Description

A fully functional melting unit and roller application system are of major importance for a smooth and reproducible adhesive application. The cleaning effort varies depending on the application system and unit, and depends largely on the type of adhesive used. It is recommended that the application system be cleaned before any downtimes and adhesive changes, and Jowat supplies a range of flushing agents and cleaners for that Purpose.

Melter and hoses

General flow behaviour
General flow behaviour
©Jowat SE

Jowat® flushing agents purge the adhesive and stop the chemical reaction of PUR hot melt adhesives. Before the cleaning of the application system is started, it must be ensured that the Jowat® flushing agents and the adhesive used are compatible. To prevent plugged hoses or nozzles due to an unwanted reaction, especially in closed application systems, it must be ensured that the PUR hot melt adhesive and the Jowat® flushing agent are melted evenly.
The primary task of a flushing agent is to push out the adhesive from the hoses and the application unit, and therefore to purge product remnants from the system. Due to the general flow behaviour of liquids (cf. figure 1, on the right), the flow velocity is significantly lower at the walls compared to the centre of the hose. To ensure that the hoses are cleaned thoroughly, it is thus necessary to use a sufficient amount of flushing agent.

Effect of viscosity on the purging process
Effect of viscosity on the purging process
©Jowat SE

Apart from flow velocity, viscosity also plays a role in the purging process. If the viscosity of the flushing agent is too low, it will only purge the adhesive in the centre of the hose. Under those circumstances, it will not be possible to remove all the adhesive. To find out the viscosity of the flushing agent and the hot melt adhesive, please refer to the corresponding Technical Data Sheets (available upon request).

Drum melters

Avoid any contamination during drum changes. The heating plate is to be cleaned and remnants around the sealing rings are to be removed. Greasing the sealing rings with a suitable water-free and acid-free grease (e.g. rolling bearing grease “Petamo GY 193” supplied by Klueber Lubrication) facilitates easier cleaning and thus considerably reduces the downtime during the change of the drum. The drum may not remain open longer than necessary.

Roller application system

Standard operation (synchronised)

roller application synchronised schema

Cleaning (reversed direction)

cleaning roller schema

1.

Drain the roller application system using the machine’s cleaning program (reversed direction). The hot melt adhesive remnants should be collected in a coated drip pan or a similar container.

2.

In addition, hot melt adhesive may be cleaned off the application roller using a wooden spatula. It is recommended that the roller rotation be turned off for this procedure.

3.

Set the roller application system to standard operation mode, fill with Jowat® cleaner 930.22 (approx. 1 kg) and melt.

4.

Allow to soak for 10 to 15 minutes while the rollers are rotating in standard operation mode.

5.

In addition, the rollers may optionally also be cleaned using the cleaner Jowat® 930.65 (approx. 1 litre), heated, and allowed to soak for approx. 10 minutes while the rollers are rotating (standard operation mode).

6.

Run the rollers in reverse (cleaning mode) to drain the liquid cleaner into the catch pan.
Then, set the roller application system to standard operation mode and repeat the procedure up to three times depending on the degree of soiling.

7.

Remove all flushing agent remnants after cooling – but while still warm – by wearing protective gloves and using a dry, lintfree cloth (if necessary, slightly soaked with cleaner Jowat® 402.38). The cleaner Jowat® 930.60 can be used for soiled metal parts. Crosslinked PUR hot melt adhesive can be removed only mechanically.

Chemical cleaning of metal parts

The cleaner Jowat® 930.60 detaches charred and cured adhesive from tools, nozzles, filters, and other small parts made of metal. The disassembled metal parts may be cleaned in a heated bath at approx. 180 °C (e.g. in a commercially available deep fryer). Depending on the degree of soiling, the cleaning procedure may take about 60 to 120 minutes. The temperature of the bath must not exceed 190 °C. Remove parts from the bath, allow for cooling, rinse with water, and dry. Please also observe all recommendations of the equipment manufacturer.

Safety note Jowat® 930.60

Seals and other plastic parts may be dissolved and may need to be replaced!

Product information

Choose a product group

Flushing agents

Appearance Viscosity [mPas] /
Temperature [°C]
Processing
temperature [°C]
Density [g/cm³] /
Temperature [°C]
Softening range
(Kofler) [°C]
Application Download
technical
data sheet (PDF)
Jowat® 930.34 red, granulate 9000 / 120 100 - 140 0,95 / 20 80 Flushing of melting units and hoses. Contains a reaction inhibitor. Low viscosity. de en fr
Jowat® 930.74 red, granulate / blocks 20000 / 120 100 - 140 0,95 / 20 80 Flushing of melting units and hoses. Contains a reaction inhibitor. Medium viscosity. de en fr
Jowat® 930.84 red, granulate 25000 / 100 approx. 100, max. 150 0,93 / 20 80 Flushing of melting units and hoses. Contains a rection inhibitor. Good dissolving of adhesive remnants. de en fr

Cleaning agents

Appearance Viscosity [mPas] /
Temperature [°C]
Processing
temperature [°C]
Density [g/cm³] /
Temperature [°C]
Softening range
(Kofler) [°C]
Application Download
technical
data sheet (PDF)
Jowat® 930.22 White, powder (solid) 120 0,81 approx. 55 for flushing roller application systems (Roller Coater) de en fr
Jowat® 930.60 colourless, fluid approx. 180, max. 190 1,1 Cleaning heavily soiled metal parts (nozzles, rollers, filters, etc.). Detaches charred and cured adhesive. de en fr
Jowat® 930.65 colourless, fluid 100 - 150 approx. 1,08 / 40 for cleaning applicator units and tools of roller application systems (Roller Coater) that are soiled with PUR hot melt de en fr
Jowat® 402.38 colourless, fluid 20 approx. 0,8 / 20 Cold cleaner for adhesive residues, especially before curing. It may cause cured adhesive to swell and become loose. de en fr

The products listed only represent a limited selection of the available product portfolio. Product availability might differ by region. The technical data, characteristics and field of application provided in the table outline the differences between the individual adhesives of the product portfolio. Our Application Technology Department and our Sales Representatives are on hand to provide advice and support you finding the best adhesive for your particular application.

Note: The information on this page is based on test results from our laboratories as well as on experience gained in the field, and does in no way constitute any guarantee of properties. Due to the wide range of different applications, substrates, and processing methods beyond our control, no liability may be derived from these indications nor from the information provided by our free technical advisory service. Customer trials under everyday conditions, testing for suitability at normal processing conditions, and appropriate fit-for-purpose testing are absolutely necessary. For the specifications as well as further information, please refer to the latest technical data sheets.