Views: 155 Author: Site Editor Publish Time: 2020-08-29 Origin: Site
During the polyurethane foaming process, the foam has shrinkage, crispness, too soft, heartburn, cracking, smoke and other problems. How to analyze the causes.
During the polyurethane foaming process, affected by the construction conditions, foaming equipment, construction technology and ambient temperature, various abnormal phenomena will occur, which will eventually affect bubble quality issues. How to solve the shrinkage, crispness, too soft, heartburn, cracking and smoke during the polyurethane foaming process?
The following material A represents polyurethane white material, that is, combined polyether; material B represents polyurethane black material, that is, polymeric MDI.
1. Material A and B do not foam after mixing: ①The temperature of the material is low; ②The distribution ratio of the two groups is inaccurate ③The catalyst of material A is missing; ④The quality of material B is poor; material A is missing a blowing agent.
⒉. Polyurethane rigid foam shrinkage: ① There are many components in the A material, which reduces the strength of the polyurethane rigid foam and causes shrinkage; ② The material and liquid in the spray gun are mixed unevenly, the spray air is too small, or the material.
The viscosity of the material is too large; ③ solidification is too fast, and more closed cells are formed; ④ the gas expands and shrinks and deforms.
3. Polyurethane hard foam is crispy: ①B material has too many components; ②Too much moisture; ③Working surface temperature is too low; ④B material has a large acid value and contains many impurities; A material flame retardant added amount excessive.
4. The rigid polyurethane foam is too soft and the maturation is too slow: ①The amount of material in the B material is small; ②The tin catalyst in the A material is too little; ③The air temperature, material temperature and blanking surface temperature are low.
5. Polyurethane rigid foam collapse: ①The foaming gas is generated too fast, and the amount of amine catalyst in material A should be reduced; ②The foam stabilizer in material A is invalid and alkaline; ③The catalyst is invalid, otherwise, the tin catalyst in material A should be added; ④The acid value in the raw material is large.
6. Thick polyurethane hard foam cells: ①The foam leveling agent in material A is invalid or missing; ②There is too much water (water in the foaming agent or polyether); ③A. The mixing of materials is uneven uniformity; ④B material has low purity, contains total chlorine or high acid value; ⑤The gas generation rate is faster than gel.
7. Rigid polyurethane foam is cracked or core burned: ①The material temperature is high; ②The catalyst of material A is too much; ③The amount of casting at one time is too large, and the foam is too thick; the amount added when making a blowing agent too much; ④There are metal salt impurities in the material.
8. The polyurethane hard foam falls off: ①The spraying working surface has high humidity, which makes the reaction insufficient, and the underlying foam is crisp, brittle, and powdery.②The sprayed working surface is unclean. oily, too much dust.
9. Fumes from rigid polyurethane foam: ①The amount of catalyst in material A is too high; ②The hydroxyl value of polyether in material A is too high; ③the temperature of material is too high, etc.
From the analysis of the above problems, it is known that in addition to objective factors, the A component involves many factors. In actual production, adjust the viscosity, milky time, and foam time, curing time, etc. are mainly to adjust A material.
In the polyurethane foaming process, it is not only the mixing of A and B materials. It is necessary to understand the principle of forming polyurethane rigid foam and the role of each component, integrate all factors, and be targeted.
After analyzing and judging that there are problems, it is not difficult to produce high-quality polyurethane.
Yesterday, the 2024 Hightop Group Annual Meeting Ceremony with the theme of “Change and Breakthrough, New Journey” came to a successful end in Wanda Jiahua Hotel. All the staff of Hightop Group gathered together to review the struggle of the past year and look forward to the new journey full of hope
All family members.According to the provisions of the national statutory holidays, and combined with the actual situation of the company, the Spring Festival holiday in 2025 is arranged as follows.First, January 25th afternoon (Saturday) to February 4th (Tuesday) holiday, a total of 10.5 days, Janua
Recently, Shandong Hightop Group ushered in a moment of great significance -- the groundbreaking ceremony of Hightop Group's headquarter base project was held in grand style. The launch of this project is not only an important milestone in the development course of Hightop Group, but also a powerful
聚氨酯发泡机 仓库室内保温防冷凝水 如何使用聚氨酯发泡机来为仓库进行室内保温,并且防止冷凝水的出现呢? 我们需要了解到仓库的保温和防冷凝水两个需求。 仓库在冬季往往面临着室内外温差大的问题,导致室内空气中的水蒸气凝结成冷凝水,聚氨酯发泡机能够有效的保温和防止水蒸气的凝结。 其次,在了解具体的应用方案前,我们还需要知道如何选择合适的聚氨酯发泡机。选择时应该考虑到机器的效率、稳定性、易用性和维护成本等因素。 最后,为了确保仓库的保温效果和防冷凝水效果,我们需要对聚氨酯发泡机进行合理的使用和维护。在使用过程中,要遵循操作规程,避免违规操作,并且定期对设备进行检查和维护。 通过以上方法
On January 11, the CNMC-E3 polyurethane spraying machine was loaded in the industrial park and will be exported to Spain. CNMC-E3 polyurethane spraying machine is widely used in industrial maintenance, tunnels, subways, roadbed waterproofing, foam film and television props production, pipeline anti-
Hey,friends!Can you believe it? 2025 is just around the corner! I wanted to reach out and send you my happiest wishes for the upcoming year.Our time working together this past year has been so much fun, and we've overcome challenges and celebrated victories side by side. I'm really looking forward t
Recently, the Department of Commerce of Shandong Province released the list of “Key Cross-border E-commerce Entities to be Cultivated in Shandong Province in 2024”, and Shandong Hightop Group has been successfully selected for the list due to its outstanding performance in cross-border e-commerce an
Solar hot water pipe casing insulation is a sandwich structure composite insulation pipe, which is composed of an inner PPR hot water pipe, an outer PVC pipe and a central polyurethane foam insulation layer. Polyurethane insulation pipe is a kind of insulation pipe that transports hot water from the
Polyurethane elastomers are typical multi-block copolymers, where the molecular chain consists of flexible chain segments with a glass transition temperature below room temperature and rigid chain segments with a glass transition temperature above room temperature. The oligomer polyol constitutes th
Cold storage spray polyurethane focuses on the overall seamless condition after spray foaming. Polyurethane has good density, insulation and cold resistance. It is basically a closed cell structure. It not only has excellent thermal insulation properties, but also has good resistance to freezing and