Motion Light Sensors

As technology becomes more stylish and unobtrusive, with increasingly compact phones and computers offering an expanding number of features, other industries have followed suit. The desire to accomplish more with less has extended into security systems, where devices such as motion light sensors provide high levels of security while taking up little space and using less energy than older security systems. The technology itself, however, isn’t anything new—the detection of infrared energy, the primary mechanism in a light sensor, has been used in numerous other applications prior to its application in security devices and in-home lighting systems.

How Motion Light Sensors Work

The process by which a motion light sensor detects motion and triggers a response is contingent upon a passive infrared detector (PIR or PID). The word passive indicates that the sensor doesn’t emit infrared, rather receives infrared data—a PID picks up on the infrared energy (light) emitted by an object, such as a person. The difference in temperature, as detected by the PID, is the primary element in triggering a response.

A PID motion sensor is typically composed of a printed circuit board with a pyroelectric sensor chip, housed within a mounting structure, which is placed in a location where the sensor is completely unobstructed. The printed circuit board serves as the decoding device, and interprets the signals the pyroelectric chip receives. The chip responds to temperature, and when the amount of infrared surpasses a pre-set limit, the pyroelectric chip will release a signal, thus activating a light or an alarm.

In order for infrared light to reach the chip sensor, a small window is built into the mounted structure, directly exposing the sensor to the designated, monitored area. If a person enters the given area, the change in infrared as a result of their body temperature is detected by the sensor, through the small window. The window is transparent for infrared light, so it doesn’t block any signals, but it also helps protect the device form dust and bugs, both of which can trigger a false response.

In order to further avoid false responses, care must be taken in selecting an installation area. Avoiding contact with air vents, such as HVAC vents, can help prevent fluctuations in air temperature from activating the sensor.

Motion Light Sensor Applications

A motion sensor light triggers a response when motion is detected. They can be installed indoors, on walls, ceilings, and in doorways, or outside, on the exterior of buildings and homes. Some kinds of motion sensor lights, called occupancy sensors, operate by turning off lights in unoccupied rooms and spaces. When motion is detected, the sensor triggers the light; when motion stops being detected, the sensor shuts off the light. Occupancy sensors are one low-maintenance method for cutting down on electricity bill charges from lights left on when no one is home or in a room.

Occupancy sensors can be controlled and adjusted to meet the user’s needs. Typically, two forms of control are offered: sensitivity and time delay. A sensitivity setting enables the user to adjust the magnitude of motion that must occur to trigger the sensor. If properly set, a person walking in a room with a motion sensor should trigger the sensor, but a fly passing through shouldn’t result in turning on the lights. A time delay setting allows the user to determine how long the lights should remain on after the sensor is triggered, if no further motion is detected.

Motion light sensors can also be used in external applications, on the outside of homes and buildings, to sound an alarm or to turn on an outside light to announce a person’s presence.

Seam Sealants

Seam sealants are chemical adhesives designed to protect joints hermetically against moisture, gas and thermal intrusions. Various kinds of sealant are available for a wide range of products, although they are typically used astiling and automotive seals.

Seam sealants are often made of polymer so that they expand while setting, filling out the seal and solidifying the connection. Seam sealants are typically used on vinyl flooring and sheet steel connections, such as in automotive applications. Seam sealants are usually available in tubes with spray/swirl applicator heads or as spreads intended for use with a brush or spatula. Application is designed to be simple so as not to require a lot of time or a specific skill set to use. Some seam sealants require 24 hours or more to set, while others set much faster and are ready for paint in twenty minutes.

Polyurethane Sealants

For automotive applications, different metal sheet units are attached and cemented together with seam sealants. Seam sealant spread and tape are available for trunks, drip rails, core supports, roof seams, cowls and many other areas. Seam sealants must be applied during various phases of automobile construction and maintenance, such as initial assembly and restoration projects. Sealants prevent smoke and moisture from entering the car interior or motor area.

Typically, automotive seam sealants are applied with a cartridge gun which resembles a caulking gun. For non-bodywork areas, bush-applied sealants can be used. Automotive seam sealants often set much faster than other types of seam sealants so that primer or paint coatings can be applied.

Polyurethane sealants are also commonly used in building construction, appearing in metal roofing, coping joints, vents and parapet walls and around window openings. Like automotive sealants, these construction sealants are also paintable after a short set time, but they also come in a variety of colors, including clear.

Epoxy Sealants

Sealants used for floor tiling are often made of epoxy, a combination polymer, or copolymer, that features sticky resin and a polyamine hardener component. Epoxy can be applied with special cartridge guns or with paint brushes or spatulas, and generally takes much longer to set than automotive examples. While some floors are laid without the use of seam sealants, sealants can help prevent moisture seep beneath the tiling which causes warping. The hermetic seal created by the sealant keeps out moisture, maintaining a level flooring, and also prevents dirt and bacteria from lodging between tiles, making clean up easier and more health efficient.

Once set, epoxy sealants create a very strong bond between structural elements. Because of this strength and their water-resistant properties, epoxy sealants are used in other applications that might come in contact with water, including technical and recreational marine products. Surfboards feature fins attached with epoxy adhesive sealants, while robot submersibles use epoxy sealants for waterproofing sensitive electronic parts. Epoxy sealants are also used in printed circuit boards designed to protect the electronic components from moisture.

General Sealant Recommendations

Sealant application requires minimal preparation, but the set-up steps are important to ensure a level, adhesive, and strong application. Seams needs to be cleared of dirt and other build-up to enable the sealant to properly bond to the surface of the seam and the sites of the materials being sealed. Additionally, moisture and gas must be absent during applications, because these elements can have unwanted effects on the sealant setting process. Moisture can cause the sealant to remain tacky and refuse to set firmly. Temperature is also an important factor in sealant application. If an application environment is too hot, usually in excess of 120 degrees Fahrenheit, the sealant remains tacky and will not set, while cold temperatures can make the sealant too hard to spread or apply.

Adhesives And Sealants

Although sealants and adhesives share many characteristics, they are not chemically or structurally identical and cannot always be used interchangeably. A sealant is typically a viscous material that becomes solid upon application, where it creates a barrier. The sealant barrier inhibits the penetration of many different elements, such as liquid, air, fire, or noise, depending on the exact nature of the sealant. A sealant is generally used to close gaps that other materials cannot successfully close. An adhesive is a mixture that bonds items together, and can exist in many states, such as liquid or powder. It often requires the application of a set temperature to cure it, and is frequently used to bond thin materials. Some very strong sealants qualify as adhesives, but weaker sealants primarily fill space, as is the case with sealant putty.

Sealant and Adhesive Functions

Whereas adhesives’ primary purpose is to bond two objects together, sealants have different functions. As stated above, they are intended to fill a space between two objects, not necessarily bond them strongly together. Secondly, sealants are responsible for creating a barrier, by means of their chemical composition and physical structure, as well as by properly adhering to the objects surrounding a space. Thirdly, sealants should maintain these functional properties under the specified conditions, if they are properly used and maintained. Adhesives, on the other hand, are not used to fill spaces and are available at much higher strengths.

Additives

Adhesives and sealants also differ in the way additives affect their chemical and physical composition. Additives are classified based on the function they perform rather than their composition, and although sealants and adhesives may share other chemical similarities sometimes they require separate additives.

Common Adhesive Additives

In many adhesives, catalysts are added to enable polymerization and cross-linking. In epoxy adhesives, catalysts include amines and anhydrides. Reactive acrylic adhesive systems also commonly include catalysts, such as peroxides, and UV adhesives often contain photo-initiators.

Colorants (additives that add color) are also frequently added to adhesives, and include dyes and pigments, such as titanium oxide coated particles of mica.

Platicisers, which typically increase the flexibility and workability of an adhesive, are another common type of adhesive additive. In latex adhesives, for example, benzoate platicisers are added because they work well in conjunction with base ingredients (for a latex adhesive, namely polyvinyl acetate or ethylene-vinyl acetate), to increase the mixture’s flexibility. Some adhesives, such as most types of hot melts, do not require plasticisers.

Fillers, additives that enhance material properties, are commonly used in both sealants and adhesives and include: mica, alumina, talc, silica, and calcium carbonate.

Common Sealant Additives

Sealants commonly require stabilizers, and as with adhesives the stabilizer will depend on the primary components already present in the mixture. A stabilizer’s primary role is to increase the shelf-life of the sealant, although it also helps improve properties. Plasticisers are also frequently used; in latex sealants, where the primary base ingredient is vinyl acrylic, phthalates are a common plasticiser additive. Polyurethane sealants require plasticizers to soften the mixture, in which case benzoates are typically added.

Aerospace Adhesives

Aerospace Adhesives Buying Guide

The aerospace industry utilizes vehicles that must function at peak performance levels in environments with extreme temperatures and pressures. Because of these constraints, aerospace technology and all supporting materials and tools must function at high level specifications as well. This includes aerospace adhesives, which are used in vehicle construction as well as maintenance on a wide variety of aerospace parts, including pipes, panels, fixtures and tools. Many companies produce different kinds of adhesives that function to various specifications for everything including hobby planes to space vehicles.

Adhesive Basics

Adhesives are classified by their adhesion principles, based on the chemical properties of the adhesive itself. Adhesives that are non-reactive do not require a chemical interaction within the adhesive, but another element to harden, such as heat or pressure.

Non-reactive Adhesives

Drying Adhesives require air drying to solidify. This occurs when the solvent evaporates, and the adhesive hardens. Examples include white glue and rubber cement.

Pressure Sensitive Adhesives require applied pressure between the adhesive and adherend to form a molecular bond between the two elements. These adhesives are not usually intended to form permanent bonds. Examples includes adhesives on sports tapes and bandaids.

Contact Adhesives are rubber variants that can attach to a surface relatively quickly. Once the bonds are formed to the surfaces, the rubbers can be pressed together and bond quite rapidly. Examples include neoprene and certain kinds of laminates.

Hot-melt Adhesives are applied in molten form. When they cool, they form bonds between different surfaces. Examples: hot glue guns

Reactive Adhesives

One-part and Multi-part Adhesives are reactive adhesives that use chemical reactions that form internally or as part of a mix of components. One-part adhesives have a latent chemical reaction that can be catalyzed through the application of an outside energy source, like heat or ultraviolet rays. Multi-part adhesives form bonds when two components are mixed together and applied to a surface. One-part adhesives are generally lighter than multi-part adhesives.

Natural adhesives are formed from animal gelatin or vegetable material, like flour, and are categorized as basic glues.

Synthetic adhesives are often reactive adhesives, and are comprised of a wide variety of materials, such as plastics and emulsions. Examples include epoxies, polyurethane, and acrylic polymers.

Adhesives in the Aerospace Industry

Adhesives are not typically used for structural sealant purposes in aerospace designs, but there are plenty of adhesive applications in aircraft and spacecraft. For instance, many circuits in aerospace applications require electrically conductive or thermally conductive adhesives, so there are many options. These adhesives usually feature metal flakes, such as silver, which is spread into the adhesive to be conductive.

Typically, aerospace adhesives are available in numerous formulations to allow for flexibility in application. Additionally, adhesives can often be custom formulated to assist with optimal application. They are available for:

Transducer seals Fuel assemblies Metal and fiber composites Electronic assemblies Antennas Optical fibers Sensors

Adhesives Over Mechanical Fasteners

Adhesives are often used over mechanical fasteners like bolts or screws when weight factors are important to structural integrity and function, which are common issues in aerospace design and manufacturing. In some instances, mechanical fastening methods must be used, but in many cases, both options are available. Adhesives can be applied to achieve certain aesthetic design or function benefits. For one, adhesives can often be hidden from view, allowing smoother body shape. This can be beneficial for aerodynamics. Additionally, some aerospace designs require very thin, fragile material use. These materials cannot undergo welding or bolting easily, but adhesives can bond materials of all shapes and sizes. Finally, adhesives generally offer lighter weight contributions to the overall vehicle weight, which is another important consideration for aerodynamics and fuel consumption.

Adhesives cannot withstand all kinds of pressures, temperatures, and function stresses. Large, bulky materials that undergo function stress cannot be attached with many types of adhesives because these pressures can wear down and tear at adhesive bonds. Additionally, in cases where adhesives must be cured, the curing method may not interact well with the other materials, resulting in damage or wear. Likewise, environmental and production techniques that structural materials are exposed to may have adverse effects on many types of adhesives.

Film and Hot Melt Adhseives Application Method

As with other types of adhesives (such as liquid, paste and powder), film and hot melt adhesives have numerous application methods. Because the compositions of films and hot melts vary, each application method varies according to the adhesive’s medium—as a result, some applications are well-suited to certain methods over others. Film adhesives are specifically for use on flat surfaces, while hot melts have a much broader range of applications. A description of each application method and appropriate use is offered below.

Film Adhesive Application Methods

Dry adhesive films offer several advantages because of their medium. The lack of mixing makes the application process relatively clean, and it doesn’t produce much waste. There are low emissions and environmental concerns associated with film adhesive application, and equipment is typically inexpensive.

Film adhesive traits can vary depending on the exact type of adhesive. Typically, film adhesives are heat-activated, solvent-activated, or pressure sensitive, with some adhesive films featuring a supportive mat.

When preparing to apply a film adhesive, the component should first be coated with a primer, which can be air-sprayed or applied using manufacturer recommended equipment. Primer thickness should be considered because it will affect how strongly the adhesive bonds to the component. Once the primer coating has air dried, application of the film adhesive can begin.

Depending on the type of film, the adhesive layer is applied using one of several methods. Typically, application begins with removing the protective supportive mat and a layer of protective film. Next, the adhesive is laid flat on the component’s surface, though it’s important to make sure that the film doesn’t wrinkle or trap any air. For solvent-activated films, a solvent is wiped on the film (care should be taken not to use too much solvent), and then pressure is used to enable the film to adhere to the component. Heat-activated films must be heated to properly adhere to a component.

Hot Melt Adhesive Application Methods

Hot melt adhesives, also called thermoplastic adhesives, are basically blocks of thermoplastic adhesive material that can be melted at very high temperatures and applied to a component. When a hot melt dries, it has adhered to the component in much the same way as glue. In fact, hot glue guns use a type of hot melt adhesive.

Typically, there are two main systems through which a hot melt adhesive is applied: melt-reservoir systems and pressure feed systems.

Reservoir systems can handle a large amount of adhesive, which begins in a heated reservoir holding area. After being pumped through a feed-hose, the adhesive is either applied via an extrusion gun or wheel, which deposits a layer of adhesive on the specific component. These types of systems are appropriate for low-performance adhesives, and can deposit about 4 to 5 kilograms (kg) of adhesive per hour.

Progressive feed systems are suited to handle a much smaller amount of adhesive. In industrial variants, adhesive pellets are transferred from a hopper to a heated grid, where they melt. Next, the heated adhesive is fed though a pump, pressurized, and then fed through a hose into a heated gun. Around 9 kg per hour, but keeps a very small amount in a melted state at any given time. For non-industrial systems, hand-held glue guns serve as a much smaller type of progressive feed system.

Printed Tapes

Printed Tapes Buying Guide

Printed tape is typically produced via the flexography printing process. These products often feature a natural or synthetic adhesive and a pressure sensitive backing. Available pre-printed or custom designed in a variety of ink colors and materials, printed tape serves as label indicators, safety tapes and branding and marketing tools, as it may have company logos printed on it. Instructional sealant tape may be used as an alternative to labeled boxes, and may also help prevent package pilferage.

Types and Associated Materials

Printed tape is available in different tensile strengths and adheres to a variety of surfaces. Fonts and prints may be custom designed from a selection of Pantone inks. Common tape backing variations include polypropylene, PVC, polyesters, reinforced and non-reinforced gummy tape and cloth materials. The adhesive materials include acrylics, hot melts and natural rubber. Printed tape is fabricated for both indoor and outdoor use, with specific applications that include:

Branding and Marketing- A printed tape featuring a company logo or design may be fabricated by manufacturers. Tape types may be printed with messages, and some suppliers accept logo and other artwork in camera ready format. Additionally, tape companies offer both an assortment of stock tape colors and custom-match options.

Identifiers- Manufacturers will often offer pre-printed messages on tape for shipment purposes and as standalone indicators, such as “caution” signs. Various manufacturers supply OSHA- compliant warning tape that can typically be applied both indoors and outdoors and are commonly fabricated with reflective materials.

Loss Prevention- Printed tape is often required to draw attention to security and shipping instructions. Pre-printed tape can be designed for loss prevention use, and can be fabricated so that it cannot be removed without detection. For example, some tape is constructed with an adhesive that remains when the tape is removed, leaving indicator messages such as “VOID.”

Additional Uses and Considerations:

Letter and Print Transfer- Tape is often sought for its transfer capability, and is used for letter placement on logos or signs. For this type of application, suppliers fabricate the tape with a natural “low-tack” adhesive backing.

To prolong the use of printed tape, it is essential to store them in a suitable (sterilized and dry) environment. As with all tape products, consult with the tape manufacturer to verify requirements.

Double Coated Tapes

An Overview: Double Coated Tapes

Double coated tapes are pressure sensitive adhesives that are generally fabricated in several types of materials, including paper, foam and cloth. They are utilized for bonding and sealing a variety of similar and disparate materials and substrates. These adhesive products are also used for sound dampening purposes. They are manufactured in a range of tensile strengths, and may be applied to low and high surface energy materials. Variants of these tapes are effective for their UV and age resistance. Additionally, manufacturers provide the option of die-cutting depending on the application requirement.

Standard Applications and Industries:

Industries that utilize double coated tapes include the medical, appliance, automotive, and electronic sectors and standard applications include:

Mounting substrates (e.g., plates, hooks and mouldings) Sound dampening Bonding (e.g., display, frames and signs) Splicing (e.g., fabric webs, paper, films, etc.) Insulation against light, dust and noise

Tape Types and Compositions

Double coated tapes feature an adhesive coating comprised of a rubber or synthetic rubber adhesive. These tapes are compatible with a range of surface materials including papers, fabrics and films. Various double coated tape products are designed for high shear and high temperature performance. Double-coated tape materials fall into the following subcategories:

Foam Tapes: These tapes are composed of open or closed cells and are typically coated with an acrylic adhesive on both sides. Common variations of this type of tape include polyethylene, urethane and vinyl materials. Foam tapes are suitable for mounting purposes and gasket applications and for sound dampening purposes. These tapes are resistant to a wide range of temperature applications.

Cotton (Cloth) Tapes: Generally, cloth tapes feature a flexibleback, and often the adhesive commonly will have a heavy coating, which is ideal for irregular and dissimilar surface applications. Standard uses for this type of tape include mounting for printing industry applications and sealing, such as carpet installation. These tapes are efficient for their easy unwind capability.

Paper Tapes: Typically hand tearable, these tapes arecoated on both sides with a rubber adhesive and are often used for general purpose bonding applications and where temporary holds are required. These tapes are also efficient for bonding irregular surfaces. Tape liners are available in different colors. Variations of this type of tape may be resistant to certain chemicals. Additionally, paper tapes may be applied manually or with an applicator. Other types of paper tapes include crepe tapes and flat back tapes.

Additional Considerations

Prior to application, it is essential to check the substrate surface area to ensure that the space is oil-free and clear of contaminants that might affect the adhesive. Manufacturers advise checking the temperature application range, as colder temperatures may not be suitable for optimal adhesive strength. Application tools are available, although various adhesives may be applied manually.

Medical Adhesives

Adhesives employed in medical practices are commonly used for surgical procedures and appliance bonding. While medical adhesives encompass a wide range of fabrication materials, they are typically composed of synthetic or biological formulations. Various adhesives are incorporated into medical devices and are either disposable (hot melt and pressure adhesives) or are used multiple times. High strength bonding adhesives are able to withstand high heat ranges; some are compatible with electronic devices. Many adhesives are ideal for bonding a wide variety of substrate surfaces, including metals, plastics and rubbers, while others are suitable for skin and suture applications. Medical adhesives may be categorized as one or two-part component epoxy systems, each featuring different curing reactions. Examples of common applications that require medical adhesives include surgical instruments, biosensors, electrodes labeling, catheters, and implantable devices.

Adhesive Types

There are various medical adhesives that feature different bonding qualities when applied to different substrates, and require different methods of application. Standard adhesives commonly found in the medical field include the following three types: pressure sensitive, dissolvable,and electrical conductive adhesives.

Pressure sensitive adhesives (PSAs) are composed of a number of different materials, including rubbers, acrylate and silicone formulations. Whereas other adhesives may require heat or water to activate or “cure” a surface, this type of adhesive bonds to a surface by being pressed on to the substrate. These adhesives are often fabricated in woven and nonwoven variations. In the medical field, various PSAs are often used for skin bandages. Variants include double-sided tapes, for more bonding control.

Dissolvable adhesive films are designed to react and dissolve when exposed to different variables, such as heat, or liquids (including body liquids).

Electrical conductive adhesives are composed of materials that are compatible with medical sensor devices and electrodes and come in either film form and in gel versions, which include active pharmaceutical ingredients.

Adhesive Composition: Synthetics and Biological

The two primary medical adhesive composition categories generally include synthetic and biological materials. Formulations are tested to meet medical safety criteria. Common variants of these adhesive types include the following: acrylics, silicone, polyurethane, and bio adhesives.

Synthetic Adhesives:

Acrylics, or cynoacrylates (CA), are a common type of adhesive, used for suturing wounds, that reduce infection and scarring. Many acrylic adhesives, such as pressure sensitive tapes, are used for bandages and disposable applications. Specific acrylate formula variations are suitable for use under wet and dry conditions. Various acrylic adhesives are solvent based, though hot melt acrylics are also used for an assortment of applications. In medical applications, curing often occurs by atmospheric moisture or UV light.

Silicone is another common material used for medical bonding. Typically, this material is popular because it is biocompatible, and there are several curing formulations.

Polyurethanes are commonly produced in bandage adhesives and are available in various strengths and are efficient in processes and applications due to their water resistance.

Biological adhesives are often used in surgical applications, such as skin grafting and for suturing wounds. The composition of these adhesives includes variations of proteins. Fibrin is a commonly used natural “clotting” protein material that is used to help mend damaged vessels and for wound applications.

Associated Processes

Curing involves the method and the amount time that the adhesive requires in order to achieve full bonding strength. For instance, an adhesive can be “cured” via heat, UV light, pressure, or by atmospheric temperature, and these processes typically

An epoxy system refers to a class of adhesive chemistry types that are fabricated from two types of chemicals. Some formulations are curable by UV light (for example, one-part systems). Other systems, such as two part variations, are cured by heat or room temperatures.

Types Of Pressure Sensitive Adhesives

Pressure sensitive adhesives (PSAs) require pressure to initiate bonding between the adhesive and the substrate, whereas other adhesives require heat, water or a solvent. Other factors that influence bonding include surface energy, preparation smoothness and temperature; if an environment is too hot or too cold the adhesive may be compromised and lose its tackiness and holding ability. Room temperature is usually preferred for optimal performance, although conditions may vary depending on the adhesive’s chemical composition.

Typically, PSAs are composed of several key elements: a fluid, adhesives micro-web, and some kind of structured backing. An elastomer functions as the primary base material, which can be any one of the following materials: natural rubber, vinyl ethers, acrylics, butyl rubber, styrene block copolymers, silicones and nitriles. A tackifier, a kind of molecular compound, is added to the elastomer to increase adhesion and can include the following common resins: terpenes, aromatic resins, hydrogenated hydrocarbon resins and terpene-phenol resins. Because tackifiers have high viscoelasticity, the adhesive shares several properties with rubber, such as shear flow resistance and strain resistance when under stress.

Product Variants

There are numerous types of pressure sensitive adhesives, which can be divided into categories according to elastomer materials: rubbers, acrylates and silicones.

Rubbers offer good shear strength, flexibility and adhesion, work well in long- and short-term applications, and are low cost. They are also prone to yellowing, do not do well with high temperatures, and require additives to sustain tack and adhesion.

Acrylates offer UV-, solvent- and hydrolosis-resistance, as well as shear strength and an ability to function at temperatures between -45 and 121 degrees Celsius (C). They tend to be more expensive, and some have low creep resistance.

Silicones can function within a wider temperature range, between -73 and 260 degrees C, and feature high chemical and solvent resistance. They are more expensive than acrylates.

Pressure sensitive adhesives, when used as labels, can also be classified based on the strength of adhesion, into the following categories: permanent, peelable, ultra-peelable, freezer and high-tack .

Permanent adhesives cannot be removed once applied, without causing damage to the substrate.

Peelable adhesives can be removed because the adhesive is weaker, without risking much

damage to the substrate. However, even peelable adhesives can sometimes be difficult to remove because adhesion remains fairly strong.

Ultra-Peelable adhesives are the easiest to remove and do not leave any reside. They are typically used on glass and substrates where residue is undesirable.

Freezer adhesives are designed to withstand extremely cold temperatures without compromising the adhesive.

High-Tack adhesives are strong and work well on uneven or rough surfaces.

Key Terms

When considering pressure sensitive adhesives and their applications, it’s useful to keep in mind several key terms and their definitions.

Shear strength refers to an item’s ability to withstand tangential force.

Flexibility refers to an item’s ability to show an increase in a range of motion, as a result of stretching.

Adhesion refers to an item’s ability to firmly attach itself to a substrate or other item.

Creep refers to the slow flow of a material that occurs when a material’s properties change as a result of high temperature or pressure.

Removing Automotive Tape Off Paint

Removing Automotive Tape off Paint

The automotive paint repair process typically involves the use of specialized masking tape. Removing the tape in a precise manner is just as critical as the paint job. While auto mechanic experts and do-it-yourself enthusiasts provide different techniques to ensure the best aesthetic finish, most offer the same basic strategies for removing tape and decals. Here is a breakdown of common tape removal tips and issues that may arise during the process.

Standard Tape Removing Methods

When preparing for the automotive tape removal process, it is essential to consult with the paint manufacturer, as different coatings and lacquers vary in thickness and drying time. Additionally, using a specialized tape (which can be found at auto body retailers) is also recommended, as not all tapes are compatible with automotive paints. To ensure the best results, these tapes should be acquired immediately before a painting job. Stored, older tapes may not have the same adhesive strength as fresh tape rolls. Some professionals may suggest applying an adhesive remover to the tape and rubbing it with a microfiber cloth in a circular motion to soften the tape. Other experts recommend using a high-wattage dryer or a heat gun to ease the removal process.

Surface Tape Removal

Most experts recommend slowly peeling the tape back away from the paint job and over itself, rather than upwards, making sure that the surface is dry. Lifting the tape at a 45 degree angle permits clean lines and cutting through thin films. Typically, the angle method is a good way to avoid the unsightly flaking or peeling that occurs when a tape is lifted straight off the surface. Another practiced method includes using a removal wheel and eraser, which should be completed at a slow speed, to avoid burning the paint.

One major component of automotive tape removal is timing. Tape that is left on a surface for too long can be difficult to remove and may leave behind a sticky residue. In contrast, tape that is removed too quickly will damage and peel the paint job. Therefore, it is advised to wait 6-8 hours for one part enamels and one hour for two-part enamels and basic lacquers. If a newly painted vehicle is left outside, wind and sun will accelerate the drying process; sun exposure causes brittle tape.

Common Tape Removal Issues

It may take some practice to achieve a flawless tape removal system. Here are some common issues and suggested solutions:

Paint left behind may occur if the tape is not fastened tightly enough or if multiple colors are used in the painting process. Extra paint can be eliminated by using the tip or edge of a utility knife or razor blade.

Wet tipe may harden and become difficult to remove.If tape gets damp or wet, it is advised toremove it as soon as possible instead of letting it air dry.

Peeling and chipping paint results from any number of factors, like removing tape too quickly or at a wrong (upright) angle. For paint that begins to lift, use a single edge razor blade or specialized cutting knife to cut the paint away from the tape. If the damage is too extensive, it is recommended that the damaged area is sanded and repainted.

Types Of Inductors and Cores

Inductors, devices that transmit and measure current in relation to the amount of voltage applied, are essentially elecotromagnets that store and release an electrical current. As the current is applied, an inductor coil stores the current to establish a magnetic field. Eventually, the coil builds a field and current is transmitted through the coil until the magnetic field collapses and the process must begin again. Inductors are commonly used in radio frequency applications to transmit a current and minimize feedback and interference, and can also be used in circuits to moderate electrical flow.

Types of Inductors

As with many electrical devices, different models exist for specific applications. Coupled, multilayer, ceramic core, and molded inductors are all common types found in commercial and industrial applications:

Coupled Inductors Coupled inductors exhibit magnetic flux that is dependent on other conductors to which they are linked. When mutual inductance is needed, coupled inductors are often used. A transformer is a kind of coupled inductor.

Multi-Layer Inductors This particular type of inductor consists of a layered coil, wound multiple times around the core. As a result of the multiple layers and the insulation between them, multi-layer inductors have a high inductance level.

Ceramic Core Inductors Although there are numerous kinds of cores, a ceramic core inductor is unique in having a dielectric ceramic core, meaning it cannot store a lot of energy but has very low distortion and hysteresis.

Molded Inductors

These inductors are molded using plastic or ceramic insulation. Often used in circuit boards, they can assume either a cylindrical or bar formation, with windings featuring terminations at each end.

Types of Cores

Aside from ceramic core inductors, other core materials can be used to achieve certain results. Because the core is the material the coil winds around, it directly affects inductance. Coils wound around iron-based cores yield greater inductance than those wound around non-iron-based cores.

Air Core In this configuration, there simply is no core. The lack of a metal core results in very little distortion, but by the same token, the coil must be very long to carry high amounts of inductance, resulting in a large inductor.

Steel Cores For low resistance, high inductance applications, steel cores are a step above air cores. The denser the steel core, the less of a problem the core will encounter with magnetic saturation.

Solid Ferrite Cores When it comes to offering the highest resistance, solid ferrite cores are at the top of the list. However, when dealing with high inductance they are not always reliable and tend to reach their magnetic saturation level relatively quickly. Ferrite cores will use a different ferrite material based on the application, such as manganese zinc for certain kinds of antenna rods, with various materials offering a different set of advantages. Powdered ferrite cores are available, which are denser and offer greater linearity than solid ferrite cores.

Inductors in Circuits and Preventing Kickback

Because inductors do not sustain a continual level of voltage between terminals, it is not possible to suddenly stop the current. If a current is running through a closed-switch circuit, the inductor will allow the current to flow and build an electromagnetic field. If the circuit switch is then opened, the inductor will continue in its attempts to transmit current and in doing so one of the inductor’s terminals may switch charges, from negative to positive. This will eventually cause the terminal contact to overload. If the contact is overloaded, the switch will experience interference and damage, resulting in a shorter life cycle. This kind of problem can be avoided by simply using a diode, though for high-speed applications a resistor may be preferable.

Common Clean Room Cleaning Tools

Workers and scientists perform some of the most sensitive production and research in cleanrooms, such as building microprocessors and studying minerals from outer space. Because of the necessity for a clean environment, cleanrooms are graded on an ISO scale to ensure workers follow and maintain strict levels of cleanliness. This maintenance includes wearing protective garments, called bunny suits, using high-powered air filters to remove particles from the air, and installing anti-static ion dischargers to prevent static electricity buildup from contaminating experiments or causing materials to fail.

In addition to these passive protective methods of maintaining cleanliness, workers also must concentrate on actively cleaning tools, materials, and equipment. To do so, workers cannot simply use standard cleaning supplies, but must employ specially designed and industrial strength cleanroom cleaning tools. There are many different methods for maintaining functioning cleanrooms and they are available in a range of forms.

Cleaning liquids and chemicals

For simple cleaning jobs in cleanrooms, such as wiping down counter tops and cleaning floors, a selection of chemicals is available that provides sterility and cleanliness. Two commonly used liquids are distilled water and isopropyl alcohol.

Rollers

Although HEPA (high-efficiency particulate air) filters are common fixtures in cleanrooms, the daily activities and coming and going of workers in the facility can expel numerous air particles into the space, which eventually settle on equipment. In order to clean flat surfaces in cleanrooms, sticky rollers are available. Workers can clean countertops by running a roller across the flat surface so that it collects these particles. The worker can then wipe down the surface with a wiper (see below) to remove any excess residue.

Brooms and Brushes

Standard broomheads and brushes can retain bacteria and lose bristles during use, so special cleanroom versions usa polypropylene fibers in their heads. These bristles resist absorption of bacteria while remaining sturdy for cleaning up spills and collecting particles.

Mops

There are several special mops available for cleanroom needs. One version is the sticky-head mop, which features an adhesive head surface for collecting dry particles on a floor or walls. These are available in flat head or roller type extensions. Sponge mops are also quite common. They absorb bacteria, liquid and particles to be disposed of outside the cleanroom. Another mop variety is the non-woven layered mop head. This mop resembles a standard mop, but its threads are made from non-woven, spongy material to absorb spills and particles.

Shoe Cleaners Because workers walk on the floor both outside and inside cleanrooms, particles and bacteria may be picked up during standard, everyday activities. Shoe cleaners are available to help clean shoes and keep cleanroom floors free of detritus. One type resembles a golf shoe cleaner and appears as a small unit with an indent for placing one’s foot. A grip extension reaches up to waist level and the user can push a button to activate the automated brushes to clean the shoe. Another shoe cleaner, which also resembles a golf shoe cleaner, hermetically seals the shoe in plastic wrap, collecting fewer particles than standard rubber soles. In some cases, special elastic coverings are available for workers’ shoes so that they may be covered before entering the cleanroom.

Wipers and Squeegees

For applying rubbing alcohol or cleaning up small liquid spills, special wipe sheets called wipers are available. These are made of materials that can soak up liquids while not breaking apart and spreading debris in the area of the spill, such as cotton, nylon, polycellulose, polyester, and others. For larger spills, squeegees can clear liquid away quickly so an area can dry faster.

Vacuum Cleaners

Dedicated cleanroom vacuum cleaners are designed to not expel carbon exhaust while performing at HEPA filter level. These types of filters can ensure that 99.999 percent of all particles 0.12 micrometers and larger are removed.

Clean Room Accessories

Cleanrooms are special facilities dedicated to the manufacture or research of materials that cannot come into contact with air particles, skin flakes, or other detritus due to their high sensitivity or need to remain sterile. Microprocessors are such delicate pieces of equipment that the smallest air particle might cause the entire machine to fail. Additionally, research on biochemicals requires a clean environment so results are not skewed by the introduction of foreign elements.

In order to work in a cleanroom, human workers and scientists require a wide array of tools, equipment and garments to protect their items from outside interference. Some of these items are specifically made for cleanroom use, while others are clean versions of everyday items.

Garments:

Special cleanroom suits, sometimes called “bunny suits,” are necessary to cover workers, because skin, hair and breath particles account for the dirtiest substances introduced into the cleanroom environment. Depending on the level of cleanliness designated by the cleanroom’s ISO rating, different levels of protection need be worn. For instance, in a higher cleanliness room, such as a cleanroom where microprocessors are produced, a full suit in addition to a hair covering, goggles, face mask and gloves would need to be worn. In a less clean facility, the face mask and goggles might not be necessary.

HEPA Filter A high efficiency particulate air (HEPA) filter is a precision high volume air filter capable of cleaning air of all particles 0.3 micrometers in diameter or larger. HEPA filters work to clean air with microfibrous membrane materials. These microfibers are able to cling to or block air particles that filter through the device in one of three ways:

Interception: HEPA air filters feature airflow designs that are aimed in a specific way to capture air particles. For interception, this airflow design is intended to force the tiny microfibrous threads to cling to air particles as they flow past.

Impaction: In impaction, the airflow attempts to force small particles to directly impact the fibers.

Diffusion: Diffusion is the last result of air filtration. Airflow swishes around in circular and other patterns, attempting to break up the particles or send them on labyrinthine trips through the microfibers, increasing the chances that the particles with be intercepted by the fibers or that the particles will impact the fibers themselves.

Pass-Thru Doors and Windows:

In order to transport items, materials and equipment from outside the cleanroom into the interior, pass-thru doors and windows are used. These are air-tight transition chamber. There are hermetically sealed doors on either side of a small chamber area. To pass an item through, a worker opens the door leading to the exterior, puts the item in the chamber, and then closes it. A worker on the other side opens the door leading to the exterior and removes the item. This way, both doors aren’t open at the same time, which would allow non-filtered, dirty air to enter the cleanroom and sully equipment.

Air Showers:

Air showers are necessary to clean dirt and skin particles that may have rubbed off on workers as they changed into their bunny suits. Because biological entities, including human beings, shed skin flakes, drop hair particles, exhale bacteria, and secrete grease and oils, there are a lot of unwanted particles that can be transmitted to a bunny suit while changing. An air shower provides a high powered blast of clean, filtered air, which will remove a great deal of the dirty particles on a bunny suit. These showers exist in pass-thru air locks or as separate chambers in the changing room.

Labware:

Because much science research is performed in cleanrooms, clean labware is a primary tool of many cleanroom workers. Additionally, because clean labware often handles biochemicals or otherwise toxic materials, it is important that it be washed and disposed of correctly after use.

Clean Tools and Equipment:

There are many other items that need to be “clean” in order to enter a cleanroom. For instance, clean pencils and paper are available to cleanroom workers in order to avoid pencil and graphite flakes getting into the air and causing problems with other equipment. Trays and other carrying equipment must be made of nonporous material to prevent particles on the equipment from entering the cleanroom. For tool and equipment cleaning, clean wipes are generally available in cleanrooms to sterilize and wipe down equipment that might have come in contact with undesirable particles.

Integrated Robotic System Elements

Integrated Robotic System Elements

As with most integrated systems, an integrated robotics system depends on the successful unification of its many components. Through careful planning and consideration of each individual part, an integrated robotic system can be implemented to streamline an existing process or to introduce a cost-effective new system. In order to make the transition from a factory with remote machines to a fully integrated system, it’s helpful to become familiar with several basic elements or robotic technology.

Robotic Elements

Regardless of the type of robotic system used, several key components are common to most system categories and can be found in most advanced robotic devices: gears, springs, clutches, and bearings. Each component works alongside the others to enable the machine to complete a given task with utmost efficiency. In industrial robots, these components depend heavily upon a computer to dictate their movement. In addition to key mechanical components, industrial robots also come equipped with arms and sensors for performing manufacturing tasks and obtaining feedback, as well as a controller.

Types of Industrial Robots

A nonservo robot, perhaps the simplest industrial variant, is primarily concerned with the simple movement and placement of an object. It can pick up an object, transport it to a new location, and place the object down. More advanced than a nonservo robot, a servo robot has a greater range of motion and depends on “arms” and “hands” (manipulators and effectors) with joints. A programmable robot features the added trait of storing commands in its database, thus allowing it to repeat a desired course of action multiple times. Lastly, a computer-programmable robot depends on a computer to control an otherwise basic servo robot. In an integrated robotic system, one of these variants or a combination thereof is manipulated and used alongside other components to stream-line a given production process.

For more information, visit Brookshire Software's page on How Servos Work.

Integrated Systems

To create an effective integrated robotic system there are three general issues to work around: complexity, price, and performance. The ultimate goal is to create a system with optimum performance for the lowest price without resorting to an overly complicated solution. In other words, the system should make ample use of modern technology to simplify the system as much as possible, but without compromising performance or price.

Achieving a balance between complexity, price, and performance often involves choosing between generalized and specific components. Generalized components can reduce the overall work involved in production and come with the added benefit of being reusable. If working with generalized components manufactured by the same company, the benefits increase because compatibility between machines is not an issue. Specialized components can tighten the system even more, but may require a larger upfront investment to gain greater cost benefits in the long-run.

In addition to component selection, there are other methods to maximize the overall performance of an automated system. Bringing together an array of basic robotic components and joining them together to achieve a higher function is the core of creating any automated system, but much of integration hinges on the complexity of the task in relation to the performance of the machinery. In order to limit a system’s overall level of complexity, joining only the necessary components for a given task creates an advanced system from basic components and minimizes unnecessary costs.

There are numerous kinds of software that can aid in creating an integrated system, so evaluation of available programs is an essential step in the planning process. However, software choices will vary with hardware components, so careful examination of the designed integrated system and components will help with this decision.