Factors influencing the compressive strength of wireless with gum

1. EVA hot melt adhesive quality relationships with compressive strength

EVA hot melt adhesive for solid at room temperature, heating melt to a certain degree will become able to flow and has a certain viscosity liquid.The main composition of EVA hot melt adhesive is resin, the resin is ethylene and vinyl acetate copolymerization under high pressure, EVA hot melt adhesive main ingredients include reinforced adhesion agent, viscosity conditioning agent and antioxidant, etc.

Among them, the resin is the main component of EVA hot melt adhesive accounts for over 50% of the total EVA hot melt adhesive;Reinforced adhesion agent is one of the main agent of EVA hot melt adhesive, and its main components in rosin substances and terpene resin and so on, main effect is to improve the liquidity of colloid and wettability, and thus improve the compressive strength;Viscosity regulator is also one of the main agent of EVA hot melt adhesive, its main composition of paraffin wax, is used to reduce the melt viscosity, increase liquidity, wettability, adjust the setting rate, to achieve the purpose of fast bond is strong, otherwise, EVA hot melt adhesive viscosity is too big, not easy flow, difficult to infiltrate into the page, not fastened to the page.The addition of antioxidant was to prevent EVA hot melt adhesive premature oxidation and deterioration, the general selection against tert-butyl methyl phenol.

Compressive strength of wireless glue order books and chooses the quality of EVA hot melt adhesive has much to do, therefore, chooses EVA hot melt adhesive for tracking detection, EVA hot melt adhesive is a necessary link in the process of use.Typically, EVA hot melt adhesive curing time should be 7 to 13 seconds, cooldown for 2 minutes.

2. EVA hot melt adhesive, the influence of temperature on compressive strength

EVA hot melt adhesive has a great influence on the compressive strength of its temperature, gel temperature is too high, although the fluidity and permeability of colloid will rise (loose), but the viscosity and the compressive strength will be significantly decreased;On the other hand, the gel temperature is too low, although colloid viscosity rise (thick), but its liquidity, wettability and permeability can be declined, it will also reduce the compressive strength of colloid, viscous resistance, toughness, etc., can appear even after gel coated between the cover and book not bond or bond fragile phenomenon.EVA hot melt adhesive temperature, therefore, must be strictly controlled in an optimal, appropriate scope, can achieve the requirement of the compressive strength of a certain.Under normal circumstances, the softening point of EVA hot melt adhesive should be above 80 degrees Celcius, to attain to the melting and the degree of bond books, heating temperature will rise to 130 ~ 180 degrees Celcius.

3. The paper texture and pasting temperature and the relationship between the compressive strength

Paper texture is different, pasting temperature and the bond strength will be different, and not just because the paper fiber is different, what is more important as a result of EVA hot melt adhesive in different solidification and cooling rate on the paper.In light of coated paper, coated paper, book version of the paper, for example, because of inorganic substances contained in the coated paper to about 10 times higher than the book version of the paper and the inorganic materials with good thermal conductivity, can accelerate EVA hot melt adhesive curing rate and the cooling speed, so EVA hot melt adhesive curing on coated paper, cooling speed, the fastest in the light of the coated paper last time, the slowest in the book version of paper.

In 170 degrees Celcius pasting temperature, for example, EVA hot melt adhesive bonding strength on the book version of the uncoated paper can reach 8.83 N/cm, and only on the coating of coated paper is 1.86 + / - 0.11 N/cm coated paper (65 g/m2) and 1.64 N/cm coated paper (100 g/m2).In coated paper on the compressive strength is so low, obviously can not meet the requirements of actual production, so you need to improve the gel strength and pasting temperature.Pasting temperature during 180 ~ 190 degrees Celcius, compressive strength of EVA hot melt adhesive on the coated paper can reach 4.1 ~ 3.9 N/cm, should also be visible on the EVA hot melt adhesive glue temperature changes with paper of different texture.