R3 Effects of combining materials.
Initial skills rating *
September 2011
Promolite is sandwich of two outer layers of aluminium whose outer surfaces have been coated with plastic and an inner core of polypropylene. The thin plastic coating accepts the dyes of dye sublimation printing providing a stable image. The aluminium provides strength which is compromised by scoring through the aluminium to the inner core. If both sides are cut you are left with a flexible hinge whereas one side scored allows for a sharp bend.
You could say the quality of one material backs up a weakness to another.
Next I will look up a concise definition and start looking for more examples of combined materials.
Promolite is sandwich of two outer layers of aluminium whose outer surfaces have been coated with plastic and an inner core of polypropylene. The thin plastic coating accepts the dyes of dye sublimation printing providing a stable image. The aluminium provides strength which is compromised by scoring through the aluminium to the inner core. If both sides are cut you are left with a flexible hinge whereas one side scored allows for a sharp bend.
You could say the quality of one material backs up a weakness to another.
Next I will look up a concise definition and start looking for more examples of combined materials.
27th October 2011
Powder Coating for metals
I have been researching the use of plastic coatings as part of our plastics presentation but we have sop much information on industrial techniques we have decided not to use everything. Instead I am going to make a post here so that I will have the information to refer back to.
Basically plastic coatings are used to protect metals. This may be to protect them form the environment as in park benches where the rain would otherwise cause corrosion or for purposes such as scratch resistance.By using a protective coating which improves corrosion resistance much cheaper metals can be used. For example stainless steel has excellent corrosive properties compared to mild steel but by applying a plastic coating mild steel can be used as a cheaper alternative.
Benefits of Powder Coatings
Epoxy - Excellent corrosion resistance, toughness, adhesion and hardness. Poor weather ability. It can be formulated to be FDA compliant for food contact applications. Decorative or functional coatings are available.
Epoxy/Polyester Hybrid - Less susceptible to yellowing when cured. It exhibits similar properties to standard epoxy coatings. Poor weather ability makes this unsuitable for outdoor use.
Polyester/Urethane - Smooth, thin film with excellent mar and chip resistance and good weather ability. These coatings are generally resistant to diluted acids, hydrocarbons and grease and oil.
Polyester/TGIC - Excellent weather ability with excellent mar, chip and corrosion resistance. It has excellent edge coverage.
Thermoplastic Powder Coatings - Vinyl’s and PVC powder coatings have a soft feel with good resistance to detergents. Good weather ability allows these coatings to be used in outdoor applications.
PCSI’s Capabilities
Basically plastic coatings are used to protect metals. This may be to protect them form the environment as in park benches where the rain would otherwise cause corrosion or for purposes such as scratch resistance.By using a protective coating which improves corrosion resistance much cheaper metals can be used. For example stainless steel has excellent corrosive properties compared to mild steel but by applying a plastic coating mild steel can be used as a cheaper alternative.
Benefits of Powder Coatings
- Tough, durable, lasting coating for metals. Excellent hardness and abrasion / impact resistance gives improved product performance over most liquid coatings.
- Wide range of colours.
- Environmentally friendly outsourcing option to avoid permitting for solvent-based paints.
- Less process variation results in consistent colour and appearance of the product.
- High film builds and excellent edge coverage gives better resistance to corrosion with proper pre-treatment.
- Coatings can be easily formulated for specific applications such as prolonged exposure to sunlight, the ability to survive in highly corrosive environments, flexibility to allow forming after coating, or high durability and resistance to chipping.
Epoxy - Excellent corrosion resistance, toughness, adhesion and hardness. Poor weather ability. It can be formulated to be FDA compliant for food contact applications. Decorative or functional coatings are available.
Epoxy/Polyester Hybrid - Less susceptible to yellowing when cured. It exhibits similar properties to standard epoxy coatings. Poor weather ability makes this unsuitable for outdoor use.
Polyester/Urethane - Smooth, thin film with excellent mar and chip resistance and good weather ability. These coatings are generally resistant to diluted acids, hydrocarbons and grease and oil.
Polyester/TGIC - Excellent weather ability with excellent mar, chip and corrosion resistance. It has excellent edge coverage.
Thermoplastic Powder Coatings - Vinyl’s and PVC powder coatings have a soft feel with good resistance to detergents. Good weather ability allows these coatings to be used in outdoor applications.
PCSI’s Capabilities
- Two automated powder coating lines
- Decorative and functional coatings
- Anti-graffiti / anti-microbial coatings
- High temperature coatings
- Manual and automatic coating systems
- Long or short runs in any colour
- Coatings available in standard or metallic, high gloss to low gloss, smooth, textured or wrinkled
- 6-stage iron-phosphate in-line spray and pre-treatment systems with deionized water rinse
- 7-stage iron-phosphate in-line immersion pre-treatment system with laser scale removal capabilities
21st November 2011 **
Ah, I have learned some more things since I visited this section.
· Fibres can be added to thermoplastics when used in compression moulding. This adds strength to the moulding.
· Plastic coatings are applied to metals during dip coating. This is used for tool handles, coat hangers etc
· Plastic coatings are also applied to metal during powder coating. Applying plastic coatings to metal provides water resistance improving the life of the product. Commonly used on car parts, outdoor benches and wheelchairs.
Just a few examples but a little bit more knowledge. I feel more confidence that materials are combined to provide beneficial qualities.
12th February 2012 ***
Ah, I have learned some more things since I visited this section.
· Fibres can be added to thermoplastics when used in compression moulding. This adds strength to the moulding.
· Plastic coatings are applied to metals during dip coating. This is used for tool handles, coat hangers etc
· Plastic coatings are also applied to metal during powder coating. Applying plastic coatings to metal provides water resistance improving the life of the product. Commonly used on car parts, outdoor benches and wheelchairs.
Just a few examples but a little bit more knowledge. I feel more confidence that materials are combined to provide beneficial qualities.
12th February 2012 ***
Artificial joints
I spotted more combined material whist visiting the science museum. The titanium implants used to make artificial joints were extremely strong but were not resilient to wear. To compensate for this the joints were given a ceramic coating. Ceramics are hard wearing and have excellent compressive properties.
I am beginning to realise combined materials are all around us.
I am beginning to realise combined materials are all around us.
Combining materials and the selection process
I suppose many man-made items actually combine materials. If I consider the design projects that I have made on this course I too have gone through a selection process that led me to choose the materials that I made them from. I have tried to capture my thought and questions that I went through with my first design and make project in the form of a mind map.
My initial designs were free flowing, uninhibited by practicalities. In fact looking back some were quite nice but I rejected them because I imagined with the limitations on manufacturing processes available to me and standard stock material sizes, they were unachievable or at least they were likely to be of a poor quality.
So after some initial ideas I started to consider the main body of my bedside cabinet first as this is the largest part of my project. I broadly considered wood, plastic and metal. I posed questions:
Aesthetics - What would it look like? Would it suit the surroundings it was intended for? Would I like it?
Cost - Could I afford it?
Availability - How easy would it be to get the materials?
Ease to work with - Did I have the capability? This may seem a strange question but when I was considering using recycled wood I learnt that I would not be able to use the machines at uni. Recycled wood may carry little pieces of metal nails buried below the surface that would damage cutting tools. This was acceptable for hand tools and small power tools where the cost of replacing cutters and blades was relatively cheap but with a circular saw blade in excess of £70 the cost of damage was too high. So if I wanted to use recycled wood I would have to make everything using hand tools. Although I wanted to use hand tools as much as possible working with recycled wood, with its warped surfaces was not really the place for a beginner. I felt I needed to master the hand tools, jointing methods, working with wood and getting everything square with a material that was going to give me the least amount of difficulty.
Weight - How much would the finished product weigh? Would I be able to lift it? Would I be able to transport it easily?
Strength - Would the material be strong enough? How thick would it need to be?
Colour - Did the material come in a colour or colours that I liked? Would they fit with the surroundings? Would they create the mood I wanted to achieve?
Water resilience - Would my glass of water cause a problem due to condensation or spillage?
Joining capabilities - What joining methods could I use? How strong would they be?
Conductivity - Would the material conduct electricity? Would this be a problem?
So having considered all these questions for wood, metal and plastic I choose the material that came back with the best answers to the above questions. In my case I selected wood. But them I needed to chose what type of wood: recycled, new, man-made, hardwood or softwood. Eventually I settled on pine ( or a generic pine like wood sold at the timber yard) I chose it because it fitted the above criteria and was cheap for a beginner to work with.
Next I needed to consider the lighting. Again asking myself questions about safety, availability, cost, size and aesthetics. I decided I not only wanted bright light but I also wanted some gentle lighting too. Because wood is opaque I chose to cut little fish shapes out of the lid and replace it using a transparent material. in this case I chose glass because of its colour and the challenge of the making process. Acrylic may have worked well too but it would not be as scratch resistant as glass and I prefer the colours available in glass.
Finally I considered the materials of all the smaller components. Hinges, screws, sliders for the shelf ,handles. and hanging hooks. I sacrificed the strength of the handle and hooks over appearance because they were not going to be put under any great loading. Even the biscuits used for joining are made of ply that will expand when made wet by the PVA. Which together, when dry, make a strong joint. So many choices and so many considerations but eventually by combining several materials I have a functioning , bespoke bedside cabinet.
I am wondering if talking about the design process really belongs in this part of my audit. I seem to be talking more about the material selection process so why does this post belong here? The only justification I can find is that say I had chosen wood for my cabinet and I did. But it was not practical to make the entire project out of wood alone. For a start I could not have hinged the lid with wood. Well actually I probably could but it would have needed to be a lot thicker. So by using a metal hinge I reduced the thickness of timber required and reduced the production time and cost. I could have made handles from wood but again they would have been larger so again using metal was both aesthetically pleasing and made for a smaller component which fitted the design criteria of minimal space. Now I could not have had light coming through the wood and still have a sealed surface so that one had to have a combined material. Now I feel confident my post belongs here.
Final skills rating ***** I feel very happy and confident about that.
So after some initial ideas I started to consider the main body of my bedside cabinet first as this is the largest part of my project. I broadly considered wood, plastic and metal. I posed questions:
Aesthetics - What would it look like? Would it suit the surroundings it was intended for? Would I like it?
Cost - Could I afford it?
Availability - How easy would it be to get the materials?
Ease to work with - Did I have the capability? This may seem a strange question but when I was considering using recycled wood I learnt that I would not be able to use the machines at uni. Recycled wood may carry little pieces of metal nails buried below the surface that would damage cutting tools. This was acceptable for hand tools and small power tools where the cost of replacing cutters and blades was relatively cheap but with a circular saw blade in excess of £70 the cost of damage was too high. So if I wanted to use recycled wood I would have to make everything using hand tools. Although I wanted to use hand tools as much as possible working with recycled wood, with its warped surfaces was not really the place for a beginner. I felt I needed to master the hand tools, jointing methods, working with wood and getting everything square with a material that was going to give me the least amount of difficulty.
Weight - How much would the finished product weigh? Would I be able to lift it? Would I be able to transport it easily?
Strength - Would the material be strong enough? How thick would it need to be?
Colour - Did the material come in a colour or colours that I liked? Would they fit with the surroundings? Would they create the mood I wanted to achieve?
Water resilience - Would my glass of water cause a problem due to condensation or spillage?
Joining capabilities - What joining methods could I use? How strong would they be?
Conductivity - Would the material conduct electricity? Would this be a problem?
So having considered all these questions for wood, metal and plastic I choose the material that came back with the best answers to the above questions. In my case I selected wood. But them I needed to chose what type of wood: recycled, new, man-made, hardwood or softwood. Eventually I settled on pine ( or a generic pine like wood sold at the timber yard) I chose it because it fitted the above criteria and was cheap for a beginner to work with.
Next I needed to consider the lighting. Again asking myself questions about safety, availability, cost, size and aesthetics. I decided I not only wanted bright light but I also wanted some gentle lighting too. Because wood is opaque I chose to cut little fish shapes out of the lid and replace it using a transparent material. in this case I chose glass because of its colour and the challenge of the making process. Acrylic may have worked well too but it would not be as scratch resistant as glass and I prefer the colours available in glass.
Finally I considered the materials of all the smaller components. Hinges, screws, sliders for the shelf ,handles. and hanging hooks. I sacrificed the strength of the handle and hooks over appearance because they were not going to be put under any great loading. Even the biscuits used for joining are made of ply that will expand when made wet by the PVA. Which together, when dry, make a strong joint. So many choices and so many considerations but eventually by combining several materials I have a functioning , bespoke bedside cabinet.
I am wondering if talking about the design process really belongs in this part of my audit. I seem to be talking more about the material selection process so why does this post belong here? The only justification I can find is that say I had chosen wood for my cabinet and I did. But it was not practical to make the entire project out of wood alone. For a start I could not have hinged the lid with wood. Well actually I probably could but it would have needed to be a lot thicker. So by using a metal hinge I reduced the thickness of timber required and reduced the production time and cost. I could have made handles from wood but again they would have been larger so again using metal was both aesthetically pleasing and made for a smaller component which fitted the design criteria of minimal space. Now I could not have had light coming through the wood and still have a sealed surface so that one had to have a combined material. Now I feel confident my post belongs here.
Final skills rating ***** I feel very happy and confident about that.