Inline color control = zero waste<\/strong><\/h3>\nA large plastics compounder and recycling specialist in Germany faced exactly this challenge:
From time to time, pellets of the wrong color contaminated a 30-ton product silo<\/strong>. The result was considerable<\/span><\/span>r<\/span><\/span><\/span> <\/span>rejects <\/span>or costly and time-consuming <\/span>reworking<\/span>rework.<\/span><\/span><\/p>\nThe reason was not a lack of quality control – on the contrary:
The company had an established, precise laboratory-based color measurement<\/strong> system. But valuable time passed between production and the measurement result. By the time color deviations were detected, the silo had already been filled.<\/p>\nThe customer’s central question was therefore:<\/p>\n
\n“Can the color of pellets be measured directly online – in the running process?”<\/strong><\/p>\n<\/blockquote>\n[\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”]<\/p>\n
The solution: Inline color measurement directly in the process<\/strong><\/h2>\nHunterLab developed the SpectraTrend HT for this application, which detects color deviations in real time – so that<\/span> <\/span>the <\/span>defective product<\/span> can be rejected <\/span>before <\/span>it <\/span>reaches the storage area.<\/span><\/p>\n<\/p>
![\"SpectraTrend](\"https:\/\/www.hunterlab.eu\/wp-content\/uploads\/2026\/01\/SpectraTrend-HT-Inline-Pellet-Measurement.jpg\")
The SpectraTrend HT determines color values during production.<\/p><\/div>[\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”]
<\/p>\n
Installed system components:<\/strong><\/h3>\n\n- \n
STHT inline spectrophotometer<\/a><\/strong><\/p>\n<\/li>\n- \n
ColorWorkbench software<\/strong> for real-time analysis and visualization<\/p>\n<\/li>\n- \n
IR thermometer<\/strong> for continuous recording of the product temperature<\/p>\n<\/li>\n- \n
Digital relay output module<\/strong> for automatic ejection<\/p>\n<\/li>\n- \n
Robust protective housing<\/strong> for use in demanding environmental conditions (dust, humidity) in production<\/p>\n<\/li>\n<\/ul>\nAs soon as the measured ΔE*<\/strong> value exceeds defined limit values, the system reacts immediately:
Deviating pellets are automatically discharged – before they reach the silo<\/strong>.<\/p>\n[\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”]<\/p>\n
Measurement practice: Ensuring quality where it is created<\/strong><\/h3>\nInline color measurement consistently shifts quality control from the laboratory to the process. While laboratory devices continue to be used for references and approvals, the inline system takes over continuous monitoring during operation. <\/p>\n
This makes color an active control parameter<\/strong> in the production process – not just a downstream inspection criterion.<\/p>\n <\/h3>\nConcrete advantages for the user<\/strong><\/h3>\nThe introduction of inline color measurement brought measurable benefits to the customer:<\/p>\n
\n- \n
✅ Immediate response to FAIL conditions<\/strong><\/p>\n<\/li>\n- \n
✅ Virtually no waste and no reworking<\/strong><\/p>\n<\/li>\n- \n
✅ Elimination of time-consuming test chips and manual tests in the QA laboratory<\/strong><\/p>\n<\/li>\n- \n
✅ Automatic protection of downstream processes<\/p>\n<\/li>\n<\/ul>\n
<\/h3>\nResult: Fast ROI and high acceptance<\/strong><\/h3>\nThe investment paid off faster than expected:<\/p>\n
\n- \n
ROI after just 3 months<\/strong> thanks to reduced reject quantities and higher process efficiency<\/p>\n<\/li>\n- \n
Significantly improved process reliability and production stability<\/p>\n<\/li>\n<\/ul>\n
Customer feedback was correspondingly positive:<\/p>\n
\n“The system has paid for itself faster than expected.”<\/em><\/p>\n<\/blockquote>\nShortly afterwards, the company decided to install a second system<\/strong> on another production line.<\/p>\n<\/p>
![\"The](\"https:\/\/www.hunterlab.eu\/wp-content\/uploads\/2026\/01\/ColorWorkbench-Software-Inline-Pellet-Measurement.jpg\")
The SpectraTrend HT measurement data is evaluated and analyzed using the colorWorkbench software on an external PC (under protective film).<\/p><\/div>
<\/p>\n
[\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”]<\/p>\n
Conclusion: Inline color measurement as the key to process reliability<\/strong><\/h3>\nThis application impressively demonstrates the contribution that inline color measurement can make to sustainable and economical plastics production:<\/p>\n
\n- Quality assurance directly on the line<\/li>\n
- G<\/span><\/span><\/span>Guarantee of high product purity<\/span><\/span><\/span> <\/span><\/li>\n
- Faster ROI thanks to less waste and greater efficiency<\/li>\n<\/ul>\n
HunterLab not only provides measurement technology, but also a decisive safeguard for quality, efficiency and competitiveness<\/strong>.<\/p>\n[\/et_pb_text][et_pb_divider _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n
Frequently asked questions about the inline measurement of plastic pellets:<\/h2>\n
[\/et_pb_text][difl_faq faq_layout=”plain” enable_schema=”on” admin_label=”FAQ” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”][difl_faqitem question=”What is inline color measurement?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]Inline color measurement refers to the continuous, instrumental recording of colour<\/a> directly in the production process – without taking samples and without time delay.
\n[\/difl_faqitem][difl_faqitem question=”Why is inline color measurement important for plastic granules?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]<\/p>\nThis allows color deviations to be detected at an early stage before large quantities are produced or fed into silos. This significantly reduces rejects and rework. <\/p>\n
[\/difl_faqitem][difl_faqitem question=”What is the difference between inline and laboratory color measurement?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]<\/p>\n
Laboratory color measurement takes place randomly and with a time delay. Inline color measurement measures continuously in real time and enables immediate reaction and adjustment of process parameters. <\/p>\n
[\/difl_faqitem][difl_faqitem question=”Which color parameters are monitored inline?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]<\/p>\n
Typically, ΔE*<\/a> values as well as L*, a* and b*<\/a> are continuously recorded and compared with defined target values. Tolerances<\/a> define when to react to deviations must be reacted to.<\/span><\/span><\/p>\n[\/difl_faqitem][difl_faqitem question=”For which industries is inline color measurement suitable?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]For plastics, chemical, recycling, compound, masterbatch and powder processing – wherever color is a critical quality factor.
\n[\/difl_faqitem][\/difl_faq][et_pb_button button_url=”@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoicG9zdF9saW5rX3VybF9wYWdlIiwic2V0dGluZ3MiOnsicG9zdF9pZCI6IjI4NjAzOCJ9fQ==@” url_new_window=”on” button_text=”Learn more about inline color measurement with the SpectraTrend HT!” _builder_version=”4.27.5″ _dynamic_attributes=”button_url” _module_preset=”default” global_colors_info=”{}”][\/et_pb_button][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"
In the plastics, chemical and recycling industries, color is much more than just an optical feature. It is a key quality indicator that allows conclusions to be drawn about material purity, process stability and batch consistency. In granulate production in particular, the smallest color deviations can have enormous economic consequences – especially if they are […]<\/p>\n","protected":false},"author":3,"featured_media":391552,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[806],"tags":[1313,1110,2239,1111,2189],"class_list":["post-383698","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-colorimetry","tag-colour-measurement-of-plastic-pellets","tag-granules-en","tag-inline","tag-pellets-en","tag-plastic"],"_links":{"self":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/posts\/383698","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/comments?post=383698"}],"version-history":[{"count":0,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/posts\/383698\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/media\/391552"}],"wp:attachment":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/media?parent=383698"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/categories?post=383698"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/tags?post=383698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
From time to time, pellets of the wrong color contaminated a 30-ton product silo<\/strong>. The result was considerable<\/span><\/span>r<\/span><\/span><\/span> <\/span>rejects <\/span>or costly and time-consuming <\/span>reworking<\/span>rework.<\/span><\/span><\/p>\n
The reason was not a lack of quality control – on the contrary: The customer’s central question was therefore:<\/p>\n “Can the color of pellets be measured directly online – in the running process?”<\/strong><\/p>\n<\/blockquote>\n [\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”]<\/p>\n HunterLab developed the SpectraTrend HT for this application, which detects color deviations in real time – so that<\/span> <\/span>the <\/span>defective product<\/span> can be rejected <\/span>before <\/span>it <\/span>reaches the storage area.<\/span><\/p>\n <\/p> The SpectraTrend HT determines color values during production.<\/p><\/div>[\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”] <\/p>\n STHT inline spectrophotometer<\/a><\/strong><\/p>\n<\/li>\n ColorWorkbench software<\/strong> for real-time analysis and visualization<\/p>\n<\/li>\n IR thermometer<\/strong> for continuous recording of the product temperature<\/p>\n<\/li>\n Digital relay output module<\/strong> for automatic ejection<\/p>\n<\/li>\n Robust protective housing<\/strong> for use in demanding environmental conditions (dust, humidity) in production<\/p>\n<\/li>\n<\/ul>\n As soon as the measured ΔE*<\/strong> value exceeds defined limit values, the system reacts immediately: [\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”]<\/p>\n Inline color measurement consistently shifts quality control from the laboratory to the process. While laboratory devices continue to be used for references and approvals, the inline system takes over continuous monitoring during operation. <\/p>\n This makes color an active control parameter<\/strong> in the production process – not just a downstream inspection criterion.<\/p>\n The introduction of inline color measurement brought measurable benefits to the customer:<\/p>\n ✅ Immediate response to FAIL conditions<\/strong><\/p>\n<\/li>\n ✅ Virtually no waste and no reworking<\/strong><\/p>\n<\/li>\n ✅ Elimination of time-consuming test chips and manual tests in the QA laboratory<\/strong><\/p>\n<\/li>\n ✅ Automatic protection of downstream processes<\/p>\n<\/li>\n<\/ul>\n The investment paid off faster than expected:<\/p>\n ROI after just 3 months<\/strong> thanks to reduced reject quantities and higher process efficiency<\/p>\n<\/li>\n Significantly improved process reliability and production stability<\/p>\n<\/li>\n<\/ul>\n Customer feedback was correspondingly positive:<\/p>\n “The system has paid for itself faster than expected.”<\/em><\/p>\n<\/blockquote>\n Shortly afterwards, the company decided to install a second system<\/strong> on another production line.<\/p>\n <\/p> The SpectraTrend HT measurement data is evaluated and analyzed using the colorWorkbench software on an external PC (under protective film).<\/p><\/div> <\/p>\n [\/et_pb_text][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” border_color_all=”#2A4175″ global_colors_info=”{}”]<\/p>\n This application impressively demonstrates the contribution that inline color measurement can make to sustainable and economical plastics production:<\/p>\n HunterLab not only provides measurement technology, but also a decisive safeguard for quality, efficiency and competitiveness<\/strong>.<\/p>\n [\/et_pb_text][et_pb_divider _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n [\/et_pb_text][difl_faq faq_layout=”plain” enable_schema=”on” admin_label=”FAQ” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”][difl_faqitem question=”What is inline color measurement?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]Inline color measurement refers to the continuous, instrumental recording of colour<\/a> directly in the production process – without taking samples and without time delay. This allows color deviations to be detected at an early stage before large quantities are produced or fed into silos. This significantly reduces rejects and rework. <\/p>\n [\/difl_faqitem][difl_faqitem question=”What is the difference between inline and laboratory color measurement?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]<\/p>\n Laboratory color measurement takes place randomly and with a time delay. Inline color measurement measures continuously in real time and enables immediate reaction and adjustment of process parameters. <\/p>\n [\/difl_faqitem][difl_faqitem question=”Which color parameters are monitored inline?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]<\/p>\n Typically, ΔE*<\/a> values as well as L*, a* and b*<\/a> are continuously recorded and compared with defined target values. Tolerances<\/a> define when to react to deviations must be reacted to.<\/span><\/span><\/p>\n [\/difl_faqitem][difl_faqitem question=”For which industries is inline color measurement suitable?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]For plastics, chemical, recycling, compound, masterbatch and powder processing – wherever color is a critical quality factor. In the plastics, chemical and recycling industries, color is much more than just an optical feature. It is a key quality indicator that allows conclusions to be drawn about material purity, process stability and batch consistency. In granulate production in particular, the smallest color deviations can have enormous economic consequences – especially if they are […]<\/p>\n","protected":false},"author":3,"featured_media":391552,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[806],"tags":[1313,1110,2239,1111,2189],"class_list":["post-383698","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-colorimetry","tag-colour-measurement-of-plastic-pellets","tag-granules-en","tag-inline","tag-pellets-en","tag-plastic"],"_links":{"self":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/posts\/383698","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/comments?post=383698"}],"version-history":[{"count":0,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/posts\/383698\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/media\/391552"}],"wp:attachment":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/media?parent=383698"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/categories?post=383698"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/tags?post=383698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
The company had an established, precise laboratory-based color measurement<\/strong> system. But valuable time passed between production and the measurement result. By the time color deviations were detected, the silo had already been filled.<\/p>\n\n
The solution: Inline color measurement directly in the process<\/strong><\/h2>\n
Installed system components:<\/strong><\/h3>\n
\n
Deviating pellets are automatically discharged – before they reach the silo<\/strong>.<\/p>\nMeasurement practice: Ensuring quality where it is created<\/strong><\/h3>\n
<\/h3>\n
Concrete advantages for the user<\/strong><\/h3>\n
\n
<\/h3>\n
Result: Fast ROI and high acceptance<\/strong><\/h3>\n
\n
\n
Conclusion: Inline color measurement as the key to process reliability<\/strong><\/h3>\n
\n
Frequently asked questions about the inline measurement of plastic pellets:<\/h2>\n
\n[\/difl_faqitem][difl_faqitem question=”Why is inline color measurement important for plastic granules?” _builder_version=”4.27.5″ _module_preset=”default” global_colors_info=”{}” que_wrapper_bg_bgcolor__hover=”1px||||false|false” que_wrapper_bg_bgcolor__hover_enabled=”on|hover”]<\/p>\n
\n[\/difl_faqitem][\/difl_faq][et_pb_button button_url=”@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoicG9zdF9saW5rX3VybF9wYWdlIiwic2V0dGluZ3MiOnsicG9zdF9pZCI6IjI4NjAzOCJ9fQ==@” url_new_window=”on” button_text=”Learn more about inline color measurement with the SpectraTrend HT!” _builder_version=”4.27.5″ _dynamic_attributes=”button_url” _module_preset=”default” global_colors_info=”{}”][\/et_pb_button][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"