Are there different types of polypropylene?

Yes!...homo-polymer and co-polymer. Most companies use homo-polymer as it is suitable for 90% of all strapping applications and nearly all the worlds strapping equipment manufacturers design for this type of strap.

Will co-polymer straps work in machines designed for use with homo-polymer strap?

No! ...and manufacturing sources for the co-polymer straps are limited when compared with the more popular homo-polymer.

Are there different grades of polyproylene strap?

Yes!.. strap is normally specified as suitable for hand tools, semi automatic and automatic machines.

Does the colour of the strap signify a particular grade?

No!...all grades of strap can be made in a wide variety of colours, although hand tool grades wound onto plastic reels are often black.

What is the difference between the various grades of strap?

Machine grade straps are normally manufactured from virgin polymers to close tolerance to minimise edge bow and bundle curve, necessary to ensure reliable strap feed in automatic machines. These considerations do not apply to handtool grades and manufacturing tolerances can be much greater and the straps often incorporate a percentage of re-grind material.

Will handtool grade straps work in automatic machines?

Yes...but not reliably and any apparent cost saving on purchase price can easily be lost thru mis-feeds, loss of production and wastage.

Should I buy or hire handtools?

Much will depend on the type of tool, the application and environment, and degree of care exercised by your operatives. If your operatives take reasonable care of equipment then it is nearly always more cost effective to buy outright, as rented tools and the maintenance thereof are nearly always linked and restrict you to purchasing strapping material from the company that supplied the tool, therefore you may be unable to benefit from lower strap prices obtainable elsewhere. If the environment is harsh however, and tools subject to rough treatment then it may be prudent to accept the tools on a hire/free maintenance arrangement

Will strap from a different supplier work in my machine?

Almost certainly...although your machine supplier may try to convince you otherwise. With the exception of those machines that use co-polymer strap, all other machines are manufactured and sold throughout the world, and must therefore be able to use locally produced strapping material. The most popular carton strapping machines are manufactured in Taiwan and Japan, and are often re-badged for sale under various brand names.

What about machine maintenance?

It is important that this aspect of machine purchase is agreed...in writing prior to placing a purchase order. Failure to do this often results in a machine supplier doubling the cost of spares, or travelling and hourly rates, or extending response times should the user buy strap from other sources.

What is the difference between a reel and a coil?

Reels have plastic moulded sides, sometimes spoked, and are generally used to for hand tool grade straps. Cores are cardboard tubes onto which all machine grades and a few handtool grade traps are wound. Popular core sizes are 200mmID x 150mm width, 200mmm ID x 190 mm width, 280mm ID x 190mm width, and 406mm ID x 150mm width.

What is the difference between polyester and polypropylene?

Polyester is much better at retaining any applied tension over long periods and is less susceptible to tension relaxation caused by increases in ambient temperatures. Polyester also offers higher recovery characteristics and stays tighter than polypropylene on packs that shrink or become compressed. UV resistance is also improved hence its popularity on product stored outside.

How do I identify polyester strap from other plastic straps?

Polyester strap is normally embossed, has a very shiny surface and is sometimes translucent. Unlike polypropylene it does not split longitudinally and weighs approx twice as much as a polypropylene coil of the same meterage.

How is polyester strap presented?

On the same reel and core types/sizes used for polypropylene.

Can the same handtools that use polypropylene be used for polyester?

Sometimes!...if the tools use a serrated or grit faced seal. Polyester is a harder material than polypropylene and if ordinary smooth faced seals are used joint strength could be reduced to the point where the system strengths become unsafe. Friction weld tools can be adjusted to use either material safely.

Do friction weld tools save time?

Sometimes!..they are obviously quicker than a two piece tooling system using separate metal seals but if the tool is being used to strap boxes rather than pallets then a semi automatic strapping machine would be faster, more reliable and far less costly to maintain.

If the application is pallet strapping at floor level then friction weld tools offer negligible savings in time. The operator would still have to pull strap from a coilholder, haul it over the top of a pallet, down the side, thread it through pallet voids and feed it into the tool at which point not a second has been saved. The same time consuming operation has to be repeated every time a strap is put on.The only area remaining for savings to be achieved is the difference in time to operate a friction weld tool and say a magazine tool...a matter of 3-4 seconds. If automatic pallet strappers are not a viable proposition then Strap Pokas are strongly recommended...they are low cost and reduce strapping times by half. (CLICK HERE)

Is there much difference in performance between the various makes of semi automatic machine?

The key manufacturers in the semi auto-machine market are those based in Taiwan and Japan. German and Swiss machines are also available and although these tend to be more expensive, they are superbly engineered and backed by excellent after sales service. Japanese machines are also excellent value and are used for high throughput situations where reliability is essential....After sales service is the key difference..

Are friction weld tools reliable?

Their more complex design compared with mechanical tools, means they are more prone to breakdown and maintenance costs per annum can amount to about the same as the purchase price - (£800 - £1600)

What is a friction weld joint?

The tool grips the straps by means of serrated plates and vibrates them causing sufficient heat to be generated enabling the two strap surfaces to be fused together.

What is a heat seal joint?

A heat seal joint is made by a flat , heated blade passing between two straps after they have been tensioned, partially melting the surfaces of the strap which are then pressed together by means of a pressure pad. In general, heat seal mechanisms are more reliable than friction weld mechanisms and require less maintenance.

Is strap thickness a reliable indicator to strap strength?

No!...some straps are extruded with a thin base thickness and then heavily embossed to make them appear to be a heavy duty strap.....conversely others are extruded with a thick base thickness and lightly embossed. The strength of a strap is to a great extent linked to the weight of polymer/metre used to produce the strap

What type of seal should be used with polypropylene straps?

Choice of seal is largely determined by the type of tool being used and/or the application. As a general guide semi open standard smooth faced seals should only be used on very light packages as their ability to stop straps slipping through under load are limited. Heavy duty smooth faced seals (32mm long x 0.6mm) are recommended for most applications. Some tools use serrated seals and these are suitable for most applications although caution should be exercised as inferior copies are appearing on the UK market..

What seals should be with polyester strap?

Serrated seals type K12 or K16 which can be used either with the Slik CP Combination tool or the new Series 5000 combination strapping tool.

Does colour affect the rate of UV degradation of polypropylene strap.

Yes! For products stored outside and secured with polypropylene strap advice should be taken from specialist strapping suppliers as certain colours can loose all load bearing capability in as little as three months.

Does exposure to normal levels of UV affect polyester strapping?

To all intents and purposes..no. Polyester is the preferred and safest strapping material for all products stored outside.

What are the benefits of printed strap?

Companies use printed strap as a low cost means of promoting their product.....it costs less than printed cartons.....is used in the same way as tamper evident labels......enables carriers easily identify all elements of a consignment.

Why do some straps have to be 'antistatic'

For use in explosive and other hazardous areas

Pitfalls to be avoided when purchasing strapping machines!