如何选择断桥铝合金门窗隔热条材料

(工程照片用SPH)

如何选择断桥铝合金门窗隔热条材料

How to choose thermal breaks for Alum. windows & doors?

断桥隔热铝合金(thermal insulation Alum. alloy)就是在传统的铝合金基础上把原来的一体性型材一分为二，然后由两支隔热条通过机械复合的手段再将分开的两部分连接在一起。

Thermal insulation aluminum alloy –divide the traditional aluminum alloy into two parts and connect them with two thermal breaks.

一、隔热条的作用

隔热条的使用性质决定了其必须同时具备高强度(high strength)和低传导性能(conductive property)，否则要么造成隔热铝合金门窗、幕墙存在重大质量隐患(强度不足会造成隔热铝型材从隔热条连接处断裂)，要么失去隔热意义(传导率高则隔热效果无法保证)，所以隔热条的材质选择及制造工艺就显得非常关键。

Functions of Thermal Breaks

With low strength, thermal insulation aluminum profile may rupture from the joint; with high conductive property, the result of thermal insulation may be influenced. Therefore, we need thermal break with high strength and low conductive property. It is necessary to choose the suitable texture and good manufacture technique.

二、隔热条的种类

1、PA66GF25隔热条：

PA66是系列改性(modification)工程塑料合金，它具有高熔点、出色的耐热性能以及自熄性(self-extinguishment)。但是没有经过改性的PA66材料在抗拉强度和线膨胀系数(coefficient of linear expansion)上与铝合金是不匹配的。

通过实验，在PA66中加25%的玻璃纤维(fiberglass)改性成工程塑料作为隔热条的基本材料，是最好，目前国际上还没有发现比这个更合理、更经济的隔热条新材料。

2、PVC隔热条：

主要原料为PVC树脂(PVC Polyvinyl Chloride)粉加25%的碳酸钙(Calcium carbonate)。

Types of Thermal Breaks

1.PA66GF25 thermal breaks:

PA66 series is modified engineering plastic alloy with high melting point, nice heat-resistance and self-extinguishment. For those unmodified PA66, the tensile strength and coefficient of linear expansion are unmatched to the aluminum alloy.

Through the experiment, we know that engineering plastic which is modified by adding 25% fiberglass to PA66, is the best basic material for thermal breaks at present. So far we haven’t a more economic or reasonable thermal insulation material internationally.

2. PA66GF25 thermal breaks:

Their principle raw materials are PVC Polyvinyl Chloride and 25% Calcium carbonate.

三、隔热条的性能：

1、抗拉强度：

PA66GF25隔热条：>126N/mm

PVC隔热条：70N/mm左右

2、热变形温度：

PA66GF25隔热条：240度

PVC隔热条：90度

3、耐老化性：

PA66GF25隔热条：经久耐用，不易老化

PVC隔热条：容易老化(east to ageing)

4、膨胀系数：

PA66GF25隔热条：与铝合金线膨胀系数一致

PVC隔热条：与铝合金线膨胀系数相差极大

Performance of Thermal Breaks

1. Tensile strength:

PA66GF25: >126N/mm

PCV: about 70N/mm

2. Heat Deflection Temperature

PA66GF25: 240 ℃

PCV: 90 ℃

3. Ageing resistance

PA66GF25: with outstanding durability

PCV: east to ageing

4. Linear expansivity:

PA66GF25: same as Alum. alloy

PCV: greatly different from Alum. alloy

四、鉴别方法

1、光泽度(glossiness)：PA66GF25隔热条的表面是一种磨砂的纹理，颜色反黑;但是PVC隔热条条看起来很平滑，光溜溜的，颜色反白。两者放在一起比较可以很清楚区分开。

2、可燃性(flammability)：PA66GF25隔热条是不燃烧的，PVC隔热条点燃一会儿就会燃烧看到小火苗，而且一般会有塑料的气味。

3、折断度(folding Strength)：PA66GF25隔热条折一到两次就断，而PVC隔热条需折十余次才会断。

4、断口面(cross section)：PA66GF25隔热条折断时声音清脆，折断后断口整齐不变形，可以对接(abutment joint)还原。PVC隔热条折断后断口发白，变形。

How to identify?

1.Glossiness: PA66 has frosted surface while PVC gets smooth surface – it is not difficult to identify when you put them

together and see.

2.Flammability: PA66 is nonflammable. But for PVC, there will be flames and plastic smell when you set fire to it for a

little while.

3.Folding strength: PA66 would rupture if we bend it one or two times while PVC needs more than ten times.

4.Cross section: PA66 would be ruptured with clear voice and trim cross section. What's more, its shape can be restored

by abutment joint. As for PVC, the cross section would turn white and be out of shape.

五：总结

在购买断桥铝合金门窗时，除了要关注门窗型材的壁厚、玻璃、五金配件及工艺外，一定还要注意区分隔热条的材质，如果用到了劣质的隔热条，不管你其他的配置有多好，使用寿命上都会大打折扣。

Conclusion: when you purchase thermal insulation aluminum windows and doors, you need to concern not only the proximate thickness, glass, hardware and manufacture technique, but also the material of thermal breaks. Inferior thermal breaks definitely do harm to the service life of windows and doors, no matter how good the other parts perform.