| Working with Recycled Plastic WoodSTORAGE It is important to ensure that Kedel's blown polystyrene synthetic wood is stored inside, and not exposed to direct sunlight or excessive temperatures (e.g. close to boilers etc). If the product has been stored in a warehouse, we recommend it be moved to the working area at least 24 hours before commencing cutting operations. GENERAL Kedel's blown polystyrene synthetic wood has many similar properties to various natural timbers when tested in the 'as made' condition. This means that many methods used for fabricating with wood can also be employed with our synthetic wood, making it an extremely versatile material. Modifications to the cutting tools/blades may be necessary to ensure optimum cut/joint. Fixing used longitudinally to any profile will be weaker than those in a transverse direction. We recommend that all fixings are made from stainless steel/brass or are plated, to retain the integrity, long life, rot free, maintenance free, quality of the final product. GENERAL MACHINING It is important that all drills, tools and cutters used on Kedel plastic wood are kept very sharp. Blunt tools will accelerate generation of heat, which in turn will lead to softening, and even melting of our synthetic wood. Cutting tools must be selected which ensure swarf is removed immediately. Any build up of swarf will increase heat generation and cause melting around the tool. SAWING Circular blades with tungsten carbide tipped blades with a tooth pitch used for soft woods (i.e. 1-3 open type teeth per inch cross cut with positive cant), have been found to be most suitable for use with synthetic wood. We suggest a saw speed between 2,000 and 4,000 rpm. The blade should cut through the profile as quickly as possible to avoid heat generation, and also to maintain a quality cut. Sawing is best done from the presentation face (the side that will be seen) and cut through to the back face of the profile. Cutting from the back face to the presentation face can sometimes cause chipping which is difficult to dress out. Saw blades should be sprayed with silicone lubricant (eg: WD40) or lubricating grease to reduce friction and help avoid any chipping. DRILLING Twist drills are best for Kedel’s Polystyrene Synthetic Wood but speeds and feeds must be controlled to avoid melt of the swarf and clogging problems. Cordless drills with speeds of 400 - 900 rpm are better than high-speed drills. Titanium nitride coated bits minimise any problems (e.g. those supplied by Dormer etc.). Holes are best placed not less than 10mm from the profile edge. PLANING Whilst Kedel’s blown polystyrene synthetic wood can be planed, often with excellent cosmetic effect, the practise is not usually recommended as it will reduce the strength of the profile due to loss of the outer skin. Asymmetrical removal of the outer skin is also likely to cause bow and twist in the section. ROUTING Small longitudinal rebates may be routed but it is not recommended that the base of such slots incorporate radii corners. To rout the groves, standard sharp tungsten carbide tipped blades running at up to 22,000 rpm should be used. Spray silicone on blades and router bed. For routing depths in excess of 20mm, it is recommended that an air blast be used to clean the bit. For cross cutting, again standard tungsten carbide tipped saw blades should be used. JOINTING AND FIXING The type of jointing method to be used with this synthetic wood will depend on the application of the product and duty or stress likely on the joint. A joint may often incorporate more than one method of fixing. Finger type and mortice and tenon type joints can be made using standard wood working machinery with the appropriate cutters and then glued. SCREWING Twin flight, parallel thread, coarse pitch screws, similar to those used with wooden particle boards or hi-low screws, have been found to be more reliable than conventional taper thread wood screws. The greatest strength is achieved when screws are inserted at right angles to the extrusion axis. Care must be taken to avoid stripping threads when driving screws in the direction of extrusion. This risk can be overcome by using torque limiting power drills and screwdrivers. NAILING / PINNING / STAPLING Nailing is not generally recommended for joining two or more pieces of Kedel’s Polystyrene Synthetic Wood. If this type of fixing is required, e.g. to hold materials in place while glue sets, then panel pins are better. Drilling pilot holes may be necessary to avoid splitting, depending on the thickness and density of the material. Stapling has been found to be an effective method of joining thinner sections of our low density synthetic wood. We recommend neumatically powered guns for use on these types of fixings. SOLVENT FUSION / GLUING Polystyrene cement manufactured by Stelmax Limited is very effecive for 'cold solvent fusion' synthetic wood. The use of double sided tape is also possible, depending on the bonding surfaces involved and the grade of tape. Details for specific applications and recommendations are available on request. HEAT FUSION WELDING Kedel’s blown polystyrene synthetic wood can be 'hot welded' (hot plate welding) using specialist machines designed for hot welding profiles. Such machines incorporate thermostatically controlled PTFE coated heating plates, which are used to heat the surfaces being joined. When the required temperature has been reached (180 - 220 c), the two surfaces are brought together and held under pressure while they fuse together. Some experimentation will be necessary to assess inevitable length loss arising from melt back. SURFACE FINISHING In the event of any rough edges, use triple '0' steel wool and a soft wax such as beeswax. This type of final finishing serves three purposes:
CLEANING This must be done using a dilute detergent solution. Solvents must not be used. All the information provided here is for guideline use only. For further in-depth technical advice, please contact our research & development team. Tel: 01282 861325
| |||||||||||||||||||||||||||||||||||
.jpg)
