Security level (DIN 66399)
The level of secrecy of the shredder according to the DIN 66399 standard. It is designated by the English letter P (from “paper”) and a number from 1 to 7.
This indicator determines how well the destruction is carried out, as well as how difficult it will be to restore the document or medium passed through the device. The DIN 66399 standard provides for seven security levels with the simplest numbering from the lowest to the highest:
P-1,
P-2,
P-3,
P-4,
P-5,
P-6,
P-7. These levels apply to both paper and other media, but shredders are used primarily for paper documents, and this option will be discussed here; similar information about other materials can be found in the "Destroys" section.
— P-1. The paper is cut into strips no more than 12 mm wide or into fragments up to 2000 mm² in area. Basic level, allowing for the easy restoration of a destroyed document; designed for the disposal of papers that do not contain classified information.
— P-2. The paper is cut into strips no more than 6 mm wide or into fragments up to 800 mm² in area. From a practical point of view, it has no fundamental differences from level P-1 — except that the shredder basket does not fill up as quickly due to the smaller size of the
...fragments.
— P-3. The paper is cut into strips no more than 2 mm wide or into fragments up to 320 mm² in area. It is impossible to restore a document destroyed in this way manually, although this can be done using special technical means.
— P-4. The paper is cut into fragments no more than 6 mm wide and no more than 160 mm² in area. This level is considered to be almost the most optimal for “delicate” materials that at the same time do not require maximum levels of secrecy — for example, everyday business documents like financial statements. Restoration after processing at level P-4 is extremely difficult even with the use of special equipment (although possible), while the shredders themselves are relatively simple and inexpensive. In addition, they can easily be designed to destroy paper clips and staples.
— P-5. The paper is cut into fragments no more than 2 mm wide and no more than 30 mm² in area. This level is suitable for business documents of strategic importance, such as long-term plans.
— P-6. The paper is cut into fragments no more than 1 mm wide and no more than 10 mm² in area. After such processing, document restoration becomes virtually impossible.
— P-7. Maximum level of secrecy: paper is cut into fragments no more than 1 mm wide and no more than 5 mm² in area. Such shredders are very expensive, and they are not very productive. Therefore, it makes sense to use them for documents of special state importance and other materials of similar significance.
It is also worth noting that when working with paper, the level of secrecy affects the speed of filling the shredder basket. The smaller the paper fragments, the more densely they fit into the basket and the more time it takes to fill it, with the same volume.Shredding Items
Types of media and materials that the shredder can utilize. Note that, by definition, all such devices are capable of working with paper documents, so paper is not mentioned in this paragraph (some models are generally
only compatible with paper and do not allow using other materials). However, shredders with the ability to utilize various additional items are more common — mainly
staplers,
paper clips,
credit cards and/or
CDs/DVDs. Here are the features of each of these options:
— Staples. An auxiliary function designed to ensure that stapled materials do not have to be separated before being loaded into the shredder. Allows you to significantly save time when utilizing of such materials, especially in large volumes; also provides a correct operation guarantee in case of accidental contact with the staples.
— Paper clips. Paper clips are removed much easier than staplers and there is no problem with them even with a large amount of documents. Therefore, this function is rather an insurance against getting such a clip into the device along with the document.
— Credit cards. The ability to recycle various plastic cards with magnetic media — credit cards, passes, etc. This feature at least prevents the illegal use of such cards, and with a high security level it allows you to
...keep the fact of the existence of a card in secret. Actually, the security level for such utilization is indicated in the generally accepted standard DIN 66399, as like as for paper, and there are seven of them:
- 1 — the card remains intact, its surface is mechanically damaged;
- 2 — the card is cut into pieces with an area of less than 2000 mm²;
- 3 — size of pieces less than 320 mm²;
- 4 — less than 160 mm²;
- 5 — less than 30 mm²;
- 6 — less than 10 mm²;
- 7 — less than 2.5 mm².
— CDs/DVDs. Ability to utilize optical discs, which can also store confidential information. For such media, DIN 66399 also provides 7 security levels:
- 1 — the disk is cut into pieces with an area of less than 2000 mm²;
- 2 — less than 800 mm²;
- 3 — less than 160 mm²
- 4 — less than 30 mm²;
- 5 — less than 10 mm²;
- 6 — less than 5 mm²;
- 7 — less than 0.2 mm².
Fragment sizes
The largest possible size of the fragments that come out from the shredder after being processed. However, it's told about fragments only in the case of using cross-cutting; for stripe cut models (see “Cut Style”), this item indicates the largest width of the stripes. The size of the fragments is directly related to the security level provided by the shredder; see the relevant paragraph above for details.
Gap Size
The gap size of the shredder is the opening where the utilization materials are placed. This indicator determines the maximum size of the material that the device can handle at one time, without the need to fold or cut the sheet. The common gap size for most office models is 220 – 230 mm — this allows you to easily work with the popular
A4 format(sheet width — 210 mm). But
for sheet A3, with a width of 297 mm, you will need at least 310 mm gap size.
Shredding speed
The speed that processed unit moves through the shredding mechanism during utilization. Accordingly, the higher this indicator, the higher the productivity of the shredder and the more units it is able to shred in a certain time. Knowing the volume of the documents to be shredded, you can easily determine the time required for batch utilization: for example, with a speed of 45 mm/s, one load of standard A4 sheets (length 297 mm) will require 297/45=6.6 s.
However, it should be taken into account that this parameter is usually indicated for paper of a certain density — 80 g/m² (standard office paper) or even 70 g/m², depending on the manufacturer. When working with thicker paper, as well as other materials (see "Shredding Items"), the shredding rate may be significantly lower than stated.
Sheets per load
The number of sheets that the shredder is capable of processing at one time — in other words, the largest size of a stack of sheets that can be loaded into the device. Most modern shredders can handle multiple sheets;
up to 5 pcs at a time is considered a very limited indicator,
up to 10 pcs — a small one,
11 – 15 pcs can be called an average value,
16 – 20 pcs — quite good, and in the most powerful models this figure
exceeds 20 pcs.
Note that this parameter is given for paper of a certain grammage (and, accordingly, thickness). At the same time, the East European standard for office paper is a grammage of 80 g/m², and in many European countries thinner paper is used with a grammage of 70 g/m², and it is for it that the capacity of many shredders is indicated. Therefore, if this moment is not specified in the specs, it is best to load the shredder not up to limit values, making a margin of 1 sheet per 8 sheets of capacity — 1 sheet with a stack thickness of up to 8 sheets, 2 sheets with a stack thickness of 8 to 16 sheets, etc. However, other conditions for density may be specified in the user manual.
Also note that the number of sheets per load is determined by manufacturers based on the results of tests under perfect conditions — in the absence of staples on paper, with low humidity,
...optimal voltage in the mains, perfect sharpening of knives, etc. In fact, any deviation from these indicators affect some decrease in efficiency.Duty cycle
The duty cycle of the shredder is the maximum time that it can work without interruption.
Limit of operating time is due to the fact that the destruction of documents and other media is associated with quite significant loads on the electric motor and gear. This leads to strong heating, while the breaks allow the hardware of the shredder to cool down. Actually, there are models with the possibility of continuous operation, but they are expensive and not always really necessary; see "Features" for details.
In small shredders for domestic use, the work cycle is often only a few minutes, and among powerful professional devices there are values of
half an hour or more. Also note that in some models, shutdown after a full cycle is provided automatically due to overheating protection (see "Features"), however, the presence of such a system does not mean the presence of an automatic shutdown on time — it can only work with a critical increase of temperature.
Break time
The minimum break time required by the shredder after a full cycle of work (see above).
A break is required so that the motor and mechanisms of the device can cool down after the intense loads that they are subjected to during operation. Moreover, if the operating time was less than a full cycle, then the break can also be made shorter; however, if the device has worked for more than half of the cycle, for a full assurance it is still worth to take a break for all the time intended for it. Some models may provide other recommendations in this regard — they should be specified in user's manual.
Sheet autofeed
The number of sheets of paper that can be loaded into
the shredder's auto feed system at one time. Auto-feed greatly simplifies work with large volumes of documents: instead of loading them manually in portions and making sure that each portion size does not exceed the recommended value (for more details, see "Sheets per load"), it is enough to place the entire stack into the automatic feeder tray and the shredder will independently process the entire stack in the optimal mode.
Note that the number of sheets is often indicated for paper, which specs differ from those accepted in East European office work; see "Sheets per load" for details.
