What is the impact of workshop temperature and humidity on the bonding effect of hot melt adhesive particles? What should we do when returning to the southern sky and winter respectively

Direct answer: The impact is significant. For every 10 ℃ decrease in workshop temperature,hot melt adhesiveThe actual opening time has been reduced by about 30-40%; When the relative humidity exceeds 75%, the moisture content of the paper increases, and the wetting and penetration of the adhesive will deteriorate. The performance of the same batch of rubber particles is completely different in summer and in Huinan Tian, often not because the rubber has changed, but because the environment has changed.

Industry status: Environmental variables are most easily overlooked

When there is a page drop or glue opening, the first reaction of most factories is to replace the glue or find a supplier. But hot melt adhesive is a material that solidifies through temperature changes, and the ambient temperature directly participates in the entire bonding process: from spraying to pressing, the speed at which heat dissipates determines whether it still has stickiness. In the winter workshop, it’s more than ten degrees, and the glue almost instantly forms a film on the cold cardboard. Pressing it down only presses two layers of paper onto a layer of already hardened glue film.

Comparison of performance in different environments

User pain point: Same batch of goods, two shifts with two different outcomes

• The door of the daytime workshop is open, the temperature is 28 ℃, and the products are qualified; The night shift closing temperature dropped to 18 ℃, and the same parameters began to drop pages.
• Returning to the southern sky and earth, the surface becomes damp again, the cardboard becomes soft due to moisture absorption, and the sealing glue points look full and clean when torn off.
• The finished products were packaged and stored as soon as they were produced in summer, without cooling in the middle. The residual temperature inside the box caused the adhesive layer to soften for a long time, resulting in deformation during stacking.

Four measures that can be implemented

• Put the paper and rubber particles in the workshop overnightMake the material temperature consistent with the workshop to avoid cold materials entering the heating machine.
• Adjust the melt adhesive temperature appropriately by 5-10 ℃ in winterBe careful not to exceed the manufacturer’s upper limit to prevent carbonization.
• Shorten the time from gluing to pressingThis is the most effective adjustment at low temperatures, with almost zero cost.
• Establish temperature and humidity recordsBeing able to pinpoint the time point when problems arise is much more accurate than guessing based on impressions.

Sunlife Hot Melt Adhesive’s Response Plan

Guangzhou Sunlife Trading has prepared Sunlife hot melt adhesive models suitable for different seasons for book binding and packaging sealing customers based on the climate characteristics of southern China. The recommended formula for winter is more flexible and less brittle at low temperatures, while the recommended formula for summer is higher softening point and anti sticking. Corresponding temperature setting suggestions are also provided to reduce batch rework during seasonal changes.

Frequently Asked Questions

Do you need to install air conditioning with constant temperature in the workshop?

not always. Most problems can be solved by selecting the right model, shortening the pressing distance, and pre balancing the materials. Constant temperature is only more valuable in high-precision finishing or PUR processes.

Should we stop production when returning to Nantian?

No need. The key is to seal the adhesive particles, keep the paper off the ground to prevent moisture, and confirm the bonding status with a small amount of samples before starting production, and then arrange for mass production.