The materials used in the manufacture of plastic bottles vary by application.
#Pet preform for water bottles code#
Main article: Blow molding A polypropylene bottle cap Plastic bottle of milk: HDPE Recycling Code 2 PET bottle preform before blow molding, filling and labeling Except for wine and beer, the food industry has largely replaced glass bottles with plastic bottles. However, the biggest advantage plastic bottles have over their glass counterparts is their superior resistance to breakage, in both production and transportation. They quickly became popular with both manufacturers and customers because compared to glass bottles, plastic bottles are lighter, cheaper and easier to transport. Plastic bottles were first used commercially in 1947, but remained relatively expensive until the early 1950s when high-density polyethylene was introduced. Plastic was invented in the 19th century and was originally used to replace common materials such as ivory, rubber, and shellac. Consumer blow molded containers often have integral handles or are shaped to facilitate grasping. The size ranges from very small bottles to large carboys. Plastic bottles are typically used to store liquids such as water, soft drinks, motor oil, cooking oil, medicine, shampoo, milk, and ink.
A plastic bottle of antifreeze large plastic bottles of waterĪ plastic bottle is a bottle constructed from high-density or low density plastic. Worldwide, 480 billions of plastic drinking bottles were sold in 2017 (and fewer than half were recycled).
I totally agree with the comments made by George Hiowlett and they are all valid pointsA water bottle. Performance Attribures: Again a long list but the main ones include 1) Top Load - the pressure the bottle can withstand before collapsing 2) Height 3) Weight 4) Diameters 6) Perpendicularity 7) Thread finish 8) Short Shots 9) Weight Distibution etc. Visual Attributes: The list here can be endless but the main ones include clarity, bubbles, haze, scratches, damage, flash on partting line (which can impact on cap torque), etcĥ. The higher the moulding melt temperature the lower the IV due to thermal cleavage of the polymer.Ĥ. Certification from your preform supplier should be adequate or if moulded in house a testing program for IV is required backed up by process control of temperatures at moulding. Also reduced shelflife for carbonated products. If it too low you will see increase wastage, scrap and downtime. IV (Intrinsic Viscosity) This is a measure of the molecular length of the polymer and is important for producing consistent quality bottles capable of meeting performance requirements. This is essentially controlled at the injection moulding stage of preforms and relates to melting temperatures of the resin.ģ. You may need to have a program for testing or certification of this parameter. AA Content: In water bottling the AA content is important since it can impart an off taste (citric) flavour from the plastic to the water. Some customers will require analysis / certification of this including heavy metal content and migration levels.Ģ. Starter Materials: You need to ensure that the PET resin used in preform manufacture is suitable and certified for contact purposes. Having said this there are a number of key areas that you need to control:ġ. If you produce to stock then your inspection program is important to ensure you don't produce large amounts of defective PET preforms and bottles. For example, if you are blow moulding direct to the filling line (and you do not produce stock) then many issues regarding performance and quality become immediately evident at filling/capping etc and you can take action at that time.
The nature of any in house facility will also determine the program you introduce. If you have in-house facilities then you need to monitor quality and safety. This is important since if you are buying them in you should not be spending too much time or money doing the job of your supplier. You do not say whether you buy in preforms / bottles or have your own in house injection / blow moulding facility.
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