MELTERS

Equipment used to melt hot-melt adhesives. Generally speaking, the hot-melt adhesive is fed (manually or via automated systems) into the adhesive melter. As the adhesive melts, it is pumped through hoses from the melter to an application system (e.g., dispensing gun).

Tank-style melters typically use cast-in heaters that heat all tank surfaces. Heaters are located in the bottom of the tanks and begin melting the adhesive at the tank floor. Heat is then conducted up the sides of the tanks, which helps maintain consistent adhesive temperature.

Grid and reservoir melters incorporate a heated grid and reservoir at the bottom of a hopper. These melters accommodate higher melt rate demands than tank melters.

Bulk, pail, or drum melters use round, heated platens that fit into bulk adhesive containers. Melted material is forced from the center of the platen into a pump. An axially finned surface design on the platen provides increased melt surface area and higher melt rates.

METER/MIX/DISPENSE EQUIPMENT

Equipment used to mix and dispense two-component adhesives. (See also Application Equipment.)

METERING EQUIPMENT

Equipment used to measure precise amounts of materials to be applied.

MILLS

Equipment used for bulk chemical and raw material grinding.

MIXERS & MIXING EQUIPMENT

The objectives of mixing are to produce a mixture with a composition and/or particle size distribution that approaches the uniform state on a scale of size appropriate to the use of the mixture, in a manner that suits the subsequent processing operations. (See specific categories for additional details.)

Bottom-Entry

Bottom-entry mixers are installed at the bottom of a mixing tank or vessel.

Coaxial

Mixer consisting of two rotating shafts.

Cone-Screw

These mixers and dryers work according to the principle of a rotating mixing screw being guided along the wall of the conical vessel at constant close distance by means of an orbital arm. The mixing screw moves through the product and transports it from the bottom of the vessel toward the top. The product is constantly moved upward along the container wall by the Archimedes-Screw principle.

At the same time, gravity pulls the product down along the opposite wall and in the center, outside the effective range of the mixing screw (convective gravity mixing). As the rotating orbit arm guides the mixing screw along the wall, a slightly horizontal force results, and thus three-dimensional product flow, giving intense yet gentle mixing.⁷

Counter-Rotating

Used for mixing and homogenizing dispersed products.

Double-Arm

Double-arm mixers (also sometimes called kneader mixers or sigma blade mixers) are heavy-duty mixers designed to mix, melt, and disperse products of high and very high viscosity (1,000,000-10,000,000 cP and beyond). The mixers typically include a double trough, two mixing blades, a hinged cover, drive system, supporting base, and hydraulic tilt discharge. Other discharge methods include bottom valves or extrusion screw. Sizes typically range from 1-4,000 L.

Double-Planetary

Mixers with two identical blades that move in a planetary motion, rotating on their own axes as they orbit on a common axis. The blades pass through every point in the product zone, physically contacting the entire batch.

Drum

Gallon drums that rotate in order to blend mixtures of low to medium viscosities, such as cement or adhesive slurries.

Dual-Shaft

Dual-shaft mixers are typically used for straightforward dispersion requirements. The saw-tooth disperser blade enables fast powder wet-out and dispersion, while the two-wing anchor supplies a steady exchange of materials from different parts of the vessel, essentially “feeding” the high-speed blade. Sample applications include glue stick hot melts, pressure-sensitive adhesives, room temperature vulcanization (RTV) silicon compounds, and woodworking adhesives.

Extruder

Extruder mixers are heavy-duty mixers designed to mix, melt, disperse, and extrude products of high and very high viscosity (1,000,000-10,000,000 cP and beyond). The mixers typically include a triple trough, two mixing blades, one extrusion screw, a hinged cover, drive system, supporting base, and extrusion barrel for discharge. Other discharge methods include bottom valves or extrusion screw. Typical sizes are from 1-4,000 L.

High-Shear Batch

High-speed machines that offer homogenization, emulsification, disintegration, particle size reduction, and dispersion for many different solid and liquid materials. Because of high-powered mixing blades called shears, the mixing time is much shorter than other standard mixers.

Products undergo shear when one section of the material is imparted with a different velocity through the use of a rotating impeller or high-speed rotor. The speed of the product while at the tip of the rotor is higher than the speed at the center, creating shear.

High-shear mixers are able to combine solids and liquids that usually are unable to mix, like powder and water or oil and water, and emulsify them (i.e., the two immiscible materials mix).⁸

High-Speed Rotor Stator

Rotor/stators are used for particle size reduction of various solids. Rotor/stators are commonly used to “cut in” rubber solids and speed up the solution of these solids into various solvents. Sometimes the rotor/stator is used to disperse or break down an additive such as an accelerator or a pigment.

High-Viscosity

Mixers that use multiple flow impellers to ensure complete product movement. (See also Mixers & Mixing Equipment, Double-Planetary.)

In-Line Mechanical

In-line mixers mount directly in the process piping, eliminating the need for a separate mixing tank. (See also Mixers & Mixing Equipment, Static.)

In-Line Motionless

Motionless mixing devices that allow for the continuous blending of fluids within a pipeline. (See also Mixers & Mixing Equipment, Static.)

Jacketed Half-Pipe or Dimple

A jacketed vessel is a container that is designed for controlling the temperature of its contents by using a cooling or heating “jacket” around the vessel through which a cooling or heating fluid is circulated. In half-pipe coil jackets, pipes are split lengthwise and then wound around the vessel and welded in place. For dimple jackets, a thin external shell is affixed to the vessel shell with spot welds located in a regular pattern. These “dimples” impart turbulence to the heating or cooling media as it flows through the jacket.9

Kneader

Kneader mixers (also sometimes called double-arm mixers or sigma blade mixers) are heavy-duty mixers designed to mix, melt, and disperse products of high and very high viscosity (1,000,000-10,000,000 cP and beyond). The mixers typically include a double trough, two mixing blades, a hinged cover, drive system, supporting base, and hydraulic tilt discharge. Other discharge methods include bottom valves or extrusion screw. Typical sizes range from 1-4,000 L.

Low-Shear

Equipment used to blend materials without reducing particle size in the mixing process. Low-shear mixing is often used to mix products that are easily combined.¹⁰

Reactor

Reactor mixers are commonly used in high-temperature and/or high-pressure applications.

Side-Entry

These mixers are installed along the side of the mixing tank or vessel.

Sigma Blade

Sigma blade mixers (also sometimes called double-arm mixers or kneader mixers) are heavy-duty mixers designed to mix, melt, and disperse products of high and very high viscosity (1,000,000-10,000,000 cP and beyond). Sigma blade mixers typically include a double trough, two mixing blades, a hinged cover, drive system, supporting base, and hydraulic tilt discharge. Other discharge methods include bottom valves or extrusion screw. Typical sizes range from 1-4,000 L.

Static

Mixers with no moving parts, but rather have ribbon-like obstructions within a cylinder to force the flow of material to mix and blend together. Also known as in-line mixers, they are used in production or processing lines where a continuous flow of material is more advantageous than batch mixing. That is, static mixers can mix a constant and steady stream of liquids, allowing for faster mixing and smooth operation.

Static mixers have an axis and attached ribbons or blades that are generally contained in a horizontal semi-cylinder of stainless steel or aluminum alloys. Titanium, thermoplastic and Teflon are also frequently used materials.¹¹

Top-Entry

Industrial mixer located at the top of a vessel.

Triple-Shaft

Equipment used for processing adhesive and sealant formulations when droplet size or particle size distribution is critical.

Twin-Shaft

A horizontal machine equipped with two paddle-blade agitators.

Vertical Screw

Vertical screw mixers are gentle yet efficient slow-speed mixer/blenders for a variety of dry, liquid, or slurried products. They typically comprise an orbital drive arm and conical-shaped screw, conical-shaped mixing body, hinged or fixed cover, drive system, support gussets or legs, and a discharge valve at the bottom of the cone. Typical sizes are from 1-700 cu ft.

MIXING/DISPERSION BLADES

Mixing blades push solids, gases, liquids, and vapors in a specific direction by way of rotating blades. The blades can be made out of plastic, aluminum, bronze, brass, composite, rubber, titanium, or stainless steel. Users should consider the specifications and features, types, applications, and materials that will be used when selecting blades.¹²

NEEDLES, DISPENSING

Dispensing needles are used to make controlled deposits of glues, inks, coatings, and epoxies. (See also Meter/Mix/Dispense Equipment.)

OVENS

Thermally insulated chambers used for the heating, baking, or drying of a substance.

PACKAGING EQUIPMENT

Packaging systems are used to administer adhesives and sealants. See specific categories for additional details.

Cartridges

Cartridges are used to dispense adhesives at remote job sites or in small volumes. Two-component cartridges can be more reliable and easier to handle than other options such as pails, cans, tubs, or tubes. The four major two-component cartridges available include: coaxial systems; side-by-side; barrier- or injection-style kits; and universal cartridge systems.

In coaxial systems, the most mature cartridge design contains one component surrounded by the other (e.g., two cylinders, one within the other). These are typically available in volumes ranging from 75 mL to 380 mL and in ratios of 1:1, 2:1, 4:1, and 10:1. They require a dispensing gun made specifically for this style of cartridge, although some of the smaller 75- and 150-mL versions can be dispensed using a screw adapter or a caulking gun and another adapter.

Side-by-side cartridges consist of two side-by-side cylinders that are either snapped together or molded into one piece. This cartridge offers a much greater range of volumes and ratios and is available in unit dose or small syringe configurations ranging from 1 mL to 30 mL. These dual syringes are usually dispensed with a hand-held plunger. The larger sizes range from 50 mL to 1,500 mL.

Barrier- or injection-style kits are specialized cartridges, and the oldest technology of the group. They are ideal for non-standard ratios that are not readily available in other cartridge systems, such as 7:1, 1:3:1, etc. Due to the design of these kits, the ratio options are almost limitless, and volumes range from 30 mL to 600 mL. The barrier style is typically used with ratios between 1:1 and 10:1, and the injection style with ratios greater than 10:1. Similar to coaxial and side-by-side cartridges, these kits require a special dispensing gun with a cartridge retainer to fit the particular size and ratio cartridge.

The universal cartridge system involves dispensing a two-component material in a cartridge that fits into standard, professional-grade 1/10th gal (310 mL) caulking guns. These systems do not require a specialized dispenser that can only be used with a specific cartridge size and ratio; the same tool can be used to dispense one- and two-component adhesives and sealants.

Chubs

A type of container formed by a tube of flexible packaging material. The cylindrical package has the appearance of a sausage with the ends sealed by metal crimps or clips.

Dual Packs

Made of a laminate film or foil for solvent- or moisture-sensitive materials, dual (two-component) pouches can be used for almost any mix ratio. Pouches come in two styles: burstable and clipped. The burstable style, which is the most widely used, has a burst seal dividing it at a location that creates the target mix ratio. Parts A and B are packed into the respective sides, and heat sealing creates the closure of the pouch. One end of the pouch is rolled up until the burst breaks, forcing the material into the other side, essentially creating a pouch with one cavity. The pouch should be repeatedly run over the edge of a table or workbench until parts A and B are completely blended. To dispense blended material, a corner is snipped off and the material is squeezed out.

Sausages

(See Packaging Equipment, Chubs.)

Syringes

Containers used for single-component adhesives, sealants, and industrial chemicals.

Tubes

Long, cylindrical containers typically made of plastic or aluminum. Tubes can be rigid or flexible depending on end-use specifications. (See also Packaging Equipment, Chubs.)

PAILS

(See Containers, Pails.)

PASTE DISPERSERS

(See Dispersers, Pastes.)

PEEL STRENGTH TESTING

(See Testing Equipment/Instrumentation, Peel.)

PLASTIC CONTAINERS

(See Containers, Plastic.)

PRESSES

Equipment used in the laminating of panels.

PRESSURE VESSEL CLAMPS

Pressure vessel clamps are used to securely close flanges on pressure vessels, tank covers, manways, port holes, and flanged openings without the need to drill and tap bolt holes into the flange surfaces. Available with ASME code certification, the clamps can replace bolts on any vessel requiring even occasional opening.

PROPORTIONING EQUIPMENT

Equipment used to provide metering of adhesives and sealants.

PUMPS

Equipment used to transport liquids.

REACTOR MIXERS

(See Mixers & Mixing Equipment, Reactor.)

RELEASE TESTING

(See Testing Equipment/Instrumentation, Release.)

RHEOMETERS

Laboratory equipment used to measure the way in which a liquid, suspension, or slurry flows in response to applied forces. It is used for those fluids that cannot be defined by a single value of viscosity and thus requires more parameters to be set and measured than is the case for a viscometer.¹³ (See also Viscometers.)

ROTOR STATOR DISPERSERS

(See Dispersers, Rotor Stator.)

SAUSAGES

(See Packaging Equipment, Chubs.)

SEALING EQUIPMENT

Application equipment for the closure and coating of cartons.

SIDE-ENTRY MIXERS

(See Mixers & Mixing Equipment, Side-Entry.)

SLITTING/REWINDING EQUIPMENT

(See Converting Equipment, Slitters/Rewinders.)

SOFTWARE

Software can be useful in the formulation process to streamline calculations, store materials information, adjust formulation details, provide output reports, ensure regulatory compliance, and more. Software is also becoming more prevalent in the production process as manufacturing operations move toward automation.

SPECTROPHOTOMETERS

Device used for measuring the intensity of light in a part of the spectrum, especially as transmitted or emitted by particular substances.

SPRAY GUNS & NOZZLES

Instruments used to dispense adhesives. (See also Dispensing Equipment.)

STATIC MIXERS

(See Mixers & Mixing Equipment, Static.)

STATIC MIXING NOZZLES

Nozzles used to combine both of the two components in two-component adhesives.

STEEL CONTAINERS

(See Containers, Steel.)

SURFACE ANALYSIS EQUIPMENT

(See Testing Equipment/Instrumentation, Surface Analysis.)

SYRINGES

(See Packaging Equipment, Syringes.)

TACK TESTING

(See Testing Equipment/Instrumentation, Tack.)

TANK-MOUNTED DISPERSERS

(See Dispersers, Tank-Mounted.)

TANKS

Large receptacle or storage chamber.

TESTING EQUIPMENT/INSTRUMENTATION

Equipment used to test various aspects of adhesives and sealants, including resistance to abrasion or scratching, bond strength, and thickness. See specific categories for additional details.

Abrasion

Many adhesives, sealants, and coatings need to be able to stand up to daily wear and tear, including physical impacts such as friction, scratching, and rubbing. Test methods include rotary or linear abrasion systems, and some systems can detect defects down to the nanoscale level. (See also Testing Equipment/Instrumentation, Friction.)

Adhesion

A test to determine the bond strength measurement of a coating to a substrate. When an adhesive is bonded to an item or surface, numerous physical, mechanical, and chemical forces are at work, which may have an effect on each other. These need to be tested before a product can be used.¹⁴

Cure Meters

Instrument used to determine the curing characteristics of crosslinking polymers. In addition, the device can also be used to measure setting time for resin.¹⁵

Dispersion

Laboratory-sized dispersion equipment is used in product development and quality testing to help ensure adequate dispersion of materials.

Force

The strength of adhesives can be measured by doing a peel test. A peel test measures the force required to remove the adhesive from the surface.

Friction

Coefficient of friction (COF) testing is used to determine the ease by which two surfaces (often of different materials) slide against each other. It is the maximum value of the frictional force divided by the normal force. The dimensionless value of the COF is the ratio of the force required to slide the surface to the force perpendicular to the surface. A low COF indicates that the surfaces are smoother (e.g., less resistant to a sliding motion).¹⁶

Hardness

Hardness of an adhesive or sealant is determined as a Vickers reading in a range of test forces from 10-1,000-g to DIN EN ISO 6507 and DIN EN ISO 4516 for micro-indentation tests.¹⁷

Impact

Impact testing is important because adhesives, like most polymer materials, are sensitive to the rate of applied force. The most common test for adhesives is analogous to the Izod impact test for plastic materials. It is often difficult to achieve reproducible results with impact testing; as a result, the test is not widely used in a production situation.

The impact strength of a viscoelastic adhesive is also affected by the rate at which the impact occurs. It is often difficult to achieve very high rates of impact with conventional laboratory testing. (ASTM D 950 is a pendulum impact test for adhesive joints with a rate of impact of 11 ft/sec.)

Peel

Test used to measure the bond strength of an adhesive. Peel strength is the average load per unit width of bond line required to separate bonded materials where the angle of separation is 180 degrees.¹⁸

Release

The strength required to separate a self-adhesive material from the substrate to which it is attached.

Surface Analysis

Many aspects of a substrate’s surface (chemical and physical) can impact an adhesives’ ability to perform properly. Tests can be run to determine various properties (e.g., adhesion, thickness) in order to help ensure optimal conditions for the desired result. See specific Testing Equipment/Instrumentation categories for additional details.

Tack

The force required to separate an adhesive and the adherend at the interface shortly after they have been brought into contact under a defined load of known duration at a specified temperature.¹⁹

Thickness

Test to measure thickness of an adhesive to a bonded surface.

Torque

Test method used to assess the securing or locking effect of anaerobic adhesives used in threaded assemblies.²⁰

THICKNESS TESTING

(See Testing Equipment/Instrumentation, Thickness.)

TOP-ENTRY MIXERS

(See Mixers & Mixing Equipment, Top-Entry.)

TORQUE TESTING

(See Testing Equipment/Instrumentation, Torque.)

TRIPLE-SHAFT MIXERS

(See Mixers & Mixing Equipment, Triple-Shaft.)

TWIN-SHAFT MIXERS

(See Mixers & Mixing Equipment, Twin-Shaft.)

UV LAMPS & EQUIPMENT

Mercury vapor and fluorescent lamps find use in the ultraviolet (UV) curing of adhesives, sealants, and coatings. Light-emitting diode (LED) devices can also provide an efficient option for some applications.

VALVES

Devices that regulate, direct, or control the flow of a fluid by opening, closing, or partially obstructing various passageways. See specific categories for additional information.

Ball Segment

Ball segment valves are used for discharging both liquid and dry abrasive products, from fine powders to course abrasives. The valve has an opening where materials cannot build up, accumulate, or be captured within the valve body.

These valves are mounted on vessels, pipelines, reactors, blenders, and tanks and are suitable for vacuum/pressure/heating/cooling. They include a movable half-sphere section, valve body, inflatable seal, and actuator (manual or automated). They are typically available with openings of up to 20-in. diameter.

Sample

Sample valves are used for sampling powders, granules, pastes, and liquids from vessels, pipelines, reactors, blenders, tanks, etc. under normal processing conditions (vacuum/pressure/heating/cooling) without exposing the sampled product to the outer atmosphere. Sample valves typically include a movable plug, valve body, actuator (manual or automated), and sample jar. They are generally available from ¾-3 in.

VISCOMETERS

Viscometers are used to measure a fluid’s viscosity (i.e., flow resistance). (See also Rheometers.)

WEATHERING TEST CHAMBERS

Chambers designed to replicate environmental conditions such as heat, cold, and humidity. Weathering tests are conducted for products (e.g., construction sealants) that will be exposed to these elements, with the goal of ensuring that the products meet weather-resistance requirements.