HOT MELT ADHESIVE USE
Hot melt adhesives are used in industry for a variety of applications, including crafts, electronic board manufacturing, parts assembly, and in the packaging industry. Hot melt adhesive (HMA), also known as hot glue, is a form of thermoplastic adhesive that is commonly supplied in solid cylindrical sticks of various diameters, designed to be melted in an electric hot glue gun. The gun uses a continuous-duty heating element to melt the plastic glue, which may be pushed through the gun by a mechanical trigger mechanism, or directly by the user.
- Instrument: Viscometer or Rheometer
- Spring Torque Range: RV
- Accessory: Thermosel Temperature Controller
- Spindle/Chamber: Disposable SC4–27 spindle with HT–2DB Sample Chamber
- Speed: 5, 10, 15, 20 rpm
- Temperature: 175°C
The experiment was performed in accordance with procedures outlined in the “Standard Test Method for Apparent Viscosity of Hot Melt Adhesives and Coating Materials”, as described in ASTM Standard D 3236–88. This test method determines the apparent viscosity of hot melt adhesives and coating materials at temperaturesup to 175°C. The method outlines how the solid adhesive material is to be heated to a molten state, allowing forapparent viscosity measurements using a Brookfield Rotational Viscometer. Please reference this standard for further details on the defined test procedure.
A Brookfield RVDV2T Rotational Viscometer was used with a Thermosel temperature controller to bring gluesticks from two different manufacturers to a temperature of 175°C. Disposable sample chamber HT–2DB and adisposable #27 spindle were used.
Temperature and rotational speeds were controlled using Brookfield RheocalcT software. Both samples were tested using the same set of speeds to ensure equivalent shear rateswere being applied. In addition, these speeds produced scale readings within the methods specified 10 and 95%.
Figure 1 was generated using our RheocalcT software to provide a visual comparison between the test resultsof the two different manufacturers. The test results clearly distinguish the material from two differentmanufacturers. The more viscous material is also shear thinning, while the less viscous material demonstratesless influence from shear rate effects.