Conversión de Liner PE (PE Liner Conversion)

Overview

Conversión de Liner PE (Process ID: 7) converts tubular polyethylene film rolls into individual bag liners (bolsas internas) through automated cutting and bottom heat-sealing. These liners provide moisture barriers for industrial bags, particularly for food, chemicals, and hygroscopic materials.

Process Characteristics

Process Type: Order-based production
Production Unit: unidades (units/liners)
Product: PE liners with sealed bottom, cut to nominal length
Machines: 1 specialized line (CONVLI)
Order Pattern: 7\d{6} (e.g., 7000234)
Production Target: 12,000 liners per shift
Speed: 25 units/min nominal

What This Process Does

The Liner PE process:

Receives: Tubular PE film rolls from Extrusión PE (Process 6)
Transforms: Continuous tubular film → Individual sealed liners
Delivers: Counted and packaged liners for insertion into bags
Method: Automated cutting and thermal bottom sealing

Production Flow

Upstream Dependencies

Liner PE consumes PE film from:

Extrusión PE (Process 6): Tubular polyethylene film rolls
- Tracked via lot ID (lote_pe_id)

Downstream Consumers

Produced liners feed into:

Conversión Sacos Vestidos (Process 9): Integrated lined bag conversion
Manual liner insertion: Offline operations (not tracked in system)

Production Tracking Method

Unit Counter Method (ConversionLinerPEContract.js:116-119):

reglasProduccion: {
  modalidad: 'contador_unidades',
  unidad: 'unidades'
}

Data Structures

Key Tables

registros_trabajo

{
  linea_ejecucion_id: FK,
  bitacora_id: FK,
  maquina_id: 8, // CONVLI
  cantidad_producida: liners_producidos,
  merma_kg: waste (returned to Extrusor PE),
  parametros: JSON {
    liners_producidos: integer,
    temperatura_sellado: decimal,
    velocidad_operacion: decimal,
    merma_kg: decimal,
    destino_merma: 'Retorno ExtrusorPE',
    observaciones: text
  }
}

linerpe_consumo_rollo_pe

PE roll consumption:

{
  bitacora_id: FK,
  maquina_id: 8,
  orden_id: FK,
  codigo_lote_pe: text,
  lote_pe_id: FK,
  registro_trabajo_id: FK
}

linerpe_calidad_muestras

Quality samples (4 inspections per shift):

{
  bitacora_id: FK,
  maquina_id: 8,
  orden_id: FK,
  inspeccion_indice: 1-4,
  parametro: 'ancho_liner' | 'largo_liner' | 'sello_fondo',
  valor: decimal,
  valor_nominal: decimal,
  resultado: 'Cumple' | 'No cumple'
}

Lot Generation

Per-Shift Lot Creation (linerPE.service.js:147-159): One lot generated per shift per order:

codigo_lote = `${codigo_orden}-${correlativo}`
// Example: 7000234-001

Correlative increments per order across all production history.

Quality Parameters

Critical Parameters

1. Liner Width (ancho_liner)

Unit: inches
Tolerance: ±0.25 inches
Nominal: From order specification (ancho_nominal)
Critical: No (informational)
Sampling: 4 inspections per shift
Input Format: Fractions of 1/8

2. Liner Length (largo_liner)

Unit: inches
Tolerance: ±0.25 inches
Nominal: From order specification (largo_nominal)
Critical: No
Sampling: 4 inspections per shift
Input Format: Fractions of 1/8

3. Bottom Seal (sello_fondo) — CRITICAL

Type: Pass/Fail (Cumple/No cumple)
Nominal: Cumple
Critical: YES
Sampling: 4 inspections per shift
Method: Visual inspection and manual leak test
Impact: Failed seal = contamination risk and product loss

Operational Parameters (Informational)

Recorded once per shift (ConversionLinerPEContract.js:89-101):

parametrosInformativos: [
  {
    nombre: 'temperatura_sellado',
    etiqueta: 'Temperatura de Sellado',
    unidad: '°C',
    grupo: 'maquina'
  },
  {
    nombre: 'velocidad_operacion',
    etiqueta: 'Velocidad de Operación',
    unidad: 'unidades/min',
    grupo: 'maquina'
  }
]

Sampling Frequency (`ConversionLinerPEContract.js:103-107`)

frecuenciaMuestreo: {
  registrosFormalsPorTurno: 4,
  omisionRequiereMotivo: true,
  permiteCopiarMuestraAnterior: false
}

Each inspection must measure all 3 parameters.

Business Logic

PE Lot Validation (`linerPE.service.js:62-68`)

for (const rollo of rollos_pe) {
  const lote = await this.loteService.getById(rollo.lote_pe_id);
  if (!lote) throw new ValidationError('El lote PE indicado no existe.');
  if (lote.estado === 'cerrado') {
    throw new ValidationError(`El lote ${lote.codigo_lote} está cerrado.`);
  }
}

Only active or paused PE lots can be consumed.

Production Validation (`linerPE.service.js:71-81`)

if (liners_producidos > 0) {
  if (rollos_pe.length === 0) {
    throw new ValidationError('Debe declarar al menos un rollo PE cuando hay producción.');
  }
  if (temperatura_sellado === undefined || temperatura_sellado === null || temperatura_sellado <= 0) {
    throw new ValidationError('La temperatura de sellado es obligatoria y debe ser mayor a 0 cuando hay producción.');
  }
  if (velocidad_operacion === undefined || velocidad_operacion === null || velocidad_operacion <= 0) {
    throw new ValidationError('La velocidad de operación es obligatoria y debe ser mayor a 0 cuando hay producción.');
  }
}

Operational parameters (temperature, speed) are mandatory when production > 0.

Quality Auto-Calculation (`linerPE.service.js:162-176`)

for (const m of muestras) {
  let resultado = m.resultado;
  let valorNominal = null;

  if (['ancho_liner', 'largo_liner'].includes(m.parametro)) {
    valorNominal = especificaciones[m.parametro === 'ancho_liner' ? 'ancho_nominal' : 'largo_nominal'];
    if (valorNominal !== undefined && valorNominal !== null) {
      if (Math.abs(m.valor - valorNominal) > 0.25) {
        resultado = 'No cumple';
      } else {
        resultado = 'Cumple';
      }
    }
  }
  // sello_fondo already validated as 'Cumple' or 'No cumple'
}

Dimensional checks auto-calculated with ±0.25” tolerance. Seal result passed through as-is from operator inspection.

Waste Destination

All waste returns to Extrusor PE (linerPE.service.js:117):

parametrosJSON = {
  liners_producidos,
  temperatura_sellado,
  velocidad_operacion,
  merma_kg,
  destino_merma: 'Retorno ExtrusorPE',
  observaciones
}

PE waste is not discarded—it’s returned for reprocessing.

API Endpoints

GET `/api/linerpe/detalle`

Returns Liner PE line status: Response:

{
  maquina: { id: 8, codigo: 'CONVLI', nombre_visible: 'Convertidora Liner PE' },
  estado_proceso: 'Completo',
  ultimo_registro: {
    id: 128,
    orden_id: 234,
    codigo_orden: '7000234',
    cantidad_producida: 12400,
    merma_kg: 8.5,
    parametros: '{ "liners_producidos": 12400, "temperatura_sellado": 165, "velocidad_operacion": 25, ... }'
  },
  rollos_pe_consumidos: [
    {
      codigo_lote_pe: '6000123-002',
      lote_pe_id: 34
    }
  ],
  muestras_calidad: [
    {
      inspeccion_indice: 1,
      parametro: 'ancho_liner',
      valor: 20.0,
      valor_nominal: 20.0,
      resultado: 'Cumple'
    },
    {
      inspeccion_indice: 1,
      parametro: 'largo_liner',
      valor: 34.0,
      valor_nominal: 34.0,
      resultado: 'Cumple'
    },
    {
      inspeccion_indice: 1,
      parametro: 'sello_fondo',
      resultado: 'Cumple'
    }
    // Repeat for inspections 2, 3, 4...
  ],
  lote_turno: {
    id: 56,
    codigo_lote: '7000234-001',
    estado: 'activo',
    fecha_produccion: '2026-03-06'
  }
}

Implementation: linerPE.service.js:13-33

POST `/api/linerpe/guardar`

Saves shift liner production data: Request Body:

{
  bitacora_id: 42,
  orden_id: 234,
  liners_producidos: 12400,
  rollos_pe: [
    {
      lote_pe_id: 34
    }
  ],
  muestras: [
    {
      inspeccion_indice: 1,
      parametro: 'ancho_liner',
      valor: 20.0
    },
    {
      inspeccion_indice: 1,
      parametro: 'largo_liner',
      valor: 34.0
    },
    {
      inspeccion_indice: 1,
      parametro: 'sello_fondo',
      resultado: 'Cumple'
    }
    // Repeat for inspections 2, 3, 4...
  ],
  temperatura_sellado: 165,
  velocidad_operacion: 25,
  merma_kg: 8.5,
  observaciones: ''
}

Response:

{
  registro_id: 128,
  estado: 'Completo'
}

Transaction Flow (linerPE.service.js:94-233):

Validate order belongs to Process 7
Validate PE lots are active (not closed)
Validate operational parameters if production > 0
Delete previous shift data (idempotent)
Get/create linea_ejecucion
Save registros_trabajo with operational params
For each PE roll:
- Validate lot exists
- Save PE roll consumption
Generate or retrieve shift lot: {codigo_orden}-{correlativo}
Save quality samples (auto-calculate dimensional pass/fail)
Calculate process state
Update bitacora_maquina_status

Implementation: linerPE.service.js:35-234
Permission Required: MANAGE_PRODUCTION

Machine Status States

Calculated in: linerPE.service.js:192-228

Sin datos: No production, samples, or waste
Parcial: Some data recorded
Completo:
- Production > 0
- At least 1 PE roll declared
- Temperature and speed recorded
- 4 inspections (indices 1, 2, 3, 4)
- Each inspection has all 3 parameters
Con desviación: Complete but quality parameters failed

Completeness Check (linerPE.service.js:204-218):

if (tieneProduccion && rollos_pe.length > 0 && temperatura_sellado > 0 && velocidad_operacion > 0) {
  const indices = [...new Set(muestrasGuardadas.map(m => m.inspeccion_indice))];
  const tiene4Inspecciones = [1, 2, 3, 4].every(i => indices.includes(i));

  let paramsOk = true;
  if (tiene4Inspecciones) {
    for (let i = 1; i <= 4; i++) {
      const paramsInspec = muestrasGuardadas.filter(m => m.inspeccion_indice === i).map(m => m.parametro);
      if (!['ancho_liner', 'largo_liner', 'sello_fondo'].every(p => paramsInspec.includes(p))) {
        paramsOk = false;
        break;
      }
    }
  }

  if (paramsOk) {
    estado = 'Completo';
  }
}

Traceability

Material and Lot Flow

Extrusión PE produces lot: 6000123-002
          ↓
Liner PE consumes 6000123-002
          ↓
Liner PE generates shift lot: 7000234-001
          ↓
Conversión Sacos Vestidos consumes 7000234-001

Waste Return Loop

Liner PE waste (8.5 kg)
          ↓
Returned to Extrusor PE
          ↓
Reprocessed into new PE film

This closed-loop waste management reduces material costs and environmental impact.

Operational Rules

Personnel Requirements (`ConversionLinerPEContract.js:46-50`)

personalOperativo: {
  minimo: 1,
  maximo: 1,
  reglasEspeciales: 'Un solo operador para alimentación y retiro de paquetes.'
}

Single-operator machine.

Stop Restrictions (`ConversionLinerPEContract.js:16-21`)

restriccionesInicio: [
  'Sin rollos de manga PE disponibles',
  'Falla en sistema de sellado',
  'Temperatura de sellado fuera de rango',
  'Orden sin dimensiones definidas (ancho o largo)'
]

Downtime Categories (`ConversionLinerPEContract.js:40-45`)

Operational: PE roll change, length adjustment, sealer bar cleaning, Teflon replacement
Mechanical: Sealing resistance failure, photocell failure, cutting pneumatics failure
Quality: Weak/leaking seal, length out of range, burnt seal
External: PE film shortage, electrical failure

Impact of Variability (`ConversionLinerPEContract.js:51-54`)

impactoVariabilidad: [
  {
    condicion: 'Variación de espesor en película',
    impacto: 'Causa sellados irregulares o quemados, requiriendo ajuste constante de temperatura.'
  },
  {
    condicion: 'Electricidad estática alta',
    impacto: 'Dificulta la apertura y el conteo de los liners, reduciendo la velocidad de empaque.'
  }
]

High static electricity is particularly problematic for liner handling and packaging.

Upstream: Extrusión PE (Process 6)
Downstream: Conversión Sacos Vestidos (Process 9)
Related: Production Orders, Lot Management

Get Started

Core Features

User Guides

Production Processes

Administration

​Overview

​Process Characteristics

​What This Process Does

​Production Flow

​Upstream Dependencies

​Downstream Consumers

​Production Tracking Method

​Data Structures

​Key Tables

​registros_trabajo

​linerpe_consumo_rollo_pe

​linerpe_calidad_muestras

​Lot Generation

​Quality Parameters

​Critical Parameters

​1. Liner Width (ancho_liner)

​2. Liner Length (largo_liner)

​3. Bottom Seal (sello_fondo) — CRITICAL

​Operational Parameters (Informational)

​Sampling Frequency (ConversionLinerPEContract.js:103-107)

​Business Logic

​PE Lot Validation (linerPE.service.js:62-68)

​Production Validation (linerPE.service.js:71-81)

​Quality Auto-Calculation (linerPE.service.js:162-176)

​Waste Destination

​API Endpoints

​GET /api/linerpe/detalle

​POST /api/linerpe/guardar

​Machine Status States

​Traceability

​Material and Lot Flow

​Waste Return Loop

​Operational Rules

​Personnel Requirements (ConversionLinerPEContract.js:46-50)

​Stop Restrictions (ConversionLinerPEContract.js:16-21)

​Downtime Categories (ConversionLinerPEContract.js:40-45)

​Impact of Variability (ConversionLinerPEContract.js:51-54)

​Related Processes

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