29 8 月, 2025
Cold weather can be tough on UPVC windows—especially at the welded corners where stress concentrates. But with careful techniques and cold-climate adjustments, you can significantly reduce the risk of cracking. Here’s how:
1. �️ Control the Cleaning Depth of Welded Seams
After welding, a narrow groove is often cleaned out along the seam. In winter, it’s crucial to keep this depth shallow—ideally between 0.3–0.5 mm. For profiles with a wall thickness of 2.0 mm or less, aim for ≤0.3 mm. In extremely cold regions, skip grooving altogether! Instead, use a hand blade to flatten the weld seam. This preserves material integrity and reduces the risk of crack formation.
2. ⚠️ Avoid Sharp Notches When Cleaning Slag
When removing excess weld material around the press strip groove, be extra cautious. Never leave sharp tool marks or deep scratches. These can act as stress concentrators—tiny weak points where cracks start under temperature-induced contraction. A smooth, polished finish is essential here.
3. ✂️ Cut Aluminum Tracks and Glass Beads Accurately
Dimensional accuracy matters, especially with temperature fluctuations:
– Glass beads should be cut 0.5 mm shorter than the measured length of the frame or sash.
– Why? This allows the bead to expand slightly in warmer conditions without pressing against the welded corners.
– Similarly, aluminum sliding tracks must be sized with thermal expansion in mind.
When beads or tracks are too long, they exert constant pressure on the weld points. As temperatures drop, the plastic contracts, and that pressure can lead to cracking.
By paying attention to these often-overlooked details, you can build UPVC windows that stay strong, tight, and crack-free—even through freezing winters. ❄️🛠️