処理合板とは
著者: Luju Leader Wood
2025-02-26
Treated plywood is an engineered wood product composed of layered wood veneers bonded with adhesives and impregnated with chemical preservatives. These preservatives enhance resistance to biological degradation (e.g., rot, fungi, termites) and environmental stressors (e.g., moisture, UV exposure). In New Zealand, treated plywood must comply with AS/NZS 1604.3:2021, a standard specifying durability requirements for wood preservatives and treatment processes.
Manufacturing Process of Treated Plywood
Veneer Preparation:
Thin wood veneers (typically radiata pine in NZ) are peeled from logs and dried to reduce moisture content.
Preservative Treatment:
Pressure Treatment: The wood veneers is placed in a retort (sealed chamber). A vacuum removes air, and preservatives (e.g., Copper Azole, Micronized Copper Quaternary – MCQ, or Boron) are forced into the wood veneers under high pressure.
Pressure Treatment: The wood veneers is placed in a retort (sealed chamber). A vacuum removes air, and preservatives (e.g., Copper Azole, Micronized Copper Quaternary – MCQ, or Boron) are forced into the wood veneers under high pressure.
Double Vacuum Process: This method minimizes chemical usage while ensuring deep penetration.
Plywood Assembly:
Veneers are layered cross-grain and bonded with waterproof adhesives (e.g., phenol-formaldehyde) under heat and pressure.
Veneers are layered cross-grain and bonded with waterproof adhesives (e.g., phenol-formaldehyde) under heat and pressure.
Curing:
Treated plywood is dried to stabilize preservatives and meet moisture content requirements (typically ≤25% for AS/NZS 1604.3:2021).
Treated plywood is dried to stabilize preservatives and meet moisture content requirements (typically ≤25% for AS/NZS 1604.3:2021).
Quality Assurance:
Testing for preservative retention levels, penetration depth, and adherence to AS/NZS 1604.3:2021 standards.
Testing for preservative retention levels, penetration depth, and adherence to AS/NZS 1604.3:2021 standards.
Why is Plywood Treated?
Durability: Protects against decay and insect attack, critical in New Zealand’s humid, coastal, and high-rainfall climates.
Compliance: Meets NZ building codes and safety standards for structural applications.
Extended Lifespan: Suitable for high-risk environments (ground contact, marine use) where untreated plywood would fail.
Sustainability: Reduces waste by prolonging service life, aligning with NZ’s focus on eco-friendly construction.
Uses of Treated Plywood (AS/NZS 1604.3:2021)
Construction: Subflooring, wall framing, and roofing in moisture-prone areas.
Outdoor Structures: Decks, fences (requires H3.2 treatment), and pergolas.
Marine Applications: Boat ramps, jetties (H5 treatment for permanent water contact).
Agricultural: Farm sheds, greenhouses.
Infrastructure: Retaining walls, playground equipment.
Construction: Subflooring, wall framing, and roofing in moisture-prone areas.
Outdoor Structures: Decks, fences (requires H3.2 treatment), and pergolas.
Marine Applications: Boat ramps, jetties (H5 treatment for permanent water contact).
Agricultural: Farm sheds, greenhouses.
Infrastructure: Retaining walls, playground equipment.
AS/NZS 1604.3:2021 Standard for Treated Plywood
This standard specifies preservative treatment requirements for plywood used in hazardous environments. Key aspects include:
1. Hazard Classes (H Classes):
H1.2: Indoor use, protected from weather (e.g., framing in dry areas).
H3.2: Above-ground exterior use (e.g., cladding, decks).
H4: Ground contact (e.g., fence posts).
H5: Severe environments (e.g., marine piles, freshwater immersion).
H1.2: Indoor use, protected from weather (e.g., framing in dry areas).
H3.2: Above-ground exterior use (e.g., cladding, decks).
H4: Ground contact (e.g., fence posts).
H5: Severe environments (e.g., marine piles, freshwater immersion).
2. Approved Preservatives:
Copper-based systems:
MCQ (Micronized Copper Quaternary): Low environmental impact, widely used in NZ.
Copper Azole (CA-B): Effective against fungi and termites.
Boron: For indoor or protected outdoor use (e.g., H1.2).
Copper-based systems:
MCQ (Micronized Copper Quaternary): Low environmental impact, widely used in NZ.
Copper Azole (CA-B): Effective against fungi and termites.
Boron: For indoor or protected outdoor use (e.g., H1.2).
3. Treatment Requirements:
Penetration Depth: Preservatives must fully penetrate the outer veneers.
Retention Levels: Minimum chemical retention (e.g., 0.8 kg/m³ for H3.2 MCQ treatment).
Testing: Compliance verified via laboratory testing (e.g., by SCION, NZ’s Crown Research Institute).
Penetration Depth: Preservatives must fully penetrate the outer veneers.
Retention Levels: Minimum chemical retention (e.g., 0.8 kg/m³ for H3.2 MCQ treatment).
Testing: Compliance verified via laboratory testing (e.g., by SCION, NZ’s Crown Research Institute).
4. Documentation:
Suppliers must provide Treatment Certificates detailing:
Preservative type, retention level, and hazard class.
Compliance with AS/NZS 1604.3:2021.
Safety Data Sheets (SDS) for handling and disposal guidance.
Suppliers must provide Treatment Certificates detailing:
Preservative type, retention level, and hazard class.
Compliance with AS/NZS 1604.3:2021.
Safety Data Sheets (SDS) for handling and disposal guidance.
Key Pain Points for Buyers
Understanding NZ Standards:
Misinterpreting H-classes or preservative requirements can lead to non-compliant purchases.
Chemical Restrictions:
NZ prohibits arsenic-based preservatives (e.g., CCA limited to non-residential H5 uses). Buyers must ensure preservatives align with NZ EPA regulations.
Certification Verification:
Fraudulent or incomplete treatment certificates are a risk. Third-party lab testing is advised.
Environmental Concerns:
NZ prioritizes low-toxicity treatments (e.g., MCQ over CCA). Buyers must balance performance with sustainability.
Shipping & Storage:
Treated plywood must stay dry during transit to prevent leaching or warping
白色16mm合板
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