How to clean the glue pot when changing glue or wire? Cleaning steps and pit avoidance for switching between different products of hot melt adhesive

The same glue pot should be switched from book back glue to box sealing glue, or from one color to another, and the most important thing is to avoid “pouring new glue directly over old glue”.The carbonized residue at the bottom of the pot and the previous formula will be mixed with new glue, which can cause slight wire drawing and weak adhesion, and severe contamination of the entire batch of products. The correct approach is:First, drain the old glue and clean the pot until the metal is exposed, then apply new glue.Here is a set of cleaning steps that can be followed.

1、 Under what circumstances must the machine be cleared

• From a type of adhesiveChange to another formula(such as book adhesive) ↔ packing tape ↔ Pearl cotton glue);
• exchangecolor(Light colored products should be cleaned before use, and cross colored products should be scrapped directly);
• Shutdown for more than one shift and obvious blackening and hardening of the pot bottom;
• The previous batch had issues with wire drawing, odor, and abnormal bonding, suspecting impurities in the pot.

If only the same type of material is replenished and the same type of glue is replenished when the liquid level drops, there is generally no need to go to great lengths to clean the pot. Just follow the daily cleaning and maintenance of the glue tank.

2、 Cleaning standard steps (6 steps)

1. Heat up and soften.Raise the glue pot to the working temperature (book glue is commonly around 160-180 ℃, according to the process card), allowing the residual glue in the pot to fully melt and become thinner, making it easier to discharge.
2. Drain the old adhesive.Open the glue outlet or use a scraper to empty the glue from the pot as much as possible, and pour it into a dedicated recycling container,Separate packaging of different formulasDon’t mess around.
3. Scrape the pot while it’s hot.Wear heat-resistant gloves and use a wooden/copper spatula to scrape off any residue on the pot wall, bottom, and mixing paddle.Disable using iron tools to forcefully scrapeIt will damage the coating of the pot body.
4. Clean the discharge port and pipeline.Remove the filter screen and discharge nozzle to remove carbide particles; It is best to use specialized cleaning materials to clean the rubber hose once, and clean it thoroughly if it cannot be disassembled.
5. Visually confirm exposed metal.The pot wall and propeller blades should have a clean metal surface, without blackening or hardening, and without any color residue, in order to be accurately calculated.
6. Apply new glue and circulate at low speed.Add new glue, cool it down first and then raise it to working temperature. Let it idle for a few minutes to exhaust the air. Confirm that the glue is evenly distributed and free of impurities before applying it.

3、 The three easiest pitfalls to tread on

• Pit 1: Only changing materials without scraping the pot.New glue has been added to the surface, but the old glue at the bottom of the pot is still there, which will inevitably affect the first batch of products.
• Pit 2: Mixing and recycling different formulas.The recycling bins for book adhesive and box sealing adhesive are not separated, and the next time they are poured back, the recipe will be mixed together.
• Pit three: Use fire/iron tools to forcibly dig.It’s dangerous to damage the pot, so the carbonized layer should be scraped while it’s hot. Don’t wait until it cools and hardens before drying it out.

4、 Daily maintenance is more important than cleaning the machine

Cleaning the machine is an action taken when changing products, and what should be done more frequently isRegularly clean the glue tank to prevent carbonizationClean the carbon deposits at the bottom of the pot once a shift or week according to regulations, which ensures a more stable lifespan and product quality for the glue pot. Sunlife will provide temperature and cleaning frequency recommendations for the corresponding adhesive type during sample testing, and follow the process card for the most secure execution.

Explanation: This article is a general operating specification, and the specific working temperature and cleaning frequency are subject to the conclusions of the accompanying process card and sample; Do not extend unverified device or certification statements. Sunlife provides trial and machine specification support for book/packaging customers, with actual sample results as the final reference.