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Machinery Regulations


With new machinery manufactured after 1996 these machines must conform to the ^CE^ regulations and carry a ^CE^ mark.

With second user machinery manufactured before 1996 there is a legal requirement for the machines to conform to the PUWER 98 regulations.

It is the responsibility of the Purchaser of the equipment to make sure that equipment complies to regulation.

We have technicians who have been trained to carry out PUWER 98 assessments aided by computer software. We can offer a full risk assessment on the machinery and carry out the work required to ensure the machines conform.


1. P.U.W.E.R 98 came into force on 5th December 1998 and is designed to clarify the safe use of work equipment; a) NEW b) EXISTING c) SECOND-HAND d) LEASED

2. P.U.W.E.R 98 covers any equipment, machinery, appliance, apparatus, tool or installation for use at work.

3. P.U.W.E.R 98 regulation applies to work activities throughout the whole of Great Britain.

4. You as the employer, self-employed or employed, to supervise the use of equipment are responsible to make sure your equipment complies to P.U.W.E.R 98.

5. It is the responsibility of the Purchaser of the equipment to make sure that equipment complies to regulation.

6. The regulation does not apply to those who have supplied or sold equipment.


Control of electromagnetic field at work


What is High Frequency?

Basically high frequency welding of PVC materials was discovered during the second world war. Apparently a new waterproof material was being used to protect the soldiers from the elements, called PVC, (Poly Vinyl Chloride). Some of the new material was placed near or onto the transmitting aerial of a tank. When the soldier went to pick up the material he found that it had somehow become joined together. This was the first weld made by this method.

It became apparent that the welding system could be used in many areas, the first recorded industrial use was for producing PVC raincoats. There are now literally thousands of products welded by High Frequency some are listed below:

Medical Industry
Blood bags
Colostomy bags
Urine & Drainage
EVA film bags
DVT bags
Welding tubes
Solution bags
Hospital patient care beds

Automotive Industry
Car carpets
Sun visors
Seats doors and tops
Cabriolet tops
Curtains and loading floors

Stationery Industry
Mouse mats

Baby care Industry
Push chairs and baby carriages

Packaging Industry
Blister pack clam shells
Soft crease boxes
Vertical form fill and seal bags

Materials used in High Frequency welding

There are many other materials which can be welded by High Frequency but generally they will have a laminate of some type of polymer to allow the High Frequency to work. The main materials used in packaging are:


How does High Frequency work?

The way that High Frequency works is with the electrical passage of electrons through a material such as PVC. The passage creates heat and therefore allows the material to become joined together.

The frequency of the machinery generators which is allowed in the EEC is 27.12 MHz. This is quite important due to the harmonics of this base frequency. A harmonic is a frequency band which is in tune with the base harmonic of 27.12 MHz. In layman^s terms, if you drop a pebble into a lake the first splash can be described as the first harmonic. The resultant ripples which emanate from this splash are called harmonics. With respect of the 27.12 MHz the harmonics are as follows:

Base frequency: 27.12 MHz
Ist Harmonic: 54.24 MHz
2nd Harmonic: 81.36 MHz
3rd Harmonic: 108.48 MHz, etc.

If the base frequency is outside the 27.12 MHz then the harmonics can interfere with other frequencies, such as:

Police band transmissions
Airports transmissions
Hospital transmissions, etc.

The differences between High Frequency and Heat welding are:

1) the tooling on High Frequency apposed to Heat welding is cooler and acts as a cooling system when the High Frequency energy has been switched off. The heat welding relies on constant high temperature at the tool.

2) There is also a difference in where the heat is generated in the product. In High Frequency the heat is generated at the centre of the product in heat welding the heat is generated at the surface, where the heated tool touches the material.

Why use High Frequency in packaging lines for food:

Normally heat welding has been used as the main technique of joining or welding base materials to top films. It has become more apparent over the last few years that the costs of these specialized films are becoming more and more expensive and also difficult to recycle. Therefore many companies are looking for a solution to this.

I hope that this brief explanation assist with the understanding of how High Frequency welding works.