Hard PVC Masterbatch Possible Problems in Production

Hard PVC masterbatch (no / low plasticizer, depending on filler, enhancer to improve performance) The main pain of production is PVC thermal stability is poor, high melt viscosity, inherent toughness is insufficient, and often add glass fiber, talc powder and other hardness Packing, the problem is focused on "degradation prevention, plasticization uniformity, fracture prevention, equipment wear" The "adhesion, plasticizer migration" with the soft PVC masterbatch forms a core difference.

I. Raw materials and mixing links: hidden risks of hard PVC masterbatch failure

1. Filler/enhancer reunification (exclusive core issues)

Performance: Calcium carbonate hard blocks, glass fiber bundles, talc powder reunion particles appear in the masterbatch, the surface of the subsequent product has Stitches, stripes, fluctuations in mechanical properties (such as local insufficient rigidity, uneven tensile strength);

Cause: ① The filler is not surface treated (e.g. calcium carbonate is not modified with coupling agent, glass fiber is not coated with silicone) Poor compatibility with PVC carrier; Insufficient use of dispersant (less than 10% of filler quality) Can't wrap hard particles; 3. Moisturized raw materials (filler moisture content > 0.1%) hydrogen bond reunion between particles;

Solution: ① Filling pre-treatment: titanate coupling agent for calcium carbonate/talc powder (1%-3%) Surface modification, glass fiber after drying at 80 ℃ for 2 h with silane coupling agent (1% -2%) Coating; ② Diffuser optimization: choose PE wax + calcium stearate composite system, increase the amount to 15% -25% of the filler (Glass fiber needs to be increased to 20%-30%) Pre-dispersion process: high-speed mixing of filler and dispersant 10-15min (rotation speed 600-800r/min) Add the PVC carrier.

2. Insufficient thermal stabilizer or mismatch (exclusive high frequency problem)

Performance: after mixing the material yellowing, when extruded to produce HCl irritating smell, the masterbatch surface has foggy spots, Fragility of subsequent products, decreased mechanical performance;

Cause: ① Thermal stabilizer consumption <3% (hard PVC no plasticizer buffer, thermal stability demand is higher) ② Type selection error (such as using soft PVC special calcium zinc stabilizer, or lead salt stabilizer for transparent hard PVC) ② No auxiliary stabilizer (such as epoxy soybean oil), narrow thermal stabilization window;

Solution: ① Precise match stabilizer: Environmentally friendly scenario selection of calcium zinc composite stabilizer (add 3%-5%) Organic tin stabilizer (2%-3%), industrial grade products optional lead salt stabilizer (1.5%-3%) ② Replication auxiliary stabilizer: add 2%-5% epoxy soybean oil to prolong the thermal stability time;②② Avoid mixing stabilizers (e.g. calcium-zinc conflict with organic tin).

3. Lubricant imbalance (hard PVC exclusive key issues)

Performance: after mixing material clot, when extruded melt adhesive, adhesive mold head, or masterbatch surface frost, products surface deposition;

Cause: 1 Internal lubricant deficiency (such as butylene stearate <1%) High melt viscosity, high processing resistance; 2 External lubricant excess (such as paraffin > 3%) , precipitated to the surface to form white cream; precipitationof lubricant and thermal stabilizer conflict (For example, some paraffins will reduce the efficiency of calcium-zinc stabilizers);

Solution: ① Lubricant combination: internal lubricant (butyl stearate / stearic acid) 1%-2% + external lubricant (polyethylene oxide wax) 0.5%-1.5%, total ≤3%;② Matching stabilizer type: calcium zinc stabilizer with polyethylene oxide wax, organic tin stabilizer with stearic acid Small batch testing to avoid overdose.

4. The raw materials are not sufficiently dried (common but the effect is more significant)

Performance: the mother particle section has a bubble, the subsequent processing produces a needle hole, the filler is dispersed unevenly;

Cause: PVC resin, calcium carbonate, glass fiber and other raw materials moisture content > 0.1%, moisture at high temperature evaporation, broken Bad PVC combined with the interface of the filler;

Solution: ① Raw material separation drying: PVC resin 80 ℃ baking 2h, calcium carbonate / talc powder 100-120 ℃ baking 4h, glass fiber 80 ℃ baking 2h, Moisture content ≤0.05%; ② The mixer is equipped with an exhaust port to avoid secondary moisture absorption after drying.

II. Melt extrusion link: the core risk point of hard PVC masterbatch processing

1. PVC degradation (exclusive fatal problem)

Performance: Release of HCl irritating odor when extruded, masterbatch yellowing / blacking, surface foggy, subsequent products brittle Crack and tensile strength decreased by more than 30%;

Cause: ① Extrusion temperature is too high (cylinder > 185 ℃, mold head > 190 ℃) Hard PVC without plasticizer buffer, high temperature directly triggers degradation; ② Cylinder partial overheating (Temperature sensor failure) ② Screw diameter ratio <28, plasticization process is insufficient, PVC is not sufficiently stable to extrude; Screw shear is too strong (rotational speed > 180r/min), shear excess raw heat;

Solution: ① Precise temperature control: cylinder 160-180 ℃, die head 170-185 ℃, regular calibration of temperature sensor;② Optimized screw parameters: length diameter ratio ≥32, choose weak-medium shear screw (avoid strong shear heat generation) Speed control at 120-160r/min Emergency treatment: immediately cooling 10-15 ℃, add 1% -2% thermal stabilizer, rinse the cylinder with PVC cleaning agent; Long-term prevention: clean the cylinder carbon accumulation every 8h (with PE wax + cleaning agent).

2. Insufficient plasticization (underplasticization)

Performance: the surface of the masterbatch is rough, there is a sense of particles, the cross-section can be seen unmelted PVC particles or undispersed filler After processing, the mold head is blocked and the surface of the product is numb;

Cause: ① Extrusion temperature is too low (<160 ℃) PVC carrier is not completely melted; ② insufficient screw shear (ordinary screw without shear components) Can't wrap hard filler; ② filler content is too high (such as calcium carbonate > 70%, glass fiber > 40%) PVC melt can not be completely covered;

Solution: ① Targeted heating: cylinder end temperature increased to 175-180 ℃, mold head temperature 180-185 ℃;② Reinforced shear: choose a screw with a barrier-type shear element, or add 0.5%-1% internal lubricant (Butylene stearate) auxiliary plasticization; ( ( (3) Control filling content: calcium carbonate ≤60%, glass fiber ≤35%, excess need to increase the proportion of PVC carrier.

3. Mould head blockage and equipment wear (hard PVC exclusive high frequency problem)

Performance: the extrusion bar suddenly broke, the mould mouth has a stack of coke paste / filler aggregate; screw, inside the cylinder severe wall wear (plasticization efficiency decreases after long-term production);

Cause: ① filler regrouping particles (such as glass fiber bundles, calcium carbonate hard blocks) Clogged mould hole; ② Carbide adhesion mould hole produced by PVC degradation; MouMouThick filler hardness (Fiberglass Mohs hardness 7, talc powder 2.5-5), long-term friction scratch screw cylinder;

Solution: ① Raw material screening: filter PVC and filler with 40 mesh screen to remove large particle aggregates;② Regular cleaning of the mould head: wipe every 2-4h downtime, or install automatic mould cleaning device; Equipment protection: optional double alloy screw / cylinder (wear-resistant and corrosion-resistant) Glass fiber reinforced masterbatch production with mold head filter core (80 mesh) Optimize the dispersion process to avoid filler reunification.

4. Melt rupture (due to high melt viscosity)

Performance: the material surface is uneven, corrugated, even broken, can not be smoothly cut;

Cause: ① Hard PVC melt viscosity is high, mold head temperature is too low (<170 ℃) Lead to poor fluidity; ② Too small gap (<2mm) The melt output resistance is large; the internal lubricant is insufficient, the melt and the mold head friction coefficient is too large;

Solution: ① raise the temperature of the mould head 5-10 ℃, to ensure the smooth flow of the melt;② Adjust the gap of the mould to 2-3mm, match the diameter of the material bar; AdAdjust 0.3%-0.5% lubricant (such as butylene stearate) Reduce melt friction; stable screw speed to avoid melt pressure fluctuations.

III. Granulation and Cooling: The Core Issues of Hard PVC masterbatch Appearance and Forming

1. masterbatch fracture/collapse edge (exclusive core pain point)

Performance: easy to break after cutting or during transportation, the section is flat without toughness, both ends have crash edge spurs, after Continued product low temperature (-10 ℃) cracking;

Causes: ① PVC degradation (broken molecular chain), decreased toughness; ② filler content is too high (>60%) The proportion of PVC carriers is insufficient and cannot provide toughness; the cooling speed is too fast (water temperature < 15 ℃) Internal stress is not released; Insufficient use of hardener (CPE / ACR < 30% in the hardening matrix);

Solution: ① Optimize the extrusion temperature to avoid PVC degradation; ② Reduce the filling ratio (Calcium carbonate ≤50%, glass fiber ≤30%) Increase the use of PVC carrier; Cooling process: water temperature control 20-25 ℃, adopt "Tank cooling + air cooled secondary cooling" Cooling time ≥30s, releasing internal stress; 4 Increase the hardening granules to increase the content of CPE / ACR plasticizer (30% -50%) Add 3%-8% PVC-g-MAH compatible agent.

2. Irregular cutting (due to excessive hardness of the material)

Performance: masterbatch length varies (deviation > 1mm) 、Both ends collapsed, there are spurs, and even when cutting grain bar broken;

Cause: ① blurred cutting knife (hard filler wear cutting knife) or too large gap (> 0.5mm) ② Traction speed and cutting speed are not synchronized; ②② Material thickness is uneven (Fluctuations in melt viscosity due to uneven dispersion of fillers);

Solution: ① Cutting knife optimization: choose carbide cutting knife (cutting glass fiber / carbon fiber granules) Grinding every 8h, adjust the cutter and die gap distance <0.5mm;② Parameters match: traction speed 1-2m/min, grain cutter speed 500-700r/min, ensure uniform length (2-3mm) ② Adjust the gap between the mould head to ensure that the diameter deviation of the material is ≤0.2mm.

3. parent cavity/bubble (due to moisture/gas degradation)

Performance: the mother particle section has hollow holes or small bubbles, easy to break when subsequent processing, affecting product density (If the pressure capacity of the pipe decreases);

Cause: 1. Moisture absorption of raw materials (moisture content > 0.1%) Water vaporization at high temperature; PVC decomposition or filler decomposition (such as partial flame retardant filler) Gas generation; 3. Vacuum exhaust is not open or the vacuum is insufficient (> 5Pa);

Solution: 1. Raw materials are thoroughly dried (moisture content ≤0.05%) ② Open the vacuum exhaust system (vacuum ≤5Pa) 、Exhaust gas;MiMixer is equipped with exhaust port, hopper cap sealed, to avoid air entrapment; Control the extrusion temperature to avoid PVC degradation.

IV. Performance and subsequent use problems: the key pain points of hard PVC masterbatch failure

1. Functional effect is not up to standard (core failure problem)

Performance: ① Enhanced masterbatch: Tensile strength improvement <20%, insufficient rigidity (bending modulus <2500MPa) ② Increased hardening of the masterbatch: low temperature (-20 ℃) impact strength improvement <30%, product brittle cracking Weatherproof masterbatch: outdoor use for 6 months is fade, become brittle; Filling masterbatch: product surface wetting point, mechanical performance fluctuations;

Cause: ① insufficient content of functional components (glass fiber <20%, toughening agent <30%, light stabilizer <3%) ② Dispersion of filler / enhancer is uneven, local concentration is not enough; ② Wrong selection of auxiliary (such as using sharp titanium-type titanium powder as an outdoor masterbatch, poor weather resistance);

Solution: ① improve the concentration of functional components (glass fiber ≥30%, toughener ≥30%, light stabilizer ≥3%) ② Optimize dispersion process (increase dispersant, prolong mixing time, strong shear screw) ② Correct selection (outdoor use of ruby type titanium powder + UV327 light stabilizer, use ACR / MBS hardening agent to increase toughness) Oh.

2. Poor compatibility with hard PVC substrate (adaptability problem)

Performance: after the masterbatch and pure hard PVC mixed processing, product stratification, cracking, or processing mobility sharply decreased (melt viscosity soars, can not be extruded smoothly);

Cause: ① Carrier PVC type does not match (If using soft PVC carrier masterbatch, the content of trace plasticizer leads to a decrease in stiffness) ② The filler content is too high, resulting in melt viscosity and the substrate do not match;②② No compatibility agent is added, the filler is weakly combined with the PVC interface;

Solution: ① Strict matching of the carrier and the substrate (hard PVC general type carrier for hard PVC products) ② Control the ratio of masterbatch addition (enhance the masterbatch 10%-30%, fill the masterbatch 15%-30%, increase the toughness of the masterbatch 5%-15%) Add 3%-5% PVC-g-MAH compatible agent to improve the interface binding force.

3. masterbatch moisture absorption / clotting (after storage performance decreased)

Performance: after 1-3 months of storage, the masterbatch surface moisture, clotting, subsequent processing to produce bubbles, thermal stability Agent failure (yellowing during product processing);

Cause: Insufficient drying after cooling (moisture content > 0.1%) ② Packaging is not tightly sealed, moisture-absorbing filler (such as calcium carbonate, glass fiber) Absorb moisture in the air; AbsAbsorb moisture from the lubricant;

Solution: ① Secondary drying after cooling (60-80 ℃ baking 1-2h, moisture content ≤0.05%) ② Sealed packaging with aluminum foil bag + dryer, stored separately (avoid mixing with moist materials) Control the use of lubricant to avoid surface precipitation.

V. Exclusive problems and targeted solutions for different types of hard PVC masterbatchs

Common problems specific to glass fiber/carbon fiber reinforced masterbatchs include glass fiber exposure, severe wear and tear of production equipment, and The rigidity of the finished product is uneven. The target solution is: firstly, the glass fiber needs to use a silane coupler for surface pre-treatment To improve the compatibility with the PVC carrier; Second, the use of double alloy screws and cylinders to enhance the wear resistance of the equipment Corrosion performance, suitable for long-term processing of hard glass fiber; third, the use of dispersant to improve the quality of glass fiber 20%-25%, by fully wrapped to avoid glass fiber reunion; Fourth, strictly control the content of glass fiber not more than 35%, avoid Excessive impurity content leads to machining difficulties and performance fluctuations.

Exclusive common problems of calcium carbonate / talc powder filling masterbatch are focused on the appearance of smear spots on the surface of the finished product, masterbatch toughness Sex decrease and filling dispersion is uneven. Targeted solution is: First, the number of items ≥2000 Fine filling, and use titanate coupling to make surface modification, improve the bonding strength with PVC; Second, the filling contains Quantity control within 50%, to avoid the loss of toughness due to insufficient carrier accounting; third, the use of PE wax and resin Calcium acid composite dispersion system, improve the dispersion uniformity of filler in PVC; Fourth, optimize the pre-dispersion process The filler and dispersant are mixed at high speed in advance and then added to the PVC carrier.

Reinforcement Granules (CPE/ACR System) Exclusive common problems are the masterbatch itself is brittle, hardening effect is not expected and with PVC substrate peeling. The solution is to increase the content of CPE or ACR to more than 30%, while adding 3% -8% PVC-g-MAH compatible agent, reinforced hardener and PVC interface combination; Second, control the extrusion temperature at 165-175 ℃ In the meantime, avoid the failure of the curing agent due to high temperature decomposition; third, the cooling water temperature is stable at 20-25 ℃, using step by step Step cooling releases internal stress and reduces the risk of fracture.

Common problems with weatherproof mother particles include inadequate anti-UV effect, easy fading of finished products and changes after outdoor use fragile. Targeted solution is: firstly, the use of photostabilizer and ultraviolet absorbent composite system, total Add no less than 5% to ensure weather resistance; Second, choose ruby type titanium powder as weather-resistant filler, instead of Sharp titanium-type titanium powder with poor weather resistance; third, the aid compatibility test is carried out in advance to avoid light stabilizers Mutual inhibition effect with thermal stabilizer; Fourth, control the extrusion temperature does not exceed 180 ℃, to prevent UV agent due to high temperature Decomposition leads to functional decline.

VI. Production process key checking logic (quick positioning problem)

1. First check raw materials: check the moisture content of raw materials (≤0.05%) Thermal stabilizer type and use, filler surface treatment status, excluding source hidden risk;

2. Re-check process: Priority check extrusion temperature (160-185 ℃), screw speed (120-160r/min) Mixing time (≥20min), these three parameters are the core of control degradation, plasticization and dispersion;

3. Rear view equipment: check the screw / cylinder wear situation (reinforcement / filling masterbatch needs wear-resistant equipment) Cutting knife sharpness, vacuum exhaust system stability, equipment failure can lead to batch problems;

4. Small test verification: after the problem, first do 5-10kg small batch test (Adjust the use of thermal stabilizer, dispersant ratio, temperature), validate the qualification and then mass production.

The core contradiction of hard PVC masterbatch production is "PVC thermal stability control + hard filler dispersion + brittle cracking prevention" Most problems can be through "raw material pre-treatment (drying + surface modification) Formula matching (thermal stabilizer + dispersant + compatible agent), process parameter optimization (temperature + shear + cooling) The key is: ① strictly control the moisture content of raw materials <0.05%; ② use of thermal stabilizer≥3% (Calcium zinc type 5%) To avoid degradation, the filler needs coupling agent modification + sufficient dispersant to ensure uniform dispersion. Cooling water temperature 20-25 ℃, to avoid brittle cracking; 5 Enhance / fill the masterbatch with wear-resistant equipment to reduce wear.

When mass production, it is recommended to establish "raw material-process-finished product performance" Testing desk, record the use of thermal stabilizer, extrusion temperature, rigidity / impact strength of the finished product, easy to quickly Tracing and troubleshooting repetitive issues.

How to avoid these problems?

To avoid all kinds of problems in the production of hard PVC masterbatch (degradation, reunification, brittleness, malfunction, etc.) The core logic is “source control + process precision control + equipment adaptation + post-processing protection” Combined with hard PVC "poor thermal stability, high melt viscosity, reliance on hard filler" Specifications, according to the entire production process to develop targeted prevention and control measures.

I. Source Control: Optimization of raw materials and formulations (avoiding 80% of basic problems)

1. Raw material pre-treatment: thorough drying + surface modification

Strictly controlled moisture content: all raw materials (PVC resin, calcium carbonate, talc powder, glass fiber, etc.) Must be dried, target moisture content ≤0.05%: PVC resin 80 ℃ baked 2h, inorganic filler (Calcium carbonate / talc powder) 100-120 ℃ bake 4h, glass fiber 80 ℃ bake 2h, use immediately after drying, to avoid secondary moisture absorption;

Surface modification of filler / enhancer: 1%-3% for calcium carbonate, talc powder Titanate coupler pre-treatment, glass fiber coated with 1%-2% silicone coupler, enhanced with PVC Compatibility of the carrier to avoid reunification from the root;

Raw material screening: with 40 Screen filters all solid raw materials, removes metal chips, large particle aggregates, avoids blockage of mold heads and scratches injury equipment.

2. Formula precise match: adjuvant adaptation + proportion balance

Sufficient amount of thermal stabilizer and suitable: environmental scenario selection of calcium zinc composite stabilizer (add 3%-5%) High-efficiency scene selection of organic tin stabilizer (2%-3%), it is strictly forbidden to mix different types of stabilizers; 2%-5% combination Epoxy soybean oil auxiliary stabilizer, extend the thermal stability window, avoid degradation;

Enough dispersant and targeted matching: PE wax + calcium stearate composite system for filling mother particles (15%-25% of filling) Glass fiber enhanced mother particle dispersant use increased to 20% -30% of glass fiber, to ensure that the hard particles are fully wrapped;

Lubricant combination and control: Internal lubricant (butane stearate / stearic acid) 1%-2% + external lubricant (polyethylene oxide wax) 0.5%-1.5%, total ≤3%, to avoid insufficient internal lubricant causing melt viscosity, or excessive precipitation of external lubricant frost;

Functional ingredient content can be controlled: calcium carbonate ≤50%, glass fiber ≤35%, toughener (CPE / ACR) ≥30%, no excessive addition of filler / enhancer, avoid PVC The carrier cannot completely cover the resulting brittleness and dispersion.

II. Mixed links: evenly dispersed + avoid local imbalances

1. Optimize mixing order and parameters

Mixing order: first add PVC carrier + thermal stabilizer (pre-mix 5min) → Add pre-treated filler / enhancer + dispersant (high speed mixing 10-15min, rotation speed 600-800r/min) → Add lubricant (last mix 5min) to ensure that the ingredients gradually merge;

Pre-dispersion process: hard filler (glass fiber, talc powder) High speed pre-mix with the dispersant separately for 10min, thoroughly disperse the reunited particles, then add PVC Carrier to avoid "filling clots";

Mixing temperature control: Mixing temperature is kept at 50-60 ℃, avoid high temperatures leading to thermal stabilizer premature failure or raw material adhesion.

III. Melt extrusion: precise temperature control + process adaptation (core prevention and control degradation, plasticization problems)

1. Precise temperature control: locking thermal stability window

Strictly set temperature range: cylinder 160-180 ℃ (Front 160-170°C, middle 170-175°C, end 175-180°C) Mould head 170-185 ℃, strictly forbidden to exceed 185 ℃ (hard PVC without plasticizer buffer, easy to degrade at high temperature);

Periodic calibration equipment: calibrate temperature sensors before each batch production to avoid local overheating of the cylinder (Local temperature > 185 ℃ will cause degradation), while checking whether the heating ring is evenly heated;

Emergency cooling mechanism: If HCl irritating odor or yellowing of the masterbatch occurs when extruding, cool immediately 10-15 ℃, add 1%-2% thermal stabilizer, rinse the cylinder with PVC cleaning agent.

2. Screw and melt state optimization

Screw fit: choose a screw with a diameter ratio of ≥32, with a weak - medium cutting element (Avoid excessive heat shear) Glass fiber reinforced masterbatch need to choose double alloy screw / cylinder (wear and corrosion resistance);

Stable speed and pressure: screw speed is controlled at 120-160r/min, to avoid too fast speed leading to shear thermal degradation, or too slow leading to insufficient plasticization; open Vacuum exhaust system (vacuum degree ≤5Pa), remove moisture and plasticizer volatiles, avoid mother particle bubbles;

Mould head parameter adjustment: mould gap adjusted to 2-3mm, ensure uniform thickness of the material (deviation ≤0.2mm) The temperature of the mould head is 5-10 ° C higher than the end of the cylinder to avoid melt breakage.

IV. Granulation cooling: avoid cracking + appearance regularity

1. Cooling process: temperature control + time control + secondary air cooling

Precise water temperature control: cooling water temperature is stable in 20-25 ℃, both avoid water temperature < 15 ℃ leading to internal stress concentration (brittle cracking) Also avoid water temperature > 25 ℃ resulting in insufficient cooling of the bar;

Extended cooling time: bar in the cooling tank stay ≥30s, after the water out, then through 10-15s Air-cooled secondary cooling to ensure that the surface temperature of the mother particle drops below 40 ℃ and the internal stress is fully released;

Separation cooling: Separation bar inside the sink, to avoid multi-root bar winding fit, reduce adhesion and outer Viewing defects.

2. Grain cutting parameter match: sharp cutting knife + synchronous speed

Cutting knife optimization: choose a carbide cutter (especially suitable for glass fiber / carbon fiber granules), every 8h Polish once, adjust the cutting knife and die gap distance <0.5mm, to avoid the cutting knife blurring leading to crash edge, burrs;

Speed synchronization: traction speed (1-2m/min) and cutting machine speed (500-700r/min) Accurate matching ensures uniform masterbatch length (2-3mm), avoiding long variations leading to stacking damage.

V. After-treatment and storage: avoid subsequent moisture absorption, clotting, and functional deterioration

1. Secondary drying: completely remove surface moisture

After cutting the masterbatch into the vibration dryer, bake at 60-80 ℃ 1-2h, ensure the surface moisture content ≤0.05%, touch hands non-sticky hands, no sense of moisture;

2. Sealed packaging + environmental control

Cooling the masterbatch to room temperature (about 25°C) Immediately after sealing the packaging with aluminum foil bag + dryer, to avoid exposure to air suction;

Storage environment control: temperature 15-25 ℃, humidity≤60%, stored separately (not mixed with moist material) In particular, to avoid weather-resistant masterbatch, enhance the masterbatch long-term exposure to high temperature and high humidity environment.

VI. Exclusive prevention and control measures for different types of hard PVC masterbatchs

1. Glass fiber / carbon fiber reinforced masterbatch

Additional 80 mesh filter element to intercept the undisturbed fiberglass bundle;

Regular inspection of screw / cylinder wear (once per 100 tons of production) Timely replacement of wear-resistant parts;

Avoid fiberglass content greater than 35%, increase the proportion of PVC carriers or add compatibility agent if necessary.

2. Calcium carbonate / talc powder filling masterbatch

Select the number of items ≥2000 purpose ultrafine filling, reduce the impact on the surface of the product;

The dispersant uses "PE wax + calcium stearate" combination to avoid uneven dispersion caused by a single dispersant;

The filling volume is controlled within 50%, ensuring that the PVC carrier can completely cover the filling without sacrificing toughness.

3. Increased hardening granules (CPE/ACR system)

Intensifier content not less than 30%, while adding 3%-8% PVC-g-MAH compatible, reinforced with PVC interface combination;

Extrusion temperature is strictly controlled at 165-175 ℃, to avoid high temperature decomposition of the curing agent;

Cooling uses "sink + air cooling" for gradual cooling to avoid cracking caused by rapid cooling.

4. Weatherproof granules

Photostabilizer and UV absorber combination (total ≥5%) Preference is given to UV327 and UV531.

Combined with diamond type titanium powder, to replace the sharp titanium type titanium powder with poor weather resistance;

Extrusion temperature does not exceed 180 ℃, to prevent UV agent failure due to high temperature decomposition.

VII. Full process control: Establish detection and traceability mechanisms

Small batch test verification: 5-10kg small test before each batch production to test the appearance of the masterbatch (no cracks, bubbles), thermal stability (no yellowing when heated to 180 ℃), dispersibility (no cross-section reunification) After qualification, mass production;

Key Parameter Record: Establish "Raw Materials - Processes - Finished Products" Record raw material moisture content, thermal stabilizer consumption, extrusion temperature, screw speed, finished product performance (rigidity, impact strength), easy to quickly trace the problem;

Equipment regular maintenance: every 8h clean cylinder accumulated carbon (rinse with PE wax + cleaning agent) Weekly inspection of cutting blade sharpness, screw wear, monthly calibration of temperature sensors and vacuum systems, Ensure stable operation of the equipment.

The core problem of avoiding hard PVC masterbatch production is "Precise control of thermal stability, ensuring dispersion uniformity, balancing toughness and machinability" : through raw material drying + modified solution reunification, through temperature control + Enough stabilizer to avoid degradation, avoid brittle cracking by adaptive cooling + cutting parameters, by formula matching + Equipment wear-resistant design for hard filling. The whole process revolves around the “low risk process window” (Temperature 160-185℃, moisture content≤0.05%, filler≤50%) By deploying, the incidence of all types of problems can be controlled below 1%.