Industrial Plastics Moulding - Revision history

DT Online at 10:02, 27 August 2017

2017-08-27T10:02:01Z

← Older revision		Revision as of 10:02, 27 August 2017
Line 5:		Line 5:
	=====Description=====		=====Description=====

	Although there are ways of modelling almost all methods of moulding plastics in schools ''(e.g. '''[[Injection Moulding]]''' and small '''[[Injection Moulding\|Injection Moulders]]''' for example are available)'', most working with plastics in '''[[Design and Technology]]''' involves '''[[Thermoforming]]''' ''(i.e. forming of heated flat sheets of plastics)''.		Although there are ways of modelling almost all methods of moulding plastics in schools ''(e.g. '''[[Injection Moulding]]''' and small '''[[Injection Moulding\|Injection Moulders]]''' for example are available)'', most working with plastics in '''[[Design and Technology]]''' involves '''[[Thermoforming Plastics\|Thermoforming]]''' ''(i.e. forming of heated flat sheets of plastics)''.

DT Online: Added Template

2016-11-18T13:52:10Z

Added Template

← Older revision		Revision as of 13:52, 18 November 2016
Line 79:		Line 79:


			{{Thermoforming Buyers Guide}}

	[[Category:Skills and Processes]]		[[Category:Skills and Processes]]
	[[Category:Working Plastics]]		[[Category:Working Plastics]]

DT Online at 11:21, 15 November 2016

2016-11-15T11:21:03Z

← Older revision		Revision as of 11:21, 15 November 2016
Line 13:		Line 13:
	=====Injection Moulding=====		=====Injection Moulding=====

	'''[[Injection Moulding]]''' is the most commonly used manufacturing process for the production of a great variety ~~plastic~~ products and components.		'''[[Injection Moulding]]''' is the most commonly used manufacturing process for the production of a great variety plastics products and components.
	[[File:Principe moulage injection polymere.svg\|300px\|right]]		[[File:Principe moulage injection polymere.svg\|300px\|right]]


	In industry, plastics granules are drawn into an [https://en.wikipedia.org/wiki/Injection_molding_machine '''Injection Moulder'''] cylinder, or barrel, via a rotating screw to a point where they are heated and melted. The screw then operates as a piston and forces the melted ~~plastic~~ into a mould to create the products as shown:		In industry, plastics granules are drawn into an [https://en.wikipedia.org/wiki/Injection_molding_machine '''Injection Moulder'''] cylinder, or barrel, via a rotating screw to a point where they are heated and melted. The screw then operates as a piston and forces the melted plastics into a mould to create the products as shown:

	# Reciprocating screw;		# Reciprocating screw;

DT Online: Changed main image

2016-11-14T19:16:02Z

Changed main image

← Older revision		Revision as of 19:16, 14 November 2016
Line 1:		Line 1:
	[[File:~~Plastic Injection Moulding Injection Phase~~.gif\|Plastic Injection Moulding Injection Phase\|400px\|right\|link=https://commons.wikimedia.org/wiki/File:Plastic_Injection_Moulding_Injection_Phase.gif]]		[[File:Www.GIFCreator.me scf30H.gif\|Plastic Injection Moulding Injection Phase\|400px\|right\|link=https://commons.wikimedia.org/wiki/File:Plastic_Injection_Moulding_Injection_Phase.gif]]
	__TOC__		__TOC__

DT Online: Corrected Links

2016-11-14T18:58:03Z

Corrected Links

← Older revision		Revision as of 18:58, 14 November 2016
Line 5:		Line 5:
	=====Description=====		=====Description=====

	Although there are ways of modelling almost all methods of moulding plastics in schools ''(e.g. '''[[Injection Moulding]]''' and small '''[[Injection Moulding\|Injection Moulders]]'~~'')~~'' for example are available, most working with plastics in '''[[Design and Technology]]''' involves '''[[Thermoforming]]''' ''(i.e. forming of heated flat sheets of plastics)''.		Although there are ways of modelling almost all methods of moulding plastics in schools ''(e.g. '''[[Injection Moulding]]''' and small '''[[Injection Moulding\|Injection Moulders]]''' for example are available)'', most working with plastics in '''[[Design and Technology]]''' involves '''[[Thermoforming]]''' ''(i.e. forming of heated flat sheets of plastics)''.


Line 33:		Line 33:

	[[File:Extruder section.jpg\|400px\|right\|Extruder section]]		[[File:Extruder section.jpg\|400px\|right\|Extruder section]]
	[https://en.wikipedia.org/wiki/Plastics_extrusion '''Extrusion'''].is an industrial process, usually continuous, which can be likened to squeezing toothpaste out of a tube. Small beads of a '''[[Thermoplastics]]''' are fed into a hopper from which they feed into the barrel of the '''Extruder'''.		[https://en.wikipedia.org/wiki/Plastics_extrusion '''Extrusion'''].is an industrial process, usually continuous, which can be likened to squeezing toothpaste out of a tube. Small beads of a '''[[Plastics\|Thermoplastics]]''' are fed into a hopper from which they feed into the barrel of the '''Extruder'''.


Line 53:		Line 53:

	The last set of rollers determines the final thickness of sheet and can also impart a textured surface finish if required.		The last set of rollers determines the final thickness of sheet and can also impart a textured surface finish if required.






Line 63:		Line 59:

	[[File:Rotational Molding Process.svg\|300px\|right]]		[[File:Rotational Molding Process.svg\|300px\|right]]
	[https://en.wikipedia.org/wiki/Rotational_molding '''Rotational Moulding'''] is an industrial process in which a hollow mould is loaded with a measured amount of .'''[[Thermoplastics]]''' then heated and rotated about two axes such that the plastics forms a coating around the inside of the mould.		[https://en.wikipedia.org/wiki/Rotational_molding '''Rotational Moulding'''] is an industrial process in which a hollow mould is loaded with a measured amount of .'''[[Plastics\|Thermoplastics]]''' then heated and rotated about two axes such that the plastics forms a coating around the inside of the mould.


			Rotation continues throughout both the heating and cooling phases to avoid deformation of the finished product. This makes for a long cycle times but it is still a cost-effective and easy way to produce large hollow pieces such as storage tanks.


	Rotation continues throughout both the heating and cooling phases to avoid deformation of the finished product. This makes for a long cycle times but it is still a cost-effective and easy way to produce large hollow pieces such as storage tanks. The moulds for		The moulds for
	[https://en.wikipedia.org/wiki/Rotational_molding '''Rotational Moulding'''] are either fabricated from welded sheet steel or cast and are significantly cheaper than some other types of mould.		[https://en.wikipedia.org/wiki/Rotational_molding '''Rotational Moulding'''] are either fabricated from welded sheet steel or cast and are significantly cheaper than some other types of mould.

Line 74:		Line 73:

	[[File:Compression molding.svg\|300px\|right]]		[[File:Compression molding.svg\|300px\|right]]
	[https://en.wikipedia.org/wiki/Compression_molding '''Compression Moulding'''] is used to create products by placing a measured amount of '''[[Thermoset Resin]]''' into a heated mould cavity then applying the top of the mould, or plug, with heat and pressure until the resin is cured.		[https://en.wikipedia.org/wiki/Compression_molding '''Compression Moulding'''] is used to create products by placing a measured amount of '''[[Plastics\|Thermoset Resin]]''' into a heated mould cavity then applying the top of the mould, or plug, with heat and pressure until the resin is cured.

DT Online: Created article

2016-11-14T15:14:56Z

Created article

New page

[[File:Plastic Injection Moulding Injection Phase.gif|Plastic Injection Moulding Injection Phase|400px|right|link=https://commons.wikimedia.org/wiki/File:Plastic_Injection_Moulding_Injection_Phase.gif]]
__TOC__

=====Description=====

Although there are ways of modelling almost all methods of moulding plastics in schools ''(e.g. '''[[Injection Moulding]]''' and small '''[[Injection Moulding|Injection Moulders]]''')'' for example are available, most working with plastics in '''[[Design and Technology]]''' involves '''[[Thermoforming]]''' ''(i.e. forming of heated flat sheets of plastics)''.

The processes listed below generally involve much more expensive plant than is normally only available in industry.

=====Injection Moulding=====

'''[[Injection Moulding]]''' is the most commonly used manufacturing process for the production of a great variety plastic products and components.
[[File:Principe moulage injection polymere.svg|300px|right]]

In industry, plastics granules are drawn into an [https://en.wikipedia.org/wiki/Injection_molding_machine '''Injection Moulder'''] cylinder, or barrel, via a rotating screw to a point where they are heated and melted. The screw then operates as a piston and forces the melted plastic into a mould to create the products as shown:

# Reciprocating screw;
# Hopper;
# Granules;
# Barrel;
# Heaters;
# Mould.

As a consequence, most injection moulded products can be identified by the presence of a small ''‘pip’'' or [https://en.wikipedia.org/wiki/Sprue_%28manufacturing%29 '''sprue'''] where the melted plastics entered the mould.

<div style="clear: both;"></div>
=====Extrusion=====

[[File:Extruder section.jpg|400px|right|Extruder section]]
[https://en.wikipedia.org/wiki/Plastics_extrusion '''Extrusion'''].is an industrial process, usually continuous, which can be likened to squeezing toothpaste out of a tube. Small beads of a '''[[Thermoplastics]]''' are fed into a hopper from which they feed into the barrel of the '''Extruder'''.

The heated '''Extruder''' contains a rotating screw which forces the softening plastics through a '''Die''' at the end which produces the extruded profile.

The general process of '''Extrusion''' can also be used to produce aluminium sections for example, and can be a hot or cold process.for metals such as [https://en.wikipedia.org/wiki/Aluminium '''Aluminium''']

<div style="clear: both;"></div>
=====Calendering=====

[[File:Inverted L Calender.png|250px|right]]
[http://www.appropedia.org/Polymer_calendering '''Calendering'''] is used to manufacture thin film or sheet in either plastics or paper - or both by laminating films together. The process takes heated and softened plastics and squeezes it through rollers until the required thickness is achieved. It has some superficlal similarities with that used in [https://en.wikipedia.org/wiki/Rolling_(metalworking) '''Steel Rolling Mills'''] and was developed originally for the production of rubber sheet.

'''Calendars''' exert immense pressure on the material which results in lower temperatures being needed. This make the process very suitable for materials which may be sensitive to heat damage and for materials such as [https://en.wikipedia.org/wiki/Polyvinyl_chloride '''PVC'''] for which there is some concern regarding fume emissions.

The last set of rollers determines the final thickness of sheet and can also impart a textured surface finish if required.

<div style="clear: both;"></div>
=====Rotational Moulding=====

[[File:Rotational Molding Process.svg|300px|right]]
[https://en.wikipedia.org/wiki/Rotational_molding '''Rotational Moulding'''] is an industrial process in which a hollow mould is loaded with a measured amount of .'''[[Thermoplastics]]''' then heated and rotated about two axes such that the plastics forms a coating around the inside of the mould.

Rotation continues throughout both the heating and cooling phases to avoid deformation of the finished product. This makes for a long cycle times but it is still a cost-effective and easy way to produce large hollow pieces such as storage tanks. The moulds for
[https://en.wikipedia.org/wiki/Rotational_molding '''Rotational Moulding'''] are either fabricated from welded sheet steel or cast and are significantly cheaper than some other types of mould.

<div style="clear: both;"></div>
=====Compression Moulding=====

[[File:Compression molding.svg|300px|right]]
[https://en.wikipedia.org/wiki/Compression_molding '''Compression Moulding'''] is used to create products by placing a measured amount of '''[[Thermoset Resin]]''' into a heated mould cavity then applying the top of the mould, or plug, with heat and pressure until the resin is cured.

[https://en.wikipedia.org/wiki/Compression_molding '''Compression Moulding'''] is a high volume process at a lower cost than '''Injection Moulding''' but not as consistent, and it is difficult to control '''''flashing'''''. It is useful also however for moulding '''''composite''''' products such as when [https://en.wikipedia.org/wiki/Fiberglass '''Fibreglass ''(GRP)'''''] reinforcement is needed.

[[Category:Skills and Processes]]
[[Category:Working Plastics]]