Moulders venturing into this specialist sector may also opt for a self-contained cleanroom moulding and packing system which are fully compliant with any GAMP and FDA requirements and have the required DQ, IQ and OQ documentation.

Biodegradable plastics look and feel exactly like the plastic products we're encouraged to recycle. So what happens if we accidentally recycle those biodegradable bags? Well, the consequences are potentially catastrophic — recycled polyethylene irrigation pumps that are contaminated with PDC additives aren't likely to last very long. In fact, plastic recyclers in South Africa feel so strongly about the inability to keep PDC-containing biodegradables out of recycling streams that they want to ban their use in that country.

Once upon a time, both moms and milkmen filled glass bottles with milk. Now look around your kitchen and you'll probably see many plastics — water bottles, soda bottles, food storage containers. Times have changed.

Production costs have mostly put PHA in the shadow of cheaper, petroleum-based plastics, but a little creativeness in sourcing inexpensive raw materials may make it a top choice soon. Corn-steeped liquor, molasses and even activated sludge could all supply the sugar the bacteria need to produce the plastic.

It’s critical that manufacturers specialising in making contact lens moulds can do it repeatedly and with the highest precision in order to mass-produce the moulds cost efficiently. Usually, there are between eight and 16 cavities in each moulding tool. To produce the lens moulds so fast without compromising on quality, Sumitomo (SHI) Demag installs its award-winning activeFlowBalance technology into the all-electric machines. This helps to combat the uneven filling of moulds by stopping the screw in the right place to allow the mould to fill naturally. This intervention reduces the cavity pressure and stress in the material. Once one cavity fills it moves on to another one.

The future of casein plastic isn't certain, but swapping it for petroleum-based polystyrene would certainly give us another reason to love milk.

The process starts with the injection moulding of a front and base curve mould. This mould is then filled with a monomer (a molecule that can be bonded to other identical molecules to form a polymer) and is then closed and cured before the lens is then hydrated and packed.

Producing plastic from processed corn may seem like a pipe dream, but it's happening every day. Polylactic acid, or PLA, is another aliphatic polyester and one that can be made from lactic acid, which is produced via starch fermentation during corn wet milling. Although most often generated from corn, PLA can be made from wheat or sugarcane as well.

That turned out to be an understatement. Today, plastics are one of the cornerstones of modern technological civilization — tough, flexible durable, impervious to corrosion, and seemingly endlessly versatile. However, there are downsides to its prevalence. That's why plastic alternatives are worth finding.

Typically yes in order to mitigate cross contamination. While contact lens moulds are not technically classed as medical devices, any airborne contaminants, such as dust and particles from the raw materials, as well as human contaminants like bacteria, could affect the lens function.

Yes. Because no two eyes are the same, there are a broad spectrum of styles and parameters to meet when producing lenses. Every contact lens that is produced requires a bespoke mould. Each lens must meet the highest levels of quality and cleanliness. Therefore, it’s essential that the moulds are repeatedly perfect too.

Search around for additive technologies and you'll come across the trade names TDPA (an acronym for Totally Degradable Plastic Additives) or MasterBatch Pellets (MBP). They're used to manufacture single-use plastics such as thin plastic shopping bags, disposable diapers, trash bags, landfill covers and food containers (including fast-food containers).

Biomedical devices and sutures are already made of the slow-degrading polymer, and tissue-engineering researchers dig it, too. It also has applications for food-contact products, such as trays.

For the production of lens moulds, both all-electric and hydraulic injection moulding machines are used – with the bias heavily weighted (90% to 10%) towards all-electric. Repeatability is the main rationale, as well as meeting ISO Class 8 clean room standards. Direct drive machines offer major improvements in efficiency, including a reduction of up to 75% in energy usage during operation and improved repeatability and cycle times. However, manufacturers of hydraulic IM machines have recently made big strides to standardise the process in order to accommodate the variations in moulds yet still meet the high quality requirements.

The winemaking industry produces a lot of grape waste — basically, the solid material that's left behind after grapes are pressed to extract the juice that's fermented into wine. (That amounts to about 25 percent of the weight of the grapes).

PHAs already are used in a variety of products, including disposable package for foods, beverages and various consumer products. They're also being used in medical applications such as sutures, and to make the agricultural foil used to store hay bales [source: Creative Mechanisms].

Our dependence upon plastic also has an increasingly serious downside, because we make so much of it, and throw so much of it away. Of the 9.1 billion tons (8.3 billion metric tons) of plastic that the world has produced since 1950, 6.9 billion tons (6.3 billion metric tons) has become waste, and only 9 percent of that has been recycled. The rest ends up in landfills and in the world's oceans, where plastic pollution is ravaging wildlife and washing up on beaches. About 40 percent of the waste is discarded packaging [source: Parker].

Manufacturers mix lignin, a byproduct of paper mills, with water, and then expose the mixture to serious heat and pressure to create a moldable composite material that's strong and nontoxic. German researchers have incorporated this plastic substitute into a variety of items including toys, golf tees and even hi-fi speaker boxes.

In a relatively new development, bifocal lenses are now being manufactured on a larger scale to correct both near and far vision. With these lenses, the centre has a different magnification than the outer ring of the lens. In addition, some companies produce Toric lenses to correct astigmatism. These lenses are thicker or shaped at the bottom and sit on the tears on your eye, rotating into the right position within the eye. All of this places greater challenges of the machines to meet the specific needs of the customer. Breakthroughs are happening all the time. We’ve not quite reached the point where lenses are 3D printed according to someone’s eye, however this might be possible in the future.

Back in 1907, Leo Baekeland invented a new material, Bakelite, that was the first true synthetic plastic, composed of molecules not found in the natural world. It was an amazing breakthrough. Bakelite was durable and heat resistant and could be molded into almost any shape. People called it "the material of a thousand uses" [source: Science History Institute].

A variety of moulds are used in the production of contact lenses, representing the different magnification levels (graded in quarter diopters) that are prescribed for each lens. The differences are in the variation in the space thickness between the front and rear of the mould, which dictates the thickness of the lens. There are a finite number of combinations and a standard number of magnifications and variations on the curve. Nevertheless, production still has to be carefully planned and controlled, to ensure the machines maintain the highest efficiency levels possible.

Toric design lenses are also expected to report significant gains due to the increased demand to reduce corneal astigmatism.

While some people are busy developing plastic substitutes, others are bent on making conventional thermoplastics biodegradable. How? By throwing in additives called prodegradant concentrates (PDCs). PDCs are usually metal compounds, such as cobalt stearate or manganese stearate. They promote oxidation processes that break the plastic down into brittle, low-molecular-weight fragments. Microorganisms gobble up the fragments as they disintegrate, turning them into carbon dioxide, water and biomass, which reportedly contains no harmful residues.

It can be traced back to 1887 and German physiologist Adolf Flick. That lens was made of glass and was called a ‘scleral’ lens because it covered the scleral – the part of the eye that is white. Some years later, in 1912, optician Carl Zeiss developed another glass lens that fitted over the cornea. The first plastic lens (manufactured from plexiglass) is believed to be the work of two scientists, who created the scleral lens in 1938. The first plastic corneal lens arrived in 1948.

Among the issues, these lenses deprived the eye of oxygen and slipped out of the eye too easily. Over time, however, the diameter of the lenses reduced to improve wearability and, with the arrival of soft contact lenses (using hydrophilic gel), their popularity grew.

You can get them festooned with patterns or printed with the name or your bank/gym/frozen yogurt shop. Everyone hands them out, and they come in canvas, woven plastic fiber, hemp, cotton and even leather. You'll find nylon ones that fold up into a pouch small enough to fit in your pocket. In reality, any type of bag will do, whether it's meant to carry groceries or not.

Disposable lenses in particular are big business, with the soft lens segment share accounting for more than 80% of the overall market. Sumitomo (SHI) Demag is a major player in supplying the injection moulding machinery that produces the moulds that make these contact lenses. UK managing director of the company Nigel Flowers explains the process and the importance of precision and quality in lens moulding.

As a totally biodegradable, low-cost, renewable and natural polymer, starch has been receiving lots of attention for developing sustainable materials. When it comes to replacing plastic, however, starch can't cut the mustard; its poor mechanical properties mean it has limited use for the sturdy products that plastics generate.

PLA looks and performs similiarly to the polyethlene used in plastic films, packing materials and bottles, and it can also be used as a substitute for the polystyrene used in foam food plates and containers and plastic cutlery. But unlike conventional petroleum-based plastics, PLA has some big advantages. For one, since it's made from plants that absorb carbon dioxide as they grow, there's no net increase in carbon dioxide from its raw materials. A 2017 study found that switching from conventional plastic to PLA would cut U.S. greenhouse gas emissions by 25 percent [source: Cho].

When added to polyethylene (the standard plastic bag material) at levels of 3 percent, PDCs can promote nearly complete degradation; 95 percent of the plastic is in bacteria-friendly fragments within four weeks [source: Nolan-ITU Pty]. While not strictly biodegradable ('bioerodable' is more like it), PDC-containing polymers are more environmentally friendly than their purer polymer cousins, which sit in landfills for hundreds of years.

But an Italian company, Vegea, is using the grape waste to make a synthetic leather that could replace vinyl imitation leather, and also into fabric for clothing. Vegea is now in the process of scaling up its production capacity to manufacture the grape-waste apparel items for sale to clothing stores, so you can add grape waste to your wardrobe [source: Stella McCartney].

Automation plays an equally big role in maintaining cleanliness and efficiency levels, as each mould is typically produced in less than three seconds. Tasks undertaken by these robots include unloading the mould tool and packing into sterile carriers.

PLA has the advantage that it's quickly biodegradable, under the right conditions. If the plastic is sent to an industrial composting facility where it's continually subjected to heat and microbes, it can degrade in two to three months. If it's tossed in a landfill, though, it won't break down any quicker than conventional plastic [source: Isom and Shughart].

So, while there is no silver bullet for making plastics greener, a combination of revitalizing old ideas and revolutionizing plastic technology is a step in the right direction.

In an industry that is continually evolving, the next milestone could be smart lenses, which have the ability to monitor a user’s health through a series of circuits, sensors and wireless technology. The production of these lenses will be the same as existing products, but the capabilities will be even greater. Already, the military, for example, is looking into telescopic lenses that will allow the human eye to zoom.

"Naturally produced polyesters" may sound like a phrase lifted from a marketing campaign, but feed sugar to certain types of bacteria and you've got yourself a plastic production line.

PHAs biodegrade via composting; a PHB/PHV composite (92 parts PHB/8 parts PHV, by weight) will almost completely break down within 20 days of cultivation by anaerobic digested sludge, the workhorse of biological treatment plants [source: Nolan-ITU Pty Ltd].

Every single mould used to make a contact lens is produced to a very high level of precision. Because the final lenses are moulded against a surface that has already been injection-moulded, any imperfection within the mould will find its way into the lens. The discarded moulds are recycled – but are not reused for moulding lenses.

Take polycaprolactone (PCL), a synthetic aliphatic polyester that isn't made from renewable resources but does completely degrade after six weeks of composting. It's easily processed but hasn't been used in significant quantities because of manufacturing costs. However, blending PCL with cornstarch reduces cost.

Batch making the moulds and then shipping to local markets where the lenses are produced offers greater flexibility and operators have the ability to stop the injection moulding machine and compensate somewhere else in the system.

That's the case with polyhydroxyalkanoate (PHA) polyesters, the two main members of which are polyhydroxybutrate (PHB) and polyhydroxyvalerate (PHV). These biodegradable plastics closely resemble man-made polypropylene. While they're still less flexible than petroleum-based plastics, you'll find them in packaging, plastic films and injection-molded bottles.

When single-use plastic bags first hit the scene, we had a choice: paper or plastic. Today, it's pretty much all plastic. And if you're not that hypervigilant person at the checkout, you'll find yourself walking home with a bag for each item.

In 2018, Bioplastics News reported that Christopher Johnson, a researcher at the U.S. Department of Energy's National Renewable Energy Laboratory, had developed a promising process for improve the conversion of lignin into a substitute material for plastics, as well as nylon.

But we could do a lot better job of recycling glass. In 2015, the most recent year for which the U.S. Environmental Protection Association (EPA) has statistics, Americans only recycled 26.4 percent of the glass containers that they used.

Currently, only one Sumitomo (SHI) Demag UK customer automates the entire lens production process. Here, the company’s IntElect injection moulding machine forms just one small part of a huge production line whereby raw material is put in and, when it comes out the other end, the final product is packed and ready to ship. Packing and sealing the lens at the point of manufacture reduces the risk of contamination during moving and storage, however the complexity, investment costs and potential downtime issues are the downside to this approach.

Today, there are estimated to be 125 million global wearers of contact lenses in a sector that was reportedly worth $10.7 billion in 2017. The lens manufacturers, many of whom are based in Ireland, expect demand to continue rising, with the sector anticipated to be valued at $17.64 billion by the end of 2024.

What one of the hottest trends in biodegradable plastic development can do is make polymer composites more biodegradable. You name it, and starch has probably been combined with it, albeit with varying degrees of success.

The next three entries on this list are all biodegradable plastics called aliphatic polyesters. Overall, they aren't as versatile as aromatic polyesters such as polyethylene terephthalate (PET), which is commonly used to make water bottles. But since aromatic polyesters are completely resistant to microbial breakdown, a lot of time and effort is being pumped into finding viable alternatives in aliphatic polyesters.

For now, plastic objects are all around us, from the food containers and bottles of milk and soda that we buy at the supermarket, to the countertops in our kitchens and the linings of our cooking pans. We wear clothes fashioned from plastic fibers, sit on plastic chairs, and travel in automobiles, trains and airplanes that contain plastic parts. Plastics have even become an important building material, used in everything from insulated wall panels to window frames [source: American Chemistry Council]. We continue to find new uses for plastic all the time.

In fact, it's tough to make a purchase without it promptly being thrown into plastic. No wonder plastic bags seem omnipresent. The U.S. produced an astonishing 4.13 million tons (3.75 million metric tons) of plastic bags in 2015 and only 530,000 tons (481,000 metric tons) of those were recycled [source: EPA]. The rest end up as litter in cities and towns — and too many find their way to the ocean, where they kill millions of sea turtles, birds and ocean mammals each year. But you have to lug those groceries home somehow. So what do you do? Reusable grocery bags, for starters.

The Asia Pacific region was valued at over $2 billion in 2016, with changing lifestyles, eye health and cosmetic solutions driving demand. This region is expected to experience the fastest growth between now and 2024, with an estimated CAGR of more than 4%. The preference of disposable lenses – and relatively lower cost – makes them a much more appealing solution to resolving short or long sightedness than glasses.

Scientists have found a way make the protein less susceptible to cracking, thanks to a silicate clay called sodium montmorillonite. Freezing sodium montmorillonite into a spongelike material called an aerogel, they infused the porous network of clay with casein plastic. The result? A polystyrene-type material that, when put in a dump environment, begins to degrade completely [source: The Economist]. The modern milk-based plastic doesn't crack as easily, thanks to that silicate skeleton, and they even made the stuff less toxic by substituting glyceraldehyde for formaldehyde during the process.

Now scientists say it could help to produce a biodegradable plastic for furniture cushions, insulation, packaging and other products. Yep, researchers are revitalizing the idea of converting casein, the principal protein found in milk, into a biodegradable material that matches the stiffness and compressibility of polystyrene.

Sometimes going back in time is a good thing. Unlike plastic, which often is derived from fossil fuels, glass is made from sand. This renewable resource doesn't contain chemicals that can leach into your food or body. And it's easily recycled — whether you throw bottles in your recycling bin to be turned into new bottles or reuse glass jars for storing leftovers. Sure, glass may break if dropped, but it won't melt in your microwave.

Starch is usually blended with aliphatic polyesters, such as PLA and PCL, and polyvinyl alcohol to make completely biodegradable plastics. Adding in starch also shaves plastic manufacturing costs. But starch content must exceed 60 percent of the composite before it has a significant effect on degradation; as the starch content increases, the polymers become more biodegradable [source: Nolan-ITU Pty Ltd]. Keep in mind, though, that adding more starch also affects the properties of the plastic. If you put wet leaves in a starch bag for a bit, you'll have a mess when you go to pick up the bag.

Casein-based plastic has been around since the 1880s, when a French chemist treated casein with formaldehyde to produce a material that could substitute for ivory or tortoiseshell. But although it's ideal for jewelry that even Queen Mary admired, casein-based plastic is too brittle for much more than adornment.

Bonus: By avoiding plastic bags, you won't have them accumulating in your cupboards, and you don't have to worry about where they go when you throw them out.

Glass bottles and jars potentially are 100 percent recyclable, and the glass in them can be reused endlessly, without any loss in quality and purity. Glass manufacturers welcome recycled glass, because when it's used as an ingredient in making new glass, it requires less energy in furnaces. Container manufacturers and the fiberglass industry (which also uses recycled glass) together purchase 3.35 million tons (3.03 million metric tons) of recycled glass annually [source: Glass Packaging Institute].

All newborn mammals survive on it. Without it, there would be no ice cream. There's really no denying the value — or pleasure — of milk.

Next up is a promising bioplastic, or biopolymer, called liquid wood. Biopolymers fake it; these materials look, feel and act just like plastic but, unlike petroleum-based plastic, they're biodegradable. This particular biopolymer comes from pulp-based lignin, a renewable resource.