According to Techspan Group , vehicle manufacturers have increasingly turned to plastics to solve design problems, and now there are over 300 kilograms of plastics on the average modern car.
Apart from improving appearance, a reduction in vehicle weight, leading to better fuel economy and increased performance, is just one of the many advantages which plastics can offer.
As for corrosion the risk to most modern vehicles is substantially reduced, since all external panels are manufactured from plastics. As for damage, the majority of plastics used in the production of modern cars today can be repaired. For the insurer, plastic repairs, rather than replacement, mean a substantial saving in costs.
For the repairer, there are many advantages: -
- Increased workflow
- Better customer service
Components on order can take some time to arrive, whereas a repair can increase workflow and get the car back to the customer that much faster.
Repairing means, most of the profits in the job go to the repairer, rather than the vehicle manufacturer.
More work opportunities
A repairer with the necessary equipment and skills has the opportunity to offer the service to other repairers.
There are a few basic rules when welding plastics. These techniques apply to both Plastics Fabrication and Repair. Techspan Group offer training courses from their head office in New Lynn Auckland.
As all plastics vary in their characteristics, so to does the temperature at which welding takes place. Each different material has a different welding temperature. This is the point where the plastic is bought to a molten state. Too cold, and the material will not flow together adequately. Too hot, and the material can degrade. So, temperature control during welding is vital.
Compatible welding rod:
Only ‘like’ materials can be welded. For example, Polypropylene (most car bumpers) can only be welded with a Polypropylene welding rod. So it is very important to identify the material to be welded.
Most plastics used in the manufacture of modern cars are stamped with plastics identification codes. However, where this identification is not present, a welding rod test kit from Techspan Group (RTK) is available to assist.
As with all forms of welding, surface preparation will ensure successful welds. Cleaning of the welding area when welding plastics is generally one of scraping away any residues left from manufacture and atmospheric soils. Emery paper or even a clean wire brush will do the trick. As long as there is no grease, dirt or silicone residues left behind, it is on to the next step.
A 90 degree "V" shaped groove must be prepared along the mating faces if users want to effect a butt weld of two plastic components. The "V" groove can be formed with careful use of the rotary burring bit, which is usually supplied together with the welding tool.
Prior to the main welding, a tacking nozzle is fitted to the welding tool and once up to temperature, the tacking nozzle is run along the entire length of area to be welded. This provides a light swaging of the two materials and this is now ready for the main welding rod.
Once the required temperature setting is obtained, a speed welding nozzle is fitted to the welding tool and the correct welding rod is fed into the speed welding nozzle with the operator applying approx. 2.5 kg of pressure, sufficient to push the now softening welding rod into the "V" groove. The correct mating between the welding rod and the parent material occurs when the rod is seen to soften, and new rod moves down the speed welding nozzle. The weld should be completed in one continuous run along the length of area to be welded.
Some applications may require the weld to be dressed. Dressing should only be carried out once the plastic has cooled completely. Plastic is a soft material that will yield easily to abrasives. For this reason, users should use an 80 grit disc first and then progress to a 180 grit disc and then a 240 grit disc, to produce a smooth finish. Further finishing may be necessary depending on the required results.
Plastics welding equipment:
Techspan Group – plastic welding tools and equipment are designed and manufactured for tough workload and environmental conditions, the Techspan plastic welders manufactured in Switzerland include a number of innovative design features.
Techspan welders are double insulated, and carry numerous test, safety and quality marks. High temperature ceramic element technology, and silicone encapsulated electronics ensures trouble free plastic welding. Primarily used for repair and fabrication welding of virtually all thermoplastics materials, Techspan plastic welders are being used in a varied range of applications - including
- rigid plastic sheet fabrication
- automotive plastic repairs
- welding vinyl and linoleum flooring
- welding plastic liners for dams and landfill sites
- welding liners for tunnels
- welding PVC cleats on conveyor belts
- welding PVC gutters and downpipes
- welding large plastic water tanks
- welding liners for the plating industry
- welding ventilation ducts
Techspan Group offer a range of welders including models in fully self contained kit form. These kits include the welding tool itself and all the necessary equipment to be fully set up and ready for plastics welding.