There are four common films used for the purpose of covering books.
Each has very different properties and it’s important to know the basic differences as they provide different levels of protection particularly over time. The four types of book covering are:
- Polypropylene (otherwise abbreviated as PP)
- Polyethylene (otherwise abbreviated as PE)
- Polyvinyl Chloride (otherwise abbreviated as PVC)
- Polyester (otherwise abbreviated as PET)
If we grade the four types of book protection film on a rating system from 1 to 10 (1=very poor and 10=excellent) for the above features it would read as follows:
Key comparisons explained
Polyester is expensive due to its base resin cost and high cost of manufacture. However, it is a very stable, strong and durable product. Bookguard 250 is made from Polyester and whilst it is more expensive it offers the ultimate in protection.
Polyethylene is both cheap and low in durability. It is not satisfactory as a library grade book covering as it is soft and wears easily. This type of film is used commonly for bread bags and
is not used by Raeco® nor recommended for library use.
3. Scratch resistance
As Polyester is extremely tough it demonstrates superior surface scratch resistance over all other films. This is useful when displaying hard covered books in Public Areas of the library.
Polyvinyl Chloride (PVC) contains plasticisers, which is the substance that makes the PVC soft so that it can be used as a book covering. Without it, the film would be a hard polymer (e.g. PVC drainpipes used in building construction). These plasticisers migrate to the surface over time causing:
- Stickiness (books may stick together on shelves, particularly in warm climates)
- Yellowing (affected by sunlight UV rays)*
* Note: Raeco’s PVC products are UV stabilised so they’re not affected by sunlight
5. Environmental impact
Both the manufacture and disposal of PVC is harmful to our environment. It gives off chlorine gas and hydrochloric vapours. As a result, it is wise to limit its use. Raeco® offers two environmentally acceptable films; both are inert and long lasting. They include Polyester (Mylar, Bookguard 250) and Polypropylene (Duraseal®, Bookguard, PROtec, Lyfguards, Pro-clear and Singlefold II). Both of these are stable products, are economically viable for even low cost paperbacks and possess all the qualities required for superior book covering.