New laminating & bonding technology for automotive interior, PUR hot melt adhesive creates eco-friendly space

March 23,2021


Adhesive for automotive interiors

Automotive plays an important role in our daily life. Not only do we need to drive for commuting to work or weekend vacations, but also accompany us through every moment of our lives. Personal preferences will affect the choice of automotive brands. The demand for automotive is no longer a means of transportation. In addition to the general needs of light weight and low fuel consumption, it also begins to emphasize the comfort, functionality and environmental protection of the interior space. Moreover, the diversity of demand also affects the adoption of automotive interior components.
 

  
(image: piqsels)
 

Interior components of automotive refer to headliners, dashboards, displays, door panels, seat trim, trunk lids, car lights, etc. In the manufacturing process, adhesives are used to compound multilayer materials to improve the comfort of car driving. The adhesives mainly used for laminating and bonding are solvent based PU, water-based PU, EVA hot melt adhesive and PUR hot melt adhesive.


Polyurethane adhesive (Solvent based PU)

Polyurethane adhesive, with a large number of polar groups and active reactive groups in the molecule, can offer unique characteristics such as good bonding performance, excellent abrasion resistance and easy processing and used in bonding of a wide variety of materials for interior components. However, solvent based polyurethane adhesives contain organic solvents, which easily release harmful substances when vehicles are exposed to high temperatures. It has become the main source of VOCs (volatile organic compounds) in the cabin environment, which seriously affects human health. With the rise of global environmental protection awareness, it will be gradually eliminated by the market.
 

Water based Polyurethane adhesive

Water based polyurethane adhesive uses water as the carrier to greatly reduce the content of volatile organic compounds (VOC). It has the advantages of non-combustibility, low odor, no environmental pollution, energy saving, and convenient operation and processing. It can replace solvent based adhesives for the bonding of automotive interior components. However, water is less volatile than organic solvents, water based polyurethane adhesives dry slowly during processing. In addition, due to the high surface tension of water, the wettability of the hydrophobic substrate on the surface is poor, which will result in poor physical properties of the adhesive layer.
 

EVA hot melt adhesive

EVA hot melt adhesive is a solvent-free, moisture-free, 100% solid content and meltable polymer, it is a solid condition at room temperature and will becomes liquid after being heated and melted. It has excellent adhesion to non-porous materials, good flexibility, the elasticity like rubber, outstandingly flexibility at -50°C, superior chemical stability, very good aging resistance and ozone resistance. However, its poor heat resistance is the disadvantage so it is not suitable to be exposed to the outdoor for a long time. In addition, the operation temperature should not exceed 120°C, otherwise it will soften the adhesive layer and cause the adhesion strength to drop significantly. Therefore, it cannot be used for products with high adhesion strength requirements.
 

PUR hot melt adhesive

PUR hot melt adhesive (moisture reactive polyurethane hot melt adhesive) is a new type of environmentally friendly adhesive, which is different from EVA hot melt adhesive. It has excellent bonding strength, weather resistance and aging resistance, which can meet the bonding demands of different substrates. Compared with solvent based adhesives, PUR hot-melt adhesives are solvent free solid compounds that can be quickly cured through moisture reaction and cross-linking to achieve highly adhesion strength without producing volatile substances and meet environmental protection requirements. It is suitable for automotive interior components, such as headliners, dashboards, seat trim, pedals, lights, compartment partitions, etc., which greatly improves the functional, aesthetic and physical requirements of automotive interiors.
 
(image: piqsels)

For headliners, the bonding structure is fabric // film // fabric. At present, the commonly used adhesives are solvent based PU, water based PU, EVA hot melt adhesive and PUR hot melt adhesive. Among them, PUR hot melt adhesive is the most environmentally friendly. Not only is it 100% solid content, it does not volatilize harmful substances to the human, and the adhesive performance is better than other adhesives.
 
The features of adhesive for automotive interior components are compared as follows:
 

Solvent based PU

Water based PU

EVA hot melt adhesive

PUR hot melt adhesive
Solid content

Not 100%

Not 100%

100%

100%

Organic solvents

Yes

Yes
(small amount)

No

No

Heat resistance

Poor
(one-component type)

Poor
(one-component type)

Poor

Good

Adhesion strength

Good

Good

Poor

Good


〈Related Story: An upgrade on fabric laminating, eco-friendly PUR adhesives bring advanced solutions

 

Top 3 safety features for automotive interiors

With limited space, various reasons may cause fires during the operation of the car, and the flammability of its interior usually aggravates the degree of fire. Therefore, the safety of car environment is a long-term concern for consumers. For safety tests of the automotive interiors, in addition to harmful substances such as ELV and VOC, it also includes the following safety performance requirements:


Flame retardant performance

For automotive interior components (textiles), flame retardant is an important indicator of safety performance, which can effectively reduce the risk of automotive fire. 


Atomization performance

If the components inside automotive contain low-molecular volatiles, it is not only harmful to the human, but also condenses on the windows and windshield when heated and volatilized, forming rime on the surface, which seriously affects the sight of the people in the car. Thus, automotive interiors must have anti-fogging function.
 

Light fastness and UV resistance

Automotive interiors may fade and degrade after long-term sunlight, heat and cold cycles, which greatly affects service life and aesthetics. Therefore, automotive interiors must have good light fastness and UV resistance. 
 

Designing comfortable and safe automotive, eco- friendly adhesives will become a key technolog

Adhesive is an indispensable material in automotive manufacturing. Good adhesive technology can improve the comfort of car driving, lighten weight, reduce energy consumption and simplify manufacturing procedures. The selection of adhesive will be a key technology in the automotive industry. As people’ awareness of environmental protection and health has increased, the control of VOCs in automotive has also attracted more attention so that manufacturers continue to search for eco-friendly and safe materials.
 
We launched the flame-retardant PUR hot-melt adhesive for automotive interiors. It is ideal adhesive for laminating and bonding all kinds of interior components includes headliners, dashboards as well as seat trim. Our product offer solutions for a widely variety of materials, such as fabric // fabric, fabric // film and can replace solvent based adhesives to meet the diverse requirements of automotive interiors.
 
PUR hot melt adhesive for automotive interior lamination is as follows. For more product information, please contact us.

【For more applications of PUR hot melt adhesive, Fabric// Fabric, Fabric// Film
Item

 PR-6510FR

Type

 PUR hot melt adhesive

Solid content  100% solid content
Laminating structure

 fabric// fabric、fabric //film

Application

 Automotive interior components, suitable for headliners, dashboards, seat trim, etc.

Features  Good flame retardant, soft hand feeling, excellent adhesion strength,
 Long operation time, UV yellowing resistance
 

Reference:
低VOCs汽車黏著劑材料 (Low VOCs automotive adhesive material)
車用材料市場前景可期,將為化學產業帶來成長新機會 (The automotive market has a promising future, which will bring new growth opportunities to the chemical industry)
汽車用聚氨酯膠粘劑的常用品種及應用 (Common varieties and applications of polyurethane adhesives for automotive)
膠粘劑在汽車工業中的應用 (Adhesives in the automotive industry)
車用內飾材料的發展趨勢探討 (The Trends of automotive Interior materials)
汽車內裝的安全性能 (Safety performance of car interiors)
汽車內裝領域為新材料帶來龐大市場 (The automotive interior brings a huge market for new materials)
汽車內飾面料,科技與藝術的完美融合 (The perfect fusion of technology and art for car interiors)
聚氨酯膠黏劑在汽車內飾件中的應用 (Application of polyurethane adhesive in automotive Interiors)
汽車行業用膠市場現狀及應用前景展望 (The current situation and application of adhesive market in the automotive industry)
一文讀懂EVA材料 (What is EVA material)
汽車內裝材料之一EVA簡介 (Introduction of EVA in the automotive industry)
水性聚氨酯接著劑在汽車領域的應用 (Application of water based polyurethane adhesive in the automotive industry)

 

 
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