In-plant plastic recycling (also called in-house or post-industrial recycling, PIR) lets a manufacturer recover clean production scrap and return it to the process—instead of paying to store, haul, and dispose of it. For a stable, single-polymer waste stream, the result is usually lower virgin-resin purchases, less handling, and tighter control over recycled-material quality.
This guide is written for injection molders, extruders, film/bag converters, and pipe/profile plants—not for commercial recyclers buying mixed post-consumer bales. It covers which scrap is suitable, what equipment you need, how to estimate savings, and when an in-plant system beats tolling or selling scrap as waste.
For plant-level capital budgeting on full commercial lines, use the separate plastic recycling machine ROI analysis. To compare compact machines vs full lines, see small plastic recycling machine vs industrial line.
What Is In-Plant (Post-Industrial) Plastic Recycling?
In-plant recycling captures off-cuts, trimmings, start-up scrap, rejected parts, and other known production waste before it mixes with outside material. Scrap is sorted by polymer and color, reduced in size, and—where required—washed, dried, and pelletized. Recovered flakes or pellets are then blended back into an approved formulation or sold as a documented industrial stream.
That is different from post-consumer recycling: you already know the resin grade, additive package, and production history. Quality risk is lower—but only if you keep polymers, colors, and degraded material separate.
Which Production Scrap Is Suitable?
| Scrap type | Examples | Typical first process step |
|---|---|---|
| PE film & bags | LDPE/LLDPE/HDPE edge trim, film rolls, bag scrap | Shredder / cutter-compactor → pelletizing |
| PP raffia & woven | Draw tape, woven-bag off-cuts, nonwoven waste | Shred + densify/pelletize |
| Rigid production scrap | Runners, flash, pipe/profile off-cuts, rejected parts | Granulator / crusher → regrind |
| Clean off-spec product | Known resin grades, separable from metal/other polymers | サイズ削減 ± 軽洗浄 |
混ぜないでください 異なるポリマーや互換性のない添加剤パッケージ、または高度に劣化したスタートアッププルージュを再利用する計画があるストリームに投入しないでください。クリーンで文書化された廃棄物ストリームは、混ざったフロアスクラップよりも再導入が容易です。.
リサイクル生産スクラップの4つのビジネス上の利点
1.廃棄物、輸送、貯蔵コストを削減
大きなスクラップは床面積を占め、繰り返しの取扱いと輸送コストが発生します。生産ライン近くでの処理は、輸送荷重を減らし、第三者からリサイクル材料を購入する必要がありません。.
2.天然樹脂の一部を代替
製品仕様が許可される場合、検証済みのリグリンドやペレットは天然樹脂とブレンドできます。許可される割合は、一般的な「X%が大丈夫」という仮定ではなく、試験、品質管理、顧客要求からきます。.
3.リサイクル材料の品質を管理
元の樹脂、カラーマスターバッチ、プロセス履歴を知っています。そのトレーサビリティが、未知の混ざったリサイクレートを購入する場合よりも、色、水分、汚染、溶融挙動を管理しやすくします。.
4.循環性とリサイクル含量報告をサポート
製造スクラップの回収は、材料を生産的な使用に保ち、廃棄物削減とリサイクル含量目標のための測定可能なデータを作成します。コンバーターの仕様に合った余剰品は、販売することもできます。.
工場内システムに必要な設備は何ですか？
ラインをスクラップの形状、汚染、水分、ピークkg/h、プロセスが受け入れる品質に合わせて選択してください。.
| Waste condition | Typical equipment | 出力 |
|---|---|---|
| クリーンな硬質ランナー、部品、プロファイル | グランュラーターやクラッシャー, ,金属保護、粉塵管理 | サイズ制御再粒化 |
| クリーンなフィルム、ラフィア、綴じ袋 | シュレッダーやカッター・コンパクタ+ ペレット化ライン | リユース可能なペレット |
| 汚れたまたは印刷されたフィルム | 洗浄ライン, ,プレッサー／乾燥機、ペレット化 | Washed flakes or pellets |
| Large hollow / thick-wall rigid scrap | シュレッダー → crusher → optional wash | 均一なフラック |
Size the system from measured peak and average scrap rates—not only the nameplate output of the production machine. Leave space for safe feeding, buffer storage, dust control, and maintenance access.
A Simple In-Plant ROI Model
Start with annual recoverable scrap, then calculate value created and costs avoided:
Annual benefit = avoided virgin-resin purchases + avoided disposal/transport costs + sale value of surplus recyclate − annual power, labor, maintenance, and consumables.
Simple payback (years) = installed project cost ÷ annual benefit.
Use conservative recovery yields. Include sorting losses, screen changes, blades, filters, utilities, floor space, and quality testing. For a broader commercial-line framework, see the cost-benefit analysis guide.
Worked example (illustrative only)
| 仮定 | 参考値 |
|---|---|
| 回収可能な生産廃棄物 | 180,000 kg/年 |
| 生成されるネット材料価値 | $0.30/kg → $54,000/year |
| Avoided hauling & disposal | $12,000/年 |
| Power, labor, maintenance, consumables | −$24,000/年 |
| 推定年間利益 | $42,000/年 |
| 設置プロジェクトコスト | $105,000 |
| シンプルな償還期間 | 2.5年 |
Run at least three scenarios: conservative, expected, and high-utilization. If the project only works under the most optimistic resin price or uptime assumption, the risk is too high.
When In-Plant Recycling Makes Sense
- The plant generates a predictable volume of separable plastic scrap.
- Recovered material has a defined internal use or a reliable external buyer.
- QC can verify polymer, color, moisture, and contamination.
- There is space for safe feeding, storage, dust control, and maintenance.
- Projected savings remain attractive under conservative resin-price and utilization assumptions.
If volumes are irregular, polymers are mixed, or the finished product cannot tolerate recycled content, toll processing or a specialist recycler may be more economical.
RFQ Checklist: What to Send Before You Ask for a Quote
- Polymers, colors, and additive packages that must stay separate
- Average and peak scrap rates in kg/h (photos of piece size help)
- Contamination, printing, labels, oils, and moisture present
- Desired output: regrind for hopper blend, pellets for internal use, or sale
- Quality tests and maximum recycled-content % allowed in the finished product
- Available floor space, power supply, and operating hours
- Representative scrap samples for a trial run
よくある質問
クリーンな生産廃棄物は洗浄が必要ですか？
Not always. Clean, single-polymer runners or edge trim may only need size reduction and metal protection. Printed, dusty, oily, or floor-contaminated material may need washing and drying.
Should in-plant scrap be reused as regrind or pellets?
Regrind is simpler when the process can feed it consistently. Pelletizing improves bulk density, mixing, and filtration—but adds capital, energy, and maintenance cost.
設備容量はどのように選定しますか？
Measure peak kg/h, bulk density, piece size, moisture, and operating hours. Ask the supplier to test representative scrap and state complete-line output—not only the crusher or extruder rating.
最も大きなROIミスは何ですか？
Using gross resin value while ignoring yield loss, labor, utilities, maintenance, screen changes, quality testing, and periods when the line is not fully utilized.
In-plant recycling vs buying a full recycling plant?
In-plant systems target あなたの clean production scrap. A commercial plant is designed for mixed external feedstock, higher contamination, and saleable flake/pellet specs. Choose based on waste origin and end use—not only machine size.
Next Step
Planning an in-plant recycling project? Send material photos, polymer type, peak kg/h, and desired output for a line-level recommendation. Explore related equipment guides: plastic pelletizer selection, プラスチック造粒機ガイド, 、および プラスチックリサイクル機械のコスト.
