilation grooves of the filter part are arranged concen- trically, gas can easily escape from any direction and the effect of pin orientation during installation on molding defects is reduced. ● Filter section details • There may be an assembly hole on the side of the pin tip due to processing when assembling this product (Fig. 1). • When light passes through the filter surface, it looks like Fig. 2. Even in sections that does not transmit light, it is a ventilation part except for part A.
100 125 150
• The filter part may move (sink) due to the pressure applied to the pin tip surface. For the relationship between pressure and amount of movement, see Fig. 8 before checking the place of use and performing installation. • If too much pressure is applied, the filter part will buckle, which may cause sliding defects in the case of ejector pins and may adversely affect the setting and extraction of core holes in the case of core pins. In particular, be careful when using it in the sprue lock part or runner part where the pressure is high. E Injection pressure is not the maximum value in the molding machine, but the pressure applied to the filter pin installation part. E The data in Fig. 8 is a reference value (reference) that was tested using GVFCM. Quality or numerical values are not guaranteed.
Filter surface ventilation groove
φ 3
φ 4
25 50 75
φ 5
φ 6
Assembling hole
A
0 0.00
0.02
0.04
0.06
0.08
0.10
Movement (mm)
Figure 8: Injection pressure and filter surface movement amount (GVFCM)
Fig. 1: Pin–side surface
Fig. 2: Filter surface
● Difference in filter end face appearance and ventilation amount • The appearance of the filter end face differs as shown in Fig. 9 (upper) depending on the difference between the medium flow rate type and the large flow rate type and the presence or absence of alteration TK. • The amount of ventilation differs depending on the product type as shown in Fig. 9 (lower). – Ejector pin and core pin: Since the outer diameter of the filter is different, the ventilation amount will be different. – Medium flow rate type and large flow rate type: Since the size of the ventilation groove is different, the ventilation amount will be different. e In the alteration TK, the wire cut may cause slight crushing of the ventilation groove, and the flow rate may drop compared to the rate before applying TK. e The data in Fig. 9 is an experimental reference value (reference). Quality or numerical values are not guaranteed.
● Tip details and installation example At the tip of the pin (Fig. 3), the filter part protrudes about 0.1mm from the total length ( L + 0.02 0
) of the main body. Also, each end face of the filter part has a C
surface of about 0.1mm.
（C0.1）
Figure 9: Difference in filter end face appearance and ventilation amount
Medium flow rate type Large flow rate type Without TK alteration With TK alteration Without TK alteration With TK alteration
Filter
Pin body
Figure 3: Filter pin tip details
Filter end face appearance
1) Example of installation where the end face of the pin is at the same height as the molded product surface • TK alteration not applied In products where the filter part protrudes slightly, there is a possibility of protrusion from the molded product surface at the C surface (B part in Fig. 4).
2) Example of installation where the end face of the pin is embedded into the molded product surface • TK alteration not applied By allowing the total length (L) of the pin to be embedded into the molded product surface by α , there is no part protruding from the molded product surface as shown in Fig. 4 (Fig. 5). e Set the α value by considering the fluidity of the resin. (Reference value α ≧ 0.05mm)
GVFE 2.6–2.8 GVFC 3.2–6.2
GVFEM
Ejector Pins
3.6–6.6
Flow rate (L/min)
GVFCM 7.3–11.3
Core Pins
e Measured at pressure 0.15 MPa e Pin shaft diameter P = 6
B
Molding
Molding
■ For use • The size of the ventilation groove hole differs depending on the flow type and the way the gas escapes as well as the degree of burr formation changes, so select it according to the application. • Since the rust preventive oil is applied at the time of shipment, the ventilation groove may be blocked. Before use, blow it off with air to remove it. • Since there is a risk of damaging the filter part, there is a limit to the range in which the tip can be machined. For the normal type (GVFE/GFEM/GVFC/GVFCM) and JIS type (GVFEJ/GVFEJM), perform within a range of 0.5mm from the end face and for the tip processing type, perform withi n a range of 3mm from the end face. Electrical discharge machining or wire cutting is recommended because the ventilation groove is deformed and the gas release function deteriorates during machining such as cutting and grinding. • Perform regular maintenance such as ultrasonic cleaning to prevent resin clogging. • Please note that excessive pressure on the filter surface may cause the filter sinking or buckling. • The pin tip has a filter that protrudes about 0.1mm. Please be careful when designing. • Specify TK alteration to remove the filter protrusion on the shaft end face and align the shaft end face.
Molding product surface
（C0.1）
Filter
Pin body
Pin body
Filter
Figure 4: When protruding from the molded product surface
Figure 5: When Total length (L) embedded
• Alteration TK applied The alteration TK removes the stepped portion due to the filter protrusion and the C surface by wire cutting (Fig. 6). e Depending on the fluidity of the resin and the molding conditions, some resin material may get into the ventilation groove of the filter part and cause burrs in the molded product.
• Alteration TK applied Burrs can be prevented from coming out of the molded product surface by allowing the entire length (L) of the pin to be embedded into the molded product by β value (Fig. 7). e Set the β value by considering the fluidity of the resin. (Reference value β ≧ 0.02mm)
Molding
Pin body
Filter
Filter
Pin body
Figure 6: Details of the tip when alteration TK is applied
Figure 7: With alteration TK applied and the total length (L) embedded
453
454
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