Introduction

 

WMB34 is produced by unique process in which carbon black is pre-dispersed, then compounded with the basic resin through plastication. It is widely used in injection and modified compounding applications.

Suitable for PP PE ABS PA+GF materials. It features low dosage, high blackness, good brightness, excellent heat resistance, outstanding dispersibility and tinting power, and minimal impact on the physical

properties of the final product.https://www.jolink-masterbatches.com/product/category/masterbatch-for-modified-plastics

 

What does "Carrier-Free" Means — and Why It Matters

 

Most traditional black masterbatches consist of roughly 20–40% carbon black dispersed in a relatively large proportion of carrier resin, typically LLDPE or HDPE.

The carrier exists to wet and bind the pigment, but it brings two inherent constraints, that is it dilutes the effective pigment loading and it must be compatible with the host polymer, 

a mismatched carrier can cause delamination, surface defects, or reduced mechanical performance.

 

Carrier-free masterbatch takes a different approach.

 

Instead of relying on  traditional carrier system, the carbon black is pre-dispersed at the finest practical particle size,

then bound into granular form with only a minimal amount of resin serving as a binder rather than full carrier.

The result  sometimes referred to in the trade name as "black sand" or high concentration black masterbatch , packs substantially more pigment into every pellet :

 

Higher pigment loading

means less masterbatch is needed to reach the target blackness, which can reduce freight, inventory and dosing complexity per ton of finished compound.

 

Minimal binder content

means the masterbatch contributes far less foreign resin to the blend, preserving the mechanical properties of the base polymer , the decisive advantage in glass-filled and engineering compounds.

 

Broader compatibility

allows one grade to serve multiple polymer families, simplifying purchasing for compounders who run PP, PE, ABS, and PA on the same line.

 

For WMB34, the pre-dispersion step is the heart of the process: carbon black agglomerates are broken down before compounding,

so the extruder's job is to distribute already-wetted pigment rather than to fracture hard agglomerates.

This is the reason the grade achieves excellent dispersion ratings at high pigment loading.

https://www.jolink-masterbatches.com/news/how-does-masterbatch-produced

 

Carrier-Free High Concentration Black Masterbatch VS. Conventional Black Masterbatch

 

Aspect	Conventional Black Masterbatch	WMB34 Carrier-Free Black Masterbatch
Carrier resin share	High (LLDPE/HDPE-based)	Minimal PE, binder function only
Polymer compatibility	Limited to matching carrier family	Broad: PP, PE, ABS, PA+GF
Carbon black content	20–40%	48% ± 1.5%
Moisture	Varies	≤ 0.30%
Typical dosage	2–5%	0.8–3.0% (injection), 1.0–4.0% (compounding)
Impact on base resin properties	Dilution effect from carrier	Minimal

 

 

The practical meaning of the last two rows: when the molder switches from a conventional 40% masterbatch to black masterbatch WMB34,

they typically reduce the feed rate by roughly half while holding the same jetness , because the masterbatch introduces less carrier resin,

the compound keeps more of its original tensile and impact performance.

 

Key Performance Features

 

High blackness and good tinting strength

WMB34 uses the fine-particle furnace carbon black and strong tinting power, giving molded parts rich and saturated black with good brightness at lower addition levels.

 

Excellent dispersion

Dispersion is rated ≤ Level 3.0 (excellent) under ISO 18553 assessment.

Uniform carbon black distribution prevents streaks, specks, and pale patches , the most common causes of rejection in appearance parts.

 

Minimal impact on physical properties

Because the binder content is minimal, WMB34 preserves the tensile strength, impact resistance, and heat performance of the base polymer.

This matters most in modified compounds and PA+GF systems, where a conventional carrier can weaken the fiber–matrix interface or shift the compound's property balance.

 

Excellent heat resistance

The grade withstands standard processing temperatures for polyolefins, ABS, and PA compounds without degradation, supporting stable color across long production runs.

 

Low moisture.

Moisture is controlled to ≤ 0.30%, reducing the risk of silver streaks and voids in injection molding and foaming applications.

 

 

OEM and custom formulations.

Carbon black content, binder system, and pellet format can be adjusted to customer requirements, including conductive and special-purpose grades developed on consultation.

 

Applications

 

Modified compounding and recycling

WMB34 is suitable for compounders coloring PP, PE, and ABS , including recycled streams where carrier compatibility is hard to predict.

Because the masterbatch contributes minimal foreign resin, it colors recycled and blended feedstocks without disturbing the compound's flow behavior or mechanical balance.

 

Injection molding

At 0.8–3.0% dosage, WMB34 serves automotive interior components, appliance housings, electronic enclosures, and technical parts where deep black,

clean surfaces, and stable mechanicals are all required simultaneously.

 

Glass-filled (GF) and engineering compounds

In PA+GF and similar systems, carrier incompatibility is a well-known source of surface defects and property loss.

WMB34's low binder content reduces this risk, making it a practical choice for structural black compounds.

 

 

General compounding

For pelletizing operations producing black compounds for pipe fittings, profiles, and consumer goods,

WMB34 provides consistent batch to batch color with straightforward dosing. 

 

Technical Parameter 

Carbon Content	48%±1.5
Carrier	PE
MFI	20-35 (g/ 10min（190℃ 10kg）
Moisture	≤0.30%
Dispersion	Excellent (≤ Level 3.0)
Compliance	RoHS，PAHs
Application	Modified Compounding/Injection/General Compounding
Dosage Advice	Injection: 0.8–3.0%   Compounding: 1.0–4.0%
OEM	Accpeted

 

Quality and Compliance

 

 

WMB34 is produced under Jolink Tech's ISO certified quality system and complies with RoHS and PAHs requirements.

Every batch is checked for dispersion quality and moisture before release.

As the leading black masterbatch manufacturer with 30 years experience, Jolink owns 20,000 m² intelligent factory and annual capacity of 30,000 tons,

Jolink  supplies more than 40 patents' worth of accumulated formulation and process know-how into each grade  and exports to over 20 countries. https://www.jolink-masterbatches.com/news/category/masterbatch-company-event

 

Packing and Storage 

25kg/bag, PE or Composite Paper bag

Stored under dry, enclosed and cool conditions, protected from UV rays and/or direct sunlight. After used, the opened packaging must be resealed properly to prevent the product from absorbing moisture, which could affect its performance.

 

Note 

The technical results are typical values and are provided for customer reference only. They are not to be regarded as a guarantee of minimum or maximum quality specifications.