Eight commonly used methods for applying hot melt adhesive

Hot melt adhesive is a type of plastic adhesive. Its physical state changes with temperature within a certain temperature range, while its chemical properties remain unchanged. It is non-toxic and odorless, and is an environmentally friendly chemical product. Hot melt adhesive is melted by heating. The molten adhesive turns into a liquid and is then delivered to the surface of the objects to be bonded through the hot melt adhesive tube and hot melt adhesive gun of the hot melt adhesive machine. The application method of hot melt adhesive determines the effect of the glue. Generally speaking, a hot melt adhesive machine melts hot melt adhesive particles. A few customers also add a hot melt adhesive stick to the hot melt adhesive machine for melting. Sunlife Hot Melt Adhesive suggests heating the hot melt adhesive particles in the hot melt adhesive machine because the heat is the same. The surface area of molten adhesive particles is larger than that of hot melt adhesive, so the heating area is also larger. The following are eight commonly used bonding methods of hot melt adhesives.

1. Rolling rubber

The melted hot melt adhesive is conveyed into the rotating rubber tank. The gluing roller rotates inside the tank, and the molten hot melt adhesive on the gluing roller is evenly scraped off by the scraper. The product is evenly bonded through contact with the rotating rubber roller. This type of adhesive is mainly used for coating and laminating fabrics, and can also be used for gluing boards, especially suitable for panel furniture such as tables, chairs and cabinets. This gluing method is often used for EPE pearl cotton.

2. Foam coating

In some special applications, to achieve buffering or shock absorption functions while reducing the amount of adhesive used, a dedicated foaming melt adhesive machine can be employed to mechanically mix nitrogen into the molten hot-melt pressure-sensitive adhesive. Form an inflatable hot-melt pressure-sensitive adhesive. Then, the already mechanically foamed hot-melt pressure-sensitive adhesive is applied to the workpiece through a nozzle. Foaming and bonding processes have been widely used in automotive parts to replace traditional rubber gaskets.

3. Spiral Spray adhesive

This is one of the common allocation methods. Hot-melt pressure-sensitive adhesives are ejected from nozzles with fine holes through the applied air pressure to discharge regular spiral gels. This way of applying glue can significantly reduce the amount of glue applied per unit area. The structural adhesives for diapers and sanitary napkins are mostly bonded with spiral adhesives.

4. Flat mold scraping material

This is a relatively common method of scraping materials. The molten hot-melt pressure-sensitive adhesive is evenly distributed in the flow channel of the die head after passing through the heated throat, and then extruded from the die lip with preset film thickness and width. Most industrial hot-melt pressure-sensitive tapes and labels are bonded using the die-cutting process.

5. Dispensing

When two stickers only need to be locally bonded, dispensing is a relatively economical, fast and simple process. Spot sizing is usually used for folding cartons or cardboard assemblies.

6. Strip of adhesive

Similar to dot gluing, this process can be used in situations where only two stickers need to be spliced into strips. Common applications include the edges of plastic boxes, such as PET curtain boxes, the edges of wine bottles and cosmetic boxes.

7. Shower curtain Rubber

Non-contact (floating) curtain spray coating can be applied in areas where the heat resistance of the coated object is insufficient (such as PE film) or the surface of the workpiece is uneven, but the coating area is fully required. The effect of gua sha.

8. Fiber spray adhesive

Its glue spraying process is basically similar to that of spiral glue spraying, except that the shape of the glue is irregular and the amount of glue applied per unit area is lower than that of spiral glue. The most common application market is disposable sanitary ware, such as disposable mattresses, surgical gowns, hats, shoe covers, etc.

Different industries will adopt different gluing methods, mainly with the aim of reducing costs or optimizing processing techniques.