Definitions

Clause 3 gives a name and description for each of the plastic strapping machines considered in the Standard and illustrates their method of operation with isometric drawings.

Clause 3 also defines the typical terminology used when discussing these plastic strapping machines like compression strapping, strap accumulator and strap arch.

Injuries caused by group packaging machines

Clause 4 of the Standard identifies the injuries that can be caused by each type of plastic strapping machine. The injuries most often caused by strapping machines are:

• crushing by the strapping while it is being tensioned
• crushing by compression or pushing mechanisms
• crushing by raise and lower mechanisms
• drawing-in by conveyors
• cutting when handling the plastic strap
• burning by heat sealing mechanisms
• shearing caused by loads moving past fixed assemblies, e.g. strap arch

Safety principles established by this Standard

Plastic Strapping tension

Clause 5.2.11.8 establishes the principle that if the strapping tension is less than 450 N there is no risk of crushing if the plastic strap is tensioned over the operator’s hands or other body parts. If the strap tension is between 450 N and 750 N the Standard requires the use of two independent product detecting devices so that the operator cannot accidentally initiate a strapping operation or the use of two hand controls.

Where the plastic strap tension is over 750N fixed or interlocking guards or safety protection devices are required to ensure that he operator cannot reach the strap arch during the strapping cycle.

Plastic Strap dispenser and feeding mechanisms

Clause 5.2.11.1 and 5.2.11.2 establish the principle that strap dispensing and feeding mechanisms can be made safe by design and provide suggestions for how this can be achieved.

Plastic Strap gripping, retraction, tensioning and cutting mechanisms

Clauses 5.2.11.3 to 5.2.11.6 indicate that these mechanisms will typically be protected using fixed or interlocking guards.

Plastic Strap sealing mechanisms

Clause 5.2.11.7 explains how the different types of sealing mechanism can be safeguarded. Special requirements apply for machines handling plastic strap where there may be a risk of burning from either heating devices or the hot strap and where polyester strapping is used the risk of generating fumes which are hazardous to health.

Compression mechanisms

The requirements for compression mechanisms depend on the type of strapping machine. Clause 5.4.5 indicates how compression devices can be made safe by design on semi-automatic plastic strapping machines and Clause 5.5.6 indicates safety by design requirements for compression forces under 250 N and guards and safety protection devices where the force is greater than 250 N.

Infeed and discharge apertures on plastic strapping machines

The infeed and discharge apertures on guarded plastic strapping machines can be big enough for a person to crawl through and in the case of pallet strapping machines walk through.

Clause 5.2.2.1.4.2 describes measures for safeguarding medium sized apertures and Annex C describes several methods of safeguarding large apertures.

Effects of the Standard

Plastic Strapping Machines are now being manufactured in a large number of countries and the market for these machines is now very competitive. At present it is evident that some plastic strapping machines are less safe than others and so it is to be hoped that this Standard will encourage all manufacturers to make machines with equivalent standards of safety.

Purchasing the Standard

EN 415-8 can be purchased as BS EN 415-8: 2008 + A1: 2009 from BSI Standards.