MOLD COOLING Benefits of Turbulent Flow Plastic Baffles
MOLD COOLING Guidelines to Efficient Water Cooling
Improve mold cooling performance over traditional brass baffles
Typical Applications
How to Check Coolant Flow Rate
• Ensure good coolant flow rates (Reynolds number of 4000 minimum. See Reference Table below.) • The golden rule for optimum cooling is to maximize GPM (gallons per minute). DME recommends in-line coolant flow meter usage. In-line coolant flow meters are available from DME Industrial Supplies • Coolant feed channels should be the same size or larger than the calculated coolant channel • Keep coolant channels clean with filtering and scheduled channel maintenance to de-scale coolant channels • Use parallel cooling versus series cooling, as appropriate • Minimize restrictions within cooling circuit
Turbulent Flow Plastic Baffles Benefits
• Remove the exit hose from a mold-cooling channel and fill a 1- or 5-gallon container while measuring the amount of time it takes to fill the container. • Calculate the amount of coolant that flowed through the exit hose into the container. • For example, filling a 5-gallon container in 8 minutes is a flow rate of .625 gallons per minute (5 over 8 or 5/8 = .625) • .625 gallons per minute is a very good flow rate for a 1/4 NPT cooling channel. However, this would NOT be turbulent flow for a 3/8 NPT flow channel. • Additionally, many other factors influence the cooling process, including coolant channel placement, distance the cooling channels are from the cavity or core molding surface, distance between each cooling channel, and the number of cooling channels. • Furthermore, if water deposits such as lime and other hard water mineral deposits are allowed to accumulate, the walls of the cooling channels will become insulated. Turbulent flow is less beneficial under these conditions. • Practice filtering the coolant along with regularly scheduled coolant channel maintenance to de-scale coolant channels. • Mold materials also play a significant role in cooling time. For example, replacing 420 Stainless Steel cores with a Copper Alloy such as Moldstar (as supplied by DME) can significantly reduce cycle time. • Lastly, remember that regular cooling channel maintenance and turbulent water flow rates for the size of the cooling channels will have an enormous effect on the mold’s cooling capacity.
• Patented side wipers prevent coolant blow- by, ensuring coolant flow to the end of baffles • Results in better cooling of targeted hot spots • Dramatically improves cooling time • Increases coolant flow velocity and lowers Delta “T” across mold surface • Built-in ribs encourage turbulent flow and reduce stagnant laminar flow • Turbulent flow dissipates about 3x the BTUs as compared to laminar flow • Non-hygroscopic, glass-reinforced engineering thermoplastic (polypthalamide) excels under high heat, providing better temperature stabilization
• Pre-wrapped with TPFE tape • Maximum coolant temperature recommended: 100°C (212°F)
T
Reynolds Number
W
In fluid mechanics, the Reynolds number is the ratio of inertial forces to viscous forces and quantifies the relative importance of these two types of forces for given flow conditions.
S
L
Slot indicates baffle position
Turbulent Flow Plastic Baffles (INCH) – PBF
Turbulent Flow Reference Table
L NOMINAL OVERALL LENGTH
APPROXIMATE MINIMUM FLOW (in gallons per minute)
T BAFFLE THICKNESS
W BAFFLE WIDTH
NOMINAL PLUG SIZE
S HEX SIZE
DRILLED PASSAGE I.D.
PIPE SIZE NPT
FLOW RATE GPM
DRILL SIZE
ITEM NUMBER
INCHES
1 ⁄
16 NPT
0.250" 0.339" 0.438" 0.593" 0.719" 0.938" 1.156"
0.33 0.44 0.55 0.74
PBF0125-04 PBF0125-08 PBF0250-05 PBF0250-10 PBF0375-06 PBF0375-12 PBF0500-08 PBF0500-16 PBF0750-12 PBF0750-24 PBF1000-12 PBF1000-24
1 ⁄ 1 ⁄
3 ⁄ 3 ⁄
4" 8" 5"
1 ⁄ 1 ⁄
5 ⁄ 5 ⁄ 7 ⁄ 7 ⁄ 9 ⁄ 9 ⁄
5 ⁄ 5 ⁄ 7 ⁄ 7 ⁄ 9 ⁄ 9 ⁄
8
16
16
16
16
1 ⁄
8 NPT
8
16
16
16
16
1 ⁄
4 NPT
1 ⁄ 1 ⁄
1 ⁄ 1 ⁄
3 ⁄ 3 ⁄ 3 ⁄ 3 ⁄ 3 ⁄ 3 ⁄
4
4
32
16
16
3 ⁄ 1 ⁄
8 NPT 2 NPT
10"
4
4
32
16
16
0.9
3 ⁄ 3 ⁄ 1 ⁄ 1 ⁄
5 ⁄ 5 ⁄
6"
8
16
32
16
16
3 ⁄ 4 NPT 1 NPT
1.17 1.44
12"
8
16
32
16
16
3 ⁄ 3 ⁄
8"
11 ⁄ 11 ⁄ 15 ⁄ 15 ⁄
11 ⁄ 11 ⁄ 15 ⁄ 15 ⁄
2
8
32
16
16
16" 12" 24" 12" 24"
2
8
32
16
16
3 ⁄ 3 ⁄
9 ⁄ 9 ⁄
1 ⁄ 1 ⁄
4
16
8
16
16
Approximate Minimum Flow (in gallons per minute) required for turbulent flow in drilled water passages based on a Reynolds number of 4000.
4
16
8
16
16
1 1
5 ⁄ 5 ⁄
3 ⁄ 3 ⁄
1 1
1 /
1 1
1 ⁄ 1 ⁄
8
16
8
8
1 ⁄
8
16
8
8
242
243
U.S. 800-626-6653 ■ Canada 800-387-6600 ■ www.dme.net ■ store.dme.net
U.S. 800-626-6653 ■ Canada 800-387-6600 ■ www.dme.net ■ store.dme.net
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