𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞 : 𝐖𝐞𝐥𝐝 𝐋𝐢𝐧𝐞𝐬: 𝐓𝐡𝐞 𝐒𝐢𝐥𝐞𝐧𝐭 𝐒𝐭𝐫𝐞𝐧𝐠𝐭𝐡 𝐊𝐢𝐥𝐥𝐞𝐫 𝐢𝐧 𝐈𝐧𝐣𝐞𝐜𝐭𝐢𝐨𝐧 𝐌𝐨𝐥𝐝𝐢𝐧𝐠

𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞

𝐖𝐞𝐥𝐝 𝐋𝐢𝐧𝐞𝐬: 𝐓𝐡𝐞 𝐒𝐢𝐥𝐞𝐧𝐭 𝐒𝐭𝐫𝐞𝐧𝐠𝐭𝐡 𝐊𝐢𝐥𝐥𝐞𝐫 𝐢𝐧 𝐈𝐧𝐣𝐞𝐜𝐭𝐢𝐨𝐧 𝐌𝐨𝐥𝐝𝐢𝐧𝐠 🔧

Two melt fronts meet → a weld line forms. Weak spot. Visible flaw. Field failure waiting to happen.

Why it happens:

→ Multiple gates or flow splits

→ Low mold or melt temperature

→ Poor venting trapping air at the meet point

How to fix it:

✅ Raise mold & melt temps — better fusion

✅ Optimize gate location — merge flows earlier

✅ Increase injection speed & pressure

✅ Use flow leaders to redirect the meet point away from critical areas

✅ Vent properly — let air escape, not get trapped

Weld lines don't have to be weak lines. Smart process design eliminates them before they become a problem.

source : Jack Liu

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