Boiling Water Shrinkage (BWS) is the percentage reduction in the length of a polyester filament after immersion in boiling water for a fixed period. It is calculated as:
BWS (%) = (Original Length – Length After Boiling) / Original Length × 100%
This indicator reflects the thermal setting level, molecular orientation, and dimensional stability of polyester fibers. It directly affects fabric performance, finishing quality, and final product stability.
1. How Boiling Water Shrinkage Is Tested
Typical test conditions simulate dyeing and washing processes:
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Temperature: 100°C
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Duration: approx. 30 minutes
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Sample: fixed-length polyester filament
Higher shrinkage indicates greater internal stress; lower shrinkage suggests better heat-setting and stability.
2. Key Factors Affecting BWS
a. Raw Material & Spinning Process
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Polyester melt quality
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Spinning temperature
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Drawing ratio and drawing method
b. Post-Processing Conditions
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False-twist texturing
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Heat-setting temperature & time
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Tension applied during heat setting
3. Why BWS Matters in Production
For Fabrics
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High BWS → shrinkage after washing, deformation, and dimensional instability
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Low BWS → stiffer hand feel, reduced elasticity
For Downstream Processing
Dyeing and weaving mills must adjust machine settings based on BWS to avoid size deviation and quality defects.
4. How to Reduce Boiling Water Shrinkage
The goal is to release internal stress in the fiber through controlled heat treatment.
(1) Strengthen Heat Setting (Most Effective)
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Increase heat-setting temperature within material limits
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Extend heat-setting time to ensure complete stress relaxation
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Use medium-low tension to avoid generating new internal stresses
(2) Optimize Spinning & Drawing
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Adjust the total drawing ratio
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Use multi-stage drawing (e.g., pre-draw + main draw)
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Improve cooling efficiency during spinning for more uniform crystallization
5. Typical Boiling Water Shrinkage Values
| Polyester Type | Typical BWS (%) | Notes |
|---|---|---|
| DTY | 3–6% | Standard textured yarn |
| FDY | 6–8% | Microfiber types: lower by ~1% |
| Low-shrinkage polyester | <3% (premium products ≤1%) | For high-end and industrial applications |
| POY | 15–50% | Not heat-set; considerable variation |
6. How BWS Influences End-Use Performance
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High or unstable BWS: fabric shrinkage, deformation, higher processing loss
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Overly low BWS: limited elasticity, stiffness, reduced comfort for knitted fabrics
Conclusion:
Boiling Water Shrinkage is not about “the lower the better.”
It must be stable, consistent, and matched to the intended application.
In the textile and synthetic fiber industry, polyester fibers occupy an essential position due to their durability, stiffness, and other advantages. Titanium dioxide (TiO₂), a key additive in polyester production, plays a crucial role in shaping the melt’s properties, directly affecting fiber performance and applications. Today, we’ll dive deep into how this “invisible regulator” alters polyester fibers by varying its content.
1. Why Is Titanium Dioxide Added to Polyester Melt?
Before discussing the impact of TiO₂ content, it’s essential to understand its primary role. TiO₂ serves two key functions in the polyester melt:
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Dulling agent: It reduces the high gloss of polyester fibers, imparting a soft matte finish to fabrics. This helps avoid the “cheap” appearance that can result from excessive shine.
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Stabilizer: During high-temperature polyester melt-spinning, TiO₂ helps reduce polymer chain degradation, thereby improving fiber-forming stability. Simply put, without TiO₂, many everyday polyester fabrics would either have an overly shiny finish or inadequate strength.
2. Content Variation: How It Affects Fiber Properties
TiO₂ content isn’t about more or less—it must be balanced to precisely influence fiber appearance, physical properties, and production efficiency. Let’s explore the three key dimensions of TiO₂ content’s effect:
1. Fiber Appearance: Determining Gloss Level
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Low content (≤ 0.1%): The fiber has a “semi-dull” finish, maintaining some natural gloss with a soft hand feel. This is commonly found in lightweight fabrics, such as shirt materials or bridal linings. It avoids the “plasticky” look of high-gloss fibers while still offering more refinement than matte fabrics.
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Medium content (0.1%-0.5%): The fiber is fully matte, offering a soft, non-glare gloss, making it the mainstream choice for everyday clothing such as casual t-shirts, suits, and bedding sets. It suits most aesthetic preferences in various applications.
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High content (> 0.5%): The fiber’s gloss is excessively muted, sometimes even appearing slightly grayish. Additionally, TiO₂ particle aggregation can create small spots on the surface, affecting the fabric’s visual appeal. This is typically used for specialized fabrics that require high opacity, like blackout curtains.
2. Fiber Physical Properties: Balancing Strength and Feel
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Strength and Toughness: With low TiO₂ content, TiO₂ particles are evenly dispersed in the polyester matrix, helping enhance the tensile strength of the fiber. However, if the content exceeds 0.8%, particles tend to clump, creating “stress concentration points.” This is similar to mixing hard lumps into dough, which makes the fiber more prone to breaking during spinning and reduces abrasion and tear resistance in the finished product.
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Hand Feel and Loft: Moderate amounts of TiO₂ (0.2%-0.4%) help achieve uniform fiber structure, creating a crisp feel without being stiff. When TiO₂ content is excessive, fibers become rough and stiff, significantly reducing comfort during wear or use. For example, low-quality polyester work pants often contain excessive TiO₂, which can cause discomfort and skin irritation.
3. Production and Cost: Invisible Impact on Efficiency
From a production perspective, TiO₂ content influences various factors:
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Melt Flow: Higher TiO₂ content reduces melt flow, requiring higher temperatures and pressures to push the melt through the spinneret. This increases energy consumption and can lead to “broken filaments” due to uneven melt flow, lowering production efficiency.
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Cost Impact: A high TiO₂ content also means more TiO₂ raw material, thereby increasing production costs. This is why fully matte fabrics are priced slightly higher than semi-matte ones, though manufacturers rarely use very high TiO₂ content due to its performance drawbacks.
3. Conclusion: Achieving the “Optimal Content” for Fiber Performance
Ultimately, the amount of TiO₂ in the polyester melt represents a balance between performance requirements and cost efficiency. For mainstream products such as everyday clothing and home textiles, a medium TiO₂ content (0.2%-0.4%) is typically chosen to achieve a soft, matte effect while maintaining fiber strength and texture, while also controlling production complexity and cost. Special applications (such as high-gloss linings or highly opaque fabrics) may require minor adjustments to the content, but it’s essential to avoid excessive levels that could compromise performance.
In the chemical fiber industry, polyester chips (or melt) are the core raw material for producing polyester fibers. Their purity directly determines the quality of the final fiber products. Today, we will discuss one easily overlooked yet crucial indicator in polyester chips—iron content —and how it affects the quality of polyester fibers.
1. What Is the Iron Content in Polyester Chips?
The iron content in polyester chips refers to the trace amount of iron introduced during polyester production, typically in the form of Fe₂O₃, measured in parts per million (ppm). These iron elements commonly originate from raw materials, catalysts, equipment corrosion, or contamination during processing.
Although iron content is usually kept very low (often 1–5 ppm), its presence significantly influences the physical properties, appearance, and spinnability of polyester fibers.
2. Problems Caused by Excessive Iron Content
1. Yellowing and Loss of Whiteness
Iron ions are typical metallic impurities. During high-temperature spinning, they easily catalyze polyester thermal degradation and oxidation reactions, breaking molecular chains and forming chromophoric groups.
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Result: Fibers become yellowish, and whiteness drops significantly.
For high-grade textiles, this visual defect can be almost fatal to product acceptance.
2. Reduced Viscosity and Poor Spinnability
The presence of iron accelerates polyester degradation during melting, leading to a decrease in the intrinsic viscosity (IV).
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Result: Lower polymerization weakens melt strength, making filaments prone to breaking or fuzzing during spinning, which reduces efficiency and yarn quality.
3. Lower Fiber Strength
Iron-induced degradation broadens the molecular weight distribution of polyester, increases weak links and chain ends, and weakens mechanical performance.
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Result: Fiber tensile strength and modulus decline, resulting in reduced durability.
4. Filtration Issues and Equipment Wear
If iron exists as particulate impurities, it can clog spinning components, shorten filter life, and increase operating costs.
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Result: Hard iron particles also accelerate wear on screws, metering pumps, and other precision equipment.
3. How to Control Iron Content in Polyester Chips
Modern polyester producers adopt strict measures at multiple stages to minimize iron contamination:
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Using high-purity PTA and MEG raw materials.
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Employing stainless steel or coated equipment to reduce corrosion.
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Regular cleaning of polymerization units is necessary to prevent the accumulation of degraded deposits.
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Adding suitable stabilizers or chelating agents to suppress the catalytic activity of metal ions.
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Applying multiple filtration and centrifugal purification steps to remove solid particles.
4. Conclusion
Although iron content is only a trace-level indicator, it plays a disproportionately critical role in polyester fiber production—“small weight, heavy impact.”
Effectively controlling iron levels is essential for achieving high-quality, high-whiteness, and high-strength polyester fibers. Beyond technical performance, it is also a key driver for improving product grade and market value.
In the chemical fiber industry, polyester chips serve as the primary raw material for producing polyester fibers. Hidden within these chips, agglomerated particles may look insignificant at first glance, but they can easily become “invisible obstacles” in fiber manufacturing. Today, let’s break down this small yet critical issue to see how it impacts production and what precautions should be taken.
1. First Things First: What Are Agglomerated Particles in Polyester Chips?
Put, agglomerated particles are solid defects formed during polyester synthesis and melting. They typically arise due to excessive local polymerization, cross-linking of molecular chains, oxidized gel-like substances, agglomerates of titanium dioxide, catalyst precipitates, or high-melting substances and carbonized residues deposited on the walls of the reaction vessel.
2. Production Troubles: Three Core Impacts of Agglomerated Particles
From melt spinning to final product quality, gel particles interfere with every step of the fiber manufacturing process.
1. Equipment Blockages: The “Choke Point” in Spinning
During Spinning, polyester chips are melted in the extruder and pushed through the tiny holes of the spinneret to form filaments. Agglomerated particles, with their higher melting point and poor fusibility, often cause problems:
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Minor impact: Particles clog spinneret holes, resulting in broken filaments or fuzzy fibers. This forces operators to stop production for cleaning, directly reducing efficiency.
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Severe impact: Particles accumulate inside the screw or damage costly spinnerets, significantly increasing maintenance and replacement costs.
2. Appearance Defects: The “Flaw Maker” in Fibers
Even if gel particles pass through the spinneret, they remain embedded in the fibers, creating invisible defects:
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Filament yarns lead to uneven fiber surfaces. Fabrics woven from such yarns show specks or defects, compromising smoothness and appearance.
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For staple fibers, particles may break during carding or Spinning, creating neps. This causes uneven yarn thickness and, during dyeing, results in color irregularities that downgrade product quality.
3. Weakened Properties: The “Hidden Killer” of Fiber Strength
Standard polyester fibers have well-aligned molecular chains, ensuring strength and elasticity. Agglomerated particles, however, are overly cross-linked and structurally rigid, bonding poorly with surrounding fibers:
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Under stress, fibers break more easily at the sites of agglomerated particles, significantly reducing tensile strength.
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Fabrics made with such fibers show lower durability, poor stretch resistance, and issues like pilling or cracking—failing to meet downstream quality standards.
3. How to Manage Agglomerated Particles? The Key Lies in Source Control
Since agglomerated particles are highly detrimental, the best strategy is to minimize their formation at the source:
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For chip manufacturers: Optimize polymerization conditions by controlling reaction temperature and time to prevent excessive cross-linking. Employ advanced filtration to remove agglomerated particles, and regularly clean reactors and equipment to reduce build-up.
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For fiber producers: Choose chips with low agglomerated particle content. Before spinning, apply pre-treatment steps such as drying or sieving to minimize the introduction of particles into production.
Final Thought
Producing polyester fibers is much like baking a cake: polyester chips are the flour, and agglomerated particles are the stones hidden in it. Unless the rocks are removed, you cannot make a smooth and high-quality cake.
From our experience, the diameter of agglomerated particles should be controlled below 15 μm, and the count should be less than 0.3 per mg of chips. By paying close attention to this “small detail,” fiber manufacturers can safeguard “big quality,” marking an essential step toward precision manufacturing in the chemical fiber industry.
In the polyester materials industry, blending and copolymerization are two common modification methods, each with distinct principles, processes, performance impacts, and application scenarios. Below is a detailed comparison of the two:
1. Definition & Principle
Blending:
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Physical Mixing: Polyester (such as PET, PBT) is mixed with other polymers (like PC, elastomers) or additives (such as fillers, toughening agents) through melt or solution blending, forming a physical blend system.
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Microstructure: Components are bonded by intermolecular forces without forming chemical bonds, potentially creating island structures or partially compatible homogeneous systems.
Copolymerization:
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Chemical Synthesis: During polyester synthesis, other monomers (such as ethylene glycol, third monomers) are introduced, forming new polymer chains through copolymerization reactions with chemical bonds between different monomers in the molecular chain.
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Microstructure: Forms random, block, or alternating copolymers, resulting in a fundamental change in the chemical structure.
2. Process Characteristics
Blending:
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Simple Process: Typically performed using extruders or internal mixers, requiring no complex chemical reactions.
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High Flexibility: Formula ratios can be quickly adjusted, making it ideal for small batches or customized needs.
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Compatibility Challenges: Compatibility agents (such as maleic anhydride grafts) are needed to improve interfacial bonding between different components.
Copolymerization:
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Strict Reaction Conditions: This process requires precise control of monomer ratios, catalysts, temperature, and reaction time, making it complex.
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Irreversible Modification: Once synthesized, the molecular chain structure is fixed, and its properties cannot be adjusted by physical methods later.
3. Performance Impact
Blending Advantages & Limitations:
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Advantages:
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Rapid improvement of specific properties (e.g., toughness, flame resistance, cost reduction).
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Retains the original properties of polyester (e.g., chemical resistance, strength) while introducing new functionalities.
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Limitations:
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Compatibility issues can lead to phase separation, resulting in poor long-term stability.
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Performance improvements are limited (e.g., heat resistance cannot surpass the matrix limitations).
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Copolymerization Advantages & Limitations:
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Advantages:
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Performance can be controlled at the molecular level (e.g., reducing crystallinity, improving transparency).
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Significantly alters intrinsic properties such as glass transition temperature (Tg) and hydrolysis resistance.
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Limitations:
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High synthesis cost and the need to redesign the polymerization process.
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May sacrifice the original advantages of polyester (e.g., mechanical strength may decrease after copolymerization).
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4. Typical Applications
Common Blending Applications:
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PET/PC Blends: Improves PET’s heat resistance and impact strength, used in electronic enclosures.
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PBT/Elastomer Blends: Enhances toughness, used in automotive parts.
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Flame Retardant Additives: For producing flame-retardant polyester fibers.
Common Copolymerization Applications:
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PCT (Polycyclohexylene Dimethylene Terephthalate): Copolymerization enhances high-temperature resistance, making it suitable for use in LED packaging.
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PEG Copolymerized PET: Introduces polyethylene glycol segments for producing biodegradable polyester.
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Amorphous Copolymer PETG: Reduces crystallinity, used for transparent sheets and 3D printing materials.
5. Selection Recommendations
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Choose Blending: When rapid, cost-effective modifications (e.g., toughening, flame resistance) are required, with less stringent performance demands.
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Choose Copolymerization: When a complete change in material properties (e.g., temperature resistance, degradability) is needed, or when developing high-end specialty materials.
Combining both methods (e.g., copolymerizing first and then blending) can further optimize overall performance, such as improving matrix compatibility through copolymerization, followed by introducing functional fillers via blending.
APET, PET, and PETG are three common polyester materials, and their differences are as follows:
1. Chemical Structure
PET (Polyethylene Terephthalate): Polymerized from terephthalic acid and ethylene glycol.
APET (Amorphous Polyethylene Terephthalate): A variant of PET with a more disordered molecular chain arrangement.
PETG (Polyethylene Terephthalate Glycol): PET modified by introducing the 1,4-cyclohexanedimethanol (CHDM) comonomer.
2. Performance Characteristics
PET: High strength, high rigidity, good heat resistance, good chemical resistance, high transparency, but relatively poor toughness.
APET: Compared to PET, APET offers higher transparency, lower haze (better optical properties), along with good toughness and impact resistance.
PETG: PETG exhibits better flexibility and impact resistance than both PET and APET, along with better low-temperature performance. It also has good processability and chemical resistance.
3. Processing Properties
PET: Relatively good processability. Can be processed into various products using methods like injection molding, extrusion, and blow molding. However, temperature and pressure must be carefully controlled during processing to avoid deformation or cracking.
APET: Processing properties are similar to PET. Due to its amorphous structure, it flows more easily during processing, making it suitable for forming products with complex shapes.
PETG: Excellent processability. Features good thermal stability and flow characteristics, allowing processing at lower temperatures. Product properties can be controlled by adjusting processing parameters.
4. Application Areas
PET: Widely used in packaging (e.g., beverage bottles, food packaging, pharmaceutical packaging), fibers, and films.
APET: Primarily used in packaging applications demanding high transparency and appearance (e.g., cosmetic packaging, gift packaging, electronic component packaging).
PETG: Commonly used in applications requiring good flexibility and impact resistance (e.g., medical supplies, toys, stationery, tubing) and also used in packaging (e.g., heat-shrinkable films, labels).
5. Price
PET: Relatively low cost; the most widely used of the three materials.
APET: Slightly higher price than PET, but its performance and appearance advantages make it widely used in high-end packaging applications.
PETG: Relatively higher price, primarily used in applications demanding higher performance specifications.
Q: Do you have low-melting PET Chips? The polymer must be semi-crystalline and not amorphous.
A: Yes. We have bright-grade 180℃ and 230℃ low-melt polyester chips for yarn/fiber spinning.
Q: We prefer the TM to be 180-205 degrees. Can your 180℃ LMP chip be used for POY yarn spinning, and the end usage is composite yarn spinning?
A: Yes. We have domestic customers who share the same application as yours. Below are the suggestions we give.
- Tg: 80℃
- Density: 1.38 g/cm3
- We suggest drying at 130℃ for 10 hours.
(The moisture content in PET chip should be less than 60 ppm, and 35ppm is better.) - Spinning temperature:
265℃ (without low-temp. diphenyl)
230℃ (With low-temp. diphenyl) - Spinning speed ( 1000 m/min->3000 m/min)
- Best crystallising temperature: 110℃
- Light fastness is the same as regular PET chip
Polyester fiber offers high strength, good elasticity, and excellent processability. It can be used alone or blended with natural fibers, requires no ironing after washing, and is widely used in apparel, home furnishings, and industrial applications. However, its lack of polar groups causes low moisture absorption (0.4%), leading to static buildup, pilling, and poor dyeability. Since its invention, efforts have focused on overcoming these drawbacks. So, how can polyester fiber be modified? Here are three main modification approaches.
1. Chemical Modification
Standard polyester (PET) has a regular, linear structure with rigid benzene rings but lacks polar groups, resulting in poor dyeability despite high strength. Adding tertiary or quaternary monomers during polymerization changes the molecular structure, improving dyeability and physical properties.
This method chemically bonds monomers into the PET chain, creating permanent changes. However, it has limited flexibility, high cost, complex processing, and few suitable monomer choices. The most successful variants are:
Cationic Dyeable Polyester (CDP): Uses the monomer sodium dimethyl 5-sulfoisophthalate (SIPM). SIPM increases molecular spacing (improving dye adsorption) and adds sulfonic acid groups (-SO₃⁻) that bind cationic dyes, significantly enhancing dye uptake. CDP chips are widely used for superfine fibers.
Easy Cationic Dyeable Polyester (ECDP/EDDP): Offers easier dyeing than CDP.
While the domestic Chinese market mainly offers bright CDP and ECDP chips, our company supplies specialized grades:
Semi-dull CDP for Korean clients.
Semi-dull ECDP for Turkish and Indian clients.
Our bright ECDP achieves a sodium content of 13% by weight. It can act as a CD masterbatch during the cationic fiber production.
For more information about CDP and ECDP PES chips, please click https://www.polyestermfg.com/cationic-dyeable-polyester-chip/.
2. Physical Modification
This simpler, lower-cost alternative to chemical modification involves melt blending functional additives (e.g., for UV resistance, antistatic properties, conductivity) with PET chips to create masterbatches. These are then mixed with standard PET for spinning.
The main drawback is that additives bind to PET via weaker intermolecular forces (van der Waals, hydrogen bonds). Consequently, the modified properties can degrade over time.
3. Process Modification
Modifying production parameters or fiber cross-section shape during spinning achieves specific properties. Examples include high-shrinkage fibers, profiled fibers, and sea-island fibers.
Sea-Island Fibers comprises two components:
“Island” (e.g., PET, PA6, PA66, PP).
“Sea” (alkali-soluble polyester – COPET).
Our COPET chips offer excellent spinnability, enabling stable composite spinning with clear interfaces.
After fiber formation, the COPET “sea” is dissolved in alkali solution (e.g., NaOH), releasing the bundled “island” components as ultra-fine fibers (single-filament fineness ≤ 0.05 denier).
Sea-island Fiber
Our company also offers pre-crystallized bright-grade high-shrinkage PES chips. The boiling water shrinkage rate of the high-shrinkage short fibers generated from them can reach 60%- 80%. For more information, please refer to https://www.polyestermfg.com/high-shrinkage-polyester-chip/.
There are mainly three methods to produce high IV PET chips.
1 Direct Polymerisation Method
This method uses continuous polycondensation and direct esterification to produce an oligomer with a high degree of esterification. As the critical ratio of the carboxyl group increases, the reaction speed accelerates and the vacuum requirement decreases, making it easier to produce high-viscosity polyester chips. However, the polymerisation process takes a long time.
High carboxyl content in high-temperature spinning causes more serious degradation, resulting in a decline in the molecular weight and ultimately affecting the tensile strength of polyester fibres.
Therefore, this method is not commonly used, but it can be used for coarse denier requirements.
2 Catalyst Addition Method
In Japan and other countries, many patents document the addition of a special catalyst to the melt polycondensation process, thereby reducing the polymerization time. When the molecular weight goes up a lot, the intrinsic viscosity generally reaches 0.8~1.1 dl/g.
3 Solid-state Polycondensation Method
The regular PET chips (IV: 0.60 ~ 0.68 dl/g) are heated to 200 – 240℃ in a vacuum or inert gas protection. At the same time, the intrinsic viscosity is increased to 0.9–1.2 dl/g. The drying of PET chips is completed during the condensation polymerization process.
This low-cost, stable quality, and easy to reach a certain production is the most widely used production method of high-strength polyester.
Solid-state polycondensation is used to produce high-viscosity PET by heating the lower-viscosity PET polymer to a temperature above Tg and below the melting point.
Under vacuum or inert gas protection, the end groups of the polymer chain have enough activity
to carry out the polycondensation reaction, increasing the relative molecular mass.
The testing method of Melting Point (Tm) our factory uses is a microscope with a Thermal Optical Microscope (TOM), which combines optical microscopy and thermal analysis techniques to observe the melting behavior of materials during heating. The specific steps are as follows:
- Sample Preparation:
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- Select a representative polyester chip sample, ensuring it has a smooth surface and appropriate size.
- Place the polyester chip on the stage of the thermal optical microscope.
- Set Temperature Program:
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- Start the thermal optical microscope and set the heating rate, typically 5-10°C/min.
- Set the appropriate temperature range, generally within the expected melting point of the polyester sample.
- Heating Process:
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- Begin heating the sample while observing its surface changes through the microscope.
- Polyester will show significant phase transition characteristics when approaching its melting point, such as the surface starting to soften or form a molten zone.
- Observe Melting Behavior:
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- Observe the sample’s morphology under the microscope. Typically, when the surface shows clear signs of melting or a liquid phase, it indicates the polyester has reached its melting point.
- Record the temperature at which the surface change occurs, which is the melting point of the polyester.
- What is the content % in your PETG Resin? —
NPG: 12.5%CHDM: 0%DEG: 1.2%
IPA: 0% - Are your chips seaming well with THF and 1.4 Dioxane solvents?
— Yes - Do you use any additives (silica) in chips to reduce CoF?
— No - Can PETG resin be pre-crystallized?
— No - What is the drying process for PETG resin?
Drying Temp.: 65℃
Drying Period: 6 – 12 hours
Common plastics are usually called “pellets,” but some plastics, such as PA nylon and PET polyester, are not called pellets. Instead, they have a more professional-sounding name, “Chips.” Why is this the case?
The biggest difference between Chip and Particle lies in molding shapes.
Common “particles” are cylindrical. Most plastics, such as PE, ABS, and PP, are molded into pellets. They are generally extruded into strips during pelletization and then cut into cylindrical shapes.
Water Pelletizing
Nylon (crystallized) and polyester(PES) are crystalline polycondensations with meager melt strength, making strip pelletizing impossible. Instead, they use underwater hot cutting or air-cooled cutting for pelletizing.
Air Cooling Cutting
The resulting pellets are flake-shaped, hence they are called “chips.” Therefore, chips generally refer to nylon, polyester, and other resins produced by polymer factories or resins modified with minor additives (e.g., PET chips modified with titanium dioxide to produce bright, semi-bright, and matte PET chips).
Typically, downstream modifications such as adding glass fiber (GF), fillers, or tougheners to nylon or polyester result in the material no longer being called chips but rather particles.
Commonalities Between Plastic Chips and Particles
We can observe that whether they are “pellets” or “flakes,” both have regular shapes and uniform sizes, making them “granular.” Their shape and size differentiate them from “powders” and “shavings.”
They also have the following advantages:
Production Convenience: Pellets can easily enter the screw, be melted, plasticized, and then molded. In general, plastic raw material transportation mainly relies on vacuum. During the transportation and processing of powders, the loss can be quite significant. Large, irregular shavings often cause “bridging” at the feed inlet, affecting continuous production. However, some products must use powder due to process limitations.
Transportation Convenience: Pellets are easier to transport. They can be easily bagged and loaded onto trucks for transportation. In contrast, many powder materials are hygroscopic. The large surface area of powder makes it more prone to clumping and even degradation, which is detrimental to processing. Large, irregular scraps, on the other hand, take up much more volume for the same weight.
Ease of Use: When using plastic pellets, the granular form allows for uniform heating and better plasticization, facilitating subsequent mixing with other additives and producing a smooth end product.
Fast Reaction Speed: The molding of polymer materials often involves more than just physical actions. The diffusion path of small molecule products within small particles is shorter than in large particles, making it easier to remove them. Additionally, smaller sample particles have a larger total surface area, increasing heat transfer rates and reaction speeds. Therefore, within a certain range, the reaction speed is inversely proportional to the size of the raw material particles. However, if the particles are too fine, they may agglomerate, adversely affecting the reaction speed. Hence, granular form is generally preferred when manufacturing materials.
Recycled polyester chips are often more expensive than virgin chips due to several factors.
Processing Costs: The recycling process involves additional steps such as collection, cleaning, sorting, and reprocessing, which add to the cost. (And the cost of high-quality bottle flakes is not cheaper than PTA+EG cost.)
Quality Control: Ensuring consistent quality in recycled materials requires rigorous testing and sorting, which increases expenses.
Environmental Regulations: Compliance with environmental standards and certifications for recycled products can incur higher costs. Recycled polyester chips need Global Recycled Standard (GRS) and Transaction Certificate (TC) certification.
As for the package, we can load 1000 kg in one jumbo bag. Or we can load 25 kgs in one small bag.
For a 20 GP container, it can load 20 bags, that’s 20 tons, or can load 960 bags, that’s 24 tons.
We do not recommend 40 GP or HQ containers.
Because according to the shipping company regulations, all the weight (container + cargo) can not exceed 30.5 tons.
20′ container can load almost the same weight as 40′, And its shipping cost is just half.
As a result, the 20 GP container is more cost-effective.
Is Hubei Decon a Manufacturer or Trading company?
Yes, we have factories and Hubei Decon is just used for overseas marketing.
Actually, we do not think the answer to this question is the most important. What matters to customers is the price, quality, and service.
We know some customers who prefer factories. For them, only factories can offer them the lowest quotation.
But not all the factories can provide the most competitive price, because they may have a higher management cost compared with some small trading agents.
Even though the price from factories is the best, what about the service? If they are not so cooperative or their company policy is very stubborn, you need to spend extra time and energy doing business with them. Time end energy is called invisible cost.
So please do not stop responding when the suppliers tell you they are not a manufacturer.
Cooperation is based on mutual choice.
1. Do You Prioritize What We Believe?
We believe in becoming a flexible and customer-driven partner.
We believe in being an extension of our customer’s team.
We believe in an open and honest relationship.
We believe in creating value through continuous innovation.
We believe everything should start and end with quality.
We believe every project deserves the very best.
And we do not believe in shortcuts.
If you prioritize our company core as above, we’re the right choice for you.
If you prioritize other things, you should choose other suppliers.
2.Are We The Right “Fit” For You?
Why you choose us is not because of how good we are boasting.
It is because our offer bridges your needs and our solution solves your pain;
It is because our product can fulfill your desired result and performance;
It is because our market position matches yours and our commitment resonates with you.
You deserve the highest quality manufacturing and packaging services every single time.
Our industry-leading Quality System extends throughout the whole supply chain, from inquiry receipt to final delivery. Complete traceability is based on national standards along with full ISO-9001 and other international compliance. You also have access to our innovative in-house labs for verification and testing solutions. We have a complete track record of robust Quality Systems.
We can definitely have a conversation about specific numbers, but let’s make sure we’re on the same page about the solution being a good fit for your needs.
We do have a discount program for those prospective clients who are willing to help us with local promotions. If you join it, we do not even need to worry about discounts.
Till now, we have about 10 customers who have joined this. Contact us, you will be the next one. Contact Us
(1) With our mission to help customers cut down-converting costs, we don’t believe in an over-priced strategy.
(2) We have been striving to keep prices as low as possible without sacrificing quality. Beyond that, We improve the competitiveness on manufacturing costs by actively seeking the best processing method and logistics service.
We hope that by giving the best support on price to you, we could help ease your capital pressure and develop a mutually beneficial business relationship together.
The raw material of our product is PTA and MEG.
After three stages of esterification reaction, they come to the granulator.
Then after drying and sorting, we get the finished products.
Hubei Decon can make your desired polymer into reality.
We are a professional manufacturer of differentiated Polyester chips.
“Differentiation” is relative to “normalization or homogenization”. Generally speaking, the development of modified PET chips has gone through three stages, “specialization”, “functionalization” and “functional compound”.
With the daily improvement of living standards, consumers have higher demands towards garment materials in aspects of appearance, hand feeling, comfort, function, etc. These demands accelerate the specialty filament development in elasticity, moisture absorption and quick-drying, anti-static, anti-pilling, cationic dyeing, easy dyeing, luster, fluffy, etc. As a result, there is not only a single modified fiber but also more composite modified one. At the same time, the rapid development of industrial and intelligent technology textile demand from the market has promoted the upgrading and development of high-quality functional fibers such as flame retardant, high strength, electrical conductivity, medical and environmental protection.
As the raw material of extrusion or melt spinning, Polyester Chips or Pellets can be customized in aspects of Chemical modification, physical modification, and technological modification.
For example, we have developed alkali-soluble PET chips for the Japan Toray company.
Q: What is your Business Model?
Manufacturer & Distributor
1. Manufacturer: we have Zhongying as our production base and can provide you with the best price and updated technology.
2. Distributor: fulfilling a value-adding function in the supply chain
2.1 Sourcing products in local market according customers’ requirement
2.2 Filling, labelling, bar-coding and palletizing
2.3 Mixing and blending according to customer specific requirements
2.4 Formulating and technical support from dedicated application laboratories
2.5 Providing just-in-time delivery and vendor-managed inventory services
2.6 Utilizing cost-effective transportation way
2.7 Offering one-stop-shop solution
What are your advantages? Let’s summarize these points in short.
1) We are willing to start the business with trial orders.
2) Free samples could be provided on request.
3) No stubborn or stupid policy, and everything could be discussed.
4) Top nice and professional sales representatives.
5) Moderate price with low-risk level. ( Please place a small order and get experienced what we promised.)
What is your product range?
-Till now, our products include water-soluble polyester chips, low melt polyester chips, (easy) cationic dyeable polyester chips, alkali-soluble polyester chips, flame retardant polyester chips, and low viscosity polyester chips.
In a word, we help customers to solve the raw material supply of polyester yarns. You put forward your requirements and we supply you with what you need.
Can you send us free samples?
Yes. Free samples are available upon your request, but the courier charge should not exceed 100$.
We have had stable cooperation with one courier agent in Shenzhen for many years. Their charges are much lower than these of courier companies, like FedEx, DHL, or UPS. We will choose the most cost-effective way to deliver free samples to your hands. Or you can tell us the favorable courier you need.
But if samples are chemical in powder shape, sorry that we can not provide them free of charge. Because it is not easy to send them. You need to offer us your courier account.
What is the Method of Adhesive Test by Using Mylar Film?
This is a question from one of our customers. And it is regarding the water-soluble polyester resin. Mylar film here refers to the polyester film.
After these potential customers receive our samples of WSP resin, they need to conduct an important test about adhesion.
Good adhesive brings a positive result to the sizing process.
Here is the method.
1. Make a 15% clear solution of polyester resin in soft water.
2. Apply this solution to dry completely by air drying
3. Solution must be applied on A4 paper size film in the form of a 3 to 5-inch circle
4. After the polyester film is fully dried, start rubbing by using a coin of yuan on that film.
(Minimum 100 runs are required for rubbing test.)
5. If the film of polyester resin is not disturbed after 100 runs, the adhesion is perfect.
1. What is the Development of Water Soluble Polyester Resin?
The technology of water-soluble polyester resin was firstly developed by EASTMAN USA Company. And then it spread to the rest of the world. Nowadays, the main manufacturers lie in India and China. And Indian companies are more popular, like Zydex and Ran Chemical.
The founders of these two factories were studying in the USA and then worked there. In 1998, they came back to India and finished the development of this product in around 2001. Hubei Decon started the research and development of this resin in 2009. Till now our product is widely used in the domestic market.
Before polyester resin came out, the sizing chemical market was dominated by Acrylic binders. Japanese Company, MATSUMOTO, and GOO CHEMICAL were leading suppliers.
2. What is Recommended Solid Percentage in Water and Solid Pick-up Percentage on Yarn?
Solid % in water: it varies from 13% to 16% based on machine condition.
Pick-up % on yarn: it varies based on different conditions, like rubber roll, steel roll pressure, and squeeze roll pressure. But the dry pickup percentage must be 6% on solid bases.
3. Is Resin Solution Stable under Alkalic Conditions?
If the polyester resin is used for yarn sizing, its solution will not be stable under alkalic conditions. Because after the weaving process, the resin in the fabric will be removed mostly by the alkali. If it is stable, the residue will affect the dyeing, printing, and finishing process.
According to our experience, some customers tend to add some alkalic chemicals during the cooking process of compound sizing chemicals. Alkali is used to improve the dissolving ability of resin.
4. Why is There Residue in the Cooking Tank?
For WSP-010, the residue percentage is from 0.3% to 1.5%. It is the lowest in winter and the highest in summer.
5. Is the resin anionic or nonionic?
Yes. Our water-soluble polyester resin is anionic and it should not be used with cationic. It is only compatible with anionic and nonionic compounds. For example, acrylic size is nonionic.
Compared with acrylic binders, polyester resin has the following advantages.
1 Less Consumption
The highest strength on yarn for the acrylic binder is 650 grams per centimeter square, while for polyester resin it is 1000 grams. So for the same amount of yarn, the resin has less consumption.
2 Lower Price
The raw material cost of polyester is always much cheaper than acrylic monomers. And it is a forever applicable formula. So polyester resin has a much lower price.
3 More Convenient Transportation
The acrylic chemical is in liquid form and polyester is in solid form. So the latter one is more convenient for transportation, especially overseas one. And at the same time, solid form has a lower transportation charge.
Hubei Decon belongs to a Limited company and there are five departments in the company structure. They are the purchasing department, production department, sales department (including after-sale service), technical department, and financial department.
Compared with these big companies, our structure is very simple. But small structure brings us less expense in company managing and labor cost. And simple structure makes flexible service and prompt response come true.
Every department plays an important role in the company and they work together to make our business more profitable.