What are the applicable scenarios for high fluidity hot melt adhesive particles? Compare with conventional liquidity models to see the differences

Direct answer: High fluidity hot melt adhesive particles are suitable for high-speed production lines, fine nozzle dispensing, thin paper/porous substrate penetration, and large-area pasting; For scenarios such as thick book back adhesive, vertical surface bonding, and heavy load bearing, conventional or high viscosity models are more suitable.There is no superiority or inferiority in liquidity, only matching or not.

First, clarify what “high liquidity” means

In the industry, the melt viscosity at a specified temperature is commonly used to characterize. At 180 ℃, the high fluidity model is generally between 1000-2500 mPa · s, the conventional model is between 3000-6000 mPa · s, and the high viscosity model can reach over 8000 mPa · s. The lower the viscosity, the thinner the adhesive, the faster it flows, and the deeper its penetration.

Horizontal comparison of two types of models

Four typical scenarios of high liquidity models

• High speed automatic sealing lineThe machine speed is fast, and it is required that the adhesive liquid spread quickly after leaving the nozzle, with low viscosity to keep up with the pace.
• Fine nozzle dispensingA dispensing valve with a diameter of 0.3-0.5mm, high viscosity glue is prone to clogging and drawing.
• Thin paper, lightweight paper adhesive packagingDictionary paper and thin writing paper have many pores and require glue to penetrate the fibers to form a bite.
• Large area pastingThe book case and gift box cover should be laminated with thin and even adhesive layer, without any accumulation or bulging.

When should you never use high liquidity

There are three situations to avoid: first, non absorbent substrates such as copperplate paper and laminated paper, where the adhesive liquid is too thin and can be squeezed to the edges during compression, causing a lack of adhesive in the middle; The second is vertical or inverted bonding, which will hang when not cured; Thirdly, for thick books with spine exceeding 25mm, it is necessary to fill the gaps between the book stickers with a full adhesive layer. If it is too thin, it will penetrate excessively, resulting in insufficient backing adhesive layer.

How to quickly determine which gear to choose

A practical rule of thumb: Look at production pace and substrate absorption together.Fast+good absorption → high liquidity; Slow+poor absorption → conventional or high viscosity.If two conditions conflict (such as high-speed running coated paper), prioritize the substrate, choose conventional viscosity, and appropriately increase the melt adhesive temperature to improve fluidity.

Frequently Asked Questions

Q: Can raising the temperature turn a regular model into one with high fluidity?
Answer: It can reduce viscosity, but the extent is limited, and prolonged high temperature will accelerate oxidation and carbonization, producing black slag. Cannot replace selection.

Q: Is the strength of high liquidity models lower?
Answer: Not necessarily. The strength depends on the formulation base material system, and low viscosity models can achieve high peel strength. When selecting, it is important to consider peel strength data rather than just viscosity.

Q: Can two different viscosities be mixed on the same device?
Answer: It is not recommended to mix directly. When it is necessary to switch, the pot should be cleaned first, otherwise there may be layering, wire drawing, and unstable glue dispensing.

Sunlife hot melt adhesive offers a complete viscosity gradient model from high fluidity to high viscosity. Guangzhou Sunlife Trading can provide selection recommendations based on machine speed, nozzle aperture, and substrate type.