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upvc profile processing in winter time



Plastic steel doors and windows are doors and windows made of PVC profiles and hardware accessories. They have both plastic and steel linings, commonly known as plastic steel doors and windows.

It has the following advantages:


  •   Heat preservation and energy saving: multi-cavity structure, low heat transfer coefficient.

  •  Air tightness: all gaps are equipped with rubber and plastic sealing strips and wool tops.

  • Water tightness: multi-chamber structure, independent drainage chamber design.

  •  Wind pressure resistance: 1.5-3mm thick steel lining can be added.

  •  Sound insulation: multi-cavity structure + good sealing.

  •  Corrosion resistance: organic polymer.

  •  Weather resistance: unique formula, adding titanium dioxide.

  •  Fire resistance: non-flammable, non-combustible, self-extinguishing, safe and reliable.

  • Insulation: Excellent electrical insulation material, non-conductive.

  • The finished product has high dimensional accuracy and no deformation.

  • Easy to protect: any cleaning agent can be used, and it will be as white as ever after cleaning.

  • Anti-theft: The glass beadings are all facing indoors, and the plastic-steel profiles have high strength, great toughness, and are not easily damaged.

 But at the same time, PVC profiles are thermoplastic cold and brittle materials, that is, when the temperature is high, their toughness is greater, and when the temperature is low, they are more brittle. Therefore, as the temperature gradually decreases, there will always be some problems in the process of cutting, welding and assembling plastic profiles.Such as cracking, material collapse, etc.!


So how to avoid the above situation from happening? We can avoid improvement in the following ways


ONE. Reasons and solutions for the occurrence of material collapse

1. Cutting saw settings and cutting skills

a. It may be that the machine head's working speed is too fast, and the joint speed can be appropriately slowed down;


b. The pressure of the air hammer is too high, you can adjust the air hammer to reduce the pressure of the air hammer appropriately;


c. Cutting and chipping may also be caused by incorrect placement of the material. You can try to adjust the angle of the material.

2、Ambient Temperature and Miter Saw Problems

a. When making doors and windows, if the processing temperature is lower than 5°C, it will not only cause chipping of the blank, but also have a series of effects on the strength of the welding angle;


b. The cutting speed is too fast when cutting the material, usually the cutting sound of the cutting saw is relatively rapid and sharp at this time;


c. The cutting saw blade is aging or has tooth loss.

3、Cracking problem during bead cutting

The cracking of the bead does not rule out the problem of the profile, but there are also reasons for the improper operation of the bead saw equipment and the assembly plant.

a. The pneumatic pressing block should be adjusted as close as possible to the saw blade, without affecting the cutting. Secondly, the rotation direction of the saw blade cutting knife is to rotate from top to bottom with the bead positioning platen, so that during the cutting process, there is The table plate has good stability, which can avoid the bead collapse.

At the same time, check whether the saw teeth are broken or missing teeth, or the blades are worn out because the blades have not been replaced for a long time, which may cause the bead to crack.


b. The speed of the saw blade is too fast during the cutting process, resulting in low rotation speed of the saw blade per unit time. At this time, the speed of the saw blade should be lowered.

4. There are other reasons for the collapse of the material

For example, when some flat-push double-angle saws cut some materials with small cross-sections, the air hammer is far away from the machine head. When the saw blade cuts, the profile moves outward. The end is not 45°, and it will be brought to the material when it is recycled. A small part of it is also very prone to collapse at this time.

二、Welding process parameters



Inlet pressure


front pressure


back pressure


Heating Time and Soldering Time


welding flux


      The optimum welding temperature for Beidi profiles is 250°C~265°C, among which, as the temperature decreases, the corresponding welding process parameters should be adjusted.

1. Generally, the welding temperature in summer is 250°C~260°C;

2. When the temperature is lower than 15°C, the welding temperature should be raised appropriately, generally 255°C~265°C;

3. The best heating time and welding time is 25~35s. The time in summer can be slightly shorter. As the temperature drops, the heating and welding time should be appropriately extended to 30~35s, so as to ensure the quality of welding.

3. Matters needing attention in the installation of doors and windows

1. When the ambient temperature of the construction site must be higher than 5°C, the installation of PVC plastic door and window frames can be carried out, because when the temperature is lower than 5°C, the installation of the window frame is easy to cause brittle cracks in profiles or welds.


2. The ambient temperature of the construction site must be above 10°C to install glass; when the ambient temperature is lower than 10°C, the bead is not easy to bend in place, and it is difficult to knock the glass bead into the groove with a wooden hammer or rubber hammer,And it is easy to break the glass or crack at the corner of the window frame. Therefore, it is best not to lengthen the size when installing the glass at the same time when the temperature is high at noon.


3. It is recommended to use fixed pieces to fix the window frame, avoid the use of expansion screws, and reduce the impact of thermal expansion and contraction on doors and windows.