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Measuring the color of plastic pellets is essential for ensuring color consistency and maintaining industry standards. Keep these six things in mind when determining the color of resin pellets. 

1. Understand That Various Components Affect the Color of Plastic Pellets

Resin pellets typically have a translucent color that can be modified through various coloring methods to become more transparent or opaque or adopt a range of different colors. In addition to coloring techniques, overheating, molding, melting, and other processes involved in production can influence the color and appearance of the pellets. 

2. Understand the Difference Between Transparent and Opaque Pellets 

Plastic pellets can vary in their optical properties, resulting in a need for different measuring methods. Spectrophotometers can measure the color of both transparent and opaque plastic pellets while factoring in their unique attributes. 

Maintaining consistent color in opaque sheet plastic is crucial for manufacturers. Even slight color variations can impact brand identity and product quality. The right tools and techniques can achieve precise color control, ensuring every sheet matches your specifications. 

The best way to measure the color of opaque sheet plastic is by using a spectrophotometer. These solutions analyze light reflected from a sample and translate it into numerical data. This data represents value in a defined color space, allowing for objective and repeatable measurements.

Factors Affecting the Appearance of Opaque Plastics

When measuring color in opaque materials, we focus on reflectance. Reflectance is how light interacts with the plastic's surface and reflects on our eyes. Various aspects can influence how color appears on opaque materials, including:

• Opacity: This refers to the material's ability to block light. Opaque plastics do not allow light to pass through. While not directly related to color measurement, opacity can affect color perception.
• Surface texture: Glossy or matte finishes impact how light interacts with the plastic, influencing the perceived color. Standardizing surface texture provides a complete picture of the plastic's visual characteristics.
• Lighting conditions: The type of light source can affect how color appears. Standardizing lighting conditions during color measurement is crucial for consistent results. 

Accurately measuring transparent plastic film's color allows you to meet industry standards and produce items that appeal to the customer. When measuring the color of transparent plastic film, keep these six things in mind:

1. Understand the Influence of the Production Process on Transparent Film Color

When measuring the color of transparent plastic film, it is important to anticipate the color changes that occur during production. The production variables that can influence transparency start with variations in the plastic film's properties, such as thickness, raw or recycled materials, and opacity. Additionally, the presence of additives or plastic colorants can also affect transparency. 

Steps involved in the production process, including heat treatments, molding, or melting during extrusion, can also cause color shifts in your plastic film. 

2. Consider the Role of Haze

Clarity is often a sought-after attribute in transparent film applications. In those cases, the aim is to have a transparent plastic film where the objects behind it can be seen clearly. Haze can create a cloudy-like appearance that lowers the clarity of objects viewed behind the film. It is caused by the scattering of light in the material.

In applications where high clarity is an important factor, haze measurement of plastic film needs to be implemented to ensure the best results.     

Using a spectrophotometer is the best way to measure the color of plastic pellets. These technological devices deliver reliable and accurate measurements that help you ensure the color remains consistent with each batch while adhering to industry standards.

Measure the Color of Plastic Pellets Using the Right Equipment

Plastic pellets vary in transparency and opacity, so you should use the appropriate measurement equipment and accessories for accurate results. Plastic pellets should be measured with a reflectance spectrophotometer. Opaque plastic pellets require only a sample cup, while transparent plastic pellets may require the use of an opaque cover. 

Keep Industry Standards in Mind

An effective color measurement system follows industry standards. As a part of quality and process control, it's important to measure the color of plastic pellets according to the testing standards set by ASTM. Plus, following the standards ensures you measure the pellets more accurately for consistent results.

Spectrophotometers can help you adhere to industry standards by offering a straightforward way to meet the outlined specifications.

Assess the Degree of Yellowness

Achieving clear and consistent colors is critical in plastic production. However, plastic resin can turn yellow when subjected to oxidation. Yellowness directly impacts the value and perceived quality of plastic products. To prevent the yellowish appearance, optical brighteners are used to make the plastics look more clear or white. 

Optical brighteners are also often used to enhance the appearance of recycled plastics. As a result, it's essential to assess the degree of yellowness in plastic resin to determine the appropriate concentration of optical brighteners needed to counteract the yellowing effect of plastics throughout the supply chain.

As the plastic production industry moves toward using recycled plastics, you'll need a robust spectrophotometer that can measure the color and fluorescence quality of virgin and recycled plastic resin and a combination of the two. By doing so, the spectrophotometer can help mitigate yellowness and ensure the optical brighteners are adjusted for at every stage of the production process. 

Measuring the color of opaque and transparent pellets is essential for ensuring consistency across production. This is especially true for plastic pellets, which are often produced in large manufacturing lines where checking each individual product can be challenging. To ensure the desired color and appearance are achieved with every batch, it's important to consider these best practices:

Evaluate the Importance of Plastic Pellet Colors

Plastic pellets are primarily used as a raw material in the creation of nearly every plastic product. As the building blocks of plastic products, pellets must maintain a specific color to align with the desired color of the final product. While the color of the pellets does not directly impact the final product's color, it is still vital for quality control.

In the plastic industry, color is essential for determining quality. Measuring the color of opaque and transparent pellets is crucial for delivering a final product with the same reliable appearance that appeals to the customer.

Consider Industry Standards for Pellet Colors

The ASTM has developed a testing standard for determining the color of pellets. Pellets are tested for their degree of yellowness or how the yellowness changes under daylight on transparent or opaque plastics. However, the yellowness attribute has to be considered with other tristimulus values from a spectrophotometer or colorimeter to quantify the color precisely.

Measure Pellet Colors With Spectrophotometers

The protective nature of the human eye makes ophthalmic medication administration extremely difficult to control. However, thanks to new technology and spectral analysis, a new form of eye medication may provide a solution. Image source: Flickr CC user Elizabeth Ellis

Drug administration is an important part of pharmaceutical effectiveness and spectrophotometry plays a vital role in the development and monitoring of various forms of prescription drugs. Pills, capsules, powder, orodispersibles, and liquid medications all utilize spectrophotometry to aid in the analysis of the APIs (active pharmaceutical ingredients), stability, and safety of these products. This one simple and effective tool spans a wide range of pharmaceutical compounds, textures, and viscosities. Current research is utilizing this technology to lead the pharma industry towards new horizons.

One main research area and need for growth has to do with the effectiveness of ophthalmic medications. Medications for the eyes remain difficult to administer effectively. “Conventional ophthalmic solutions frequently show poor bioavailability and a weak therapeutic response because they are often eliminated before they can reach the cornea, when patients blink or their eyes tear.”1 This greatly reduces the effectiveness of these medications, making proper dosing difficult and optimal results inconsistent. Not only do the APIs in these solutions lose their effectiveness quickly after administration, but the protective nature of the human eye efficiently removes these formulations through the tear ducts and transfers this medication to other unaffected areas of the body. This can inadvertently affect the gastrointestinal track leading to adverse responses that might otherwise be avoided.

Finding a New Solution

Various kinds of ophthalmic medications are used to treat diseases of the eye, but the effectiveness wears off rapidly once surface contact is induced. Whether medication is in the form of eye drop, ointment, or capsule, studies show that drug concentration diminishes rapidly within minutes of administration. New advancements in ophthalmic solutions have led to the development of formulations that convert to a gel-type substance once contact is made with the surface of the eye. As these solutions change in viscosity, continual monitoring must be used to confirm that drug effectiveness and uniformity prevails throughout these changes.

UV spectrophotometry is a simple way to continuously monitor these changes and is already used for a variety of applications in the pharmaceutical industry. To ensure that gelatinous ophthalmic solutions maintain drug content uniformity, it is necessary to quantify the concentration of active ingredients throughout the suspension.2 UV spectrophotometers use absorption rates to quantify these concentrations and provide continual data and feedback on uniformity and changes that are otherwise unobservable through visual inspection. Determination of these ingredients can then be given as numerical data for consistency and repeatability testing.

UV spectrophotometers use light absorption measurements to quantify the concentration and uniformity of ophthalmic solutions. Image Source: Flickr CC user peasap

Color analysis of food and beverage containers can enhance your ability to create pleasing, complementary color schemes that increase the appeal of your product. Image Source: Flickr user ND Strupler

Eating and drinking are intense multisensory experiences informed by the appearance, aroma, texture, and taste of foods. Color has long been recognized as a central component of how food and drink are perceived. Now, research indicates that product-extrinsic color, specifically the color of containers, also has a significant psychological impact on consumer expectations and consumption habits. By combining color analysis with an understanding of the relationship between container color, perception, and behavior, food and beverage manufacturers can create packaging that maximizes appeal and enhances consumer relationships with their products.

Lattes served in a white mug is perceived as having a more intense flavor than lattes served in a clear glass mug. Image Source: Unsplash user Drew Coffman