Opaque and transparent preforms
Preforms are injection-molded and then stretch-blown into the shape of plastic bottles, jugs and other containers. They are used to package beverages, detergents, spices and numerous other consumer products. Managing the colour of these preforms is the first step in ensuring consistent colour quality of the final product they become.
Preforms come in a range of sizes, shapes and colours. They can be opaque, translucent or transparent and therefore require different measurement techniques depending on the type of sample.
Opaque preforms are not penetrated by light and are best measured using a reflectance meter with a diffuse d/8° spherical geometry.
Translucent preforms allow light to pass through, regularly, but also diffusely, so that objects on the other side cannot be clearly distinguished. Both reflective and transmissive measurement modes work well depending on the light transmittance of the sample.
Transparent preforms allow light to pass through with little or no interruption or distortion, so that objects on the other side can be seen clearly. These preforms can easily be measured in transmission.
Please note: Which method is used must always be checked individually.
Suitable measuring devices for the application:
- UltraScan VIS for opaque, transparent and translucent preforms
- Vista for transparent and translucent preforms
