PUR hot melt adhesive machine precautions which _PUR hot melt adhesive

PUR (Polyurethane Reactive) Chinese name is called moisture curing reactive polyurethane hot melt adhesive. The main component is an isocyanate-terminated polyurethane prepolymer. PUR's adhesiveness and toughness (elasticity) can be adjusted, and it has excellent adhesive strength, temperature resistance, chemical resistance and aging resistance. Has become one of the important varieties of the adhesive industry. Is now widely used in packaging, wood processing, automotive, textile, mechanical and electrical, aerospace and other national economic areas. PUR adhesives are polar and chemically reactive urethane (-NHCOO-) or isocyanate (-NCO) molecular structures, and materials containing active hydrogen, such as wood, leather, fabrics, paper, ceramics, and other porous materials. And plastic, metal, glass, rubber and other surface finish materials have excellent adhesion.

This article first introduced the characteristics and working principle of the PUR hot melt adhesive machine, followed by the PUR hot melt adhesive compounding machine in the installation of safety issues and PUR hot melt adhesive machine daily operation and precautions, and finally introduced the PUR hot melt adhesive changer Note, detailed follow the small series to learn more about.

Due to the particularity of PUR hot melt adhesives, PU hot melt adhesives are also known as wet cure reactive polyurethane hot melt adhesives, also known as wet hardening reactive polyurethane hot melt adhesives, abbreviated as PUR hot melt adhesives, in hot melt When used in contact with the water vapor in the air will react and solidify, so in the process of melting and using the PUR hot melt machine need to be completely isolated from the air, PUR hot melt adhesive machine is designed for polyurethane hot melt adhesive coating .

The biggest difference between the polyurethane hot-melt adhesive machine and the ordinary hot-melt adhesive machine is that the entire hot-melt adhesive process is completely insulated from the air. The ordinary hot-melt adhesive machine melts the hot melt adhesive from bottom to top, and the PUR hot melt adhesive machine The PUR hot melt is melted down, so one of the core components of the PUR hot melt machine is the hot melt pressure plate heating element.

1. When installing the hot melt machine, a correct and effective grounding wire must be connected. Any equipment that uses high-voltage electricity needs a grounding wire. When a grounding wire is not used, any insulating element on the hot-melt adhesive machine may still form a voltage conductor, causing a risk of electric shock.

2. According to the load required by the hot melt adhesive machine and its surrounding peripheral equipment, check the power cord used, and whether the insulation protection meets the requirements, the load of the wire must be higher than the rated power of the hot melt machine.

3, to ensure that the external connection to the hot melt machine voltage is in line with the hot melt machine itself, such as single-phase 220v voltage standard hot melt machine equipment if you use 380V power supply will damage the hot melt machine spraying equipment, such as single-phase 220v voltage standard hot-melt adhesives equipment if you use less than 220V power supply, can not achieve the device design performance, it may also damage the hot melt machine, wiring should ensure that the power cord is properly connected to the outside of the location of the breaker .

4. The hot melt machine operates at a specified voltage. If the voltage used is different from the one specified, it may cause the hot melt machine to be burned.

1. Storage conditions: PUR hot melt adhesive storage temperature 8 ~ 22 °C, stored in a dry place away from light, to avoid excessive air humidity. Do not use damaged packaging.

2. Before using PUR hot melt adhesive:

1) Before using the PUR glue, it is necessary to check whether the vacuum package is in good condition and do not use the leak.

2) Use glue after returning to room temperature;

3) Pre-heating: The glue is preheated (usually 5 to 15 minutes) without tearing the aluminum foil, or the packaged glue can be placed in an oven for pre-heating. It is recommended to control the temperature at 100 °C;

4) After the preheating is completed, the top and the tail of the PUR glue hoses are picked out. After that, the glue can be used;

5) Remove oil, dust, paint, release agent, oxide layer, etc. on the surface of the adhered part and remove the substances that affect adhesion to ensure that the surface of the bonded workpiece is dry.

3, dispensing:

1) When the PUR hot melt adhesive dispensing temperature and pressure vary due to different projects, the specific consultation KY technical staff;

2) Stainless steel needles should be used as far as possible, and the inner diameter of the needle tip depends on the specific item;

3) Before installing the needle, discharge a small amount of glue to ensure that PUR hot melt can be used normally;

4) The length of the needle outside the heater should not exceed 3mm.

Tips: It is recommended not to exceed the heating time of 4 hours in a row. Do not heat the same hose three times. If the heating time is long, it will make the back of the hose crust. At this point, the skin can be smashed to reduce the pressure of the glue.

4, assembly pressure:

At the sizing temperature, PUR01 is applied to the surface of the adhered part; after the position of the adhered part is determined, the two parts of the adherend are pressed together during the opening time to complete preliminary bonding.

5, curing:

Store the pre-bonded parts under the appropriate conditions for complete curing (The complete cure time will vary depending on the amount of glue applied, the ambient temperature, and the ambient humidity. For assistance, contact KY Technical Department).

1. Avoid using PUR hot-melt adhesives around volatile and explosive materials or gases. PUR hot-melt adhesives can't store flammable and explosive materials around spraying equipment.

2. Do not operate the hot melt machine without a suitable protective device and a good insulator or a good protective panel.

3, when the PUR hot-melt adhesives need to be repaired must be trained personnel to disassemble maintenance.

4. When the ambient temperature is lower than -20°C or the ambient temperature is higher than 80°C, the PUR hot melter cannot be used.

5, the use of PUR hot melt adhesive machine occasions should ensure that no rapid flow of air. When the PUR glue drum and the melt pressure plate used in the PUR hot melter are exposed to fast-flowing air, the rapid cooling will affect the flow of the hot melt glue of the PUR hot melt machine and waste energy.

6. When PUR hot melt adhesive is added, check whether the PUR hot melt adhesive barrel is deformed. The PUR polyurethane hot melt adhesive barrel with serious deformation should be discarded to avoid damaging the PUR hot melt adhesive machine pressure plate.

7. At any time when disassembling the PUR hot melt machine throat pipe or spray glue gun, you must immediately use silicone oil to seal the PUR hot melt adhesive that may be exposed to prevent the wet reaction from curing.

8. When the PUR hot melt machine is not used for a long time, the PUR hot melt machine heating platen should be sealed with silicone oil on the circumference to ensure the performance of the PUR hot melt adhesive in the plastic barrel.

1. When cleaning the PUR polyurethane hot melt machine, the hot-melt adhesive heating plate must be detached from the PUR hot-melt adhesive barrel. After the PUR polyurethane hot-melt adhesive rubber barrel is separated from the PUR hot melt machine heating plate, it should be kept in the lifting cylinder. In case of stress, cut off all power.

2. When the polyurethane hot-melt adhesive machine is taking off the barrel, the pressure of the filling should be gradually increased from small to large. In any case, it is not allowed to directly use the high-pressure gas to take off the barrel directly to avoid accidents.

3. When the PUR polyurethane hot melt machine heating plate pressure plate and the polyurethane hot melt barrel are detached, the PUR hot melt machine must be passed through a special mechanism on the pressure plate to close the pressure plate and the pump body before cleaning the PUR hot melt adhesive. Between the channels to prevent curing.

4. When cleaning the PUR hot melt machine heating platen, the staff must wear a special high temperature resistant protective clothing with high temperature resistant gloves. Do not allow the skin to come into contact with the hot melt barrels, melting PUR hot melt adhesives and heating plates and other high temperature parts. To avoid burns.

5, PUR hot melt machine in the de-drum, the best way is to fill the 5-gallon hot melt plastic bucket of dried nitrogen, avoid the direct use of un-dried compressed air, if you need to fill the compressed air, The compressed air needs to be thoroughly dried. And often check the use of desiccants.

6. After the PUR polyurethane hot-melt adhesive machine is detached from the hot-melt adhesive barrel, the PUR hot-melt adhesive remaining on the hot-melt adhesive pressure plate must be thoroughly cleaned. When cleaning the PUR hot-melt adhesive machine, the heating plastic plate cannot use any Hard tool to prevent scratching the pressure plate Teflon coating.

7. For the special construction of the PUR hot melt machine pressure plate cleaning, because of the special structure PUR hot melt machine heating plate can not completely clean the residual PUR polyurethane hot melt adhesive in a short time, you must clean the residual PUR polyurethane hot melt Protect it with dry nitrogen, and clean the residue for no more than 10 minutes. Do not use any hard tools to clean the PUR hot melt machine heating plate.

8. After the pressure plate of the PUR hot melt machine is cleaned, the platen should be immediately pressed into the new PUR hot melt tank to avoid leaving the pressure plate exposed to the air for a long time. When the heating plate is pressed into the plastic bucket, the pressure of the lifting cylinder should be from small to large, and high-pressure gas must not be directly used to prevent accidents and pay attention to the safety of the operator.

9. When pressing the PUR hot melt press platen into the plastic bucket, apply a small amount of silicone oil on the sealing ring of the pressure plate to lubricate it, so as to create lubrication between the pressure plate and the plastic bucket to protect the use of the seal ring. 10. After the PUR hot melt machine heating platen is pressed into the new polyurethane plastic barrel, the overflow rubber valve should be opened, the residual air in the plastic barrel should be completely discharged, and the pur hot melt adhesive with air bubbles should be eliminated to avoid Airborne polyurethane hot melt adhesive flows into the pump body and the melter throat.

11. After the PUR hot melt machine pressure plate is placed in the polyurethane hot-melt adhesive barrel and the air is removed, the rubber overflow valve is locked. At this time, the pressure in the stroke cylinder can be appropriately increased to make the work smoother.

12. After replacing the PUR polyurethane hot melt adhesive, it must wait for at least 20 minutes for the PUR hot melt adhesive to heat up before starting the gear pump and the motor. If the gear pump and the motor are immediately started, the polyurethane gear pump may be damaged, and the PUR hot melt adhesive may be reduced. The service life of the machine.