[China Aluminum Industry Network] 1 Current Market Situation of Thermal Insulation Bars With the development of concepts and materials industry, building doors and windows started from early single glass doors and windows, to single glass solid steel windows, fasting steel windows, aluminum alloy doors and windows, and steel. Window, later developed to the current situation of aluminum alloy doors and windows broken bridge, double glass energy-saving wooden windows, double-glass aluminum doors and windows and other energy-saving doors and windows coexist.
Aluminum alloy doors and windows have the characteristics of light weight, high strength, good rigidity, corrosion resistance and non-toxicity, excellent fireproof performance, large lighting area, good decorative effect, long service life, etc. Therefore, they are widely accepted by the society. However, the disadvantage is that the thermal conductivity is relatively large and the thermal insulation performance is poor. With the domestic and foreign manufacturers of aluminum profiles using "bridge insulation aluminum" to make up for the intrinsic defects of aluminum alloy, the new broken bridge heat insulation aluminum alloy doors and windows gradually been recognized, the amount of its annual growth rate of more than 10%.
The key component of “Broken-Breaker Insulation Aluminum Profile†is the “insulation bar†that plays a role in the connection between the two parts of the aluminum alloy profile. This use of the insulation bar determines that it must have both high mechanical properties and Excellent stability, otherwise, in the course of long-term use, due to its own aging, it is easy to cause windows and doors and curtain walls to break off, and there are major quality and safety risks. Therefore, the material selection and stability of the heat insulation bar are very important. However, due to the substantial increase in raw materials and production costs, the domestic insulation strip market is extremely chaotic. Various kinds of inferior heat insulation strips are inundated with water and are inundated, and even the so-called glass fiber-reinforced nylon 66 insulation strips of manufacturers are far from graded. Differences in quality, performance, and quality of genuine materials, outlet materials, and recycled waste materials are quite different. However, due to the use of a certain composite material modification technology by the manufacturer, the initial strength of thermal insulation strips will not be significantly different due to the difference in raw material grades. The difference makes our customers difficult to distinguish. However, due to the complex composition of inferior raw materials, there is a fundamental defect in its stability. After a period of use, the heat-insulating strip is very likely to age and its mechanical properties are degraded. This poses a great quality risk and safety hazard to the product. This article will focus on the above phenomenon, starting from the chemical stability of nylon 66, a detailed analysis of the various factors that affect the weatherability of nylon 66 insulation strip; and analyze the status of raw materials used in the domestic insulation strip market.
2 The chemical stability of nylon 66 The stability of nylon 66 involves three aspects: First, the thermal and oxygen stability of the nylon 66 insulation strip, the second is the stability of the wet oxygen, and the third is the light stability. Thermal oxygen stability plays a decisive role in guaranteeing the quality of the nylon 66 insulation strip during processing. The wet oxygen stability and light stability have an inestimable effect on the long-term safe use of the nylon 66 insulation strip.
2.1 Thermal Oxygen Stability Nylon 66 is a polymer material made from polycondensation of hexamethylenediamine and adipic acid. Its molecular structure is as follows:
-(CH2)5-CO-NH-CH2-(CH2)5-
The methylene-CH2- located next to the -NH group in the nylon 66 molecular structure is the weaker link. In the presence of oxygen at high temperatures (above 120°C), oxygen first attacks the aforementioned hydrogen in -CH2-. The atoms form peroxides. The peroxides are easily cracked to form free radicals at high temperatures. The radicals return to attacking -CH2-, which is next to the -NH group, and nylon molecular chain breakage occurs. This is the thermal degradation of nylon 66. process.
2.2 Moisture Oxygen Stability (1) High Temperature Moisture Oxygen Stability Due to the strong polarity of polyamide molecular Chains, polar molecules such as water molecules have a great influence on the mechanical properties and dimensional stability of polyamides. This is because nylon The synthesis reaction of 66 is a chemical equilibrium process, which is reversible as follows:
nHOOC-(CH2)4-COOH+nNH2-(CH2)6-NH2=HO-[CO-(CH2)4-CO-HN-(CH2)6-NH]n-H+(2n-1)H2O When the temperature is high In the presence of water, the above reaction proceeds to the left, that is, hydrolysis, and the hydrolysis also results in the breakage of the nylon molecular chain.
(2) Ambient temperature and wet oxygen stability In a heterogeneous system, the accumulation of water at the phase interface will reduce the interface adhesion, causing delamination or cracking. If water penetrates into this area, it will produce mechanical tension. This tension will separate the filler from the matrix. For the nylon 66 insulation strip, it will cause the glass fiber and other fillers to be detached from the nylon 66 matrix, and the mechanical properties of the material will be reduced.
2.3 Light Stability Since the heat-insulating strip is inevitably subject to outdoor sunlight ultraviolet rays as part of the overall window frame, the light stability of nylon 66 is closely related to the long-term use of the heat-insulating strip. When nylon 66 is exposed to ultraviolet light in the range of 300nm-400nm, the carbon-nitrogen bond in the nylon chain breaks, and methylene-CH2- beside the -NH group also disproportionates to generate free radicals. As a result, the nylon molecular chain is broken, the molecular weight of nylon decreases, and the strength decreases.
2.4 Stabilized Modification of Nylon 66
Kinze Planter Parts/Kinze Spare Parts:
Our Kinze Planter Parts is good in quality and competitive in price. We are manufacturer and supplier of Kinze Planter Parts following your specific requirement. We are looking forward to your E-mail and establishing cooperative relationship with you! We would provide professional Kinze Planter Parts with good services for you!
China Kinze Planter Parts manufacturers, visit here to find the Kinze Farm Equipment, Kinze Repalcement Parts that you are searching for.Please contact us!
Kinze Planter Parts,Kinze Farm Equipment,Kinze Repalcement Parts,Kinze Spare Parts
NINGBO BORINE MACHINERY CO.,LTD , https://www.borine-agroparts.com