Keywords:
Welcome!Dongguan Green TPU Co.
Ltd. TPU film
Hot melt film
TPU apron
Electroplating tpu film
Dongguan Green TPU Co.,Ltd.
15year TPU film/TPU hot melt adhesive film custom manufacturer
Service Hotline
13686006083
Welcome to us
Film forming methods of TPU hot melt adhesive film and their comparison
Blow molding The resin is melted and plasticized by the extruder, pulled vertically upward from the annular die head, expanded, introduced into the traction roller by the herringbone plate, and then passed through the guide roller and the coiling device to obtain the finished product. Blow molding has a blowing process, which makes the longitudinal and transverse molecules of TPU hot melt adhesive film stretch to different degrees. The temperature resistance and heat sealing performance of TPU hot melt adhesive film will be greatly affected. Casting method The resin is melted and plasticized by the extruder, and extruded from the machine head through the slit mold, so that the melt is close to the cooling roller, and then the TPU hot melt adhesive film is obtained through stripping, stretching, cutting and coiling.
2023-01-31
Back List

Film forming methods of TPU hot melt adhesive film and their comparison

Blow molding

The resin is melted and plasticized by the extruder, pulled vertically upward from the annular die head, expanded, introduced into the traction roller by the herringbone plate, and then passed through the guide roller and the coiling device to obtain the finished product. Blow molding has a blowing process, which makes the longitudinal and transverse molecules of TPU hot melt adhesive film stretch to different degrees. The temperature resistance and heat sealing performance of TPU hot melt adhesive film will be greatly affected.

Casting method

The resin is melted and plasticized by the extruder, and extruded from the machine head through the slit mold, so that the melt is close to the cooling roller, and then the TPU hot melt adhesive film is obtained through stripping, stretching, cutting and coiling.

Tape casting method has high production efficiency and good quality stability of TPU hot melt adhesive film. There are few wastes in the production process, and it is easy to recycle leftovers and wastes online, and the material utilization rate is high.

Blow molding and tape casting

The circular die head and multi-layer stacked die core used in the blow molding method require high machining accuracy and assembly accuracy, which is particularly difficult to control. If there is a slight error in processing and fitting accuracy, it cannot be compensated by adjustment, so the thickness tolerance of TPU hot melt adhesive film is basically about 10%.

The casting method adopts a flat die with a special retention groove in the die, which can ensure the uniformity of material flow. The uniformity of the die lip gap can be automatically controlled by the automatic adjustment device of the die. The control accuracy is high, and the thicker film can also be controlled below 3%.

Blow molding can produce some TPU hot melt adhesive films, but the flatness and uniformity of TPU hot melt adhesive films are not as good as that of tape casting, especially the hot melt adhesive adhesion. During the heating process of hot melt adhesive, the thermal shrinkage of blown TPU hot melt adhesive film is large, which is easy to lead to poor adhesion.

The film molecules of the tape casting method are arranged orderly, and the TPU hot melt adhesive film is cooled quickly, which is conducive to improving the transparency, glossiness and thickness uniformity of the TPU hot melt adhesive film, and the TPU hot melt adhesive film is soft and tough. Impact resistance, heat resistance and low temperature adaptability are better than blow molding.

免喷胶膜.jpg

View Other
TPU hot melt adhesive film vs anaerobic adhesive: "Scene flexibility" difference in automotive interior bonding
2025-09-11
​From the perspective of curing conditions, TPU hot melt adhesive film does not need to rely on special environments, while anaerobic adhesives are severely restricted by "auerobicity". The curing principle of anaerobic glue is to undergo polymerization under conditions of lack of oxygen and catalyzed by metal ions (such as iron and copper). If it is in an environment where air circulation or metal substrates are not available, the curing speed will be greatly slowed down or even unable to cure. In automotive interiors, most bonding scenarios are "open" (such as bonding the door panel skin to PP substrate, and the ceiling fabric to the sponge), the air can freely contact the bonding surface, and the substrate is mostly non-metallic (PP, ABS, fabric, etc.), lacking metal ion catalysis, and additional catalyst is required when using anaerobic glue, and the curing time is as long as several hours, which is difficult to meet the needs of industrial production. The TPU hot melt adhesive film only needs to be melted by heating (120-160℃) and can be cured after pressurization and cooling. It does not need to rely on the ambient oxygen concentration or the base material. It can be cured stably in open or closed bonding scenarios, and the curing time only takes a few dozen seconds to a few minutes, adapting to the fast-paced needs of the interior production line.
MORE