How long should the hot melt adhesive particles be preheated before starting up? A startup accident

Hot melt adhesive granulesHow long should I preheat before starting up?

The new operator Xiao Wang was in a hurry to rush the goods in the morning. As soon as the glue tank reached 160 ℃, he poured particles into it and opened the line. As a result, the first fifty books had blank glue channels and a missing page. The old master understood at a glance: it was not preheated thoroughly and the glue was not melted evenly before being put on the machine.

Root cause of the accident

Hot melt adhesive particles need to be preheated before starting up, not just ‘can be used when they reach temperature’. It takes time for the glue tank to melt uniformly from cold to the whole, especially for large glue tanks; The temperature gauge shows 160 ℃, which may be due to the heat near the probe. The lower layer of the tank is still in a semi melted state with insufficient fluidity, making it difficult to apply.

Later established rules

• Start up with no load preheating first, and follow the time given in the Sunlife hot melt adhesive process card (usually 20-40 minutes, depending on the size of the adhesive slot).
• After preheating, first apply a few waste books to test the glue path, and then apply them evenly.
• First piece inspection: spreading, pulling pages, and checking the glue path. Only after passing the inspection can mass production be carried out.
• After switching to Sunlife hot melt adhesive, each batch of process cards should specify the preheating time, and newcomers should follow the instructions without overturning.

Frequently Asked Questions (FAQ)

Q: Is it better to preheat for a longer period of time?
Answer: No, burning in the air for too long can cause coking. Press the card.

Q: Does the small rubber groove take so long?
Answer: The time is shorter, but we still need to wait for the overall uniformity before opening.

Q: How to determine if the preheating is done?
Answer: The adhesive solution is uniform without particles and has good fluidity. First piece verification is required.

Start up frequently and encounter problems. Please contact Guangzhou Sunlife Trading to obtain the Sunlife hot melt adhesive process card and clearly state the preheating time.