Buying A Used Tape Machine - Recorders

The sound of analogue tape is still revered, but acquiring and maintaining your own machine presents a unique set of challenges.

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At least a generation has grown up without hearing high&#;quality analogue tape recordings, and with no experience of using reel&#;to&#;reel machines, but as more people move to digital recording, the old technology is becoming more affordable, and there's a resurgence of interest in tape. There are plenty of reasons to want to use it ('Analogue Warmth' in February's SOS explores them in detail), but buying and maintaining a tape machine can be a minefield for the unwary...

Let's start with a reality check. If you want good results, a tape machine can be expensive to run and is likely to become more so over time: there are lots of moving parts in even the simplest machines, and they spend their time slowly wearing themselves out. No big manufacturer has built new machines for years, so some spare parts are becoming scarce and expensive. Motor bearings, tape guides and rollers, pinch wheels, brakes and tape heads are all essentially consumable parts. The electronics also need regular alignment, so recording and replay remain within appropriate tolerances. Most settings need adjusting as heads wear or if tape type is changed, and ideally should be optimised for each new batch of tape. If everything isn't aligned and properly maintained, quality suffers quickly and obviously.

Routine maintenance includes cleaning the tape path, heads and pinch roller of the oxide and other deposits that gather as tape runs through. Running a magnetised tape over ferrous objects in the tape path will also induce some magnetism in them, so you should also consider degaussing (demagnetising) the machine: how often depends on the machine's design and the amount of tape run through it, but could vary from weekly to annually. Decent degaussing tools aren't expensive, but they need to be used with care: it's easy to end up magnetising the machine quite strongly if you're unsure what you're doing, which could damage any tapes you play on it.

Electronic alignment comes down to physical head alignment, replay gain and EQ, record gain, EQ and bias. To align the heads and replay circuitry you need a decent test and alignment tape, which will also wear out eventually. This might set you back around £130, and you'll need an oscilloscope and audio level meter. To set up the record electronics, an audio signal generator will be required too. It's not hard to align a tape machine's electronics if you have the equipment and knowledge, but if you don't the machine will need to go to a specialist.

Mechanical alignment of the transport is often quite straightforward on more modern three&#;motor servo&#;controlled machines: little is needed other than lubrication with the correct oils or greases in the appropriate places. Older machines, though, often relied on friction brakes to control tape tension and arrest fast winds, can be fiddly to set up, and may require specialist spring gauges and other tools. The medium itself (tape) isn't especially cheap, either!

The oldest machines tend to have valve electronics, which can add an extra sonic dimension, but they also tend to have wide replay head gaps, which limits top&#;end response dramatically, and they're mostly mono rather than stereo. The heads can be replaced with modern, narrow&#;gap alternatives (they may have to be replaced, due to wear and tear). More modern machines tend to have better specifications, including more headroom, making them better able to cope with modern high&#;output tape formulations. Better machines also have sophisticated servo&#;controlled motors, providing much gentler tape&#;handling and better wow&#;and&#;flutter figures.

The narrowest common open&#;reel tape format is quarter&#;inch, generally available on five&#;, seven&#; or 10.5&#;inch spools, the first two with 'cine' centre sprockets and the latter usually with NAB centres (which usually require cine&#;NAB adapter hubs). Domestic tape recorders generally record two tracks (or stereo) in one direction, and another two tracks in the other direction. This is usually called a 'quarter&#;track' format, and the track width is the narrowest in common use. Narrow tracks mean fewer magnetic particles to record the signal on to, and hence a poor signal&#;to-noise ratio: they tend to be hissy. This is made worse because such machines run at low speed, typically 3.75 or 7.5 inches per second (ips): the slower the speed, the fewer magnetic particles pass the heads. It's impossible to be precise, but machines of this type would usually have perhaps a 55dB signal&#;to&#;noise ratio, with high frequencies rolling off increasingly above 14kHz.

Next up is the 'half&#;track' format on quarter&#;inch tape. The tape runs in a single direction, capturing two tracks (or stereo) along its length. The doubling of the track width brings a reduction in tape noise, and most half&#;track machines can also be run faster (typically 7.5 or 15ips), bringing a further quality improvement. Pro and semi&#;pro stereo machines usually employ this format, and well set&#;up half&#;track machines running at 15ips pretty much defined 'broadcast&#;quality sound' for half a century: a signal&#;to&#;noise ratio of 65dB and a bandwidth close to 20kHz is perfectly achievable.

The primo format is half&#;track, half&#;inch at 15 or 30 ips. These are popular high&#;end mastering formats, and provide well over 20kHz bandwidth and a 75dB signal&#;noise ratio. Machines are relatively rare and expensive, the Ampex ATR100 being among the most favoured for this role.

The quarter&#;inch, quarter&#;track format was also used for semi&#;pro four&#;channel multitrack recorders, with the tape only running in one direction, usually at 7.5ips or faster. Scaling this format up, half&#;inch tape allowed eight channels with the same track widths and speeds, and one&#;inch tape gave 16 tracks. In each case, the relatively poor signal&#;to&#;noise ratio was a problem when mixing four, eight or 16 tracks together, so various double&#;ended noise&#;reduction systems were employed. Dbx systems were very common on semi&#;pro and project&#;studio machines, while some later machines adopted Dolby C or Dolby S.

Professional multitrack machines tended to extrapolate from the professional two&#;track formats: half&#;inch tape generally supported four tracks, one&#;inch carried eight, and two&#;inch had 16 or 24 tracks. Sixteen tracks on two&#;inch tape provides broadly the same quality as half&#;track quarter&#;inch and is a highly regarded format &#; but 24 tracks offered versatility, and in the '70s, 24&#;track became the de facto standard. Again, noise&#;reduction systems were commonly used (Dolby A and latterly Dolby SR being the favoured choices), and were absolutely necessary with the two&#;inch, 24&#;track format.

The cheapest available machines these days will be simple, two&#;head, low&#;speed, quarter&#;track machines using quarter&#;inch tape. These have an erase head and a combined record/replay head, much like most cassette recorders. They're a nightmare to align, and best avoided for serious work. On the next rung are several reliable three&#;head domestic machines, the Akai D, DS (Mk I and MII) and DB. The Sony TC377 or TC399 recorders were particularly popular, but there were many more from the likes of Tandberg, Philips, Ferrograph, Dokorder, Technics and others. Three&#;head machines use an erase head, and physically separate record and play heads (making off&#;tape monitoring possible), and are usually much easier to use and maintain. Most can't accommodate spools larger than seven inches (diameter) and use the quarter&#;track format, but they're fine machines for messing around with tape loops and learning basic tape-editing skills, or for providing lo&#;fi tape saturation. They're unsuitable for high&#;quality recording or mastering.

Moving up a notch brings us into the realm of the mighty Revox, the domesticated half of the Studer&#;Revox group, which shared much of its professional sibling's DNA. There's massive support available for virtually the entire Studer&#;Revox lineage, from valve machines like the G36, through the A77 and A700 and onto the B77 and PR99s. Quarter&#;track, slow&#;speed Revox variants do exist, but the majority on the market tend to be high&#;speed (7.5/15ips) half&#;track machines, and all accept 10.5&#;inch reels of quarter&#;inch tape. It's possible to convert low&#;speed quarter&#;track machines to high&#;speed half&#;tracks, but it's not a cheap option.

With the broadcasting industry's wholesale move to digital recording, countless Studer (and other) machines flooded onto the market and are now easily found: models ranging from the elderly B67s, through the A810s and A80s to the A807 are all quite common. You may also find the A80's broadcast&#;studio rival, the Telefunken M15, both huge flat&#;bed machines ideal for fast tape editing. There are plenty of other equally high-quality machines from Sony, Ampex, Ferrograph and others, and Nagra should get an honourable mention too: the Nagra T is a stunningly good studio machine, and for transportable applications you can't beat a Nagra IV&#;S, but the Nagra name inevitably attracts a high price. Other professional options include machines from Otari (MX and its siblings), and the unusual but impressive Technics RS, with its unique 'closed loop' transport.

Perhaps the most dominant name after Studer&#;Revox is TEAC&#;Tascam, who produced a wide range of two&#;track and multitrack machines over a long period. They're reliable workhorses, and their four&#;track and introduced affordable multitrack recording into the project studio market.

I've focused largely on stereo machines because that's where it's easiest to get quality on a budget, but the same names crop up in the multitrack market. The high end was dominated by the Studer A800 and Otari MTR90 (and their forebears and derivatives), followed by various Tascam models, with a wide variety of Fostex machines popular in the home market. The Fostex machines tended to use narrower tape formats (eight tracks on quarter&#;inch tape, 16 tracks on half&#;inch) and slower speeds, so the quality isn't up to that of the large&#;format high&#;speed recorders, but they generally included Dolby C or Dolby S noise reduction, and are perfectly adequate for most semi&#;pro purposes.

One thing you shouldn't forget is that the recording medium's characteristics have an impact on other aspects of the recording process. Recording to tape will inherently impose a certain sonic character (however subtle), which will change the way you work compared with DAW recordings and mixes: you might prefer to use a rich&#;sounding valve mic, or a mic pre with generous transformers when recording to a DAW (to impart musical character), but when working with tape you may prefer something that sounds a little 'cleaner' or 'sharper' as a source. Similarly, you may find that when working with all&#;digital audio, you choose plug&#;ins to smooth the sound, but with tape you work to add air and sparkle. There's nothing wrong with either approach, but they are different, and you have to take that into account. Blending the best of both worlds can be a great option, whether that means tracking with a DAW to capture a pristine, accurate source, and selectively bouncing tracks to tape and back to introduce tape saturation or character, or recording to multitrack tape and transferring to your DAW for editing and processing &#; or working completely in your DAW but bouncing the mix down to a tape master.  

Good Head? Checking For Head Wear

How do you know if your prospective purchase is in good condition? One thing you must do is check the condition of the record, play and erase heads.

In a well set&#;up machine, it can be tricky to assess the amount of head wear by looking, unless you know what a new head looks like.

• The most tell&#;tale sign is an obviously flat surface: a new head is generally convex and touches the tape over a relatively small horizontal area. As it wears, the surface flattens and the contact area broadens.
• If the head is not aligned accurately, the wear pattern will be asymmetrical with respect to the gap: wider at top or bottom implies a zenith error; not centred vertically suggests a height error; and not centred horizontally suggests a wrap error. Correcting mechanical alignment will result in sub-optimal tape contact, so head may need replacing.
• In a well&#;maintained machine, wear should be modest, and the worn area nicely centred and linear relative to the gap. The head should also be clean; not covered in sticky tape residue, oxide dust or grease-pencil marks!

The Brown Stuff: Which Tape To Buy

When it comes to buying tape, there are fewer options than there once were, but still enough to cater for most machines' requirements. The easiest brands to find are ATR, RMGI and Zonal: the first two are available in widths from quarter&#;inch to two&#;inches, but Zonal seem only to offer quarter&#;inch. Most types are 'matt backed standard play' types, but you'll also find long&#;play versions. The latter are thinner, so more tape fits on a reel, for more recording time, but there's more risk of tape stretch, print&#;through and other damage. RMGI produce the LPR35 long&#;play tape and Zonal produce type 840. The matt backing is now standard and offers improved tape handling and winding.

The magnetic compound is formulated in different ways for different applications, producing different noise&#;floor and print&#;through characteristics. There are no set rules about which tape works best with which machine, so experimentation may be required. Older machines often can't cope with the high recording flux levels some modern high&#;output tapes require, but those that can benefit from lower noise&#;floors. Here's a few tape guidelines.

&#; TAPE TYPE: 'Standard Bias' tapes (normally best for old machines) include RMGI SM911 and Zonal 820. 'High output' tapes (for modern pro machines) include all ATR stock, Zonal's type 700 and RMGI's SM468. Mid&#;range alternatives include the Zonal type 675 and RMGI's SM900.

&#; ALIGNMENT: Ideally, the recorder should be realigned to optimise performance with the tape type, and in doing so you'll normally find that one type suits the machine best. If you can't realign the machine to the tape, experiment with different types to see which allows the machine to deliver its best performance. An experienced technician should be able to advise which tape is best for your machine.

&#; PRICE: At the lower end, budget Zonal tapes range from about £11 to £20 per 10.5&#;inch reel of quarter&#;inch tape in the UK. A 10.5&#;inch reel of two&#;inch tape may cost £130-plus. There's still some 'new old stock' (NOS) tape available, but buying NOS tape is a gamble: heat, cold, sunlight and humidity during storage all have a damaging affect, and there are issues of binder decay that affect some tapes (notably, some Ampex), resulting in a gooey mess on heads and tape guides, and damaging the audio in potentially catastrophic ways.

&#; RE-USE: Tape can be re&#;used several times, but repeated passing over the heads gradually wears the magnetic coating and performance declines (with a loss of high frequencies and increased noise). How tolerable this decline is depends on the circumstances: when I started in the pro audio business, tape was cheap enough to use fresh reels for almost everything (although the BBC had a tape&#;recycling facility). In a project studio, the cost of tape today might make re&#;use a practical necessity, You could expect to get around five re&#;uses before you notice a reduction in quality.

Tape Heads

The three magnetic heads of a professional tape recorder are each carefully optimised to perform their own particular job, but basically comprise an iron C&#;shaped core, the back of which is carries a coil of wire. When an electric current is passed through the winding, a magnetic field is produced in the core and bridges the gap, which is arranged to be in contact with the recording tape. If the current through the head varies with the wanted audio signal the magnetic field strength and direction also varies. The magnetic layer on the tape captures the magnetic state, and as it is moved past the head gap it moves outside the magnetic influence and retains the magnetic field at that time. This recording would ordinarily be grossly distorted on replay because of the very non&#;linear magnetic characteristics of the recording particles within the tape. The solution is to add a high&#;frequency ( typically about 150kHz) 'bias' signal to the audio signal which forces the magnetisation process to become far more linear. The bias signal is not retained by the tape, it merely linearises the recording process.

The size of the gap in the recording head is not particularly critical, provided a sufficient field strength can be created, so relatively large gaps tend to be used to ensure that the magnetic field is large enough to penetrate the full depth of the magnetic layer in the tape. In fact, the effective recording zone is not actually in front of the head at all, but is at the point where the tape moves out of the influence of its magnetic field.

A replay head is constructed in a similar way to the record head but operates in reverse: the magnetic field carried on the tape is focussed through the head's C&#;core and induces an alternating electric current in the coil of wire. These currents are then amplified and processed to reproduce the wanted audio signal.

The replay head must be extremely sensitive to capture the relatively weak magnetic flux stored on the passing tape, which means that some care must be taken to shield it from external magnetic fields generated by the transport motors and mains transformer. Consequently, the head is usually enclosed in a protective mu&#;metal case, often with a fold&#;down front plate which can be raised after the tape has been laced.

The signal voltage induced across the replay head windings increase in direct proportion to the rate of change of the magnetic field on the tape, so there will be a much greater output for a high&#;frequency audio signal recorded on tape than for a low&#;frequency one. This is compensated for with a 6dB/octave low&#;pass equaliser in the replay electronics, but various magnetic anomalies result in a slightly uneven low frequency response, often referred to as 'head bumps.' The size of the replay head gap is critical for the high frequency response because when the recorded signal on the tape has a wavelength equal to the width of the head gap there will be no net magnetic flux, and no output. This is called the 'extinction frequency'. To ensure that the extinction frequency is well above the highest required audio frequency, a very narrow head gap must be used &#; typically one micron or less. The recorded wavelength is related to the tape speed of course, and lower tape speeds mean shorter wavelengths and a lower extinction frequency, so less top end.

Given the very different requirements for the head gap between the recording and replay functions, professional machines are generally equipped with three heads, each optimised for its specific requirements. Some machines have only two heads, erase and a dual&#;purpose rec/rep head, although this compromises both the record ability and replay performance. In multitrack machines, where it is necessary to switch some channels of the record head to replay to generate a synchronous overdubbing cue feed, the output is often noticeably duller sounding than when auditioned via the replay head.

It is worth noting that modern machines have far narrower replay head gaps than was possible in the early machines of the s and 60s, and as a result can extract a far wider and flatter frequency response from old archive tapes than was ever possible at the time of their recording. Since the recording process is largely independent of the record head's construction, recordings made in the s and 60s are frequently found to be of extremely good technical quality when replayed on modern machines &#; the recordings were often of a far higher quality than could be replayed at the time!

The erase head may be a single unit covering the entire tape width, but is more usually split to allow independent erasure of the individual tracks in a dual or multitrack machine. Erasure is achieved by sending the same bias signal as was used to linearise the record process into the erase head's wire coil. The tape is not capable of storing this high&#;frequency bias signal, but it does shake up the magnetic particles, leaving them in a random arrangement, thus erasing any previous recordings and guaranteeing a clean tape for the new recording.

Additional Background Information

Practical magnetic audio recording first appeared in the s but the form we know it in today was developed by the Germans during the Second World War. Recording tape is, essentially, a sophisticated rusty ribbon, with the shape and depth of the 'rust' particles providing the required recording properties. The first recording 'tape' was paper&#;backed and made by BASF in Germany, but later polyester designs proved more durable, and the magnetic coating (a metal oxide or metal alloy) improved dramatically over the years, reaching peak performance in the s. The mechanics and electronics of the recording machines also improved steadily over the years, again reaching a zenith in the mid s... and just as digital recording started to become cost effective and largely took over.

Magnetic tape recording is inherently imperfect as various harmonic and dynamic distortion artefacts are an integral part of the medium. However, these characteristics are so familiar to us all that many feel the indisputably more accurate digital medium lacks 'warmth' in comparison.

The way recording tape works is that a strong and flexible polyester backing tape is coated with a metallic compound capable of storing a varying magnetic pattern. This magnetisation is varied in strength and polarisation to represent the air pressure variations of the wanted sound as captured by a microphone.

'Standard Play' open&#;reel tape is typically around 50 microns in thickness, allowing a full 10.5&#;inch reel to run for just over 30 minutes at a speed of 15 inches per second. 'Long Play' types are typically about 35 microns thick and are used wither where extended recording times are required, or where the recorder has a particularly tight tape path or restricted spool size capability is restricted &#; such as in small portable recorders like the infamous Nagra machines.

All modern tapes are 'back coated' with a dull matt and rough&#;feeling surface (as opposed to the shiny, slippery nature of older tape types). This matt back coating provides more friction between layers which helps to give more consistent and stable handling and smoother fast winding characteristics because less air gets trapped between the tape layers. Neat, even winding reduces the risk of edge damage which is the most common cause of drop&#;outs and poor head&#;to&#;tape contact. On a well set up machine, the tape shouldn't touch either spool flange &#; it should sit neatly between them. If the tape spool is bent such that it rubs against the tape as it revolves, it should be discarded and replaced with new straight one to avoid causing edge damage and potential dropouts.

Adhesive tapes are one of the greatest inventions made in the history of civilization. They are practically used by every human being and have even become a necessity at this point. They are utilized in many ways, but the essential function is to secure. A broad spectrum of sticky tape types can be categorized depending on their use and application to materials. Security is one of their many important uses. Keep reading to know all about adhesives, their origin, their types, and their applications.

What Exactly Are Adhesive Tapes?

Many familiarize themselves with sticky tapes, cello tapes, and adhesive tapes. However, they all mean the same thing, sticky tape. They are one of the most widely used materials in most security industries due to their powerful securing abilities.

To put it simply, adhesive tapings make use of an adhesive coating. These coatings are susceptible to pressure, so they are taped using gentle force and heat from fingers. They use a material backing on which the adhesive layer is coated. This material can range from plain paper to tin foil or even a piece of cloth. Some also claim to use plastic films as the backing material. While understanding tapes can seem like an easy task, there is a shocking number of adhesive tapes, each possessing no-like characteristics. 

Daily-use adhesive tapes have a cover or a lining material that seals the sticky adhesive intact. This arrangement allows the user to peel the lining off when the tape is ready for use without losing much of the valuable adhesive. Other adhesive tapes are used for various purposes; hence, they are found with different coverings to serve that purpose. Pressure-sensitive tapes, also known as PSA tapes, are the most convenient adhesive taping, as their application requires no solvent or external factor to make it stick. When the adhesive is applied only on one side, it is called a single-sided adhesive, while double-sided ones have both sides coated with pressure-sensitive adhesive.

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PSA tapes can be applied the way they are because they are glued at room temperature. They have great gumming ability without any external application of heat or water. It is a surprising fact that domestic tapes fall into this category. Other adhesives require applicators for bonding with the material because they exhibit viscous qualities through such pressures. These pressures are technically referred to as &#;bonding pressure&#;. In a nutshell, the backing material is referred to as the &#;tape&#;, on which an adhesive fluid is coated. This sticky coating differs from tape to tape, giving rise to many types of tape such as resealable bag sealing tape.

The History Behind Adhesive Tapes

As already mentioned, the invention of viscous structures called adhesives carved humanity into what it is today. It is mind-boggling how a simple function of sticking to materials and objects caused a sensation, especially during the industrialization phase. Before moving on to the &#;tape&#; part, it is first essential to understand the concept behind tackiness.

It began in ancient Egypt, where there was a need to keep specific tangibles together. However, a tamper-proof tape is still far out of reach. The history and invention of viscid adhesives are accredited to the woodworkers of that time, who noticed this characteristic right inside mother nature. In the late s, the first natural adhesive took the form of sap (resins), honey wax from honeybees, and animal collagen. 

However, this was not adequate at those times. As they work with harsh substances and materials, mere gum would not do the trick. Even epoxies had severe disadvantages in terms of durability, strength, and extra stickiness. In the early s, this problem was wiped out for good. Adhesive tapes came into existence. 

Since then, their usage has expanded to lengths one could not imagine, and it still is in the process of expansion. Old adhesive tapes have been developed using simple materials like paper and gum. This was not feasible, primarily when they were used in painting work. This caused such a mess in position and fuss from the bosses for peeling off the paint along with the adhesive. They had no choice but to develop a dry glue that does its job without ruining the material underneath. That&#;s right, masking tapes were invented, and it is a canvas artist&#;s favorite tool.

Need is indeed the mother of invention.

What Are Adhesive Tapes Made Of?

Tapes are essentially a combination of adhesive and backing material and are glue and paper, respectively, in their simplest form. The adhesive coating is made on this carrying medium and rolled together to form regular tape. They can further be cut down into sizable lengths and widths to serve different purposes.

What Types Of Adhesives Are Used For Tapes?

As noted earlier, a broad spectrum of sticky tape types can be categorized depending on their use and application on materials. While some can be activated through pressure, others have complex designs that can only work in certain conditional mediums. Tapes are made of carrier material and the respective adhesive. That said, not all adhesives can be used for taping purposes. The following are most commonly used in the security industry:

• Acrylic: Provides strong and intense resistance from environmental conditions; minimal setting time in comparison to other kinds of adhesives
• Epoxies: Also known as resins, gum material that does not shrink with curing and is self-protective of environmental and chemical changes
• Rubber: Based on solid compounds such as butadiene-styrene, polyisobutylene, butyl, and nitrile; extraordinarily flexible and adjustable sealants
• Silicone: Highly flexible and temperature resistant
• Other: Isocyanate sealants and polyurethane-based adhesives form a combination of all the above characteristics; They exhibit strength, utility, long lifespan, and adjustability.

Knowing the type of adhesive used in a tape can reduce wrong applications and increase security.

Which Materials Are Used For The Backing Or Carrier?

Adhesives and backing materials go hand-in-hand. They are complementary; not one can be prioritized over another regarding tape manufacturing. Tapes have two essential components- the adhesive and the carrying material. Although understanding the adhesive can prove crucial for its usage, the backing material is equally important because it must go along with being used. Adhesive films can be made from various materials depending on the purpose. The most common ones are listed below:

• Paper: Also referred to as flat-back tape
• Cloth: Uses a fabric or a piece of the woven layer
• Felt: Non-woven materials that provide scratch resistance and protection
• Foam: Usually combined with a cover liner; its primary purpose is for mounting and sealing.
• Metal Foil: Aluminum and tin metals are often used as backing materials. Lead foils are also widely used due to their heat-resistance properties. They are excellent backing materials for holding objects exposed to high moisture and humidity. While metallic tape designs typically cater to sealing and seaming, aluminum-based ones are pre-laminated on plastic or paper bases to exhibit strong properties. Copper carriers are widely used in manufacturing PCBs.
• Plastic Film or Polymers: They are generally categorized as thermoplastics and thermosets based on the number of plastic layers it incorporates. They are widely used for designing due to their layering abilities and because they can come in any style- clear, organized, or mono-colored. 
• Mylar: Mylar is also known as polyester or polyester-based products
• Filament bundles (or strap tape) consist of millions of fiberglass filaments converted into a thread-like structure. It is more versatile than other backing materials and can stick differently shaped objects. They are commonly used for storage and shipping.
• Double-sided tapes must have a covering liner or release liner on at least one surface. These liners are preferably made from solid and smooth materials like silicone or paper.

Adhesive tapes mimic ribbons in terms of appearance. These carrying materials are typically films that are coated with different adhesives. Once rolled into a tape, they are cut into various widths via a slitting machine. Multiple factors affect the quality of a tape, such as winding tension. The tension that is too high or too low can cause defects and imperfections in the tape. The high degree of pressure will increase the stretchability of the tape. These defects in an adhesive security tape are referred to as telescoping or gapping. They need to be carefully done. Any compromisation shall affect other after-process factors like storage and application.

Different Types Of Adhesive Tapes

Security Tape

Security tapes are one of the primary essentials every security industry should possess in adequate numbers. They are beneficial for packaging and shipping over long distances and even overseas. Security tape is a security label that protects the objects stored inside. They are handy for the storage of sensitive and fragile things. As their primary purpose is to secure contents, they are naturally strong and versatile, so much so that sometimes shippers use them on the whole box for good measure. They have a similar appearance and function to packing tape, but security labels are often on the cheaper side of the spectrum.

In a nutshell, they prevent the risk of shipping losses through pilferage, theft, and adulteration. This falls under the category of a PSA, just with tamper-evident tape properties. It is essentially a security seal against common types of pilferage. They are quite a necessity in the case of authentication products. They have been in use for an extremely long period, and the reason is because of their versatile applications and advantages.

Security Tape Applications:

• Security labels can be used on containers of any size, such as small bottles or even corrugated boxes. In these instances, the adhesion and strength of bonding are essential. They are excellent for securing contents for shipping or storage.
• A tamper-evident tape is all you need when mimicking regular packaging tapes. It sometimes happens that a queer tape can draw attention and suspicion among people. A security tape that does not look special can conceal the item&#;s value. They are available in different colors as well!
• As mentioned earlier, security tapes are part and parcel of the solid security, and no securing department can be successful without one. One layer of security taping can only do so much. As such, they are accessible to solvents and environmental temperatures.

Security Tape Advantages:

• Capacity: A tamper-evident tape can conceal a box of any size. There has been a growing demand for storage optimization, and security tapes can fulfill that need by providing bulkiness and high capacity volume.
• Cost: Not only do they secure bags and bottles, but they are also cost-friendly and well within the budget of the standard security industry. It is the most cost-efficient option when securing any item.
• Lost-lasting: Another reason to be fed is that they are insanely durable for their kind. They do not lose their adhesive and strength properties. A good security tape can last for several years or even more! 
• Resistance: They require efficient and minimal storage due to their excellent resistance to heat and other environmental factors.

Security Bag Tape

Security bag tapes are great protectors from unauthorized openings of valuable packages. The number of companies currently using these taped for carton packaging and sorts is increasing by hours. They are extensively used in securing bags and cargo crates. These cannot be tampered with, or at least without evidence. These tapes are used on bags to prevent damage from ambient temperatures and chromic action.

Security Bag Tape Applications:

• As these tapes are fabric-friendly, they have been extensively used in the clothing and medicine industries to protect valuable contents. They have indeed been expanding to regular manufacturers and retailers for supply-chain working.
• A bag sealing tape is also used for cash boxes and is designed for all types of material. Once applied to the bag, there is no doubt that it is safe for transportation and conveyance.
• They are used in industries and are also accessible for domestic use. They create a void and protect the contents from the ambient temperature.
  

Security Bag Tape Advantages:

• Prevents theft and crime: The most impressive thing about security bag tape manufacturing is that they are the epitome of &#;prevention before cure&#;. This is one of the most cost-effective solutions for theft-proofing. Rather than tracking down through expensive and inefficient means like cameras, they provide first and second-hand security by offering protection and leaving evidence in the time it doesn&#;t.
• Secures brand imaging: Not only does it connect things physically, but these tapes can also prevent theft of brand- counterfeiting. Various valuable consumables like clothing and electronic industries are at risk for this issue. Thanks to inexpensive security bag tapes, theft is no longer an issue to worry about. One can design their own custom tamper-proof tape to further make it original for their branding
• Lifts customer experience: Security bag tapes can secure a good product experience by preventing any damage to it in the first place. The customer service department can kick back and relax while the reviewing goes so high through the roof.
• Cost-beneficial: A simple cost-profit analysis can prove that they can secure the company&#;s goodwill

Duct Tape

Almost everyone would require duct tape due to its versatility. They are the standard solution for most housing problems and repairs. The first ever duct tape has been blinded by gray, but presently they are designed so brightly that they can be used for making wallets and whatnot! They fall into PSAs, as a combination of polyethene. They were initially called &#;duck-tape&#; due to their duck-feet adhesiveness property. 

There are totally 7 types of duct tape that one can find. The general ones are extremely versatile, but it sacrifices their long life span. The industrial-grade duct tape is made with polyethylene, which contributes to sturdiness and weighted adhesive coating. Professional grade ones are an upgraded version of industrial grade duct tape, having more strength and durability. The other ones include stucco tape, cloth tape, and true duct tape. Stucco tapes are used for construction purposes and window repairs. The main backlog that keeps people from choosing this tape is its weakness in extreme heat or cold conditions.

Duct Tape Applications:

• Domestic repairs
• DIYs
• Industrial grade workings

Duct Tape Advantages:

• Durability
• Sturdiness
• Versatility

Electrical Tape

Commonly known as insulation tape, they are a domestic necessity for houses having electricity issues. They can pretty much be used for anything that conducts electricity. It is made from several plastics but is mainly available in vinyl. This is because of its long life span, with added stretchability and insulation properties. Electrical tapes come in a wide range of varieties and colors, facilitating labeling and grouping functions. They are normally used in industries to indicate different voltages and degrees of security. 

Being on the expensive side of the budget spectrum, it would be extremely time-consuming to use them. They require great attention to detail and expertise to use them effectively. Not only are they used for its incredible heat and electric sustenance, but they are also used for decorations and sorts. Electrical tapes must be tightly wrapped around the wires for best performance. Avoiding outdoor usage of electrical tapes can expand its life. They can hide any scratches or openings present in a wire as well. A tamper-resistant tape with electrical insulation properties is extremely useful. Astonishingly, these tapes don&#;t stick to the opposite surface!

Electrical Tape Applications:

• Insulation
• Wound dressing
• Temporary fasteners
• Adhesive to metals and plastics

Electrical Tape Advantages:

• Flame resistance
• Pressure-sensitive
• Versatile
• Multi-purpose
• Conformability

Magic Scotch Tape

The first thing that comes to mind when people hear &#;adhesive tape&#; or &#;tape&#; is scotch magic tape. Being the most ubiquitous tapes, they are extremely popular for their versatility and invisibility. They are called so because of their outstanding quality to turn invisible when applied to envelopes or gift wrappers. They can also be written on and are available in every stationery shop. The scotch tape makes use of cellulose acetate, which is the cocktail of all adhesives. Mixing that with deionized water gives the tape a matte finish with a fuzzy look when wrapped around itself.

It was also used during the period of the Great Depression. Man-made acrylic-type adhesives also contribute to their stickiness and durability. The secret to its matte-like finish is due to the acetate compounds present in the adhesive backing. This is why it has a vinegar-ish appearance. They are the first choice when it comes to gifting and decorations. Though their adhesiveness is nothing compared to other types, they are in a league of their own!

Magic Scotch Tape Applications:

• Matte finish
• Photo-safe
• Dispenser availability
• Projects and files
• Mending tracings
• Drawings and illustrations
• Legal documents

Magic Scotch Tape Advantages:

• Invisibility
• Pen-friendly
• Moisture-free
• Easy storage
• Smooth application
• No yellowing or splitting

Masking Tape

They are an artist&#;s need and a painter&#;s shield. It is also called &#;painting tape&#; for this reason. Being pressure-sensitive, these tapes are called what they are due to their masking-off capabilities. Their weakness happens to be their strength. They can be torn effortlessly due to the paper component. They are among the first adhesive tapes to be invented back in . They can easily be removed without peeling the under-surface. Another variant is called a washi-tape, which essentially masks tapes with decorations and designs. 

Masking tapes are available in various ratings and grades, indicating their lifespan, durability, and residues. Different ratings are used for different purposes; for example, longer ratings are designed for smoother surfaces such as a vinyl backing sheet. They are essentially made of 3 layers just like any other adhesive tape: the PSA, backing or carrier, and release liner. As they are used for painting, it is easy to find them in a wide range of sizes and widths to fit the canvas. Masking tape can be acrylic-based or silicone-based, depending on their usage.

Masking Tape Applications:

• Decorations and paintings
• Insulation for cable wires
• Blueprint holding
• Domestic purposes

Masking Tape Advantages:

• Convenient and easily available
• No residues

Surgical Tape

Lastly, surgical tape is among the PSAs widely used in the medical industry. Medical adhesive tapes are a bit different in relation to their species. Their primary purpose is to hold bandages in place. They are allergy-proof and have been invented for being used on the skin without being the cause of a wound it closes. It encourages healing through breathability. They are simple to put and remove as well. As a matter of fact, they are pressure-sensitive, and there is no requirement for a solvent or a heat medium for its activation. They are often combined with a tamper proof evidence tape for bags, so the medicines are secured well. 

Surgical tapes can come in their own varieties; some of them include micropore paper tape, transpore polyethylene tape, and zinc oxide tape. The adhesive used is a mixture of semi-fluid acetates and compounds. Medical requirements revolve around speedy application and versatility, and these functions are all combined in this kind of tape. However, they cannot be used more than once for sanitation purposes. They are so diverse in their applications that they can be used for domestic first-aid, athletic purposes, and even in moisture-filled environments.

Surgical Tape Applications:

• Surgeries
• First-aid
• Wound-dressing gauze

Surgical Tape Advantages:

• Waterproof
• Stretchy
• Cost-friendly

How Does Adhesiveness Work?

The first invention of an adhesive &#;tape&#; in created a plethora of inconveniences. Masking tape resulted from a need to paint vehicles without peeling the paint off. The introduction of different tapes began, and manufacturing in industries was never the same. Cello tapes (short for cellophane tapes) were the hero during the period of the great depression. Not only did they do their job, but they also added a sense of aesthetic building. Labeling uses matte covers, while adhesive tapes are made from regular cello finishes. They were highly versatile and multipurpose friendly, so much so that they were used in the medical industries for bandaging. It became a necessity, and people took it for granted. But how exactly does it work?

It is a remarkable invention. The adhesiveness is one thing, and that in the form of a tape is another. 

The Science Behind Tackiness

The working of an adhesive is slightly varied when used in the form of tape. PSAs have components like silicones and acrylic rubbers, to which a gummy epoxy resin is added for added adhesiveness. PSAs stand apart from other adhesive tapes because they require physical factors for activation rather than chemical. To understand the process of its working, one must familiarize with two concepts- the concept of wetting and the physics behind Van Der Waal&#;s forces, the former responsible for adhesiveness and the latter for its strength.

The process of wetting does not need much explanation. It is essentially a process of penetrating the adhesive into a substrate, the backing material or carrier. The glue used in this case is in the solid state, as this process leads to unstable surface molecules. Low surface energy leads to weak bonds and smoothens the penetration process. All that is required is some pressure. The lower the surface energy, the greater the flow of molecules, and the stronger the resultant bond. And that is how sealing tape for plastic bags is made.

Different adhesives would have different levels and degrees of penetration. To add to the strength of these PSAs, the adhesion is amplified using a phenomenon of molecular attractions called Van Der Waal forces.

They are essentially weak molecular attracting forces with partially neutral charges. Bonds cannot be formed if molecules do not have charges. As these are not entirely neutral, their imbalance in the number of electrons and protons causes weak charges. This enables them to attract themselves to other partially charged molecules in its proximity and thus results in a bond.

Storage methods are essential, especially for those made with silicone or rubber. Adding a liner may increase its life. Paper carriers may be weak against moisture. As such, knowing proper storage conditions for different adhesives is useful.

This brings us to our next point, storing methods.

Storing Considerations And Methods

The storage environment can heavily affect an adhesive tape&#;s shelf life. Many variables, like temperature changes, UV, moisture, and seasons, must be considered while storing a sticking tape. We will cover three aspects of storage factors:

UV radiation: This electromagnetic radiation is also present in X-rays and Infrared lights. Though they are practically invisible to the naked eye, they have a marginal impact on the use of adhesive tape. The chemistry behind it comes back to the sticky charges. Certain degrees and periods of UV radiation exposure can lead to variations in its properties. They can sometimes become brittle and rough and wear out the stickiness. One way to avoid this possibility is to treat it with UV stabilizers or use a carrier with that protection. Keep asking, &#;what kind of tape will protect it from UV radiation?&#;.

Temperature: Heat can be a friend or a foe for sticky tape. That said, low temperatures are excellent for PSA storage. It retains stickiness and also makes it stronger. A narrow 60 degrees or hotter environment is recommended for most PSAs. And the last one;

Manufacturer&#;s Expiry Dates: That&#;s right. An essential thing to do is to follow the maker&#;s orders. All security tape manufacturers provide this information on the product&#;s datasheet. Not only does it specify the period of use before expiration, but these suppliers also take the extra step to recommend environmental specifications for storing. Keep lead time in mind, and don&#;t forget to roll the stock to maintain its performance.

How To Choose Adhesive Tapes Through Testing Methods

To choose a suitable adhesive tape material, one must familiarize oneself with the different types of adhesives available. Some notable ones are as follows: 

Resin Rubber: Being the older kind of adhesive, it combines rubber and sap. It is affordable and solid in comparison to other types of adhesive tapes. It holds together materials, even if they are hard to stick. Thanks to their strong bonds, they can resist higher temperatures to some extent. However, they oxidize quickly in the presence of air and UV rays.

Synthetic Rubber: They are manufactured rubber materials that are super adhesive instead of natural rubber. It is widely used for shipping and security purposes due to its sheer strength.

Acrylics: They form the weakest of adhesives. They resist environmental factors such as temperature, UV ray exposure, and oxidation. As a limitation, they seem to be out of budget for commercial usage. They also require lag time to activate their stickiness.

Silicone adhesives: These adhesives are long-lasting. They are incredibly durable and skin-friendly. Due to this property, they are used in bandaids in the medicine industry. Thanks to excellent heat resistance, they are widely used in the electrical and temperature-based industries. Unfortunately, they are on the expensive side of the budget spectrum, even more so than acrylics.

That said, there are some testing variables to understand the various properties of the tape. They are as follows:

• Peel adhesion: The force required to break a bond between the PSA and the surface material. This testing method tests the adhesion strength by peeling the tape at a uniform pressure and speed at a certain angle. It calculated the extent of bond breakage. It is represented by oz/in.
• Tack: It is the adhesive property of the tape. To put it more elaborately, the tape can wet the adhesive on the surface upon contact. This measures bond formation, as opposed to peel adhesion. This is used in most tamper evident tapes.
• Shear: It is essentially the speed of movement of an adhesive tape. It measures the sticking power and can be calculated statically or dynamically. When a static load is applied on a vertically-pulled tape, the shear is referred to as static shear. Similarly, dynamic shear measures the horizontal stress of the tape.
• Tensile Strength and Elongation: Lastly, this factor measures the strength of the tape concerning its construction. Conversely, elongation is calculated as the percentage change in the tape&#;s length when pulled from both sides with a special force.

Storage Life And Impacting Factors

Temperature: As mentioned earlier, heat is crucial for adhesive retention. And this includes the adhesive, the carrier, and the surface to which it is applied. Make sure that these materials are at least 65 degrees Fahrenheit. 

Surface: Many complaints about the adhesive tape are actually the problem of the surface. Vestiges of dirt or moisture can destroy the tape&#;s properties and create a barrier. To avoid this, give it a quick wash of rubbing alcohol with a dry clean cloth. Another factor to consider is the uniformity (regularity) of the surface too. Irregular surfaces can slightly damage the thin, smooth surface. 

Chemistry: The composition of the surface also plays a massive role. The adhesive tape can be secured differently based on whether it is made of plastic, covered with paint coating, has a release liner, etc. Keep in mind that if the surface is waxed, there is a need to buy tackier tape. This applies to the adhesive, backing material, release liner, etc.

Humidity: Moisture can wear out the stickiness if the adhesive happens to be a weak one. 

Shelf life: The security tape manufacturers best determine the usable period. This must be the first factor when looking for adhesive tape. It would be shown in the datasheet or behind the package under normal circumstances. Pay attention to their recommendations as well.

Other: The type of adhesive, carrier, covering liner, application method, adhesive tape manufacturer, and storage conditions can also determine the strength and usable period of using the tape effectively and efficiently.

Tips On Adhesive Tape Removal

• Before attempting to remove the adhesive tape or any residue, it is crucial to test the removal method on a negligible area to ensure minimal damage. This is because painted or glossed surfaces are sensitive to most removal methods, and using these methods can destroy, discolor, or peel the shell. Be extremely careful in this regard.
• Be agile and speedy. While removing the adhesive tape, create imagery of removing a bandaid. Speed can make a clean removal with minimal residue. This needs to be done, especially in case of a void tape.
• Scraping can also prove helpful under certain circumstances. This is especially true for construction adhesives. Just be mindful about protecting the surface and preventing damage.
• Soap proves helpful in removing adhesives made of plaster, enamel, and vinyl. This also works for copper and asphalt-based bonds. Make sure the water is warm, as this will soften the tape.
• Apart from the heat from warm water, try to apply dry heat from dryers or blow torches. As mentioned above, the tape can be sensitive to heat and moisture; and exposure to them can reduce tackiness by a significant degree.
• Applying rubbing alcohol can remove it smoothly without damage. This is especially the case for handling PSAs. Wait for a while after application for penetration. Any kind of alcohol-based solvents works in this regard.

Conclusion

There are as many types of adhesives as there are carriers of so. The kind of adhesion used, or the substrate and liner it is coated, heavily influences the tape&#;s lifespan, durability, and strength. Although usually, they range from 1-2 years, they can vary by a marginal degree depending on their storage environment. This is extremely important as these adhesive tapes risk characteristic variations and changes in its property. One thing to remember is that adhesives are a broader topic, while tapes fall under it. Security tapes provide multipurpose versatility and robust security for securing packages. Contact us to get some now!

If you want to learn more, please visit our website Tape Coating Machine.