GAS VENT UNIT
SPACER FOR GAS VENT UNIT
Part Number T Type D 0.1mm increments
MSTV
MSTVS
E When T dimension is 15 or smaller, V1 = V No discrimination groove
V V1
Cross–sectional view
5 8
1.5 2
MSTVS
5.0–50.0
A part
① ②
2 2.5
Part Number – T MSTVS5 – 19.5
Order
10 （ 2 ）
Discriminant groove
Quotation
Delivery
0 －
T ＝ 6
Step at the tip F ± 0.02 (When valve is closed)
0.02
Part Number – T – (TK) MSTVS5 – 18.95 – TK
③
Alterations
L ± 0.01 Details of part A
Alterations Code
Spec.
0 － 0.1
＋ 0.1 0
T
D
D = 2
D = (3/6)
D = 2
D = (3/6)
Changes T dimension tolerance. T + 0.1 0 c T 0 –0.02 E When TK is used, T dimension designation in 0.01 increments possible
St
St
TK
TK T
M Material
(1) Sleeve (body): SUS303 (2) Valve: SUS303 (3) Spring: SUS type Heat–resistant temperature: 200 ℃
M Material
SUS303
h
L
h
Part Number
M (Coarse thread)
Hex (S)
MSTVM
φ D
T
V
Type
No.
Open valve
Closed valve
3
12
3 4 1.5 8 (P1.25)
M
MSTVM
10 (P1.5)
6
15
6 5 2
Tip
(Spring load)
Part Number
Head diameter H
Gas exhaust clearance t
Spring outer diameter d
Stroke st
L
F
d1 d2 h
N
Type
D
Part Number – T MSTVM6 – 15
Order
2
20
–
4
1.0 0.9
0.05–0.1
0.03–0.06
2.9
0.68
MSTV
3
20
0.3
5
1.0
0.9
0.3
0. 2–0.3
0. 1–0.15
2.9
0.68
Quotation
6
25
0.5
8
1.5
1.3
0. 3–0.4
0.15–0.2
3.8
1.96
Delivery
T
S
Part Number – L – F MSTV2 MSTV3 – – 20 20 – 0.3
Order
M Material SUS304 equivalent
■ Operation principle The valve is opened by the spring, and the gas that resins produce as well as air in the mold are exhausted.
Quotation
■ Example of dimensions for mounting holes (for MSTV)
Delivery
When resins reach the valve, the valve closes by resin pressure and exhaust finishes.
Example
■ Features 1. Effective gas exhaust
• If the base plate is thick for L dimension, use spacer (MSTVS/MSTVM), etc. • If you use MSTVM and you are concerned about the case it loosens, take measures against loosening such as double lock.
＋ 0.01 φ D 0
• reduces molding defects. (reduction of burns, shrink, poor potting, weld lines, etc.) • can shorten a molding cycle. 2. Resistant to corrosion because it is made of stainless steel. ■ Notes on handling • Resin leak from the valve and burrs may occur depending on the molding con- dition and the type of resin. • Select a mounting location carefully because the shape of the gas vent unit will be transferred on the surface of mold products. • Cleanse the resin gas exhaust passage and the gas vent unit periodically. • For the shape of a gas exhaust passage, refer to the right diagram to set it. • Take the tip steps (value F) into account for a residence area of resin gas to set L. ■ Example of processing dimensions for gas exhaust passage Part Number s×w ℓ Type D Cross–sectional area of the gas vent
Resin
Resin
Plate
Plate
Resin
Resin
Plate
Plate
MSTVS
MSTVM
Back plate
Discharge path
Back plate
φ H1
Part Number Type D
Tip steps F
L
T H1
s = 0.5 or longer 0.85mm 2 or larger s = 0.5 or longer 0.85mm 2 or larger
5 ※
2 20 3 20 6 25
–
2
l
MSTV
0.3 0.5
6
6
Specify the spring seating surface that is 3/4 or longer of the entire perimeter.
MSTV
3
8.5
Back plate
Back plate
※ If you use the spacer for gas vent unit MSTVS or MSTVM for the gas vent unit MSTV2–20, H1 = 6 and use MSTVS5/MSTVM5.
6 s = 0.5 or longer 2.30mm 2 or larger E A gas exhaust passage that leads outside the mold is required. The exhaust should be air emission or forced exhaust (vacuuming) by a vacuum pump, a vacuum generator, etc. Note that the valve may close if exhaust pressure is high .
447
448
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