Application of reactive hot melt polyurethane PUR

544px; white-space: normal; background-color: rgb(255, 255, 255); text-align: center; box-sizing: border-box ; overflow-wrap: break-word ;'>Author: Yu-Wei

544px; white-space: normal; background-color: rgb(255, 255, 255); text-align: center; box-sizing: border-box ; overflow-wrap: break-word ;'>(Foshan Kingwanda Technology Co.

, Ltd.

com" style="margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0.

544px; white-space: normal; color: rgb(38, 38, 38); font-family: Arial, , , " Pro", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro He", Helvetica, sans-serif; background-color: rgb(245, 245, 245); box-sizing: border-box ; overflow-wrap: break-word ;'>544px; display: flex; justify-content: center; align-items: center; overflow-wrap: break-word ;">Key words544px; border-width: 1px; border-style: solid; border-color: rgb(30, 155, 232); overflow-wrap: break-word ;">5px; line-height: 1.

com" style="margin: 0px; padding: 0px; max-width: 100%; box-sizing: border-box ; word-wrap: break-word ; letter-spacing: 0.

com" style="margin: 0px; padding: 0px; max-width: 100%; box-sizing: border-box ; word-wrap: break-word ; letter-spacing: 0.

544px; font-family: -apple-system-font, BlinkMacSystemFont, Arial, sans-serif; display: flex; justify-content: center; align-items: center; overflow-wrap: break-word ;"> 544px; font-family: -apple-system-font, BlinkMacSystemFont, Arial, sans-serif; display: flex; justify-content: center; align-items: center; overflow-wrap: break-word ;">2 Typical application industries of reactive hot melt polyurethane PUR544px; font-family: -apple-system-font, BlinkMacSystemFont, Arial, sans-serif; border-width: 1px; border-style: solid; border-color: rgb(30, 155, 232); overflow-wrap: break-word ;">5px; line-height: 1.

With the popularization of handheld electronic devices, especially smart phones, people have put forward more and more requirements for large screens, diversified materials, and so on.

 

In this field, due to different material requirements, such as mobile phone middle frame magnesium-aluminum alloy, special nylon parts, screen coatings, etc.

 

2.

The application of PUR in the automotive industry is mainly the assembly or bonding of parts, including the assembly of headlight shells, the bonding of the roof sunroof frame, the composite of the spare tire cover, the vacuum composite of the interior parts, and the bonding of the structural parts of the door panel.

 

The assembly of the headlight shell is a major application of PUR in the automotive industry.

 

Due to the high strength and heat resistance of the PUR adhesive, it just meets the need for load-bearing and heat-resistant canopy skylight frames.

The rolls are then unrolled in a short period of time (usually no more than 3 hours) and automatically formed on the equipment, so that a production line only needs one worker.

 

Foreign parts manufacturers such as Johnson Controls used Sika's PUR products for automatic gluing production as early as 2005, and domestic manufacturers such as Paige/Huaxiang/Hongyongsheng also use PUR products for automatic or semi-automatic production in some projects.

 

2.

The woodworking industry is currently one of the most important industries for domestic PUR applications.
The consumption in 2020 is expected to exceed 15,000 tons.
It is also the most concentrated and competitive industry for domestic and foreign PUR manufacturers.
Foreign manufacturers such as Henkel, Fuller, Boss Glue, Glue King, Kelibao, etc.
, domestic manufacturers such as Wuxi Wanli, Lion, Suzhou Golden Gun, Guangzhou Jiwei, Zhejiang Warwick, Guangdong Xingusheng, Guangdong Zhongnian, etc.
The main application points of the woodworking industry include flat lamination and cladding of large surfaces of furniture, aluminum alloy window frame lamination, furniture edge sealing, etc.
Different application materials and technological processes put forward different requirements for PUR, which are mainly divided into flat lamination.
Glue and coating glue, the former has relatively low requirements for initial strength, while the latter has high requirements for initial strength.
There is also a 10% to 20% difference in price between the two.
PUR users in the woodworking industry are relatively scattered.
There are differences in equipment, climate, materials, production speeds, etc.
The requirements of PUR are different and the barriers to entry are relatively low.
It can be expected that the woodworking industry will continue to be in the next few years.
The focus of PUR.

 

2.
4 Building Materials Industry

With more and more personalized requirements for home decoration, on-site decoration requires more manpower and material resources, and more construction waste is generated.
Therefore, customized home decoration building materials are becoming more and more popular, mainly reflected in integrated wall panels and Ceiling, and this is exactly the main application point of PUR in building materials.
It can be said that the building materials industry has a relatively large relationship with the woodworking industry and the application scenarios are similar.
The PVC skins of different colors and patterns are attached to the wood-plastic board to obtain various types of panels.
The wallboard manufacturers then follow different individual blanks.
The requirements and dimensions of the house are cut into the panels, and then these panels can be directly installed in the rough house, instead of scraping walls, painting, carpentry, wallpaper and so on.
Lower cost, faster decoration speed, more diversified choices, integrated wall panels and suspended ceilings are a new trend in the building materials industry, so many wall panel manufacturers have also appeared, which also means that the PUR adhesive glue opportunity.
In the application of this material, quite a few manufacturers still use solvent-based products (the solvent products of Chongqing Hantuo account for most of the market share), but PUR has the characteristics of solvent-free, high bonding strength and low overall cost.
To completely replace solvent glue, manufacturers including Chongqing Hantuo are also promoting PUR, Hunan Tianxi, Guangzhou Jiwei and other manufacturers are actively exploring this market, in the next few years, the consumption of PUR in this market may see explosive growth.

 

2.
5 Home appliance industry

With the intensification of competition in the home appliance industry, home appliance manufacturers have become more and more concentrated.
Many small manufacturers have closed down.
For cost considerations, large manufacturers have also reduced the manpower input on the production line and increased their efforts in automated production.
Traditional tape bonding or other fixing methods require a lot of manpower, and the emergence of PUR just meets the requirements of home appliance manufacturers for automation.
Considering the cost reduction of automation and consumers' preference for glass panels, the substrate for bonding home appliances is mainly the bonding of glass panels and ABS frames.
Therefore, the application points of PUR include air conditioning panels, washing machine cover glass, and drinking fountain glass.
Panel, range hood control panel and so on.
For example, domestic air conditioner wall-mounted panels, air conditioners, water dispensers, range hoods, etc.
almost all use PUR bonding.
PUR manufacturers Henkel, Fuller and Sika use the method of sending equipment to bind customers, and basically occupy the entire share.
At the same time, its own robot can greatly reduce the cost of the transformation of the production line; Galanz microwave ovens also use PUR in the application of glass bonding; Siemens, Gree air conditioners, TCL air conditioners, etc.
are all using or testing PUR.
.
.
Home appliances use PUR products not only It is the replacement of adhesives and the progress of production technology.
It can be expected that PUR for household appliances will become more and more widespread.

 

2.
6 Textile industry

The textile industry is also one of the earliest applications of PUR.
As early as the end of the last century, many textile companies have used PUR for fabric bonding, including the water-repellent fabric of the jacket and the breathable film, the bonding of different fabrics, and the bonding of women's underwear fabrics.
Fit, wetsuit fabric fit and so on.
Although the application of PUR in the textile industry is relatively early, due to the variety of textile companies and the small output dispersion, the coexistence of solvent glue/PUR has always been the situation.
Until now, quite a number of companies still use solvent-based glue.
For the PUR adhesive in the textile industry, low surface energy (water repellent treatment) bonding, softness, and washing resistance are the usual requirements.
For special fabrics, fire-resistant clothing fabrics are also required to be flame-retardant.
Textile PUR is relatively soft after curing, the initial strength is also relatively low, and the curing is slower.
It uses polyether polyurethane, which has lower cost and relatively low sensitivity to moisture.
Therefore, domestic manufacturers have entered earlier this field.
At present, the domestic textile industry’s PUR profit is low, but the consumption is large.
It is expected to exceed 10,000 tons in 2020.
Therefore, it also attracts Fule, Bostik, Kelibao, Sika, Golden Gun, Badfu, Wanli And other domestic and foreign manufacturers.

 

Reactive hot-melt polyurethane PUR is still being gradually promoted in other industries, such as shoe industry, handicraft assembly, etc.
, especially in the shoe industry.
If reactive hot-melt polyurethane PUR manufacturers overcome the problems of adhesion and construction, PUR will replace solvent glue.
Position in the shoe industry.
544px; background-color: #F5F5F5; font-size: 16px;"> 

544px; overflow-wrap: break-word ;'>544px; display: flex; justify-content: center; align-items: center; overflow-wrap: break-word ;">3 Research direction of reactive polyurethane544px; border-width: 1px; border-style: solid; border-color: rgb(30, 155, 232); overflow-wrap: break-word ;">5px; line-height: 1.
75em; overflow-wrap: break-word ;">

According to the above analysis of the application of reactive polyurethane PUR in multiple fields, according to the pain points and needs of each market, the research direction of PUR is also constantly increasing with the increasing performance requirements, environmental protection requirements, and the replacement of other solvent-based glues.
The deepening of the system, the continuous generalization of functions, and the continuous expansion of applications.
Mainly in the following aspects.

 

3.
1 Function generalization

Although PUR is a new type of adhesive, in woodworking, building materials, home appliances and other industries, due to different applications/substrates/regional climate environment/equipment, a variety of different product models are required to meet the needs of different applications, such as woodworking In the industry, even if it is the same application of PVC laminated wood, the north and the south require different models, and different automation levels must have differentiated products.
Different manufacturers have different surface tensions and require a variety of PUR products to adapt, etc.
, various The small quantity is a pain point in the current PUR industry.
The development of one or several PUR products with good versatility and wide substrate adaptability is a current research direction.

 

3.
2 Double curing method

PUR products obtain initial strength through cooling and physical cross-linking, and subsequent moisture solidification forms other ways of bonding and cross-linking to obtain final strength, but the initial cooling physical bond strength is not high to meet the requirements, and the same subsequent moisture Too slow curing will also affect production efficiency.
For example, in the electronics industry, it takes 2 hours or more to reach a certain strength after the PUR construction is used for the bonding of the middle frame screen of the mobile phone.
The pressing mold is disassembled and the next process is carried out.
This not only requires a large number of pressing molds, but also greatly reduces The entire production process.
Therefore, according to the pain points and difficulties of different industries, PUR manufacturers research and develop dual-curing PUR products, such as UV curing + moisture curing.
After construction, UV radiation can instantly accelerate the curing of PUR to reach a certain operating strength.
There are also reactions that occur when heating and melting are used.
After cooling, in addition to moisture curing, the bond strength is also instantaneously achieved.
This is a heat-curing one-component PUR adhesive, which is stable at room temperature and chemical reactions occur inside when heated.
While curing, no by-products are produced, the bonding strength is exceptionally high, and the stability is good.
There are three types of two-phase system, masking active hydrogen and masking isocyanate.

 

3.
3 Diversified construction methods and packaging

As a type of hot melt adhesive, PUR exists in a sealed package in the form of solid or viscous liquid.
The usual packaging methods of PUR are 55 gallons, 5 gallons, 2 kg, 300 mL, 30 mL, etc.
, and different packaging methods There are different construction methods and construction equipment; but no matter what the packaging form, it is heated and melted and then applied with adhesive strips, dots, squeegee, roller coating, spraying, etc.
Because PUR is sensitive to moisture, the above construction methods are all right The airtightness of the entire colloidal flow pipeline of construction equipment is required, so professional equipment and operating procedures greatly limit the application scenarios of PUR.
Research on the diversification of PUR packaging forms, and the civilization of construction equipment can greatly expand the application of PUR, such as 50 mL metal tube packaging and small glue guns, Kelibao 150 mL aluminum tube packaging and corresponding glue guns, and 200 g iron cans.
Packaging and corresponding spraying equipment, research and development of different packaging and corresponding construction tools and equipment, to simplify the construction, civilian use is also a direction of the current PUR adhesive promotion.

com" style="margin: 0px; padding: 0px; max-width: 100%; letter-spacing: 0.
544px; white-space: normal; color: rgb(38, 38, 38); background-color: rgb(245, 245, 245); font-family: mp-quote, -apple-system-font, BlinkMacSystemFont, Arial, sans-serif; box-sizing: border-box ; overflow-wrap: break-word ;">544px; display: flex; justify-content: center; align-items: center; overflow-wrap: break-word ;">

 

544px; overflow-wrap: break-word ;'>4 Conclusion75em; overflow-wrap: break-word ;">

544px; text-align: justify; box-sizing: border-box ; overflow-wrap: break-word ;"> 

544px; text-align: justify; box-sizing: border-box ; overflow-wrap: break-word ;">With China’s overall well-off 544px; overflow-wrap: break-word ;">society , a happy and healthy life has become the goal of the people’s increasing pursuit 544px; overflow-wrap: break-word ;">.
Social development cannot be at the expense of the environment.
The country and society 544px; overflow-wrap: break-word ;">attach importance 544px; overflow-wrap: break-word ;">to environmental protection and 544px; overflow-wrap: break-word ;">safety, desolvate, and eliminate VOC emissions, especially in the European and American markets.
the 544px; overflow-wrap: break-word ;">driven, non-solvent adhesives was a great development.
544px; overflow-wrap: break-word ;">As a new type of adhesive, 544px; overflow-wrap: break-word ;">reactive hot-melt polyurethane PUR 544px; overflow-wrap: break-word ;">will be promoted and applied in more industries and fields.
544px; text-align: start;">