Problem & Solution

Practical answers to common plastic material challenges

Browse Articles →

Q

PET preform yellowing

A

Preform yellowing is investigated along three routes: drying, temperature, and residence; the treatment of both oxidation and thermal degradation is material change plus temperature reduction; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent re...

Material Drying PET;preform;yellowing;oxidation;residence time

Q

PET preform white haze

A

Preform white haze is a clear signal of insufficient drying; preform inspection interception plus drying rectification prevents defects from flowing into blowing and being amplified; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence

Material Drying PET;preform;white haze;drying;plasticization

Q

PET sheet gel particles and impurities

A

The root of gel particles lies in the material, not the machine; raw material purity management plus process filtration is the quality bottom line of transparent PET sheet; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence

Material Drying PET;gel particle;regrind;raw material purity;filtration

Q

PET filter mesh selection

A

Filter mesh is configured by material source grading; fine screens for recycled material are the gel particle defense line, and pressure differential monitoring determines the screen change rhythm; after confirming effectiveness, fix the parameters and practices into the work instruction to preve...

Production & Quality PET;filter screen;mesh;gel particle;pressure differential

Q

PET melt pump pressure stabilization

A

The melt pump is the heart of PET sheet thickness stability; upstream fluctuations must be eliminated at the source, and downstream closed-loop is only a remedy; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence

Molding Process PET;melt pump;thickness fluctuation;coupling;pressure stabilization

Q

PET die lip buildup early warning

A

Die lip buildup is a sentinel of degradation; frequent scraping plus temperature reduction plus residence time check keeps whole-roll scrapping from happening; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence

Molding Process PET;die lip buildup;degradation;copper scraping;early warning

Q

PET die-to-roll distance 8cm

A

The 8cm roll distance is the geometric guarantee of PET sheet transparency; fast cooling through the crystallization zone plus roll temperature control, a two-pronged approach to keep transparency; after confirming effectiveness, fix the parameters and practices into the work instruction to preve...

Extrusion & Post PET;sheet;roll distance;8cm;crystallization whitening

Q

PET sheet transverse streaks

A

PET sheet transverse lines point to roll system speed accuracy; upgrading the speed regulation system can cure such periodic defects better than adjusting the process; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence

Extrusion & Post PET;sheet;transverse lines;three rolls;speed regulation accuracy

Q

PET sheet inter-roll bank

A

The inter-roll bank is the compaction guarantee of PET calendering; without a bank, water marks are inevitable; uniform bank rotation is the operator's visual standard; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence

Extrusion & Post PET;sheet;orange peel mark;inter-roll bank;calendering

Q

PET sheet die lines and flow marks

A

Die lines are a chronic appearance disease of PET sheet; frequent die lip cleaning plus stable pressure and temperature, together with intact filter screens, can maintain a mirror surface; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurr...

Processing Machinery PET;sheet;die line;die lip buildup;flow mark

Prev 1 ... 768 769 770 771 772 773 774 ... 1164 Next

Categories

All Topics 11636 Material Drying 1439 Injection Molding 1506 Molding Process 740 Molds & Tooling 1506 Processing Machinery 2025 Extrusion & Post 2239 Blow Molding 315 Thermoforming 141 Material Analysis 1343 Production & Quality 382